WO1998058456A2 - Cdma communication system which selectively allocates bandwidth upon demand - Google Patents

Cdma communication system which selectively allocates bandwidth upon demand Download PDF

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Publication number
WO1998058456A2
WO1998058456A2 PCT/US1998/010600 US9810600W WO9858456A2 WO 1998058456 A2 WO1998058456 A2 WO 1998058456A2 US 9810600 W US9810600 W US 9810600W WO 9858456 A2 WO9858456 A2 WO 9858456A2
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WO
WIPO (PCT)
Prior art keywords
subscriber unit
channel
rcs
communication
data
Prior art date
Application number
PCT/US1998/010600
Other languages
French (fr)
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WO1998058456A3 (en
Inventor
Fatih M. Ozluturk
Original Assignee
Interdigital Technology Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=26727376&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO1998058456(A2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority to AU77982/98A priority Critical patent/AU743633B2/en
Priority to DE0990312T priority patent/DE990312T1/en
Priority to KR1020097007063A priority patent/KR101053135B1/en
Priority to KR1020127015295A priority patent/KR101359780B1/en
Priority to KR1020127029272A priority patent/KR101434081B1/en
Priority to KR1020087027396A priority patent/KR101336439B1/en
Priority to EP98926060A priority patent/EP0990312A2/en
Application filed by Interdigital Technology Corporation filed Critical Interdigital Technology Corporation
Priority to BR9810164-1A priority patent/BR9810164A/en
Priority to KR1019997011795A priority patent/KR100693844B1/en
Priority to KR1020077014138A priority patent/KR100873462B1/en
Priority to JP50443499A priority patent/JP2002513540A/en
Priority to CA2294226A priority patent/CA2294226C/en
Priority to KR1020137017653A priority patent/KR101434126B1/en
Priority to KR1020117020116A priority patent/KR101235332B1/en
Priority to KR1020107008530A priority patent/KR101139990B1/en
Publication of WO1998058456A2 publication Critical patent/WO1998058456A2/en
Publication of WO1998058456A3 publication Critical patent/WO1998058456A3/en

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Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B7/00Radio transmission systems, i.e. using radiation field
    • H04B7/24Radio transmission systems, i.e. using radiation field for communication between two or more posts
    • H04B7/26Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
    • H04B7/2628Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA]
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B1/00Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/69Spread spectrum techniques
    • H04B1/707Spread spectrum techniques using direct sequence modulation
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J13/00Code division multiplex systems
    • H04J13/16Code allocation
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04JMULTIPLEX COMMUNICATION
    • H04J3/00Time-division multiplex systems
    • H04J3/16Time-division multiplex systems in which the time allocation to individual channels within a transmission cycle is variable, e.g. to accommodate varying complexity of signals, to vary number of channels transmitted
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • H04L5/003Arrangements for allocating sub-channels of the transmission path
    • H04L5/0053Allocation of signaling, i.e. of overhead other than pilot signals
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q11/00Selecting arrangements for multiplex systems
    • H04Q11/04Selecting arrangements for multiplex systems for time-division multiplexing
    • H04Q11/0428Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
    • H04Q11/0435Details
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W28/00Network traffic management; Network resource management
    • H04W28/16Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
    • H04W28/18Negotiating wireless communication parameters
    • H04W28/22Negotiating communication rate
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04TPC
    • H04W52/18TPC being performed according to specific parameters
    • H04W52/26TPC being performed according to specific parameters using transmission rate or quality of service QoS [Quality of Service]
    • H04W52/267TPC being performed according to specific parameters using transmission rate or quality of service QoS [Quality of Service] taking into account the information rate
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W52/00Power management, e.g. TPC [Transmission Power Control], power saving or power classes
    • H04W52/04TPC
    • H04W52/38TPC being performed in particular situations
    • H04W52/42TPC being performed in particular situations in systems with time, space, frequency or polarisation diversity
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/04Wireless resource allocation
    • H04W72/044Wireless resource allocation based on the type of the allocated resource
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/04Wireless resource allocation
    • H04W72/044Wireless resource allocation based on the type of the allocated resource
    • H04W72/0453Resources in frequency domain, e.g. a carrier in FDMA
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management
    • H04W72/20Control channels or signalling for resource management
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W84/00Network topologies
    • H04W84/02Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
    • H04W84/10Small scale networks; Flat hierarchical networks
    • H04W84/14WLL [Wireless Local Loop]; RLL [Radio Local Loop]
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04BTRANSMISSION
    • H04B2201/00Indexing scheme relating to details of transmission systems not covered by a single group of H04B3/00 - H04B13/00
    • H04B2201/69Orthogonal indexing scheme relating to spread spectrum techniques in general
    • H04B2201/707Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation
    • H04B2201/70703Orthogonal indexing scheme relating to spread spectrum techniques in general relating to direct sequence modulation using multiple or variable rates
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/1307Call setup
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13098Mobile subscriber
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13174Data transmission, file transfer
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13204Protocols
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13208Inverse multiplexing, channel bonding, e.g. TSSI aspects
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13209ISDN
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13294CDMA, code division multiplexing, i.e. combinations of H04Q2213/13291 and/or H04Q2213/13292 with space division
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04QSELECTING
    • H04Q2213/00Indexing scheme relating to selecting arrangements in general and for multiplex systems
    • H04Q2213/13332Broadband, CATV, dynamic bandwidth allocation
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W24/00Supervisory, monitoring or testing arrangements
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/06Reselecting a communication resource in the serving access point
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W76/00Connection management
    • H04W76/10Connection setup
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W76/00Connection management
    • H04W76/30Connection release
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W88/00Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/02Terminal devices
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W88/00Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08Access point devices

Definitions

  • This invention generally relates to wireless communication systems. More particularly, the invention relates to a wireless digital Code Division Multiple Access (CDMA) communication system including a base station and a plurality of subscriber units which selectively allocates bandwidth upon demand by a subscriber unit or an entity desiring to establish a communication with a subscriber unit.
  • CDMA Code Division Multiple Access
  • POTS integrated services digital network
  • ISDN integrated services digital network
  • VBR variable bit rate
  • the present invention is a CDMA wireless digital communication system which supports all types of voice and data communications while utilizing the minimum amount of bandwidth for the particular application.
  • the system efficiently allocates ISDN bandwidth on demand by a subscriber.
  • the system Upon initialization of the subscriber unit, the system establishes a channel and generates the necessary spreading codes to support the highest capacity channel desired by the subscriber unit. However, the system does not set aside portions of the communication bandwidth until actually required by the subscriber unit. Since the call setup is performed at the beginning of any call from that particular subscriber unit, including the assignment of spreading codes, a subscriber unit can quickly gain access to the portion of the spectrum that is required to support the particular application.
  • Figure 1 is a block diagram of a code division multiple access spread spectrum communication system according to the present invention.
  • Figure 2A is a block diagram of the interface between the subscriber unit of the present invention and an ISDN terminal
  • Figure 2B is a block diagram of the interface between the subscriber unit of the present invention and a POTS terminal
  • Figure 2C is a block diagram of the interface between the subscriber unit of the present invention and a packet terminal
  • Figure 2D is a block diagram of the interface between the subscriber unit of the present invention and a wideband connection
  • Figure 2E is a block diagram of the interface between the subscriber unit of the present invention and a leased line terminal ;
  • Figure 2F is a block diagram of the interface between the subscriber unit of the present invention and an ISDN and POTS network;
  • Figure 2G is a block diagram of the interface between the subscriber unit of the present invention and a wideband and packet network
  • Figure 2H is a block diagram of the interface between the subscriber unit of the present invention and a leased line network
  • FIG. 3 is a block diagram of a subscriber unit in accordance with the present invention
  • Figure 4 is a block diagram of an RCS in accordance with the present invention
  • Figure 5 is a flow diagram of the procedure for dynamic allocation of bandwidth for ISDN service
  • Figures 6A and 6B are flow diagrams of the establishment of the bearer channel between the subscriber unit and the RCS for POTS service;
  • Figure 7 shows the layered protocol of the communications between the subscriber unit and RCS
  • FIG. 8A illustrates the simplified bearer switching method as initiated by the subscriber unit
  • Figure 8B illustrates the simplified bearer switching method as initiated by the RCS
  • Figures 9A and 9B are flow diagrams of the establishment of the bearer channel between the subscriber unit and the RCS for ISDN service.
  • the system of the present invention provides local-loop telephone service using radio links between one or more base stations and at least one remote subscriber unit.
  • the radio link is described for a base station communicating with a fixed subscriber unit (FSU) , but the system is equally applicable to systems including multiple base stations with radio links to both fixed subscriber units and mobile subscriber units (MSUs) . Consequently, the fixed and mobile subscriber units will be referred to herein as subscriber units.
  • a base station 101 provides call connection to a local exchange 103 or any other telephone network switching interface, such as a private branch exchange
  • PBX radio carrier station
  • RCS radio carrier station
  • RCSs 104, 105...110 connect to a radio distribution unit (RDU) 102 through links 131, 132, 137, 138, 139 and RDU 102 interfaces with the local exchange 103 by transmitting and receiving call set-up, control, and information signal through telco links 141, 142, 150.
  • the subscriber units 116, 119 communicate with the RCS 104 through radio links 161, 162, 163, 164, 165.
  • another embodiment of the invention includes several subscriber units and a "master subscriber unit" with functionality similar to the RCS 104. Such an embodiment may or may not have connection to a local telephone network.
  • the radio links 161 to 165 operate within the frequency bands of the CDS1800 standard (1.71-1.785 GHz and 1.805-1.880 GHz); the US-PCS standard (1.85-1.99 GHz); and the CEPT standard (2.0-2.7 GHz) . Although these bands are used in the described embodiment, the invention is equally applicable to any RF frequency band including the entire UHF and SHF bands, and bands from 2.7 GHz to 5 GHz .
  • the transmit and receive bandwidths are multiples of 3.5 MHz starting at 7 MHz, and multiples of 5 MHz starting at 10 MHz, respectively.
  • the described system includes bandwidths of 7, 10, 10.5, 14 and 15 MHz.
  • the minimum guard band between the uplink and downlink is 20 MHz, and is desirably at least three times the signal bandwidth.
  • the duplex separation is between 50 to 175 MHz, with the described invention using 50, 75, 80, 95 and 175 MHz. Other frequencies may also be used.
  • the present invention is readily extended to systems using multiple spread-spectrum bandwidths for the transmit channels and multiple spread- spectrum bandwidths for the receive channels.
  • the same spread-spectrum bandwidth for both the transmit and receive channels may be employed wherein uplink and downlink transmissions will occupy the same frequency band.
  • the present invention may also be readily extended to multiple CDMA frequency bands, each conveying a respectively different set of messages, uplink, downlink or uplink and downlink.
  • the spread binary symbol information is transmitted over the radio links 161 to 165 using quadrature phase shift keying
  • QPSK QPSK modulation with Nyquist pulse shaping
  • MSK offset QPSK minimum shift keying
  • GPSK Gaussian phase shift keying
  • MPSK M-ary phase shift keying
  • the radio links 161 to 165 incorporate broadband code division multiple access (B-CDMATM) technology as the mode of transmission in both the uplink and downlink directions .
  • CDMA also known as spread spectrum
  • CDMA modulator generates the spread-spectrum spreading code sequence, which can be a pseudonoise sequence, and performs complex direct sequence modulation of the QPSK signals with spreading code sequences for the In-phase (I) and Quadrature (Q) channels.
  • Pilot signals, spreading codes which are not modulated by data, are generated and transmitted with the modulated signals.
  • the pilot signals are used for synchronization, carrier phase recovery, and for estimating the impulse response of the radio channel .
  • Each subscriber unit 111-118 includes a code generator and at least one CDMA modulator and demodulator, which together comprise a CDMA modem.
  • Each RCS 104, 105, 110 has at least one code generator plus sufficient CDMA modulators and demodulators for all of the logical channels in use by the subscriber units .
  • the CDMA demodulator despreads the signal with appropriate processing to reduce or exploit multipath propagation effects.
  • the radio links support multiple traffic channels with data rates of 8, 16, 32, 64, 128 and 144 kb/s.
  • the physical channel to which a traffic channel is connected operates with a 64k symbol/sec rate.
  • Other data rates may be supported, and forward error correction (FEC) coding can be employed.
  • FEC forward error correction
  • FEC forward error correction
  • the RCS 104 interfaces to the RDU 102 through a plurality of RF links or terrestrial links 131, 132, 137 with, for example, 1.533 Mb/s DS1, 2.048 Mbs/ El; or HDSL formats to receive and send digital data signals. While these are typical telephone company standardized interfaces, the present invention is not limited to these digital data formats only.
  • the exemplary RCS line interface (not shown in Figure 1) translates the line coding (such as HDB3 , B8ZS, AMI) and extracts or produces framing information, performs alarms and facility signaling functions, as well as channel specific loop-back and parity check functions.
  • the system of the present invention also supports bearer rate modification between the RCS 104 and the subscriber unit 111 for both POTS service and ISDN service.
  • the subscriber units 111-118 may interface with a telephone unit 170, a local switch (PBX) 171, a data terminal 172, an ISDN interface 173 or other types of equipment shown in Figures 2A-2H.
  • the input from the telephone unit 170 may include voice, voiceband data and signaling.
  • the present invention is applicable to the communications between a plurality of subscriber units 111-118 and a plurality of RCSs 104-110, reference hereinafter will be made to a particular subscriber unit and RCS for simplicity.
  • the subscriber unit 111 translates the analog signals into digital sequences for transmission to the RCS 104.
  • the subscriber unit 112 encodes voice data with techniques such as ADPCM at rates of 32 kb/s or lower.
  • the RCS 104 detects voiceband data or facsimile data with rates above 4.8 kb/s to modify the bearer rate of the traffic channel for unencoded transmission. Also A-law, u-law, or no companding of the signal may be performed before transmission.
  • the transmit power level of the radio interface between the RCS 104 and the subscriber unit 111 is controlled using a different closed loop power control method for the downlink and uplink directions.
  • the automatic forward power control (AFPC) method determines the downlink transmit power level
  • the automatic reverse power control (ARPC) method determines the uplink transmit power level .
  • the logical control channel by which the subscriber unit 111 and the RCS 104 transfer power control information operates at an update rate of at least a 16 kHz. Other embodiments may use a faster or slower update rate, for example 64 kHz.
  • the system also uses an optional maintenance power control method during the inactive mode of the subscriber unit 111.
  • the subscriber unit 111 When the subscriber unit 111 is inactive or powered-down to conserve power, the subscriber unit 111 occasionally activates to adjust its initial transmit power level setting in response to a maintenance power control signal from the RCS 104.
  • the maintenance power control signal is determined by the RCS 104 by measuring the received power level of the subscriber unit 111 and present system power level and calculating the necessary initial transmit power.
  • the method shortens the channel acquisition time of the subscriber unit 111 to begin a communication and prevents the transmit power level of the subscriber unit 111 from becoming too high and interfering with other channels during the initial transmission before the closed loop power control reduces the transmit power.
  • the RCS 104 obtains synchronization of its clock from an interface line such as, but not limited to, El, Tl, or HDSL interfaces.
  • the RCS 104 can also generate its own internal clock signal from an oscillator which may be regulated by a global positioning system (GPS) receiver.
  • GPS global positioning system
  • the RCS 104 generates a global pilot code, which can be acquired by the remote subscriber unit 111. All transmission channels of the RCS 104 are synchronized to the global pilot channel .
  • the spreading code phases of code generators (not shown in Figure 1) used for logical communication channels within the RCS 104 are also synchronized to the spreading code phase of the global pilot channel.
  • all subscriber units 111-118 which receive the global pilot code of the RCS 104 synchronize the spreading and de-spreading code phases of their code generators to the global pilot code.
  • a prior art channel is regarded as a communications path which is part of an interface and which can be distinguished from other paths of that interface without regard to its content.
  • CDMA communications separate communications paths are distinguished by their content .
  • All logical channels and subchannels of the present invention are mapped to a common 64 kilo-symbols per second (ksym/s) QPSK stream.
  • Some channels are synchronized to associated pilot codes which are generated from, and perform a similar function to, the global pilot code.
  • the system pilot signals are not considered logical channels.
  • Each logical communication channel either has a fixed, pre-determined spreading code or a dynamically assigned spreading code.
  • the code phase is synchronized with the global pilot code.
  • the spreading codes are specified by the seeds used to generate the codes.
  • a pool of "primary seeds" exists within the RDU 102, a portion of which comprise global primary seeds and the remainder comprise assigned primary seeds.
  • the RDU 102 allocates these primary seeds to the RCSs 104 on an as- needed basis.
  • a global primary seed generates all of the global channel codes for use by an RCS 104 within a cell. However, assigned primary seeds are used to generate secondary assigned seeds.
  • One primary assigned seed generates fifty- seven (57) secondary assigned seeds.
  • Each secondary assigned seed is input into the code generators within the RCS 104 and the subscriber unit 111 to generate a set of assigned channel codes to support each communication link.
  • each RCS 104 is given one global primary seed for generating global channel codes and two primary assigned seeds. Accordingly, the RCS 104 and its corresponding subscriber units 111-118 may generate up to 114 secondary assigned seeds.
  • Each secondary assigned seed is assigned by the RCS 104 to generate the codes for an active link, thereby permitting enough codes for up to 114 simultaneous communication links.
  • Logical communication channels are divided into two groups: 1) global channels; and 2) assigned channels.
  • the global channel group includes channels which are either transmitted from the RCS 104 to all subscriber units 111-118 or from any subscriber unit 111-118 to the RCS 104 regardless of the identity of the subscriber unit 111-118.
  • Channels in the assigned channels group are those channels dedicated to communication between the RCS 104 and a particular subscriber unit 111.
  • the global channel group provides for: 1) broadcast control logical channels, which provide point-to- ulti-point services for broadcasting messages to all subscriber units 111-118 and paging messages to subscriber units 111-118; and 2) access control logical channels which provide point-to-point services on global channels for subscriber units 111-118 to access the system and obtain assigned channels .
  • the RCS 104 of the present invention has one broadcast control logical channel and multiple access control logical channels.
  • a subscriber unit 111-118 of the present invention has at least one broadcast control logical channel and at least one access control logical channel .
  • the global logical channels controlled by the RCS 104 are the fast broadcast channel (FBCCH) which broadcasts fast changing information concerning which services and which access channels are currently available, and the slow broadcast channel (SBCCH) which broadcasts slow changing system information and paging messages.
  • FBCCH fast broadcast channel
  • SBCCH slow broadcast channel
  • the subscriber unit 111 uses an access channel (AXCH) to begin communications with the RCS 104 and gain access to assigned channels .
  • AXCH access channel
  • Each AXCH is paired with a control channel (CTCH) which is sent from the RCS 104 to the subscriber unit 111.
  • CTCH control channel
  • the CTCH is used by the RCS 104 to acknowledge and reply to access attempts by the subscriber unit 111.
  • SAXPT short access pilot
  • LAXPT long access pilot
  • the SAXPT is transmitted by the subscriber unit 111 while it ramps up its transmit power to initiate access to the RCS 104.
  • the SAXPT is a relatively short code it permits the RCS 104 to detect the subscriber unit 111 quickly and avoids power overshoot by the subscriber unit 111. Further detail regarding transmit power ramp-up using the SAXPT is described in more detail in an application entitled A METHOD OF CONTROLLING INITIAL POWER RAMP-UP IN CDMA SYSTEMS BY USING SHORT CODES, Serial No. 08/670,162; filed June 27, 1996 which is herein incorporated by reference as if fully set forth. Until the SAXPT is detected by the RCS 104, subscriber unit 111 does not send any other signal.
  • the subscriber unit 111 starts transmitting the LAXPT which provides the RCS 104 with a time and phase reference and permits the RCS 104 to determine the channel impulse response .
  • this group contains the logical channels that control a single communication link between the RCS 104 and the subscriber unit 111.
  • a pair of power control logical message channels for each of the uplink and downlink connections is established and one or more pairs of traffic channels, depending on the type of connection, is established.
  • the bearer control function performs the required forward error control, bearer rate modification and encryption functions.
  • Each subscriber unit 111-118 has at least one assigned channel group when a communication link is established, and each RCS 104-110 has multiple assigned channel groups, one for each communication link in progress.
  • An assigned channel group of logical channels is created for a communication link upon successful establishment of the communication link.
  • the assigned channel group includes encryption, FEC coding, and multiplexing on transmission, and decryption, FEC decoding and demultiplexing on reception.
  • Each assigned channel group provides a set of communication link oriented point-to-point services and operates in both directions between a specific RCS 104 and a specific subscriber unit 111.
  • An assigned channel group formed for a communication link can control more than one bearer over the RF communication channel associated with a single communication link.
  • An assigned channel group can provide for the duplication of traffic channels to facilitate switchover to 64 kb/s PCM for high speed facsimile and modem services for the bearer rate modification function.
  • the assigned logical channels formed upon a successful communication link and included in the assigned channel group are dedicated signaling channel order wire (OW) , APC channel and one or more traffic channels (TRCH) which are bearers of 8, 16, 32, or 64 kb/s depending on the service supported.
  • OW dedicated signaling channel order wire
  • TRCH traffic channels
  • voice traffic moderate rate coded speech ADPCM or PCM can be supported on the traffic channels.
  • two 64 kb/s TRCHs form the B channels and one 16 kb/s TRCH forms the D channel.
  • the APC subchannel may either be separately modulated on its own CDMA channel, or may be time division multiplexed with a traffic channel or OW channel .
  • Each subscriber unit 111-118 of the present invention supports up to three simultaneous traffic channels.
  • a subscriber unit is preferably commissioned to be a POTS subscriber unit 112 or an ISDN subscriber unit 115.
  • POTS subscriber unit 112 does not support ISDN service in accordance with the present invention, bandwidth resources can be dynamically allocated for either service type.
  • a POTS subscriber unit 112 can set up an additional POTS line and tear it down, or an ISDN subscriber unit 115 can dynamically add B channel-carrying bearers or tear them down.
  • an active 32 kb/s ADPCM service modifies the bearer type from 32 kb/s to 64 kb/s unencoded data to support facsimile transmission. The presence of a facsimile call is determined by the RCS 104 by monitoring the existence of the 2100 Hz answer tone.
  • the RCS 104 monitors the ISDN D channel messages to determine when a B channel is requested and when it should be torn down. Once the RCS 104 determines the need for changing the bearer channel allocation, the RCS 104 initiates the dynamic bearer allocation procedure which will be described in greater detail hereinafter.
  • Table 1 The mapping of the three logical channels for TRCHs to the user data is shown below in Table 1:
  • Table 1 Mapping of service types to the three available TRCH channels
  • a subscriber unit 200 made in accordance with the present invention is generally shown in Figure 3.
  • the subscriber unit 200 includes a receiver section 202 and a transmitter section 204.
  • An antenna 206 receives a signal from RCS 104, which is filtered by a band-pass filter 208 having a bandwidth equal to twice the chip rate and a center frequency equal to the center frequency of the spread spectrum system's bandwidth.
  • the output of the filter 208 is down-converted by a mixer 210 to a baseband signal using a constant frequency (Fc) local oscillator.
  • the output of the mixer 210 is then spread spectrum decoded by applying a PN sequence for each logical channel to a mixer 212 within the PN Rx generator 214.
  • the output of the mixer 212 is input to a codec 218 which interfaces with the communicating entity 220.
  • a baseband signal from the communicating entity 220 is pulse code modulated by the codec 218.
  • a 32 kb/s adaptive pulse code modulation (ADPCM) is used.
  • the PCM signal is applied to a mixer 222 within a PN Tx generator 224.
  • the mixer 222 multiplies the PCM data signal with the PN sequence for each logical channel.
  • the output of the mixer 222 is applied to low-pass filter 226 whose cutoff frequency is equal to the system chip rate.
  • the output of the filter 226 is then applied to a mixer 228 and suitably up-converted, as determined by the carrier frequency Fc applied to the other terminal.
  • the up-converted signal is then passed through a band-pass filter 230 and to a broadband RF amplifier 232 which drives an antenna 234.
  • a band-pass filter 230 and to a broadband RF amplifier 232 which drives an antenna 234.
  • the digital signal processor (DSP) 236 controls the acquisition process as well as the Rx and Tx PN generators 214, 224.
  • the base station 101 which includes a plurality of RCSs
  • the base station 101 includes a receiver section 302 and a transmitter section 304.
  • An antenna 306 receives a signal from the subscriber unit, which is filtered by a bandpass filter 308 having a bandwidth equal to twice the chip rate and a center frequency equal to the center frequency of the spread spectrum system's bandwidth.
  • the output of the filter 308 is down-converted by a mixer 310 to a baseband signal using a constant frequency (Fc) local oscillator.
  • the output of the mixer 310 is then spread spectrum decoded at each modem by applying a PN sequence to a mixer 312 within the PN Rx generator 314.
  • the output of the mixer 316 is then forwarded to the RDU 318.
  • a baseband signal is received from the RDU 318.
  • a 32 kb/s ADPCM signal is used.
  • the ADPCM or PCM signal is applied to a mixer 322 within a PN Tx generator 324.
  • the mixer 322 multiplies the ADPCM or PCM data signal with the PN sequence.
  • the output of the mixer 322 is applied to low- pass filter 326 whose cutoff frequency is equal to the system chip rate.
  • the output of the filter 326 is then applied to a mixer 328 and suitably up-converted, as determined by the carrier frequency Fc applied to the other terminal.
  • the up- converted signal is then passed through a band-pass filter 330 and to a broadband RF amplifier 332 which drives an antenna 334.
  • the digital signal processor (DSP) 336 controls the acquisition process as well as the Rx and Tx PN generators 314, 324.
  • the system provides a wireless link between the RCS 104 and the plurality of subscriber units 111-118. In order to conserve as much bandwidth as possible, the system selectively allots the bandwidth required for supporting the data transmission rate required by particular communication. In this manner, the system ensures that the bandwidth is utilized efficiently. For example, referring back to Table 1, voiced communications may be effectively transmitted across a 32 kb/s adaptive pulse code modulation (ADPCM) channel.
  • ADPCM adaptive pulse code modulation
  • a high speed facsimile or data modem signal requires at least a 64 k/bs PCM signal to reliably transmit the communication.
  • a subscriber unit 115 has paid for ISDN service, which includes two 64 kb/s B channels and one 16 kb/s channel, the entire ISDN capacity is rarely utilized at all times .
  • Many different data transmission rates may also be utilized by originating and terminating nodes.
  • the originating and terminating nodes may comprise computers, facsimile machines, automatic calling and answering equipment, data networks or any combination of this equipment.
  • the system must be able to effectively allocate bandwidth and dynamically switch between these data communication rates on demand by the user. Modification of the transmission rate from a low rate (that supports voice communication) to a high rate (that supports encoded data communication) ensures that data will be reliably and quickly transmitted over a communication channel. Additionally, if an ISDN D channel is presently allocated and one or two B channels are required, the system must ensure that the code generators are activated in order to support the communication.
  • the bearer channel For POTS, there are two basic scenarios where the bearer channel (TRCH channel) is either modified or a new bearer channel is added or torn down.
  • the bearer channel is modified from 32 kb/s coded ADPCM type to 64 kb/s uncoded PCM service to support a facsimile transmission.
  • a new bearer channel is added or torn down when the subscriber goes off hook while an OA&M (overhead, administration and maintenance) call is in progress, or when an OA&M call is initiated while a POTS call is in progress.
  • OA&M overhead, administration and maintenance
  • the subscriber unit 112 can determine that the user is initiating a new POTS call by monitoring the changes at the A/B interface between the subscriber unit 112 and the communication equipment 170 (on- hook/off-hook sensor) . More detail regarding the dynamic allocation of bandwidth for POTS may be found in an application entitled CODE DIVISION MULTIPLE ACCESS (CDMA) COMMUNICATION SYSTEM, Patent Application Serial No. Not Yet Known, filed March 11, 1997, which is a continuation-in-part of Serial No. 08/669,775, filed June 27, 1996 by Lomp et al . , which is incorporated herein by reference as if fully set forth.
  • CDMA CODE DIVISION MULTIPLE ACCESS
  • the dynamic bandwidth allocation refers to selective allocation of the D and B channels in a D, D and B, or D and 2B bearer channel configuration as needed and tearing them down when they are idle.
  • the ISDN D channel carries control messaging and cannot be torn down while the ISDN call is still active. Accordingly, dynamic bandwidth allocation for ISDN service only relates to the addition and tearing down of B channels .
  • the procedure 400 for dynamic allocation of bandwidth for ISDN service in accordance with the present invention will be explained in greater detail with reference to Figure 5.
  • the D channel is established first (step 402) .
  • the bandwidth required for the particular application is communicated from the calling ISDN equipment to the called ISDN equipment through messages on the D channel (step 404) .
  • These messages are in HDLC format and the RCS 104 monitors these messages via an HDLC interface (step 406) .
  • step 408 it initiates establishment of these bearer channels over the air interface (step 410) .
  • the RCS continues monitoring the HDLC messages on the D channel during the ISDN call (step 412) and determines if additional B channels are to be switched in or out. In case that additional B channels should be switched in or out, the RCS 104 initiates the establishment or tearing down of the bearer channels over the air interface (step 414) .
  • a flow diagram showing simplified procedure 600 of the bearer channel establishment will be described with reference to Figures 6A and 6B.
  • the subscriber unit 111 quickly ramps up its transmit power (step 602) while sending the SAXPT (step 604) .
  • the RCS 104 When the RCS 104 detects the SAXPT (step 606), it turns the traffic light bit to "red" on the FBCCH (step 608) to signal to the subscriber unit 111 that it has been detected.
  • the RCS 104 transmits the FBCCH (step 610) .
  • the subscriber unit 111 monitors the FBCCH (step 612) and it stops the fast ramp-up when it sees the "traffic light” turn red on the FBCCH (step 614) .
  • the subscriber unit 111 then continues a slow ramp-up of its transmit power (step 616) while transmitting the LAXPT (step 618) .
  • the RCS 104 acquires the LAXPT (step 620) , it informs the subscriber unit 111 via the SYNC-OK message on CTCH (step 622) . This completes the transmit power ramping up part of the access procedure .
  • the subscriber unit 111 After the subscriber unit 111 receives the SYNC-OK message on the CTCH (step 624) , it sends the access request message on the AXCH (step 626) . Upon receiving the request
  • the RCS 104 confirms receipt of the AXCH message with a message on CTCH (step 630) , which includes the assigned code seed.
  • the subscriber unit 111 detects and acknowledges the bearer confirmation message that carries the assigned code seed on the AXCH (steps 632 and 634) , which the RCS 104 detects (step 636) .
  • the code switchover is now negotiated and subscriber unit 111 and RCS 104 simultaneously switch to using the assigned code (steps 638 and 640) .
  • the bearer channel is now established.
  • the layered protocol of the communications between the subscriber unit 111 and the RCS 104 is shown in Figure 7 along with its correspondence to the layers of the Open Systems Interconnection (OSI) reference model.
  • the physical (PHL) layer performs the following functions: 1) generation of CDMA codes; 2) synchronization between transmitter and receiver;
  • the MAC layers performs the following functions: 1) encoding and decoding for forward error correction (FEC) ; 2) assignment of CDMA codes; 3) encryption and decryption; 4) providing bearers which are encrypted and error-corrected as appropriate; 5) framing, error checking and discrimination of MAC peer to peer messages and data; 6) link control (DLC) frames; and 7) processing of automatic power control information.
  • the data link control layer (DLC) provides an error- free link between higher level layers of the protocol stack.
  • the signaling between the subscriber unit 111 and the RCS 104 involves the MAC and DLC layers of the protocol.
  • the bearer channel for POTS service is established as described above, the service is available and remains unchanged until it is torn down or unless it has to be modified to support a facsimile transmission or a second call, in the case of a simultaneous OA&M call and POTS call.
  • the procedure as shown in Figure 8A is entered. This figure illustrates the simplified bearer switching method as initiated by the subscriber unit 111.
  • the messages go between the data link control layer (DLC) , medium access control layer (MAC) of the subscriber unit 111, and the corresponding layers in the RCS 104.
  • DLC data link control layer
  • MAC medium access control layer
  • the DLC layer of the subscriber unit 111 initiates a switch request to the MAC layer of the subscriber unit 111, which refers this switch request to the MAC layer of the RCS 104.
  • the RCS 104 sends a confirmation over the MAC layer to the subscriber unit 111 and also sends a switch indication to the DLC layer of the RCS 104.
  • the switch confirmation sent from the RCS 104 over the MAC layer is forwarded to the DLC layer of the subscriber unit 111.
  • FIG. 8B illustrates the simplified bearer switching method as initiated by the RCS 104.
  • the RCS 104 initiates a switch indication message over the MAC layer to the subscriber unit 111.
  • the subscriber unit 111 then relays this message via the DLC layer.
  • Steps 902-940 are the same as the corresponding steps 602-640 in Figures 6A and 6B. However, several additional steps are required after the subscriber unit 111 and the RCS 104 both switch to the assigned codes (steps 938 and 940) . Once the subscriber unit 111 and RCS 104 switch to assigned codes (steps 938 and 940) the ISDN D channel becomes active. At this point the S/T interface between the subscriber unit 111 and the ISDN equipment is already active. The RCS 104 starts monitoring the D channel messages (step 942), which are in HDLC format.
  • the RCS 104 Upon detecting that one or more B channels are needed for the particular application (step 944) the RCS 104 initiates establishment of these bearer channels over the air interface. The process is then continued in accordance with the procedure shown in Figure 5.
  • the MAC and DLC message flow for this procedure is the same as in Figure 8B .
  • the bearer channels for POTS and ISDN is switched in or out via the same message flow. Whether the bearer channel is switched in or out is indicated by appropriate values in corresponding fields of the D channel messages. Therefore the flow diagram in Figure 8B apply to both dynamic switching in of bearer channels as well as dynamic switching out of bearer channels .

Abstract

A CDMA wireless digital communication system which supports all types of voice and data communications while utilizing the minimum amount of bandwidth for the particular application. The system efficiently allocates ISDN bandwidth on demand by a subscriber. Upon initialization of the subscriber unit, the system establishes a channel and generates the necessary spreading codes to support the highest capacity channel desired by the subscriber unit. Portions of the communication spectrum bandwidth are not reserved until actually required by the subscriber unit. Since the call setpup is performed at the beginning of a call from that subscriber unit, including the assignment of spreading codes, a subscriber unit can quickly gain access to the portion of the spectrum that is required to support the particular application.

Description

CDMA COMMUNICATION SYSTEM WHICH SELECTIVELY ALLOCATES BANDWIDTH UPON DEMAND
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of Provisional Application No. 60/049,637, filed June 16, 1997.
BACKGROUND OF THE INVENTION Field of the Invention
This invention generally relates to wireless communication systems. More particularly, the invention relates to a wireless digital Code Division Multiple Access (CDMA) communication system including a base station and a plurality of subscriber units which selectively allocates bandwidth upon demand by a subscriber unit or an entity desiring to establish a communication with a subscriber unit.
Description of the Related Art
The use of wireless technology by the telecommunication industry has increased dramatically as the capacity and reliability of wireless communication systems has improved. Once considered only to be a convenient method for sending voiced communications, digital wireless communications systems are now a necessity for providing transmission of all forms of communications including plain old telephony service
(POTS) , integrated services digital network (ISDN) , variable bit rate (VBR) data service, wideband service, leased line service and packet data services. Although it has been technically feasible to transmit all of these types of services, the large amount of bandwidth required for high data rate communications has made many of these services uneconomical . As the number of subscribers requiring access to wireless digital communication systems has increased, the reliance on a wide bandwidth for each communication is no longer realistic.
The finite bandwidth allocated to wireless communications systems for public use has become increasingly valuable. Since it is unlikely that additional bandwidth to support user growth will be allocated for existing applications, many of the recent advances in telecommunication hardware and software have been directed toward increasing the transmission rate of data while utilizing a decreased amount of bandwidth.
Accordingly, there exists a need for a wireless digital communication system which supports the same high data rate services as conventional wired networks while utilizing the allocated bandwidth more efficiently.
SUMMARY OF THE INVENTION
The present invention is a CDMA wireless digital communication system which supports all types of voice and data communications while utilizing the minimum amount of bandwidth for the particular application. The system efficiently allocates ISDN bandwidth on demand by a subscriber. Upon initialization of the subscriber unit, the system establishes a channel and generates the necessary spreading codes to support the highest capacity channel desired by the subscriber unit. However, the system does not set aside portions of the communication bandwidth until actually required by the subscriber unit. Since the call setup is performed at the beginning of any call from that particular subscriber unit, including the assignment of spreading codes, a subscriber unit can quickly gain access to the portion of the spectrum that is required to support the particular application.
Accordingly, it is an object of the invention to provide a wireless digital spread spectrum communication system which supports a range of telephone services including POTS and ISDN while efficiently utilizing the spread spectrum bandwidth.
Other objects and advantages of the present invention will become apparent after reading the description of a presently preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram of a code division multiple access spread spectrum communication system according to the present invention;
Figure 2A is a block diagram of the interface between the subscriber unit of the present invention and an ISDN terminal; Figure 2B is a block diagram of the interface between the subscriber unit of the present invention and a POTS terminal ; Figure 2C is a block diagram of the interface between the subscriber unit of the present invention and a packet terminal ; Figure 2D is a block diagram of the interface between the subscriber unit of the present invention and a wideband connection; Figure 2E is a block diagram of the interface between the subscriber unit of the present invention and a leased line terminal ;
Figure 2F is a block diagram of the interface between the subscriber unit of the present invention and an ISDN and POTS network;
Figure 2G is a block diagram of the interface between the subscriber unit of the present invention and a wideband and packet network; Figure 2H is a block diagram of the interface between the subscriber unit of the present invention and a leased line network;
Figure 3 is a block diagram of a subscriber unit in accordance with the present invention; Figure 4 is a block diagram of an RCS in accordance with the present invention;
Figure 5 is a flow diagram of the procedure for dynamic allocation of bandwidth for ISDN service;
Figures 6A and 6B are flow diagrams of the establishment of the bearer channel between the subscriber unit and the RCS for POTS service;
Figure 7 shows the layered protocol of the communications between the subscriber unit and RCS;
Figures 8A illustrates the simplified bearer switching method as initiated by the subscriber unit;
Figure 8B illustrates the simplified bearer switching method as initiated by the RCS; and Figures 9A and 9B are flow diagrams of the establishment of the bearer channel between the subscriber unit and the RCS for ISDN service.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment will be described with reference to the drawing figures wherein like numerals represent like elements throughout.
The system of the present invention provides local-loop telephone service using radio links between one or more base stations and at least one remote subscriber unit. In the exemplary embodiment, the radio link is described for a base station communicating with a fixed subscriber unit (FSU) , but the system is equally applicable to systems including multiple base stations with radio links to both fixed subscriber units and mobile subscriber units (MSUs) . Consequently, the fixed and mobile subscriber units will be referred to herein as subscriber units.
Referring to Figure 1, a base station 101 provides call connection to a local exchange 103 or any other telephone network switching interface, such as a private branch exchange
(PBX) , and includes at least one radio carrier station (RCS)
104, 105...110. One or more RCSs 104, 105, 110 connect to a radio distribution unit (RDU) 102 through links 131, 132, 137, 138, 139 and RDU 102 interfaces with the local exchange 103 by transmitting and receiving call set-up, control, and information signal through telco links 141, 142, 150. The subscriber units 116, 119 communicate with the RCS 104 through radio links 161, 162, 163, 164, 165. Alternatively, another embodiment of the invention includes several subscriber units and a "master subscriber unit" with functionality similar to the RCS 104. Such an embodiment may or may not have connection to a local telephone network.
The radio links 161 to 165 operate within the frequency bands of the CDS1800 standard (1.71-1.785 GHz and 1.805-1.880 GHz); the US-PCS standard (1.85-1.99 GHz); and the CEPT standard (2.0-2.7 GHz) . Although these bands are used in the described embodiment, the invention is equally applicable to any RF frequency band including the entire UHF and SHF bands, and bands from 2.7 GHz to 5 GHz . The transmit and receive bandwidths are multiples of 3.5 MHz starting at 7 MHz, and multiples of 5 MHz starting at 10 MHz, respectively. The described system includes bandwidths of 7, 10, 10.5, 14 and 15 MHz. In the exemplary embodiment of the invention, the minimum guard band between the uplink and downlink is 20 MHz, and is desirably at least three times the signal bandwidth. The duplex separation is between 50 to 175 MHz, with the described invention using 50, 75, 80, 95 and 175 MHz. Other frequencies may also be used.
Although the system may use different spread-spectrum bandwidths centered around a carrier for the transmit and receive spread-spectrum channels, the present invention is readily extended to systems using multiple spread-spectrum bandwidths for the transmit channels and multiple spread- spectrum bandwidths for the receive channels. Alternatively, the same spread-spectrum bandwidth for both the transmit and receive channels may be employed wherein uplink and downlink transmissions will occupy the same frequency band. The present invention may also be readily extended to multiple CDMA frequency bands, each conveying a respectively different set of messages, uplink, downlink or uplink and downlink.
The spread binary symbol information is transmitted over the radio links 161 to 165 using quadrature phase shift keying
(QPSK) modulation with Nyquist pulse shaping. However, other modulation techniques may be used including, but not limited to, offset QPSK minimum shift keying (MSK) , Gaussian phase shift keying (GPSK) and M-ary phase shift keying (MPSK) .
The radio links 161 to 165 incorporate broadband code division multiple access (B-CDMA™) technology as the mode of transmission in both the uplink and downlink directions . CDMA (also known as spread spectrum) communication techniques used in multiple access systems are well-known, and are described in U.S. Patent 5,228,056 entitled SYNCHRONOUS SPREAD-SPECTRUM COMMUNICATION SYSTEM AND METHOD by Donald Schilling. The system described utilizes the direct sequence spreading technique. The CDMA modulator generates the spread-spectrum spreading code sequence, which can be a pseudonoise sequence, and performs complex direct sequence modulation of the QPSK signals with spreading code sequences for the In-phase (I) and Quadrature (Q) channels. Pilot signals, spreading codes which are not modulated by data, are generated and transmitted with the modulated signals. The pilot signals are used for synchronization, carrier phase recovery, and for estimating the impulse response of the radio channel . Each subscriber unit 111-118 includes a code generator and at least one CDMA modulator and demodulator, which together comprise a CDMA modem. Each RCS 104, 105, 110 has at least one code generator plus sufficient CDMA modulators and demodulators for all of the logical channels in use by the subscriber units .
The CDMA demodulator despreads the signal with appropriate processing to reduce or exploit multipath propagation effects. The radio links support multiple traffic channels with data rates of 8, 16, 32, 64, 128 and 144 kb/s. The physical channel to which a traffic channel is connected operates with a 64k symbol/sec rate. Other data rates may be supported, and forward error correction (FEC) coding can be employed. For the described embodiment, FEC with a coding rate of 1/2 and a constraint length 7 is used. Other rates and constraint lengths can be used consistent with the code generation techniques employed.
Referring again to Figure 1, the RCS 104 interfaces to the RDU 102 through a plurality of RF links or terrestrial links 131, 132, 137 with, for example, 1.533 Mb/s DS1, 2.048 Mbs/ El; or HDSL formats to receive and send digital data signals. While these are typical telephone company standardized interfaces, the present invention is not limited to these digital data formats only. The exemplary RCS line interface (not shown in Figure 1) translates the line coding (such as HDB3 , B8ZS, AMI) and extracts or produces framing information, performs alarms and facility signaling functions, as well as channel specific loop-back and parity check functions. This provides 64 kb/s PCM encoded or 32 kb/s ADPCM encoded telephone traffic channels or ISDN channels to the RCS 104, 105, 110 for processing as will be described in greater detail hereinafter. Other voice compression techniques can be used consistent with the sequence generation techniques. The system of the present invention also supports bearer rate modification between the RCS 104 and the subscriber unit 111 for both POTS service and ISDN service. The subscriber units 111-118 may interface with a telephone unit 170, a local switch (PBX) 171, a data terminal 172, an ISDN interface 173 or other types of equipment shown in Figures 2A-2H. The input from the telephone unit 170 may include voice, voiceband data and signaling. Although the present invention is applicable to the communications between a plurality of subscriber units 111-118 and a plurality of RCSs 104-110, reference hereinafter will be made to a particular subscriber unit and RCS for simplicity. If the signals input into the subscriber unit are not digital, the subscriber unit 111 translates the analog signals into digital sequences for transmission to the RCS 104. The subscriber unit 112 encodes voice data with techniques such as ADPCM at rates of 32 kb/s or lower. The RCS 104 detects voiceband data or facsimile data with rates above 4.8 kb/s to modify the bearer rate of the traffic channel for unencoded transmission. Also A-law, u-law, or no companding of the signal may be performed before transmission. As is well known to those of skill in the art, data compression techniques for digital data such as idle flag removal may also be used to conserve capacity and minimize interference . The transmit power level of the radio interface between the RCS 104 and the subscriber unit 111 is controlled using a different closed loop power control method for the downlink and uplink directions. The automatic forward power control (AFPC) method determines the downlink transmit power level and the automatic reverse power control (ARPC) method determines the uplink transmit power level . The logical control channel by which the subscriber unit 111 and the RCS 104 transfer power control information operates at an update rate of at least a 16 kHz. Other embodiments may use a faster or slower update rate, for example 64 kHz. These algorithms ensure that the transmit power of a user maintains an acceptable bit-error rate (BER) , maintain the system power at a minimum to conserve power and maintain the power level of the subscriber unit 111 as received by the RCS 104 at a nearly equal level .
The system also uses an optional maintenance power control method during the inactive mode of the subscriber unit 111. When the subscriber unit 111 is inactive or powered-down to conserve power, the subscriber unit 111 occasionally activates to adjust its initial transmit power level setting in response to a maintenance power control signal from the RCS 104. The maintenance power control signal is determined by the RCS 104 by measuring the received power level of the subscriber unit 111 and present system power level and calculating the necessary initial transmit power. The method shortens the channel acquisition time of the subscriber unit 111 to begin a communication and prevents the transmit power level of the subscriber unit 111 from becoming too high and interfering with other channels during the initial transmission before the closed loop power control reduces the transmit power.
The RCS 104 obtains synchronization of its clock from an interface line such as, but not limited to, El, Tl, or HDSL interfaces. The RCS 104 can also generate its own internal clock signal from an oscillator which may be regulated by a global positioning system (GPS) receiver. The RCS 104 generates a global pilot code, which can be acquired by the remote subscriber unit 111. All transmission channels of the RCS 104 are synchronized to the global pilot channel . The spreading code phases of code generators (not shown in Figure 1) used for logical communication channels within the RCS 104 are also synchronized to the spreading code phase of the global pilot channel. Similarly, all subscriber units 111-118 which receive the global pilot code of the RCS 104 synchronize the spreading and de-spreading code phases of their code generators to the global pilot code.
Typically, a prior art channel is regarded as a communications path which is part of an interface and which can be distinguished from other paths of that interface without regard to its content. However, for CDMA communications, separate communications paths are distinguished by their content . All logical channels and subchannels of the present invention are mapped to a common 64 kilo-symbols per second (ksym/s) QPSK stream. Some channels are synchronized to associated pilot codes which are generated from, and perform a similar function to, the global pilot code. The system pilot signals are not considered logical channels.
Several logical communication channels are used over the RF communication link between the RCS 104 and the subscriber unit 111. Each logical communication channel either has a fixed, pre-determined spreading code or a dynamically assigned spreading code. For both predetermined and assigned codes, the code phase is synchronized with the global pilot code. The spreading codes are specified by the seeds used to generate the codes. A pool of "primary seeds" exists within the RDU 102, a portion of which comprise global primary seeds and the remainder comprise assigned primary seeds. The RDU 102 allocates these primary seeds to the RCSs 104 on an as- needed basis. A global primary seed generates all of the global channel codes for use by an RCS 104 within a cell. However, assigned primary seeds are used to generate secondary assigned seeds. One primary assigned seed generates fifty- seven (57) secondary assigned seeds. Each secondary assigned seed is input into the code generators within the RCS 104 and the subscriber unit 111 to generate a set of assigned channel codes to support each communication link. In the preferred embodiment, each RCS 104 is given one global primary seed for generating global channel codes and two primary assigned seeds. Accordingly, the RCS 104 and its corresponding subscriber units 111-118 may generate up to 114 secondary assigned seeds. Each secondary assigned seed is assigned by the RCS 104 to generate the codes for an active link, thereby permitting enough codes for up to 114 simultaneous communication links.
Logical communication channels are divided into two groups: 1) global channels; and 2) assigned channels. The global channel group includes channels which are either transmitted from the RCS 104 to all subscriber units 111-118 or from any subscriber unit 111-118 to the RCS 104 regardless of the identity of the subscriber unit 111-118. Channels in the assigned channels group are those channels dedicated to communication between the RCS 104 and a particular subscriber unit 111.
With respect to the global channel group, the global channel group provides for: 1) broadcast control logical channels, which provide point-to- ulti-point services for broadcasting messages to all subscriber units 111-118 and paging messages to subscriber units 111-118; and 2) access control logical channels which provide point-to-point services on global channels for subscriber units 111-118 to access the system and obtain assigned channels . The RCS 104 of the present invention has one broadcast control logical channel and multiple access control logical channels. A subscriber unit 111-118 of the present invention has at least one broadcast control logical channel and at least one access control logical channel . The global logical channels controlled by the RCS 104 are the fast broadcast channel (FBCCH) which broadcasts fast changing information concerning which services and which access channels are currently available, and the slow broadcast channel (SBCCH) which broadcasts slow changing system information and paging messages.
The subscriber unit 111 uses an access channel (AXCH) to begin communications with the RCS 104 and gain access to assigned channels . Each AXCH is paired with a control channel (CTCH) which is sent from the RCS 104 to the subscriber unit 111. The CTCH is used by the RCS 104 to acknowledge and reply to access attempts by the subscriber unit 111. The short access pilot (SAXPT) and the long access pilot (LAXPT) are transmitted synchronously with AXCH to initiate access and to provide the RCS 104 with a time and phase reference. The SAXPT is transmitted by the subscriber unit 111 while it ramps up its transmit power to initiate access to the RCS 104. Since the SAXPT is a relatively short code it permits the RCS 104 to detect the subscriber unit 111 quickly and avoids power overshoot by the subscriber unit 111. Further detail regarding transmit power ramp-up using the SAXPT is described in more detail in an application entitled A METHOD OF CONTROLLING INITIAL POWER RAMP-UP IN CDMA SYSTEMS BY USING SHORT CODES, Serial No. 08/670,162; filed June 27, 1996 which is herein incorporated by reference as if fully set forth. Until the SAXPT is detected by the RCS 104, subscriber unit 111 does not send any other signal. Once the SAXPT is detected, the subscriber unit 111 starts transmitting the LAXPT which provides the RCS 104 with a time and phase reference and permits the RCS 104 to determine the channel impulse response . With respect to the assigned channel group, this group contains the logical channels that control a single communication link between the RCS 104 and the subscriber unit 111. When an assigned channel group is formed, a pair of power control logical message channels for each of the uplink and downlink connections is established and one or more pairs of traffic channels, depending on the type of connection, is established. The bearer control function performs the required forward error control, bearer rate modification and encryption functions.
Each subscriber unit 111-118 has at least one assigned channel group when a communication link is established, and each RCS 104-110 has multiple assigned channel groups, one for each communication link in progress. An assigned channel group of logical channels is created for a communication link upon successful establishment of the communication link. The assigned channel group includes encryption, FEC coding, and multiplexing on transmission, and decryption, FEC decoding and demultiplexing on reception. Each assigned channel group provides a set of communication link oriented point-to-point services and operates in both directions between a specific RCS 104 and a specific subscriber unit 111. An assigned channel group formed for a communication link can control more than one bearer over the RF communication channel associated with a single communication link. Multiple bearers are used to carry distributed data such as, but not limited to, ISDN. An assigned channel group can provide for the duplication of traffic channels to facilitate switchover to 64 kb/s PCM for high speed facsimile and modem services for the bearer rate modification function.
The assigned logical channels formed upon a successful communication link and included in the assigned channel group are dedicated signaling channel order wire (OW) , APC channel and one or more traffic channels (TRCH) which are bearers of 8, 16, 32, or 64 kb/s depending on the service supported. For voice traffic, moderate rate coded speech ADPCM or PCM can be supported on the traffic channels. For ISDN service types, two 64 kb/s TRCHs form the B channels and one 16 kb/s TRCH forms the D channel. Alternatively, the APC subchannel may either be separately modulated on its own CDMA channel, or may be time division multiplexed with a traffic channel or OW channel .
Each subscriber unit 111-118 of the present invention supports up to three simultaneous traffic channels. A subscriber unit is preferably commissioned to be a POTS subscriber unit 112 or an ISDN subscriber unit 115. Although POTS subscriber unit 112 does not support ISDN service in accordance with the present invention, bandwidth resources can be dynamically allocated for either service type. For example, a POTS subscriber unit 112 can set up an additional POTS line and tear it down, or an ISDN subscriber unit 115 can dynamically add B channel-carrying bearers or tear them down. For dynamic bandwidth allocation of a POTS service, an active 32 kb/s ADPCM service modifies the bearer type from 32 kb/s to 64 kb/s unencoded data to support facsimile transmission. The presence of a facsimile call is determined by the RCS 104 by monitoring the existence of the 2100 Hz answer tone.
For dynamic bandwidth allocation of ISDN service, the RCS 104 monitors the ISDN D channel messages to determine when a B channel is requested and when it should be torn down. Once the RCS 104 determines the need for changing the bearer channel allocation, the RCS 104 initiates the dynamic bearer allocation procedure which will be described in greater detail hereinafter. The mapping of the three logical channels for TRCHs to the user data is shown below in Table 1:
Figure imgf000019_0001
Table 1: Mapping of service types to the three available TRCH channels
A subscriber unit 200 made in accordance with the present invention is generally shown in Figure 3. The subscriber unit 200 includes a receiver section 202 and a transmitter section 204. An antenna 206 receives a signal from RCS 104, which is filtered by a band-pass filter 208 having a bandwidth equal to twice the chip rate and a center frequency equal to the center frequency of the spread spectrum system's bandwidth. The output of the filter 208 is down-converted by a mixer 210 to a baseband signal using a constant frequency (Fc) local oscillator. The output of the mixer 210 is then spread spectrum decoded by applying a PN sequence for each logical channel to a mixer 212 within the PN Rx generator 214. The output of the mixer 212 is input to a codec 218 which interfaces with the communicating entity 220.
A baseband signal from the communicating entity 220, for example the equipment shown in Figures 2A-2H, is pulse code modulated by the codec 218. Preferably, a 32 kb/s adaptive pulse code modulation (ADPCM) is used. The PCM signal is applied to a mixer 222 within a PN Tx generator 224. The mixer 222 multiplies the PCM data signal with the PN sequence for each logical channel. The output of the mixer 222 is applied to low-pass filter 226 whose cutoff frequency is equal to the system chip rate. The output of the filter 226 is then applied to a mixer 228 and suitably up-converted, as determined by the carrier frequency Fc applied to the other terminal. The up-converted signal is then passed through a band-pass filter 230 and to a broadband RF amplifier 232 which drives an antenna 234. Although two antennas 206, 234 are shown, the preferred embodiment includes a diplexer and a single antenna for transmission and reception. The digital signal processor (DSP) 236 controls the acquisition process as well as the Rx and Tx PN generators 214, 224. The base station 101, which includes a plurality of RCSs
104, 105, 110 made in accordance with the present invention is shown in Figure 4. For simplicity, only one RCS 104 is shown. The base station 101 includes a receiver section 302 and a transmitter section 304. An antenna 306 receives a signal from the subscriber unit, which is filtered by a bandpass filter 308 having a bandwidth equal to twice the chip rate and a center frequency equal to the center frequency of the spread spectrum system's bandwidth. The output of the filter 308 is down-converted by a mixer 310 to a baseband signal using a constant frequency (Fc) local oscillator. The output of the mixer 310 is then spread spectrum decoded at each modem by applying a PN sequence to a mixer 312 within the PN Rx generator 314. The output of the mixer 316 is then forwarded to the RDU 318.
A baseband signal is received from the RDU 318. Preferably, a 32 kb/s ADPCM signal is used. The ADPCM or PCM signal is applied to a mixer 322 within a PN Tx generator 324. The mixer 322 multiplies the ADPCM or PCM data signal with the PN sequence. The output of the mixer 322 is applied to low- pass filter 326 whose cutoff frequency is equal to the system chip rate. The output of the filter 326 is then applied to a mixer 328 and suitably up-converted, as determined by the carrier frequency Fc applied to the other terminal. The up- converted signal is then passed through a band-pass filter 330 and to a broadband RF amplifier 332 which drives an antenna 334. Although two antennas 306, 334 are shown, the preferred embodiment includes a diplexer and only one antenna for transmission and reception. The digital signal processor (DSP) 336 controls the acquisition process as well as the Rx and Tx PN generators 314, 324. The system provides a wireless link between the RCS 104 and the plurality of subscriber units 111-118. In order to conserve as much bandwidth as possible, the system selectively allots the bandwidth required for supporting the data transmission rate required by particular communication. In this manner, the system ensures that the bandwidth is utilized efficiently. For example, referring back to Table 1, voiced communications may be effectively transmitted across a 32 kb/s adaptive pulse code modulation (ADPCM) channel. However, a high speed facsimile or data modem signal requires at least a 64 k/bs PCM signal to reliably transmit the communication. Additionally, although a subscriber unit 115 has paid for ISDN service, which includes two 64 kb/s B channels and one 16 kb/s channel, the entire ISDN capacity is rarely utilized at all times . Many different data transmission rates may also be utilized by originating and terminating nodes.
The originating and terminating nodes may comprise computers, facsimile machines, automatic calling and answering equipment, data networks or any combination of this equipment. For robust communication of data it is imperative to ensure that the communication system switches to the data transmission rate required by the communicating nodes prior to the transmission of any data. The system must be able to effectively allocate bandwidth and dynamically switch between these data communication rates on demand by the user. Modification of the transmission rate from a low rate (that supports voice communication) to a high rate (that supports encoded data communication) ensures that data will be reliably and quickly transmitted over a communication channel. Additionally, if an ISDN D channel is presently allocated and one or two B channels are required, the system must ensure that the code generators are activated in order to support the communication.
For POTS, there are two basic scenarios where the bearer channel (TRCH channel) is either modified or a new bearer channel is added or torn down. First, the bearer channel is modified from 32 kb/s coded ADPCM type to 64 kb/s uncoded PCM service to support a facsimile transmission. Second, a new bearer channel is added or torn down when the subscriber goes off hook while an OA&M (overhead, administration and maintenance) call is in progress, or when an OA&M call is initiated while a POTS call is in progress. While an OA&M silent call is in progress, the subscriber unit 112 can determine that the user is initiating a new POTS call by monitoring the changes at the A/B interface between the subscriber unit 112 and the communication equipment 170 (on- hook/off-hook sensor) . More detail regarding the dynamic allocation of bandwidth for POTS may be found in an application entitled CODE DIVISION MULTIPLE ACCESS (CDMA) COMMUNICATION SYSTEM, Patent Application Serial No. Not Yet Known, filed March 11, 1997, which is a continuation-in-part of Serial No. 08/669,775, filed June 27, 1996 by Lomp et al . , which is incorporated herein by reference as if fully set forth.
For ISDN service, the dynamic bandwidth allocation refers to selective allocation of the D and B channels in a D, D and B, or D and 2B bearer channel configuration as needed and tearing them down when they are idle. The ISDN D channel carries control messaging and cannot be torn down while the ISDN call is still active. Accordingly, dynamic bandwidth allocation for ISDN service only relates to the addition and tearing down of B channels .
The procedure 400 for dynamic allocation of bandwidth for ISDN service in accordance with the present invention will be explained in greater detail with reference to Figure 5. When an ISDN call is initiated, the D channel is established first (step 402) . The bandwidth required for the particular application is communicated from the calling ISDN equipment to the called ISDN equipment through messages on the D channel (step 404) . These messages are in HDLC format and the RCS 104 monitors these messages via an HDLC interface (step 406) .
Once the RCS 104 determines how many B channels are required
(step 408) it initiates establishment of these bearer channels over the air interface (step 410) . The RCS continues monitoring the HDLC messages on the D channel during the ISDN call (step 412) and determines if additional B channels are to be switched in or out. In case that additional B channels should be switched in or out, the RCS 104 initiates the establishment or tearing down of the bearer channels over the air interface (step 414) . A flow diagram showing simplified procedure 600 of the bearer channel establishment will be described with reference to Figures 6A and 6B. The subscriber unit 111 quickly ramps up its transmit power (step 602) while sending the SAXPT (step 604) . When the RCS 104 detects the SAXPT (step 606), it turns the traffic light bit to "red" on the FBCCH (step 608) to signal to the subscriber unit 111 that it has been detected. The RCS 104 transmits the FBCCH (step 610) . The subscriber unit 111 monitors the FBCCH (step 612) and it stops the fast ramp-up when it sees the "traffic light" turn red on the FBCCH (step 614) . The subscriber unit 111 then continues a slow ramp-up of its transmit power (step 616) while transmitting the LAXPT (step 618) . When the RCS 104 acquires the LAXPT (step 620) , it informs the subscriber unit 111 via the SYNC-OK message on CTCH (step 622) . This completes the transmit power ramping up part of the access procedure .
After the subscriber unit 111 receives the SYNC-OK message on the CTCH (step 624) , it sends the access request message on the AXCH (step 626) . Upon receiving the request
(step 628) the RCS 104 confirms receipt of the AXCH message with a message on CTCH (step 630) , which includes the assigned code seed. The subscriber unit 111 detects and acknowledges the bearer confirmation message that carries the assigned code seed on the AXCH (steps 632 and 634) , which the RCS 104 detects (step 636) . The code switchover is now negotiated and subscriber unit 111 and RCS 104 simultaneously switch to using the assigned code (steps 638 and 640) . The bearer channel is now established. The layered protocol of the communications between the subscriber unit 111 and the RCS 104 is shown in Figure 7 along with its correspondence to the layers of the Open Systems Interconnection (OSI) reference model. The physical (PHL) layer performs the following functions: 1) generation of CDMA codes; 2) synchronization between transmitter and receiver;
3) providing bearers to the Medium Access Control (MAC) layer;
4) spreading and transmission of bits on a CDMA code specified by the MAC and at a power level specified by the MAC; 5) measurement of received signal strength to allow automatic power control; and 6) generation and transmission of pilot signals. The MAC layers performs the following functions: 1) encoding and decoding for forward error correction (FEC) ; 2) assignment of CDMA codes; 3) encryption and decryption; 4) providing bearers which are encrypted and error-corrected as appropriate; 5) framing, error checking and discrimination of MAC peer to peer messages and data; 6) link control (DLC) frames; and 7) processing of automatic power control information. The data link control layer (DLC) provides an error- free link between higher level layers of the protocol stack.
As shown in Figure 8A, the signaling between the subscriber unit 111 and the RCS 104 involves the MAC and DLC layers of the protocol. Once the bearer channel for POTS service is established as described above, the service is available and remains unchanged until it is torn down or unless it has to be modified to support a facsimile transmission or a second call, in the case of a simultaneous OA&M call and POTS call. When there is an OA&M call in progress and the subscriber unit 111 initiates a POTS service call, the procedure as shown in Figure 8A is entered. This figure illustrates the simplified bearer switching method as initiated by the subscriber unit 111. The messages go between the data link control layer (DLC) , medium access control layer (MAC) of the subscriber unit 111, and the corresponding layers in the RCS 104. First, the DLC layer of the subscriber unit 111 initiates a switch request to the MAC layer of the subscriber unit 111, which refers this switch request to the MAC layer of the RCS 104. The RCS 104 sends a confirmation over the MAC layer to the subscriber unit 111 and also sends a switch indication to the DLC layer of the RCS 104. In the subscriber unit 111, the switch confirmation sent from the RCS 104 over the MAC layer is forwarded to the DLC layer of the subscriber unit 111.
When there is a POTS service call in progress and the RCS 104 initiates an OA&M call to the same subscriber unit 111, the procedure as shown in Figure 8B is entered. This figure illustrates the simplified bearer switching method as initiated by the RCS 104. The RCS 104 initiates a switch indication message over the MAC layer to the subscriber unit 111. The subscriber unit 111 then relays this message via the DLC layer.
The bearer channel establishment for ISDN will be explained with reference to Figure 9A and 9B. Steps 902-940 are the same as the corresponding steps 602-640 in Figures 6A and 6B. However, several additional steps are required after the subscriber unit 111 and the RCS 104 both switch to the assigned codes (steps 938 and 940) . Once the subscriber unit 111 and RCS 104 switch to assigned codes (steps 938 and 940) the ISDN D channel becomes active. At this point the S/T interface between the subscriber unit 111 and the ISDN equipment is already active. The RCS 104 starts monitoring the D channel messages (step 942), which are in HDLC format. Upon detecting that one or more B channels are needed for the particular application (step 944) the RCS 104 initiates establishment of these bearer channels over the air interface. The process is then continued in accordance with the procedure shown in Figure 5. The MAC and DLC message flow for this procedure is the same as in Figure 8B . The bearer channels for POTS and ISDN is switched in or out via the same message flow. Whether the bearer channel is switched in or out is indicated by appropriate values in corresponding fields of the D channel messages. Therefore the flow diagram in Figure 8B apply to both dynamic switching in of bearer channels as well as dynamic switching out of bearer channels .
Although the invention has been described in part by making detailed reference to certain specific embodiments, such details is intended to be instructive rather than restrictive. It will be appreciated by those skilled in the art that many variations may be made in the structure and mode of operation without departing from the spirit and scope of the invention as disclosed in the teachings herein.

Claims

What is claimed is :
1. A wireless digital CDMA communication system, including a base station and at least one subscriber unit, for transmitting a plurality of communications having independent data rates between a base station and a subscriber unit, the system comprising: at least one base station comprising: means for processing a communication for transmitting to said at least one subscriber unit including means for determining the data rate required to support said communication; and transmission means for transmitting communications at one of a plurality of data rates having data rate selection means responsive to said determining means; and at least one subscriber unit comprising: means for processing a communication for transmitting to said at least one subscriber unit including means for determining the data rate required to support said communication; and transmission means for transmitting communications at one of a plurality of data rates including data rate selection means responsive to said determining means.
2. The system of claim 1 wherein said subscriber unit further includes means for establishing a communication channel having a capacity of a first data communication rate; and means for communicating at a second data communication rate; wherein said first data communication rate is higher than said second data communication rate.
3. The system of claim 2 wherein said communication channel is an ISDN channel including two B channels and a D channel; wherein said system selectively utilizes said B and said D channels depending upon the data rate required to support said desired communication.
PCT/US1998/010600 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand WO1998058456A2 (en)

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BR9810164-1A BR9810164A (en) 1997-06-16 1998-05-26 Digital cdma wireless communication system.
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DE0990312T DE990312T1 (en) 1997-06-16 1998-05-26 CDMA MESSAGE TRANSMISSION SYSTEM WHICH SELECTIVELY ASSIGNS BANDWIDTH ON REQUEST
KR1020077014138A KR100873462B1 (en) 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand
KR1020127029272A KR101434081B1 (en) 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand
KR1020087027396A KR101336439B1 (en) 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand
EP98926060A EP0990312A2 (en) 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand
AU77982/98A AU743633B2 (en) 1997-06-16 1998-05-26 CDMA communication system which selectively allocates bandwidth upon demand
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KR1020097007063A KR101053135B1 (en) 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand
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JP50443499A JP2002513540A (en) 1997-06-16 1998-05-26 CDMA communication system for selectively allocating bandwidth in response to demand
CA2294226A CA2294226C (en) 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand
KR1020137017653A KR101434126B1 (en) 1997-06-16 1998-05-26 Cdma communication system which selectively allocates bandwidth upon demand
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Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2351632A (en) * 1999-06-28 2001-01-03 Nokia Telecommunications Oy CDMA radio systems
FR2797130A1 (en) * 1999-07-29 2001-02-02 Kurtosis Ingenierie Digital word transmission technique having coded division multiple access coding forming chip sets and transmission filtering interlaced frequency bands dividing output response.
WO2001093600A2 (en) * 2000-05-31 2001-12-06 Telefonaktiebolaget L M Ericsson (Publ) Session dispatcher at a wireless multiplexer interface
WO2002017507A1 (en) * 2000-08-23 2002-02-28 British Telecommunications Public Limited Company Spread spectrum modulation system
US7498935B2 (en) 2002-01-24 2009-03-03 Panasonic Corporation Power-line carrier communication apparatus
JP2013048424A (en) * 1999-10-29 2013-03-07 Wi-Lan Inc Method for data synchronization and transportation in wireless communications system
JP2014096842A (en) * 2002-01-08 2014-05-22 Ipr Licensing Inc Maintaining maintenance channel in reverse link of wireless communication

Families Citing this family (117)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI96558C (en) * 1994-09-27 1996-07-10 Nokia Telecommunications Oy Method for data transmission in a TDMA mobile radio system and a mobile radio system for carrying out the method
US6075792A (en) 1997-06-16 2000-06-13 Interdigital Technology Corporation CDMA communication system which selectively allocates bandwidth upon demand
US6081536A (en) * 1997-06-20 2000-06-27 Tantivy Communications, Inc. Dynamic bandwidth allocation to transmit a wireless protocol across a code division multiple access (CDMA) radio link
US6542481B2 (en) 1998-06-01 2003-04-01 Tantivy Communications, Inc. Dynamic bandwidth allocation for multiple access communication using session queues
US6151332A (en) 1997-06-20 2000-11-21 Tantivy Communications, Inc. Protocol conversion and bandwidth reduction technique providing multiple nB+D ISDN basic rate interface links over a wireless code division multiple access communication system
US6434125B1 (en) * 1997-10-24 2002-08-13 Lucent Technologies Inc. Automatic data service selection method and apparatus for digital wireless communication networks
US7394791B2 (en) 1997-12-17 2008-07-01 Interdigital Technology Corporation Multi-detection of heartbeat to reduce error probability
US9525923B2 (en) 1997-12-17 2016-12-20 Intel Corporation Multi-detection of heartbeat to reduce error probability
US7936728B2 (en) 1997-12-17 2011-05-03 Tantivy Communications, Inc. System and method for maintaining timing of synchronization messages over a reverse link of a CDMA wireless communication system
US6222832B1 (en) * 1998-06-01 2001-04-24 Tantivy Communications, Inc. Fast Acquisition of traffic channels for a highly variable data rate reverse link of a CDMA wireless communication system
US20040160910A1 (en) * 1997-12-17 2004-08-19 Tantivy Communications, Inc. Dynamic bandwidth allocation to transmit a wireless protocol across a code division multiple access (CDMA) radio link
US7496072B2 (en) * 1997-12-17 2009-02-24 Interdigital Technology Corporation System and method for controlling signal strength over a reverse link of a CDMA wireless communication system
JP4048510B2 (en) * 1998-03-05 2008-02-20 富士通株式会社 Radio base station in CDMA mobile communication system
US7773566B2 (en) 1998-06-01 2010-08-10 Tantivy Communications, Inc. System and method for maintaining timing of synchronization messages over a reverse link of a CDMA wireless communication system
US8134980B2 (en) 1998-06-01 2012-03-13 Ipr Licensing, Inc. Transmittal of heartbeat signal at a lower level than heartbeat request
US7221664B2 (en) * 1998-06-01 2007-05-22 Interdigital Technology Corporation Transmittal of heartbeat signal at a lower level than heartbeat request
US6680922B1 (en) 1998-07-10 2004-01-20 Malibu Networks, Inc. Method for the recognition and operation of virtual private networks (VPNs) over a wireless point to multi-point (PtMP) transmission system
US6452915B1 (en) 1998-07-10 2002-09-17 Malibu Networks, Inc. IP-flow classification in a wireless point to multi-point (PTMP) transmission system
US6862622B2 (en) * 1998-07-10 2005-03-01 Van Drebbel Mariner Llc Transmission control protocol/internet protocol (TCP/IP) packet-centric wireless point to multi-point (PTMP) transmission system architecture
US6628629B1 (en) 1998-07-10 2003-09-30 Malibu Networks Reservation based prioritization method for wireless transmission of latency and jitter sensitive IP-flows in a wireless point to multi-point transmission system
US6594246B1 (en) 1998-07-10 2003-07-15 Malibu Networks, Inc. IP-flow identification in a wireless point to multi-point transmission system
US6590885B1 (en) 1998-07-10 2003-07-08 Malibu Networks, Inc. IP-flow characterization in a wireless point to multi-point (PTMP) transmission system
US6640248B1 (en) 1998-07-10 2003-10-28 Malibu Networks, Inc. Application-aware, quality of service (QoS) sensitive, media access control (MAC) layer
FI106896B (en) * 1998-07-22 2001-04-30 Nokia Networks Oy Communication method, radio network subsystem and subscriber terminal
DE19834634C2 (en) * 1998-07-31 2002-06-20 Siemens Ag Communication arrangement with at least one central communication device to which wireless network termination devices can be connected for the connection of communication terminals
US6567418B1 (en) * 1998-12-23 2003-05-20 At&T Corp. System and method for multichannel communication
US6903755B1 (en) 1998-12-31 2005-06-07 John T. Pugaczewski Network management system and graphical user interface
JP3792517B2 (en) * 1999-04-26 2006-07-05 ルーセント テクノロジーズ インコーポレーテッド Method for performing a call on a multiple bit rate transmission channel, bit rate switching method, corresponding network section and transmission network
US6614776B1 (en) * 1999-04-28 2003-09-02 Tantivy Communications, Inc. Forward error correction scheme for high rate data exchange in a wireless system
CN100380874C (en) * 1999-05-17 2008-04-09 艾利森电话股份有限公司 Method and apparatus for providing radio access bearer services
US6925068B1 (en) 1999-05-21 2005-08-02 Wi-Lan, Inc. Method and apparatus for allocating bandwidth in a wireless communication system
US20090219879A1 (en) 1999-05-21 2009-09-03 Wi-Lan, Inc. Method and apparatus for bandwidth request/grant protocols in a wireless communication system
US8462810B2 (en) 1999-05-21 2013-06-11 Wi-Lan, Inc. Method and system for adaptively obtaining bandwidth allocation requests
US7006530B2 (en) 2000-12-22 2006-02-28 Wi-Lan, Inc. Method and system for adaptively obtaining bandwidth allocation requests
US6526034B1 (en) * 1999-09-21 2003-02-25 Tantivy Communications, Inc. Dual mode subscriber unit for short range, high rate and long range, lower rate data communications
JP4074036B2 (en) * 1999-09-29 2008-04-09 株式会社東芝 Wireless communication terminal
US8463255B2 (en) 1999-12-20 2013-06-11 Ipr Licensing, Inc. Method and apparatus for a spectrally compliant cellular communication system
FR2803711B1 (en) * 2000-01-06 2002-04-05 Cit Alcatel METHOD FOR MANAGING CALL COLLISION IN A D-CHANNEL TYPE CHANNEL
EP1117191A1 (en) * 2000-01-13 2001-07-18 Telefonaktiebolaget Lm Ericsson Echo cancelling method
AU3673001A (en) 2000-02-07 2001-08-14 Tantivy Communications, Inc. Minimal maintenance link to support synchronization
US6728218B1 (en) * 2000-02-14 2004-04-27 Motorola, Inc. Method of dynamic rate switching via medium access channel layer signaling
CA2302461A1 (en) * 2000-03-27 2001-09-27 William Martin Snelgrove Wireless local loop
EP1148750A1 (en) * 2000-04-22 2001-10-24 Deutsche Thomson-Brandt Gmbh Channel preselection method for a RF communication system
US8321542B1 (en) 2000-05-05 2012-11-27 Ipr Licensing, Inc. Wireless channel allocation in a base station processor
US6804252B1 (en) * 2000-05-19 2004-10-12 Ipr Licensing, Inc. Automatic reverse channel assignment in a two-way TDM communication system
KR100678150B1 (en) * 2000-06-29 2007-02-01 삼성전자주식회사 System for link adaptation and method thereof in code division multiple access system
GB2366136B (en) * 2000-08-09 2004-03-03 Airspan Networks Inc Handling of data packets and voice calls in a wireless telecommunications system
US7433340B1 (en) 2000-10-19 2008-10-07 Interdigital Technology Corporation Staggering forward and reverse wireless channel allocation timing
US8842642B2 (en) 2000-10-19 2014-09-23 Ipr Licensing, Inc. Transmitting acknowledgement messages using a staggered uplink time slot
KR100847187B1 (en) * 2000-11-16 2008-07-17 소니 가부시끼 가이샤 Information processing apparatus and communication apparatus
US6847629B2 (en) 2000-11-30 2005-01-25 Qualcomm Incorporated Method and apparatus for scheduling packet data transmissions in a wireless communication system
US8155096B1 (en) 2000-12-01 2012-04-10 Ipr Licensing Inc. Antenna control system and method
US7346918B2 (en) 2000-12-27 2008-03-18 Z-Band, Inc. Intelligent device system and method for distribution of digital signals on a wideband signal distribution system
US6990086B1 (en) 2001-01-26 2006-01-24 Cisco Technology, Inc. Method and system for label edge routing in a wireless network
US7107342B1 (en) 2001-01-26 2006-09-12 Cisco Technology, Inc. Method and system for providing service trigger management in a wireless network
US7551663B1 (en) 2001-02-01 2009-06-23 Ipr Licensing, Inc. Use of correlation combination to achieve channel detection
US6954448B2 (en) 2001-02-01 2005-10-11 Ipr Licensing, Inc. Alternate channel for carrying selected message types
DE60101662T2 (en) * 2001-03-12 2005-04-14 Alcatel Resource management in a wireless business communication system
FR2822568B1 (en) * 2001-03-22 2003-06-06 Mitsubishi Electric Inf Tech GMMSE TYPE EQUALIZATION METHOD AND DEVICE
US6657980B2 (en) * 2001-04-12 2003-12-02 Qualcomm Incorporated Method and apparatus for scheduling packet data transmissions in a wireless communication system
US7623496B2 (en) * 2001-04-24 2009-11-24 Intel Corporation Managing bandwidth in network supporting variable bit rate
SG185139A1 (en) 2001-06-13 2012-11-29 Ipr Licensing Inc Transmittal of heartbeat signal at a lower level than heartbeat request
US7149204B2 (en) * 2001-06-20 2006-12-12 Matsushita Electric Industrial Co., Ltd. Base station device and channel assigning method
DE60107407T2 (en) * 2001-07-05 2005-05-19 Mitsubishi Electric Information Technology Centre Europe B.V. Multi-user detection in a MC-CDMA telecommunications system
US6957071B1 (en) 2001-07-18 2005-10-18 Cisco Technology, Inc. Method and system for managing wireless bandwidth resources
US20030027579A1 (en) * 2001-08-03 2003-02-06 Uwe Sydon System for and method of providing an air interface with variable data rate by switching the bit time
US7447163B1 (en) * 2001-09-25 2008-11-04 Atheros Communications, Inc. Method and system for testing and optimizing the performance of a radio communication device
EP1300977A1 (en) * 2001-10-04 2003-04-09 Mitsubishi Electric Information Technology Centre Europe B.V. Parallel interference cancellation in an MC-CDMA telecommunication system
US7526297B1 (en) 2001-10-30 2009-04-28 Cisco Technology, Inc. Method and system for managing pushed data at a mobile unit
US6788687B2 (en) 2001-10-30 2004-09-07 Qualcomm Incorporated Method and apparatus for scheduling packet data transmissions in a wireless communication system
WO2003049456A1 (en) * 2001-11-27 2003-06-12 Siemens Aktiengesellschaft Procedure for exchanging useful information generated according to different coding laws between at least 2 pieces of user terminal equipment
US7133375B1 (en) * 2002-03-05 2006-11-07 Sprint Spectrum L.P. Dynamic adaptive multifunctional base station for wireless networks
US7876726B2 (en) * 2002-04-29 2011-01-25 Texas Instruments Incorporated Adaptive allocation of communications link channels to I- or Q-subchannel
US6920320B2 (en) * 2002-09-30 2005-07-19 Lucent Technologies Inc. Method and apparatus for stable call preservation
US7518997B2 (en) * 2002-10-22 2009-04-14 Texas Instruments Incorporated Wireless mobile communication stations for operation in non-exclusive spectrum
US7376106B2 (en) * 2002-11-27 2008-05-20 International Business Machines Corporation Code-division-multiple-access (DS-CDMA) channels with aperiodic codes
US9374828B2 (en) * 2003-01-13 2016-06-21 Hamilton Sundstrand Corporation Channel allocation for a multi-device communication system
US7151949B2 (en) * 2003-07-09 2006-12-19 Lexmark International, Inc. Wireless facsimile adapter and system for printer and all-in-one devices and methods using the same
US7471932B2 (en) * 2003-08-11 2008-12-30 Nortel Networks Limited System and method for embedding OFDM in CDMA systems
US7295513B2 (en) * 2003-09-23 2007-11-13 Telecommunications Research Laboratories Scheduling of wireless packet data transmissions
US7222196B2 (en) * 2003-12-22 2007-05-22 Nokia Corporation Apparatus, and associated method, for facilitating communication of packet data in a packet radio communication system using interactions between mid-stack and upper-level layers
US20060136424A1 (en) * 2004-03-25 2006-06-22 Jayasimha Nuggehalli Approach for collecting and reporting status data from network devices
US20060251114A1 (en) * 2004-03-25 2006-11-09 Jayasimha Nuggehalli Approach for collecting and reporting status data from network devices
LT1779055T (en) * 2004-07-15 2017-04-10 Cubic Corporation Enhancement of aimpoint in simulated training systems
GB2417167B (en) * 2004-08-13 2007-02-14 Ipwireless Inc Apparatus and method for communicating user equipment specific information in cellular communication system
US7664832B1 (en) * 2004-10-08 2010-02-16 Sprint Spectrum L.P. RF data channel API for mobile station client applications
US20060146758A1 (en) * 2004-12-30 2006-07-06 Harris John M Method to facilitate dynamic allocation of spreading code resources
US20070076708A1 (en) * 2005-09-30 2007-04-05 Mikolaj Kolakowski Error protection techniques for frames on a wireless network
WO2007053361A2 (en) * 2005-11-01 2007-05-10 Rotani, Inc. Method and apparatus for client control of wireless communications
KR100705447B1 (en) 2005-12-07 2007-04-09 한국전자통신연구원 Mobile terminal and method for qos setting
WO2007108885A2 (en) 2006-02-28 2007-09-27 Rotani, Inc. Methods and apparatus for overlapping mimo antenna physical sectors
US7873385B2 (en) * 2006-04-05 2011-01-18 Palm, Inc. Antenna sharing techniques
CN101155395B (en) * 2006-09-26 2010-11-10 华为技术有限公司 Band width distribution method, system and device based on wireless system
US8036683B2 (en) * 2006-10-31 2011-10-11 Hewlett-Packard Development Company, L.P. Coordination among multiple co-located radio modules
US8755747B2 (en) 2006-10-31 2014-06-17 Qualcomm Incorporated Techniques to control transmit power for a shared antenna architecture
US8538449B2 (en) 2006-12-29 2013-09-17 At&T Intellectual Property Ii, L.P. Method and apparatus for allocating bandwidth for a network
US8089854B2 (en) 2007-04-03 2012-01-03 Qualcomm, Incorporated Companded transmit path for wireless communication
US8254393B2 (en) * 2007-06-29 2012-08-28 Microsoft Corporation Harnessing predictive models of durations of channel availability for enhanced opportunistic allocation of radio spectrum
US8531962B2 (en) 2008-04-29 2013-09-10 Qualcomm Incorporated Assignment of ACK resource in a wireless communication system
JP5206256B2 (en) * 2008-09-09 2013-06-12 沖電気工業株式会社 Bandwidth allocation method and bandwidth allocation apparatus
US8909165B2 (en) 2009-03-09 2014-12-09 Qualcomm Incorporated Isolation techniques for multiple co-located radio modules
US20100299621A1 (en) * 2009-05-20 2010-11-25 Making Everlasting Memories, L.L.C. System and Method for Extracting a Plurality of Images from a Single Scan
US9693390B2 (en) 2009-06-01 2017-06-27 Qualcomm Incorporated Techniques to manage a mobile device based on network density
JP5497968B2 (en) * 2010-11-03 2014-05-21 エンパイア テクノロジー ディベロップメント エルエルシー Joint data sharing for CDMA interference subtraction
US11026169B2 (en) 2010-11-09 2021-06-01 Qualcomm Incorporated Physical layer power save facility
US8868126B2 (en) * 2011-06-30 2014-10-21 Htc Corporation Mobile apparatus with radio frequency architecture supporting simultaneous data and voice communications
US8781512B1 (en) * 2011-10-22 2014-07-15 Proximetry, Inc. Systems and methods for managing wireless links
US9264747B2 (en) * 2012-03-11 2016-02-16 Broadcom Corporation Audio/video channel bonding configuration adaptations
US8895452B2 (en) 2012-05-31 2014-11-25 Lam Research Corporation Substrate support providing gap height and planarization adjustment in plasma processing chamber
US8731577B2 (en) * 2012-08-14 2014-05-20 GM Global Technology Operations LLC Method and apparatus for enabling vehicle applications using heterogeneous wireless data pipes
US8989167B2 (en) 2012-10-10 2015-03-24 Motorola Solutions, Inc. Method and apparatus for establishing radio communications on a trunked network using an inbound proxy
JP6098114B2 (en) * 2012-10-26 2017-03-22 アイコム株式会社 Relay device and communication system
US9031567B2 (en) 2012-12-28 2015-05-12 Spreadtrum Communications Usa Inc. Method and apparatus for transmitter optimization based on allocated transmission band
JP2014179741A (en) * 2013-03-14 2014-09-25 Panasonic Corp Transmitter and bandwidth adjustment method
US10334588B2 (en) 2013-12-11 2019-06-25 Qualcomm Incorporated Carrier sense adaptive transmission (CSAT) coordination in unlicensed spectrum
AU2016243733B2 (en) * 2015-03-31 2021-09-02 Visa International Service Association Multi-protocol data transfer
JP2018015403A (en) * 2016-07-29 2018-02-01 株式会社大都技研 Game machine

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5442625A (en) * 1994-05-13 1995-08-15 At&T Ipm Corp Code division multiple access system providing variable data rate access to a user
WO1995026094A1 (en) * 1994-03-21 1995-09-28 Omnipoint Corporation Pcs pocket phone/microcell communication over-air protocol
WO1997009810A1 (en) * 1995-09-01 1997-03-13 Motorola Inc. Method and apparatus for multirate data communications

Family Cites Families (77)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3700820A (en) * 1966-04-15 1972-10-24 Ibm Adaptive digital communication system
US3761610A (en) * 1971-02-16 1973-09-25 Graphics Sciences Inc High speed fascimile systems
US4069392A (en) * 1976-11-01 1978-01-17 Incorporated Bell Telephone Laboratories Dual speed full duplex data transmission
US4284848A (en) * 1979-08-01 1981-08-18 Frost Edward G Switched network telephone subscriber distribution system
JP2813181B2 (en) 1987-08-20 1998-10-22 株式会社リコー Wireless data communication device
JP2560410B2 (en) 1988-05-06 1996-12-04 日本電気株式会社 Wireless telephone equipment
CN1012314B (en) 1988-10-14 1991-04-03 日本电气株式会社 Method of converting and controlling channel in radio telephone system
JPH02274131A (en) 1989-04-17 1990-11-08 Toshiba Corp Transmission control system for mobile radio communication system
US5056109A (en) * 1989-11-07 1991-10-08 Qualcomm, Inc. Method and apparatus for controlling transmission power in a cdma cellular mobile telephone system
US5114796A (en) * 1990-04-17 1992-05-19 Advanced Products Inc. Fast curing and storage stable thermoset polymer thick film compositions
US5103459B1 (en) * 1990-06-25 1999-07-06 Qualcomm Inc System and method for generating signal waveforms in a cdma cellular telephone system
JPH0490664A (en) 1990-08-06 1992-03-24 Nissan Motor Co Ltd Radio facsimile equipment
US5212803A (en) * 1990-09-06 1993-05-18 Telefonaktiebolaget L M Ericsson Method for reducing equalizer usage in mobile radio communication systems
US5228056A (en) 1990-12-14 1993-07-13 Interdigital Technology Corporation Synchronous spread-spectrum communications system and method
US5360910A (en) 1991-04-30 1994-11-01 Rhone-Poulenc Ag Company Pesticidal 1-aryl-5-(substituted alkylideneimino)pyrazoles
CA2483322C (en) * 1991-06-11 2008-09-23 Qualcomm Incorporated Error masking in a variable rate vocoder
US5239678A (en) 1991-11-21 1993-08-24 Motorola, Inc. Method of assigning a control channel as a temporary voice/data channel in a radio communications system
DE4210305A1 (en) * 1992-03-30 1993-10-07 Sel Alcatel Ag Method, transmitter and receiver for information data transmission with variable traffic volume and control station for coordinating several such transmitters and receivers
US5313457A (en) * 1992-04-14 1994-05-17 Trimble Navigation Limited Code position modulation system and method for multiple user satellite communications
JP3168063B2 (en) 1992-05-18 2001-05-21 富士通株式会社 Spread spectrum communication apparatus and communication method therefor
PL173299B1 (en) * 1993-01-13 1998-02-27 Motorola Inc System of transmitting multipled access incoming messages with code (cdma) sharing employing reuse of sequence
FI932373A0 (en) 1993-05-25 1993-05-25 Nokia Telecommunications Oy Basstation Foer cellular radio system as well as cellular radio system
DE4326749C2 (en) * 1993-08-05 1995-05-04 Klaus Dr Ing Jaeckel Local ISDN radio transmission system
KR960010935B1 (en) * 1993-12-24 1996-08-13 양승택 Cdma
US5671218A (en) * 1994-04-28 1997-09-23 Lucent Technologies Inc. Controlling power and access of wireless devices to base stations which use code division multiple access
US5555244A (en) * 1994-05-19 1996-09-10 Integrated Network Corporation Scalable multimedia network
ZA955600B (en) * 1994-07-13 1996-04-02 Qualcomm Inc System and method for simulating interference received by subscriber units in a spread spectrum communication network
GB2292286B (en) * 1994-08-06 1998-09-09 Motorola Inc Radio communications device and method
US6334219B1 (en) * 1994-09-26 2001-12-25 Adc Telecommunications Inc. Channel selection for a hybrid fiber coax network
US5621723A (en) * 1994-09-27 1997-04-15 Gte Laboratories Incorporated Power control in a CDMA network
FI96558C (en) * 1994-09-27 1996-07-10 Nokia Telecommunications Oy Method for data transmission in a TDMA mobile radio system and a mobile radio system for carrying out the method
US5583869A (en) * 1994-09-30 1996-12-10 Motorola, Inc. Method for dynamically allocating wireless communication resources
US20100208634A1 (en) * 1994-10-11 2010-08-19 Arbinet Corporation System and Method For Managing Multimedia Communications Across Convergent Networks
US5642348A (en) * 1994-12-30 1997-06-24 Lucent Technologies Inc. Access director interface for narrowband/broadband information distribution network
JP3224334B2 (en) * 1995-01-17 2001-10-29 沖電気工業株式会社 Transmission device
MY121893A (en) * 1995-04-28 2006-03-31 Qualcomm Inc Method and apparatus for providing variable rate data in a communications system using statistical multiplexing.
GB9509921D0 (en) 1995-05-17 1995-07-12 Roke Manor Research Improvements in or relating to mobile radio systems
US5841768A (en) 1996-06-27 1998-11-24 Interdigital Technology Corporation Method of controlling initial power ramp-up in CDMA systems by using short codes
ZA965340B (en) * 1995-06-30 1997-01-27 Interdigital Tech Corp Code division multiple access (cdma) communication system
US7929498B2 (en) * 1995-06-30 2011-04-19 Interdigital Technology Corporation Adaptive forward power control and adaptive reverse power control for spread-spectrum communications
JP3212238B2 (en) * 1995-08-10 2001-09-25 株式会社日立製作所 Mobile communication system and mobile terminal device
AU697851B2 (en) 1995-08-16 1998-10-15 Starguide Digital Networks, Inc. Dynamic allocation of bandwidth for transmission of audio signals and a video signal
KR0145867B1 (en) 1995-08-28 1998-08-17 김광호 Cdma type cellular phone and its data processing method
US5950124A (en) 1995-09-06 1999-09-07 Telxon Corporation Cellular communication system with dynamically modified data transmission parameters
JPH0983600A (en) 1995-09-14 1997-03-28 Kokusai Electric Co Ltd Multilevel adaptative modulation radio device
US5734646A (en) * 1995-10-05 1998-03-31 Lucent Technologies Inc. Code division multiple access system providing load and interference based demand assignment service to users
US6418148B1 (en) * 1995-10-05 2002-07-09 Lucent Technologies Inc. Burst-level resource allocation in cellular systems
US5790551A (en) * 1995-11-28 1998-08-04 At&T Wireless Services Inc. Packet data transmission using dynamic channel assignment
US5940452A (en) * 1995-11-29 1999-08-17 Motorola, Inc. Dual mode radio subscriber unit having a diversity receiver apparatus and method therefor
US5752199A (en) * 1995-12-18 1998-05-12 Paradyne Corporation Method and apparatus for sending faxes over analog cellular
US6088600A (en) * 1996-03-12 2000-07-11 Paradyne Corporation Discontinuous transmission of circuit-switched analog cellular data
EP0891681A1 (en) 1996-04-04 1999-01-20 Siemens Aktiengesellschaft Control of the change of telecommunications channels in a dect-specific rll/wll partial system bound to an isdn-system
KR0176109B1 (en) * 1996-04-24 1999-05-15 양승택 Method of allocating radio channel in cdma system
US6396804B2 (en) * 1996-05-28 2002-05-28 Qualcomm Incorporated High data rate CDMA wireless communication system
US6678311B2 (en) * 1996-05-28 2004-01-13 Qualcomm Incorporated High data CDMA wireless communication system using variable sized channel codes
US5926500A (en) * 1996-05-28 1999-07-20 Qualcomm Incorporated Reduced peak-to-average transmit power high data rate CDMA wireless communication system
US5930230A (en) * 1996-05-28 1999-07-27 Qualcomm Incorporated High data rate CDMA wireless communication system
US5859840A (en) * 1996-05-31 1999-01-12 Qualcomm Incorporated Spread spectrum communication system which defines channel groups comprising selected channels that are additional to a primary channel and transmits group messages during call set up
US5828662A (en) * 1996-06-19 1998-10-27 Northern Telecom Limited Medium access control scheme for data transmission on code division multiple access (CDMA) wireless systems
US5926755A (en) * 1996-08-07 1999-07-20 Telefonaktiebolaget Lm Ericsson Method and an arrangement for conducting multiple calls simultaneously
US5805585A (en) * 1996-08-22 1998-09-08 At&T Corp. Method for providing high speed packet data services for a wireless system
US6212377B1 (en) * 1996-11-27 2001-04-03 Ericsson Telefon Ab L M System and method of providing group wireless extension phone service in a radio telecommunications network
US5892774A (en) * 1996-12-12 1999-04-06 Qualcomm Incorporated Phase shift encoded subchannel
US5923650A (en) * 1997-04-08 1999-07-13 Qualcomm Incorporated Method and apparatus for reverse link rate scheduling
US5914950A (en) * 1997-04-08 1999-06-22 Qualcomm Incorporated Method and apparatus for reverse link rate scheduling
US6094428A (en) 1997-04-30 2000-07-25 Motorola, Inc. Method and apparatus for transmission and reception of a transmission rate in a CDMA communication system
US6073021A (en) * 1997-05-30 2000-06-06 Lucent Technologies, Inc. Robust CDMA soft handoff
US6075792A (en) * 1997-06-16 2000-06-13 Interdigital Technology Corporation CDMA communication system which selectively allocates bandwidth upon demand
US6081536A (en) * 1997-06-20 2000-06-27 Tantivy Communications, Inc. Dynamic bandwidth allocation to transmit a wireless protocol across a code division multiple access (CDMA) radio link
US6389000B1 (en) * 1997-09-16 2002-05-14 Qualcomm Incorporated Method and apparatus for transmitting and receiving high speed data in a CDMA communication system using multiple carriers
US6377809B1 (en) * 1997-09-16 2002-04-23 Qualcomm Incorporated Channel structure for communication systems
US6574211B2 (en) * 1997-11-03 2003-06-03 Qualcomm Incorporated Method and apparatus for high rate packet data transmission
US6064678A (en) * 1997-11-07 2000-05-16 Qualcomm Incorporated Method for assigning optimal packet lengths in a variable rate communication system
US6222832B1 (en) * 1998-06-01 2001-04-24 Tantivy Communications, Inc. Fast Acquisition of traffic channels for a highly variable data rate reverse link of a CDMA wireless communication system
JP2011233197A (en) * 2010-04-27 2011-11-17 Sony Corp Information processing device and head retraction method
JP5923865B2 (en) * 2011-04-20 2016-05-25 コニカミノルタ株式会社 Fixing apparatus and image forming apparatus
JP6017828B2 (en) * 2012-05-02 2016-11-02 京セラ株式会社 Electronic device, control method, and control program

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995026094A1 (en) * 1994-03-21 1995-09-28 Omnipoint Corporation Pcs pocket phone/microcell communication over-air protocol
US5442625A (en) * 1994-05-13 1995-08-15 At&T Ipm Corp Code division multiple access system providing variable data rate access to a user
WO1997009810A1 (en) * 1995-09-01 1997-03-13 Motorola Inc. Method and apparatus for multirate data communications

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
AZAD H ET AL: "MULTIRATE SPREAD SPECTRUM DIRECT SEQUENCE CDMA TECHNIQUES" IEE COLLOQUIUM ON SPREAD SPECTRUM TECHNIQUES FOR RADIO COMMUNICATIONS SYSTEMS (DIGEST NO.95), 27 APRIL '93, 15 April 1994, pages 4/1-4/05, XP000570787 *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2351632A (en) * 1999-06-28 2001-01-03 Nokia Telecommunications Oy CDMA radio systems
GB2351632B (en) * 1999-06-28 2003-10-29 Nokia Telecommunications Oy Manipulating physical channels having different spreading ratios in a CDMA rad io system
FR2797130A1 (en) * 1999-07-29 2001-02-02 Kurtosis Ingenierie Digital word transmission technique having coded division multiple access coding forming chip sets and transmission filtering interlaced frequency bands dividing output response.
JP2013048424A (en) * 1999-10-29 2013-03-07 Wi-Lan Inc Method for data synchronization and transportation in wireless communications system
JP2015084542A (en) * 1999-10-29 2015-04-30 ウィ‐ラン、インコーポレーテッドWi−Lan, Inc. Method for synchronizing and transmitting data in wireless communication system
WO2001093600A2 (en) * 2000-05-31 2001-12-06 Telefonaktiebolaget L M Ericsson (Publ) Session dispatcher at a wireless multiplexer interface
WO2001093600A3 (en) * 2000-05-31 2002-03-28 Ericsson Telefon Ab L M Session dispatcher at a wireless multiplexer interface
US6807178B1 (en) 2000-05-31 2004-10-19 Telefonaktiebolaget Lm Ericsson (Publ) Session dispatcher at a wireless multiplexer interface
WO2002017507A1 (en) * 2000-08-23 2002-02-28 British Telecommunications Public Limited Company Spread spectrum modulation system
JP2014096842A (en) * 2002-01-08 2014-05-22 Ipr Licensing Inc Maintaining maintenance channel in reverse link of wireless communication
US10390311B2 (en) 2002-01-08 2019-08-20 Ipr Licensing, Inc. Maintaining a maintenance channel in a reverse link of a wireless communications system
US8072323B2 (en) 2002-01-24 2011-12-06 Panasonic Corporation Power-line carrier communication apparatus
US7800491B2 (en) 2002-01-24 2010-09-21 Panasonic Corporation Power-line carrier communication apparatus
US7498935B2 (en) 2002-01-24 2009-03-03 Panasonic Corporation Power-line carrier communication apparatus

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