CA2001339C - Repeater for a controlled radio system - Google Patents
Repeater for a controlled radio systemInfo
- Publication number
- CA2001339C CA2001339C CA002001339A CA2001339A CA2001339C CA 2001339 C CA2001339 C CA 2001339C CA 002001339 A CA002001339 A CA 002001339A CA 2001339 A CA2001339 A CA 2001339A CA 2001339 C CA2001339 C CA 2001339C
- Authority
- CA
- Canada
- Prior art keywords
- repeater
- subscriber unit
- central station
- channel
- communication
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W84/04—Large scale networks; Deep hierarchical networks
- H04W84/08—Trunked mobile radio systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/14—Relay systems
- H04B7/15—Active relay systems
- H04B7/155—Ground-based stations
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/24—Radio transmission systems, i.e. using radiation field for communication between two or more posts
- H04B7/26—Radio transmission systems, i.e. using radiation field for communication between two or more posts at least one of which is mobile
- H04B7/2603—Arrangements for wireless physical layer control
- H04B7/2606—Arrangements for base station coverage control, e.g. by using relays in tunnels
Abstract
ABSTRACT OF THE DISCLOSURE A repeater (30) is provided for relaying communication between a subscriber unit (24) and a central station (10) when the repeater recognizes transmission from the subscriber unit to the central station but detects a lack of response by the central station to that subscriber unit or when the repeater recognizes a transmission from a subscriber unit (26) requesting the repeater for service. The repeater asks the central station for a channel upon which to communicate. Alternately, a predetermined channel may be used for the relayed communication.
Description
~00~339 Docket No.: CM00534J
Inventor: ~)aime A~ Borras REPEATER FOR A CONTROLLED
RADIO SY~TEM
BACKGROUND QF THE ~VENTI ;?N
This invention relates generally to radio communication systems, and more particularly to a repeater for use when a subscriber unit is not in communication with a central station as in trunked radio frequency communication systems.
As disclosed in U.S. Patent No. 4,723,264, to establish communication between trunked subscriber units, a requesting subscribsr unit transmits a call requsst to a central station (or central controller). Upon receipt of the request, the central station returns a channel grant code (if a channel is available), which instructs the requesting subscriber unit to move to a specifi~d communication channel as a transmitting unit, while causing all called subscriber units to move to the same communication channel as receiving units.
Generally, trunksd communication channels comprise a pair of frequencies. An inbound frequency carries information from the subscriber units to the central station, while the outbound frequency carries information from the central station to tha subscriber units. Subscriber units may be portable, mobile or fixsd. A portable unit is typically understood to be a transceiving device designed to be carried on or about the person. A mobile is a transceiving device designed to be installed in vehicles. A fixed . . .
. I .
: ' ' ' ' .
Z~0:1339 station is typically a permanent or semi-permanent installation in a building or another fixed site. As used h~rein, all of these transceiving devices are collectively referred to as subscriber units.
One situation where a subscriber unit is not in communication with a central station occurs when the subscriber unit is operating at such a distance (or range) from the central station that the subscriber unit has insufficient power to transmit to the csntral station; even though the more powerful central station's transmission can reach the subscriber unit. In this area of weak signal strength, the subscrib~r unit is out-of-range.
Usually, the weak signal strength zone is located in a remote or nural area, where there are very few subscribers present to utilize the system. Therefore, it is not economically to install a conventional repeater or another central station.
One approach is to provide more than one conventional repeater at each weak signal strength araa in a simulcast system to amplify all the channels in the coverage area. However, simulcast overlap problems such as intermodulation interferences may occur.
As illustrated in U.S. Patent No. 4,677,687, one solution pertaining to mobile units involves installing or operating a repeater bstween the central station and the mobile units to selectively relay information on a booster channel. When the mobile unit detects a weak signal, th~ mobile unit automatically switches to a predetermined booster channel for communication with the repeater, which will relay the communication to tha central station and (and vice versa). This approach requires that each of the mobile units be capable of recognizing the necessity to switch ~o the booster channel. Generally, for cost efficiency, installing an economical repeater is preferred over recalling and changing existing units in the field.
Even though the central station generally has mor~ power to transmit than the subscriber unit, beyond a certain distance at a fixed power level, the central station will have insufficient power to reach the subscriber unit, especially if the unit roams farther - . .
Inventor: ~)aime A~ Borras REPEATER FOR A CONTROLLED
RADIO SY~TEM
BACKGROUND QF THE ~VENTI ;?N
This invention relates generally to radio communication systems, and more particularly to a repeater for use when a subscriber unit is not in communication with a central station as in trunked radio frequency communication systems.
As disclosed in U.S. Patent No. 4,723,264, to establish communication between trunked subscriber units, a requesting subscribsr unit transmits a call requsst to a central station (or central controller). Upon receipt of the request, the central station returns a channel grant code (if a channel is available), which instructs the requesting subscriber unit to move to a specifi~d communication channel as a transmitting unit, while causing all called subscriber units to move to the same communication channel as receiving units.
Generally, trunksd communication channels comprise a pair of frequencies. An inbound frequency carries information from the subscriber units to the central station, while the outbound frequency carries information from the central station to tha subscriber units. Subscriber units may be portable, mobile or fixsd. A portable unit is typically understood to be a transceiving device designed to be carried on or about the person. A mobile is a transceiving device designed to be installed in vehicles. A fixed . . .
. I .
: ' ' ' ' .
Z~0:1339 station is typically a permanent or semi-permanent installation in a building or another fixed site. As used h~rein, all of these transceiving devices are collectively referred to as subscriber units.
One situation where a subscriber unit is not in communication with a central station occurs when the subscriber unit is operating at such a distance (or range) from the central station that the subscriber unit has insufficient power to transmit to the csntral station; even though the more powerful central station's transmission can reach the subscriber unit. In this area of weak signal strength, the subscrib~r unit is out-of-range.
Usually, the weak signal strength zone is located in a remote or nural area, where there are very few subscribers present to utilize the system. Therefore, it is not economically to install a conventional repeater or another central station.
One approach is to provide more than one conventional repeater at each weak signal strength araa in a simulcast system to amplify all the channels in the coverage area. However, simulcast overlap problems such as intermodulation interferences may occur.
As illustrated in U.S. Patent No. 4,677,687, one solution pertaining to mobile units involves installing or operating a repeater bstween the central station and the mobile units to selectively relay information on a booster channel. When the mobile unit detects a weak signal, th~ mobile unit automatically switches to a predetermined booster channel for communication with the repeater, which will relay the communication to tha central station and (and vice versa). This approach requires that each of the mobile units be capable of recognizing the necessity to switch ~o the booster channel. Generally, for cost efficiency, installing an economical repeater is preferred over recalling and changing existing units in the field.
Even though the central station generally has mor~ power to transmit than the subscriber unit, beyond a certain distance at a fixed power level, the central station will have insufficient power to reach the subscriber unit, especially if the unit roams farther - . .
2~3()1339 out-of-ran~e. Here, the central station has insu~ficient communication range for efficient system operation. Tharefore, an inexpensive roaming coverage may be needed in som~
systems as in a trunked specializ6cl mobile radio (SMR~ system.
Likewise for a system where the central station is located far away from a building, it is desirable to extend the distance the c~ntral station can transmit to facilitate communication coverage anywhere within the building.
SUMMARY OF THE INVE~TIO~
Accordingly, it is an object of the present invention to provid0 an inexpensive repeater without simulcast overlap problems to know when it is needed to extend the coverage range of a central station andlor a subscriber unit by an automatic activation or the like.
Basically, a repeater is provided for relaying communication between a subscriber unit and a central station when the repeater recognizes transmission from the subscriber unit to the central station, but detects a lack of response by the central station to that subscriber unit. This aspect of the present invention will extend the coverage range of the subscriber unit operating at such a distance as to have insufficient power to transmit to the central station ~out-of-range subscriber unit).
In another aspect of the invention, when a central station has insufficient coverage range to transmit to the subscriber unit, a repeater is provided for relaying communication between the subscriber unit and the central station. When the repeater recognizes a transmission from the subscriber unit requesting the rapeater for ser~ice, the repeater asks the central station for a channel upon which to communicate. Alternately, a predetermined channel may be used for the relayed communication.
BRIEF DES~eTlON QF ~E DRAW!NGS
FIG. 1 is a block diagram of a communication system utilizing a repeater in accordance with the present invention.
.
~ . :
?~01339 FIG. 2 is an illustration of a protocol of a conventional trunking system.
FIG. 3 is a block diagram of the repeater of FIG. 1.
FIGS. 4 is a flow diagram illustrating the operation of the 5 trunking repeater of FIG. 3.
FIG. ~ is an illustration of a protocol of the present invention for use with the repeater of FIG. 3.
FIG. 6 is a flow diagram for use with the repeater of FIG. 3 when the subscriber unit is operating at such a distance that it can 10 not receive transmissions from the central station.
FIG. 7 is an illustration of a protocol for use with the repeater ot FIG. 3 when the subscriber unit is operating at such a distance that it can not receive transmissions from the central station.
DESCRIPTION QF THE PREFERRE12 EMBO~IMENT
Referring to FIG. 1, a communication system utilizing a r~peater in accordance with the present invention is illustrated. A
central station 10 is utilized in conjunction with a plurality of 20 subscriber units 22, 24, and 26. The central station 10 preferably comprises a central controll~r and a plurality of repeaters, which form the fixed equipment of a trunk~d radio frequency communication system. Subscriber unit 22 is shown operating at such a distance as to have sufficient power to transmit directly 25 with the ccntral station 10. Ordinarily, the central station 10 has enough power to transmit to the subscriber unit 24, but the subscriber unit 24 is shown operating at such a distance or at such a low power that it has insufficient power to transmit back (12) to the central station 10. Additionally, subscriber unit 26 is 30 shown at a range further away from the central station 10 than that of subscriber unit ?4. Therefore, central station 10 and subscriber unit 26 are shown mutually not having sufficient power to trans nit to each oth~r. To extend the coverage range of the central station 10, a r~peater 30 is illustratcd relaying communications 35 between the subscriber unit 26 and the central station 10.
.
' :
2(~01339 As is known, the central station 10 rec0ives call requests and transmits channel grants (if a channel is available) and other control and status codes according to a protocol illustrated in Fl~;.
2. To initiate a call, the subscriber unit 22 transmits to the central 5 station 10 at least one Inbound Signalling Word (ISW) on the inbound control channel 200. The ISW 202 preferably contains at least the ID field of the subscriber unit 22. ~Rer processing the call requ0st, the central station 10 returns at least one Outbound Signalling Word (OSW ) via the outbound control channel 300.
10 The OSW 206 is a command for th~3 subscribQr unit 22 along with other r~ceivirig subscriber units to move to a first communication channel (such as a voice channel A). As the subscriber unit 22 switches to the assigned communication channel, a high speed handshake is transmitted on channel A from the central station 10 15 to be received by the subscriber unit 22 and the receiving subscriber units on the outbound communication channel A (500).
After receiving the highspeed handshake 212, the requesting subscriber unit 22 transmits an acknowledge code 214 to the central station 10. In response, the central station 10 sends 20 a sync word 226 for the receiving and requesting subscriber units.
A low speed handshake 228 tollows on tha outbound communication channel A (500). The re~uesting subscrib~r unit 22 subsequently initiates a message 216, which consists of an information signal (for example a voice signal 218) and a connect 25 tone 220, which is used by the central station 10 to maintain the assigned channels as long as the connect tone is received.
At the conclusion of the highspeed handshake 212 and sync 226, the receiving subscriber units receive the message 218 on the outbound communication channel A (500). The msssage 30 requires the receivinQ subscriber units to remain on the outbound communication channel A (5G0) as long as they are receiving the low speed handshake 228. It will be appreciated that the described protocol is an example of a conventional trunking piotocol. Other variations may require more or less signalling, or 35 operate with or without two speed handshakes or acknowledgement, etc.
., ~ ' . - ~ .
. . .
.
. .
Z~01339 For use with the present invention, th~ repeater 30 is substituted for the subscriber unit in processing information to and from the central station 10 as will be further illustrated in FIG. 7.
According to the invention, the subscriber unit 24 transmits a call 5 request on the inbound control channsl to initiate a call. This transmission is monitored by the rspeater 30. If the transmission was received by the central station 10, the central station 10 normally returns a channel grant code with the communication channel assignment via the outbound control channel. Without 10 receiving a grant, the subscfiber unit 24 continues to re-transmit the call request. However, since the transmission of sui scriber unit 24 is out-of-range for its transmi~sion to be received by the central station 10, the repeater 30 receives the retrials of ISW
without rec~iving a corresponding Outbound Signalling Word 15 channel grant from the central station 10. After a predetermined number of ISW retries have been received without a corresponding OSW, the repeater 30 transmits to the central station 10 a dual Inbound Signal Word sequence This sequence comprises the first ISW that subscriber unit 24 has been 20 transmitting, and a second ISW indicating that the transmission is being relayed by the repeater 30. Following a proper decode sequence of the dual ISW at the central station 10, the central station 10 responds with two consecutive Outbound Signalling Words (OSWs), which instructs the units being called by the 25 requesting subscriber unit 24 to receive on a second communication channel (designated as B for convenience).
Additionally, the repeater 30 is instructed to communicate with the out-of-range subscriber unit 24 on communication channel A
(which may bs a voice channel), while the repeater 30 30 communicates with the central staticn 10 on communication channel B (which may also be a voice channel). The subscriber unit 24 is instructed to transmit on inbound channel A.
Subsequently, subscriber unit 24 transmits its message (which may be a voice signal), which is repeated by the repeatsr 30 and 35 by the central station 10 for reception by the listening subscribsr units.
.
ZO(;~339 To enable acGess for more than one subscriber, the repeater may include two full-duple~ units as illustrat0d in FIG. 3.
An antenna 42, is coupled via a duplexer 61 to a receiver section 46 and a transmitter section 48 ~for receiving ISWs on the 5 inbound control channel and other signals on the inbound communication channel and for transmitting signals on the outbound communication channel, respectiv~ly). The synthesizer 52 sets the frequency for the r~ceiver 46 and transmitter 48. Tha output of th0 receiver 46 and the input of the 10 transmitter 48 are coupled to a controller 54, which also controls the synthesizer ~2. Any well known microprocessor or general purpose computer containing memory may constitute the controller 54. A second controller 54' is coupled to the first controller 54. The other half of the duplex transceiver similarly 15 includes an antanna 42', a duplexer 61', a synthesizer 52', a receiver 46' (for receiving OSWs on the outbound control channel and other signals on the outbound communication channel) and a transmitter 68' (for ~ransmitting ISW on the inbound control channel and other signals on the inbound communication 20 channel)~ As is known, th~ duplexers 61, 61' may be replaced by antenna switches to reduce the cost of the repeater.
The operation of the r~peater of FIG. 3 will be describcd with reference to FIG. 4, which are flow diagrams of the steps executed by the controllers ~4, 54' of the repeater 30. These 25 steps are followed when the requesting subscriber unit is out-of-range. Repeater 30 is normally monitoring the control channel at step 72. Decision 74 determines whether a channel request ISW
was received from the requesting subscriber unit calling th~
central station. If no ISW was detected by the receiver 46, the 30 standby monitorin~ mode of block 72 is maintained. If, however, an ISW has been detected, the requesto~s ID is stored at block 76 in a memory portion of the controller 54. ~ecision 78 determines whether a ohannel grant code OSW has been transmitted from the central station 10 to the subscriber unit 24. If tha OSW has 35 been received by the receiver 46', the requestors ID is erased from memory at block 82, and the repeater 30 returns to the 20~1339 normal standby monitoring mode oF block 72. If, however, an OSW directed to ths requesting subscriber unit 24 was not detected in step 78, decision 84 sear~hes for an ISW retry by the subscnber. If no ISW retry occurs within a predetermined time 5 iimit (block 83), the requesto~s l.D. is erased (block 82), and the repeater returns to its monitoring state, block 72. Alternately, if the ISW retry has been detected at decision block 84, the repeater 30 looks for an OSW directed to the subscriber unit 24 at decision block 85. If an OSW is detected the routins branches back to 10 block 82. If the OSW is not detected, the repeater transmits a dual ISW sequence informing the central station 10 of the ll~s of ths out-of-range subscriber unit and the repeater, respectively, in block 86 via the transmitter 48'. In response to the central station's grant, the repeater receives the first OSW, at block 88, 15 which determines its receive frequency for receiving communication transmissions from the out-of-range subscriber unit. At block 92 the repeater 30 receives the channel frequency information for relaying the received information signai (which may be a voice signal) to the central station 10. The repeater 30 20 (at block 94) acting on the information, switches to the assigned frequancies for repeating the communication transmissions of the subscriber unit 24 to the central station 10.
Refsrring to FIG. 5, a signalling protocol of the repeater of FIG. 3 is illustrated when the subscriber unit is operating at such a 25 distance as to have insufficient power to transmit to the central station. When the repeater 30 recognizes a sequence of ISW
retrials without an OSW grant to the out-of-range subscriber unit 24, the repeater 30 transmits to the csntral station 10 a dual ISW
sequence on the inbound control channel 200. The first ISW 202 30 contains at least the ID field of the out-of-range subscriber unit 24 and the second ISW 204 contains at least the ID of the repeater 30. After processing the call request, the central station 10 returns a dual OSW via the outbound control channel 300. Tha first OSW
206 is a command for the out~of-range subscriber unit 24 and that 35 half of the repeater directed ~owards th~ subscriber unit to move to communication channel A. The second OSW 208 commands ths . ' :
.
. .
` Z001339 o~her half of the duplex transceiver within the repeater 30 along with other receiving subscriber units in the requesting subscriber unit's group to switch to communication channel B.
Simultaneously, the central station 10 generates a high speed 5 handshake code 210 for the receiving subscriber units moving to the outbound communication channel B 400 to receive the highspeed handshake and prepare to receive an information signal. As the out-of-range subscriber unit 24 and the repeater 30 switch to their respective communication channels, the high 10 speed handshake is routed in the repeater 30 (from the rec~iver 46' set on channel B to transmitter 48 set for channel A) to be received by the subscriber unit 24 on the outbound communication channel A (500).
After receiving the highspeed handshake 212, the 15 requesting subscriber unit 24 transmits an acknowledge code 214. The repeater 30 immediately routes the high speed acknowledge signal 222 on inbound communication channel B
(700) (from receiver 46 to transmitter 48') for transmission to the central station 10. In response, the central station sends the sync 20 word 226 for the receiving subscriber units followed by the low-speed handshake 228 on the outbound communication channel B (400). Subsequently, the requesting subscriber unit 24 initiates its messag0 216, which consists of an information signal (for example a voice signal 218) and a connect tone 220, which is re-25 transmitt0d by repeater 30 on inbound communication channel B(700) to the central station 10 to maintain the assigned channels 400, 500, 600 and 700 as long as the connect tone is received even if ths information signal 216 might cease.
At the conclusion of the acknowledge signal 222 and the 30 highspeed handshake 210 the receiving subscriber units r~ceive the message 224 (same message as in 216) on the outbound communication channel B (700). The message includes the repeated information 230 and ths low-speed handshake 228, which requires the receiving subscriber units to rernain on the 35 outbound communication channel B (400) while they are receiving the low-spsed handshake 228.
If the central station has insufficient communication range for efficisnt system operation such that it cannot directly transmit to the subscriber unit 26, the repeater of FIG 3 follows the steps for the controllers 54,~4' in the flow diagram of FIG 6. When the 5 subscriber unit 26 stops receiving from the central station 10, it transmits a requesting service ISW to the repeater 30 to relay its transmissions and receptions. Rapeater 30 is normally in the stand-by mode of block 72, monitoring the control channel.
Decision 74~ determines whether a repeater service request ISW
10 was rec~iv~d from the subscriber unit 26. If no service request ISW was detècted by the receiver 46 the standby monitoring mode of block 72 is maintained. If, however, a service requsst ISW has been detected, the requestor's ID is stored at block 76 in a memory portion of the controller 54. the repeater transmits via 15 the transmitter 48', a dual ISW sequence informing the central station 10 of the IDs of the subscriber unit and of the repeater, respec~ively, in block 86. After the central station processes the information, the repeater receives the flrst OSW from the central station, at block 88, which determines the repeate~s receive 20 frequency for receiving communication transmissions from the subscriber unR 26. At block 92 the repeater 30 receives the channel fr~quency Tnformation for transmitting the received information signal to the central station 10. Alternately, if a specific channel has been predetermined for USQ by the repeatsr 25 30, steps 86, 88, and 92 are bypassed. Step 94 follows to establish communication with the subscriber unit 26 and the central station 30 on that predetermined channel.
FIG. 7 is an illustration of a protocol for use with the repeater of FIG. 3 when the central station needs range extension 30 since it has insufficient communication range for efficient system operation. Once the subscriber unit 26 stops decoding the outbound control channel, it sends a dual ISW 302 on ~he last inbound control channel C (800) to advise the pre-assigned repeater that the subscriber unit 26 cannot receiva from the out-of-35 range central station. In r~sponse, the repeater 30 asks th~central station 10 for a channel assignment 304 for itself and the 200~339 subscriber unit on inbound control channel C (900) as in FIG. 7~
After receiving and processing the request 304, the central station 10 transmits a channel E assignment 306 for the subscriber unit and the half of the repeater 30 communicating with the subscriber 5 unit and the channsl D assignment 308 for the other half of the repeater 30 and the rest of the subscribers on outbound control channel C (1000). Once there is a call for the out-of-range unit then, repeater 30 immediately routes the High Speed Handshake ~HSH) 310 on the outbound control channal D (1100) from the 10 receiver 46' to the transmitter 48 for transmission on the outbound communication channel E (1200) as llSH 312. Altsrnately, the repeater 30 may have a predetermined channel assigned for its use and will not need to follow the channel requesting protocol.
However, regardlass of how the channel is assigned, the 15 subscriber unit 26 scans through a list of possible channels for wide area coverage where channel E is included. Once the subscriber unit decodes the HSH 312 from the repeater, the subscriber unit acknowledges and operates on the correct channel during the remainder of the conversation.
I claim as my invention:
.
.. ~ .
systems as in a trunked specializ6cl mobile radio (SMR~ system.
Likewise for a system where the central station is located far away from a building, it is desirable to extend the distance the c~ntral station can transmit to facilitate communication coverage anywhere within the building.
SUMMARY OF THE INVE~TIO~
Accordingly, it is an object of the present invention to provid0 an inexpensive repeater without simulcast overlap problems to know when it is needed to extend the coverage range of a central station andlor a subscriber unit by an automatic activation or the like.
Basically, a repeater is provided for relaying communication between a subscriber unit and a central station when the repeater recognizes transmission from the subscriber unit to the central station, but detects a lack of response by the central station to that subscriber unit. This aspect of the present invention will extend the coverage range of the subscriber unit operating at such a distance as to have insufficient power to transmit to the central station ~out-of-range subscriber unit).
In another aspect of the invention, when a central station has insufficient coverage range to transmit to the subscriber unit, a repeater is provided for relaying communication between the subscriber unit and the central station. When the repeater recognizes a transmission from the subscriber unit requesting the rapeater for ser~ice, the repeater asks the central station for a channel upon which to communicate. Alternately, a predetermined channel may be used for the relayed communication.
BRIEF DES~eTlON QF ~E DRAW!NGS
FIG. 1 is a block diagram of a communication system utilizing a repeater in accordance with the present invention.
.
~ . :
?~01339 FIG. 2 is an illustration of a protocol of a conventional trunking system.
FIG. 3 is a block diagram of the repeater of FIG. 1.
FIGS. 4 is a flow diagram illustrating the operation of the 5 trunking repeater of FIG. 3.
FIG. ~ is an illustration of a protocol of the present invention for use with the repeater of FIG. 3.
FIG. 6 is a flow diagram for use with the repeater of FIG. 3 when the subscriber unit is operating at such a distance that it can 10 not receive transmissions from the central station.
FIG. 7 is an illustration of a protocol for use with the repeater ot FIG. 3 when the subscriber unit is operating at such a distance that it can not receive transmissions from the central station.
DESCRIPTION QF THE PREFERRE12 EMBO~IMENT
Referring to FIG. 1, a communication system utilizing a r~peater in accordance with the present invention is illustrated. A
central station 10 is utilized in conjunction with a plurality of 20 subscriber units 22, 24, and 26. The central station 10 preferably comprises a central controll~r and a plurality of repeaters, which form the fixed equipment of a trunk~d radio frequency communication system. Subscriber unit 22 is shown operating at such a distance as to have sufficient power to transmit directly 25 with the ccntral station 10. Ordinarily, the central station 10 has enough power to transmit to the subscriber unit 24, but the subscriber unit 24 is shown operating at such a distance or at such a low power that it has insufficient power to transmit back (12) to the central station 10. Additionally, subscriber unit 26 is 30 shown at a range further away from the central station 10 than that of subscriber unit ?4. Therefore, central station 10 and subscriber unit 26 are shown mutually not having sufficient power to trans nit to each oth~r. To extend the coverage range of the central station 10, a r~peater 30 is illustratcd relaying communications 35 between the subscriber unit 26 and the central station 10.
.
' :
2(~01339 As is known, the central station 10 rec0ives call requests and transmits channel grants (if a channel is available) and other control and status codes according to a protocol illustrated in Fl~;.
2. To initiate a call, the subscriber unit 22 transmits to the central 5 station 10 at least one Inbound Signalling Word (ISW) on the inbound control channel 200. The ISW 202 preferably contains at least the ID field of the subscriber unit 22. ~Rer processing the call requ0st, the central station 10 returns at least one Outbound Signalling Word (OSW ) via the outbound control channel 300.
10 The OSW 206 is a command for th~3 subscribQr unit 22 along with other r~ceivirig subscriber units to move to a first communication channel (such as a voice channel A). As the subscriber unit 22 switches to the assigned communication channel, a high speed handshake is transmitted on channel A from the central station 10 15 to be received by the subscriber unit 22 and the receiving subscriber units on the outbound communication channel A (500).
After receiving the highspeed handshake 212, the requesting subscriber unit 22 transmits an acknowledge code 214 to the central station 10. In response, the central station 10 sends 20 a sync word 226 for the receiving and requesting subscriber units.
A low speed handshake 228 tollows on tha outbound communication channel A (500). The re~uesting subscrib~r unit 22 subsequently initiates a message 216, which consists of an information signal (for example a voice signal 218) and a connect 25 tone 220, which is used by the central station 10 to maintain the assigned channels as long as the connect tone is received.
At the conclusion of the highspeed handshake 212 and sync 226, the receiving subscriber units receive the message 218 on the outbound communication channel A (500). The msssage 30 requires the receivinQ subscriber units to remain on the outbound communication channel A (5G0) as long as they are receiving the low speed handshake 228. It will be appreciated that the described protocol is an example of a conventional trunking piotocol. Other variations may require more or less signalling, or 35 operate with or without two speed handshakes or acknowledgement, etc.
., ~ ' . - ~ .
. . .
.
. .
Z~01339 For use with the present invention, th~ repeater 30 is substituted for the subscriber unit in processing information to and from the central station 10 as will be further illustrated in FIG. 7.
According to the invention, the subscriber unit 24 transmits a call 5 request on the inbound control channsl to initiate a call. This transmission is monitored by the rspeater 30. If the transmission was received by the central station 10, the central station 10 normally returns a channel grant code with the communication channel assignment via the outbound control channel. Without 10 receiving a grant, the subscfiber unit 24 continues to re-transmit the call request. However, since the transmission of sui scriber unit 24 is out-of-range for its transmi~sion to be received by the central station 10, the repeater 30 receives the retrials of ISW
without rec~iving a corresponding Outbound Signalling Word 15 channel grant from the central station 10. After a predetermined number of ISW retries have been received without a corresponding OSW, the repeater 30 transmits to the central station 10 a dual Inbound Signal Word sequence This sequence comprises the first ISW that subscriber unit 24 has been 20 transmitting, and a second ISW indicating that the transmission is being relayed by the repeater 30. Following a proper decode sequence of the dual ISW at the central station 10, the central station 10 responds with two consecutive Outbound Signalling Words (OSWs), which instructs the units being called by the 25 requesting subscriber unit 24 to receive on a second communication channel (designated as B for convenience).
Additionally, the repeater 30 is instructed to communicate with the out-of-range subscriber unit 24 on communication channel A
(which may bs a voice channel), while the repeater 30 30 communicates with the central staticn 10 on communication channel B (which may also be a voice channel). The subscriber unit 24 is instructed to transmit on inbound channel A.
Subsequently, subscriber unit 24 transmits its message (which may be a voice signal), which is repeated by the repeatsr 30 and 35 by the central station 10 for reception by the listening subscribsr units.
.
ZO(;~339 To enable acGess for more than one subscriber, the repeater may include two full-duple~ units as illustrat0d in FIG. 3.
An antenna 42, is coupled via a duplexer 61 to a receiver section 46 and a transmitter section 48 ~for receiving ISWs on the 5 inbound control channel and other signals on the inbound communication channel and for transmitting signals on the outbound communication channel, respectiv~ly). The synthesizer 52 sets the frequency for the r~ceiver 46 and transmitter 48. Tha output of th0 receiver 46 and the input of the 10 transmitter 48 are coupled to a controller 54, which also controls the synthesizer ~2. Any well known microprocessor or general purpose computer containing memory may constitute the controller 54. A second controller 54' is coupled to the first controller 54. The other half of the duplex transceiver similarly 15 includes an antanna 42', a duplexer 61', a synthesizer 52', a receiver 46' (for receiving OSWs on the outbound control channel and other signals on the outbound communication channel) and a transmitter 68' (for ~ransmitting ISW on the inbound control channel and other signals on the inbound communication 20 channel)~ As is known, th~ duplexers 61, 61' may be replaced by antenna switches to reduce the cost of the repeater.
The operation of the r~peater of FIG. 3 will be describcd with reference to FIG. 4, which are flow diagrams of the steps executed by the controllers ~4, 54' of the repeater 30. These 25 steps are followed when the requesting subscriber unit is out-of-range. Repeater 30 is normally monitoring the control channel at step 72. Decision 74 determines whether a channel request ISW
was received from the requesting subscriber unit calling th~
central station. If no ISW was detected by the receiver 46, the 30 standby monitorin~ mode of block 72 is maintained. If, however, an ISW has been detected, the requesto~s ID is stored at block 76 in a memory portion of the controller 54. ~ecision 78 determines whether a ohannel grant code OSW has been transmitted from the central station 10 to the subscriber unit 24. If tha OSW has 35 been received by the receiver 46', the requestors ID is erased from memory at block 82, and the repeater 30 returns to the 20~1339 normal standby monitoring mode oF block 72. If, however, an OSW directed to ths requesting subscriber unit 24 was not detected in step 78, decision 84 sear~hes for an ISW retry by the subscnber. If no ISW retry occurs within a predetermined time 5 iimit (block 83), the requesto~s l.D. is erased (block 82), and the repeater returns to its monitoring state, block 72. Alternately, if the ISW retry has been detected at decision block 84, the repeater 30 looks for an OSW directed to the subscriber unit 24 at decision block 85. If an OSW is detected the routins branches back to 10 block 82. If the OSW is not detected, the repeater transmits a dual ISW sequence informing the central station 10 of the ll~s of ths out-of-range subscriber unit and the repeater, respectively, in block 86 via the transmitter 48'. In response to the central station's grant, the repeater receives the first OSW, at block 88, 15 which determines its receive frequency for receiving communication transmissions from the out-of-range subscriber unit. At block 92 the repeater 30 receives the channel frequency information for relaying the received information signai (which may be a voice signal) to the central station 10. The repeater 30 20 (at block 94) acting on the information, switches to the assigned frequancies for repeating the communication transmissions of the subscriber unit 24 to the central station 10.
Refsrring to FIG. 5, a signalling protocol of the repeater of FIG. 3 is illustrated when the subscriber unit is operating at such a 25 distance as to have insufficient power to transmit to the central station. When the repeater 30 recognizes a sequence of ISW
retrials without an OSW grant to the out-of-range subscriber unit 24, the repeater 30 transmits to the csntral station 10 a dual ISW
sequence on the inbound control channel 200. The first ISW 202 30 contains at least the ID field of the out-of-range subscriber unit 24 and the second ISW 204 contains at least the ID of the repeater 30. After processing the call request, the central station 10 returns a dual OSW via the outbound control channel 300. Tha first OSW
206 is a command for the out~of-range subscriber unit 24 and that 35 half of the repeater directed ~owards th~ subscriber unit to move to communication channel A. The second OSW 208 commands ths . ' :
.
. .
` Z001339 o~her half of the duplex transceiver within the repeater 30 along with other receiving subscriber units in the requesting subscriber unit's group to switch to communication channel B.
Simultaneously, the central station 10 generates a high speed 5 handshake code 210 for the receiving subscriber units moving to the outbound communication channel B 400 to receive the highspeed handshake and prepare to receive an information signal. As the out-of-range subscriber unit 24 and the repeater 30 switch to their respective communication channels, the high 10 speed handshake is routed in the repeater 30 (from the rec~iver 46' set on channel B to transmitter 48 set for channel A) to be received by the subscriber unit 24 on the outbound communication channel A (500).
After receiving the highspeed handshake 212, the 15 requesting subscriber unit 24 transmits an acknowledge code 214. The repeater 30 immediately routes the high speed acknowledge signal 222 on inbound communication channel B
(700) (from receiver 46 to transmitter 48') for transmission to the central station 10. In response, the central station sends the sync 20 word 226 for the receiving subscriber units followed by the low-speed handshake 228 on the outbound communication channel B (400). Subsequently, the requesting subscriber unit 24 initiates its messag0 216, which consists of an information signal (for example a voice signal 218) and a connect tone 220, which is re-25 transmitt0d by repeater 30 on inbound communication channel B(700) to the central station 10 to maintain the assigned channels 400, 500, 600 and 700 as long as the connect tone is received even if ths information signal 216 might cease.
At the conclusion of the acknowledge signal 222 and the 30 highspeed handshake 210 the receiving subscriber units r~ceive the message 224 (same message as in 216) on the outbound communication channel B (700). The message includes the repeated information 230 and ths low-speed handshake 228, which requires the receiving subscriber units to rernain on the 35 outbound communication channel B (400) while they are receiving the low-spsed handshake 228.
If the central station has insufficient communication range for efficisnt system operation such that it cannot directly transmit to the subscriber unit 26, the repeater of FIG 3 follows the steps for the controllers 54,~4' in the flow diagram of FIG 6. When the 5 subscriber unit 26 stops receiving from the central station 10, it transmits a requesting service ISW to the repeater 30 to relay its transmissions and receptions. Rapeater 30 is normally in the stand-by mode of block 72, monitoring the control channel.
Decision 74~ determines whether a repeater service request ISW
10 was rec~iv~d from the subscriber unit 26. If no service request ISW was detècted by the receiver 46 the standby monitoring mode of block 72 is maintained. If, however, a service requsst ISW has been detected, the requestor's ID is stored at block 76 in a memory portion of the controller 54. the repeater transmits via 15 the transmitter 48', a dual ISW sequence informing the central station 10 of the IDs of the subscriber unit and of the repeater, respec~ively, in block 86. After the central station processes the information, the repeater receives the flrst OSW from the central station, at block 88, which determines the repeate~s receive 20 frequency for receiving communication transmissions from the subscriber unR 26. At block 92 the repeater 30 receives the channel fr~quency Tnformation for transmitting the received information signal to the central station 10. Alternately, if a specific channel has been predetermined for USQ by the repeatsr 25 30, steps 86, 88, and 92 are bypassed. Step 94 follows to establish communication with the subscriber unit 26 and the central station 30 on that predetermined channel.
FIG. 7 is an illustration of a protocol for use with the repeater of FIG. 3 when the central station needs range extension 30 since it has insufficient communication range for efficient system operation. Once the subscriber unit 26 stops decoding the outbound control channel, it sends a dual ISW 302 on ~he last inbound control channel C (800) to advise the pre-assigned repeater that the subscriber unit 26 cannot receiva from the out-of-35 range central station. In r~sponse, the repeater 30 asks th~central station 10 for a channel assignment 304 for itself and the 200~339 subscriber unit on inbound control channel C (900) as in FIG. 7~
After receiving and processing the request 304, the central station 10 transmits a channel E assignment 306 for the subscriber unit and the half of the repeater 30 communicating with the subscriber 5 unit and the channsl D assignment 308 for the other half of the repeater 30 and the rest of the subscribers on outbound control channel C (1000). Once there is a call for the out-of-range unit then, repeater 30 immediately routes the High Speed Handshake ~HSH) 310 on the outbound control channal D (1100) from the 10 receiver 46' to the transmitter 48 for transmission on the outbound communication channel E (1200) as llSH 312. Altsrnately, the repeater 30 may have a predetermined channel assigned for its use and will not need to follow the channel requesting protocol.
However, regardlass of how the channel is assigned, the 15 subscriber unit 26 scans through a list of possible channels for wide area coverage where channel E is included. Once the subscriber unit decodes the HSH 312 from the repeater, the subscriber unit acknowledges and operates on the correct channel during the remainder of the conversation.
I claim as my invention:
.
.. ~ .
Claims (10)
1. A fixed repeater for facilitating communication between a subscriber unit and a central station when said subscriber unit is located in a zone of weak signal strength wherein direct communication between said central station and said subscriber unit cannot occur, comprising:
receiver means for receiving signals transmitted by said subscriber unit and said central station;
transmitter means for transmitting signals to said subscriber unit and said central station; and control means, responsive to received signals, for recognizing a transmission from said subscriber unit to said central station, and an absence of a channel assignment from said central station in response to said transmission from said subscriber unit, wherein said fixed repeater repeats transmissions between said subscriber unit and said central station by utilizing said receiver means and said transmitter means for transmitting signals to said subscriber unit and said central station.
receiver means for receiving signals transmitted by said subscriber unit and said central station;
transmitter means for transmitting signals to said subscriber unit and said central station; and control means, responsive to received signals, for recognizing a transmission from said subscriber unit to said central station, and an absence of a channel assignment from said central station in response to said transmission from said subscriber unit, wherein said fixed repeater repeats transmissions between said subscriber unit and said central station by utilizing said receiver means and said transmitter means for transmitting signals to said subscriber unit and said central station.
2. A fixed repeater for facilitating communication between a central station and a subscriber unit, said subscriber unit having transmitting means to request service of said repeater, comprising:
monitoring means in said fixed repeater for receiving signals from said subscriber unit on a first channel;
receiver means for receiving a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station transmitted by said subscriber unit on said first channel; an control means responsive to said signal request of repeater service to relay transmissions between said subscriber unit and said central station by switching to an assigned channel already designated for said fixed repeater.
monitoring means in said fixed repeater for receiving signals from said subscriber unit on a first channel;
receiver means for receiving a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station transmitted by said subscriber unit on said first channel; an control means responsive to said signal request of repeater service to relay transmissions between said subscriber unit and said central station by switching to an assigned channel already designated for said fixed repeater.
3. A method for a repeater to facilitate communication between a subscriber unit and a central station, comprising the steps of:
(a) receiving in said repeater signals transmitted by said subscriber unit;
(b) receiving in said repeater signals transmitted by said central station;
(c) controlling operation responsive to received signals for recognizing transmission from said subscriber unit to said central station, and a lack of response by said central station to said transmission from said subscriber unit, wherein said repeater automatically transmits a signal representing a call to said central station;
(d) receiving in said repeater a signal representing an answer from said central station wherein said step (d) comprises receiving a message representing at least a channel assignment from said central station, and switching to assigned channels for communication with said subscriber unit and said central station in response to said channel assignment; and (e) operating to repeat transmissions between said subscriber unit and said central station.
(a) receiving in said repeater signals transmitted by said subscriber unit;
(b) receiving in said repeater signals transmitted by said central station;
(c) controlling operation responsive to received signals for recognizing transmission from said subscriber unit to said central station, and a lack of response by said central station to said transmission from said subscriber unit, wherein said repeater automatically transmits a signal representing a call to said central station;
(d) receiving in said repeater a signal representing an answer from said central station wherein said step (d) comprises receiving a message representing at least a channel assignment from said central station, and switching to assigned channels for communication with said subscriber unit and said central station in response to said channel assignment; and (e) operating to repeat transmissions between said subscriber unit and said central station.
4. A method for a fixed repeater to facilitate communication between a subscriber unit and a central station, comprising the steps of:
(a) monitoring in said fixed repeater signals received from said subscriber unit on a first channel;
(b) receiving a request of repeater service signal transmitted by said subscriber unit on said first channel wherein said request of repeater service signal being received in step (b) comprises a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station being received; and (c) operating thereafter to relay transmissions between said subscriber unit and said central station by switching itself to an assigned channel already designated for said fixed repeater.
(a) monitoring in said fixed repeater signals received from said subscriber unit on a first channel;
(b) receiving a request of repeater service signal transmitted by said subscriber unit on said first channel wherein said request of repeater service signal being received in step (b) comprises a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station being received; and (c) operating thereafter to relay transmissions between said subscriber unit and said central station by switching itself to an assigned channel already designated for said fixed repeater.
5. A method for a repeater to facilitate communication in a communication system between a subscriber unit and a central station, comprising the steps of:
(a) monitoring in said repeater signals received from said subscriber unit on a first channel;
(b) receiving a request of repeater service transmission from said subscriber unit on said first channel requesting said repeater to repeat transmission;
(c) switching itself to at least one system predetermined channel for communication with said subscriber unit and said central station in response to said request of repeater service transmission;
(d) scanning by said subscriber unit to determine said at least one predetermined channel; and (e) repeating transmissions from said subscriber unit and said central stations on said at least one system predetermined channel.
(a) monitoring in said repeater signals received from said subscriber unit on a first channel;
(b) receiving a request of repeater service transmission from said subscriber unit on said first channel requesting said repeater to repeat transmission;
(c) switching itself to at least one system predetermined channel for communication with said subscriber unit and said central station in response to said request of repeater service transmission;
(d) scanning by said subscriber unit to determine said at least one predetermined channel; and (e) repeating transmissions from said subscriber unit and said central stations on said at least one system predetermined channel.
6. A method for a repeater to facilitate communication between a subscriber unit and a central station via at least one control channel and at least one communication channel, comprising the steps of:
(a) monitoring in said repeater a message representing at least a call request from said subscriber unit to said central station on said control channel;
(b) monitoring in said repeater a message representing at least a channel assignment from said central station to said subscriber unit on said control channel;
(c) detecting an absence of said message representing at least a channel assignment from said central station and at least another message representing at least a call request from said subscriber unit on said control channel;
(d) transmitting a message representing at least a call request to said central station in response to step (c) on said control channel;
(e) receiving in said repeater a signal representing an assignment from said central station on said control channel for said subscriber unit to communicate with said repeater on a first communication channel and for said repeater to communicate with said central station on a second communication channel; and (f) repeating transmissions between said subscriber unit and said central station.
(a) monitoring in said repeater a message representing at least a call request from said subscriber unit to said central station on said control channel;
(b) monitoring in said repeater a message representing at least a channel assignment from said central station to said subscriber unit on said control channel;
(c) detecting an absence of said message representing at least a channel assignment from said central station and at least another message representing at least a call request from said subscriber unit on said control channel;
(d) transmitting a message representing at least a call request to said central station in response to step (c) on said control channel;
(e) receiving in said repeater a signal representing an assignment from said central station on said control channel for said subscriber unit to communicate with said repeater on a first communication channel and for said repeater to communicate with said central station on a second communication channel; and (f) repeating transmissions between said subscriber unit and said central station.
7. A method for a repeater to facilitate communication in a communication system between a subscriber unit and a central station via at least one control channel and at least one system predetermined communication channel, comprising the steps of:
monitoring, in said repeater, signals received from said subscriber unit on said control channel;
receiving a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station from said subscriber unit on said control channel;
switching to said at least one system predetermined communication channel for communication with said subscriber unit and said central station in response to said signal requesting said repeater to repeat transmissions between said subscriber unit and said central station; and repeating transmissions between said subscriber unit and said central station.
monitoring, in said repeater, signals received from said subscriber unit on said control channel;
receiving a signal requesting said repeater to repeat transmissions between said subscriber unit and said central station from said subscriber unit on said control channel;
switching to said at least one system predetermined communication channel for communication with said subscriber unit and said central station in response to said signal requesting said repeater to repeat transmissions between said subscriber unit and said central station; and repeating transmissions between said subscriber unit and said central station.
8. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units and each subscriber unit having at least an individual identification code, said subscribers constructed and arranged to communicate information on any of the communication channels, a method for a repeater having at least an individual identification code to initiate communication between any of the plurality of subscribers and said at least one central controller comprising the steps of:
(a) receiving in said repeater a first message from said subscriber unit comprising at least a call request information word representing said subscriber unit's identification code;
(b) receiving in said repeater a second message from said central controller representing said subscriber unit's identification code and a channelassignment;
(c) determining whether said second message from said central controller has been received before receiving a predetermined number of said first messages from said subscriber comprising at least said call request;
(d) transmitting a third message to said central controller representing said subscriber's individual identification code and said repeater's identification code, in response to receiving a predetermined number of said first messages from said subscriber unit before receiving said second message from said central controller; and (e) receiving in said repeater a fourth message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units.
(a) receiving in said repeater a first message from said subscriber unit comprising at least a call request information word representing said subscriber unit's identification code;
(b) receiving in said repeater a second message from said central controller representing said subscriber unit's identification code and a channelassignment;
(c) determining whether said second message from said central controller has been received before receiving a predetermined number of said first messages from said subscriber comprising at least said call request;
(d) transmitting a third message to said central controller representing said subscriber's individual identification code and said repeater's identification code, in response to receiving a predetermined number of said first messages from said subscriber unit before receiving said second message from said central controller; and (e) receiving in said repeater a fourth message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units.
9. In a trunked communication system having at least one central controller for allocating a limited number of communication channels among a plurality of subscriber units and each subscriber unit having at least an individual identification code, said subscriber unit constructed and arranged tocommunicate information on any of the communication channels, said communication channels includes a plurality of designated channels, a method for a repeater having at least an individual identification code to provide communication between any of the plurality of subscriber units requesting access to said repeater and said at least one central controller comprising the steps of:
at said subscriber unit:
(a) transmitting a message to said repeater comprising at least a call request information word being organized in fields, wherein a first field represents said subscriber's individual identification code, and a second field represents a status code when a signal ceases to be received from said central station;
(b) scanning through said plurality of designated channels for reception of a signal representing a handshake on one of said plurality of designated channels;
(c) transmitting a signal representing an acknowledgement when said handshake has been received on one of said plurality of designated channels;
at said repeater:
(a) receiving said message from said subscriber unit comprising at least a call request information word representing said subscriber's individual identification code and said status code;
(b) transmitting a message to said central controller comprising at least a call request information word representing said subscriber's individual identification code and said repeaters identification code;
(c) receiving a message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units;
(d) transmitting said signal representing said handshake to said subscriber unit on said one of said plurality of designated channels;
(e) receiving said signal representing said acknowledgement from said subscriber unit on said one of said plurality of designated channels.
at said subscriber unit:
(a) transmitting a message to said repeater comprising at least a call request information word being organized in fields, wherein a first field represents said subscriber's individual identification code, and a second field represents a status code when a signal ceases to be received from said central station;
(b) scanning through said plurality of designated channels for reception of a signal representing a handshake on one of said plurality of designated channels;
(c) transmitting a signal representing an acknowledgement when said handshake has been received on one of said plurality of designated channels;
at said repeater:
(a) receiving said message from said subscriber unit comprising at least a call request information word representing said subscriber's individual identification code and said status code;
(b) transmitting a message to said central controller comprising at least a call request information word representing said subscriber's individual identification code and said repeaters identification code;
(c) receiving a message from said central controller comprising at least channel grant information words each representing a channel assignment for said subscriber to communicate with said repeater, and a channel assignment for said repeater to communicate with said central controller and other subscriber units;
(d) transmitting said signal representing said handshake to said subscriber unit on said one of said plurality of designated channels;
(e) receiving said signal representing said acknowledgement from said subscriber unit on said one of said plurality of designated channels.
10. The method of step 9, wherein step (c) at said repeater comprises the step of switching to an assigned channel already designated for said repeater.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US27899888A | 1988-12-02 | 1988-12-02 | |
| US278,998 | 1988-12-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2001339A1 CA2001339A1 (en) | 1990-06-02 |
| CA2001339C true CA2001339C (en) | 1993-12-21 |
Family
ID=23067258
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002001339A Expired - Fee Related CA2001339C (en) | 1988-12-02 | 1989-10-24 | Repeater for a controlled radio system |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US5133080A (en) |
| CA (1) | CA2001339C (en) |
Families Citing this family (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5159701A (en) * | 1989-03-31 | 1992-10-27 | E. F. Johnson Company | Method and apparatus for a distributive wide area network for a land mobile transmission trunked communication system |
| US5459761A (en) * | 1992-06-29 | 1995-10-17 | Motorola, Inc. | Intelligent repeater for trunked communications |
| US5381346A (en) * | 1992-06-30 | 1995-01-10 | Motorola, Inc. | Virtual data source for a radio transceiver |
| FR2708814B1 (en) * | 1993-07-30 | 1995-09-01 | Alcatel Mobile Comm France | Method for covering the shadow areas of a radiocommunication network, and radio repeater for implementing this method. |
| GB2286505B (en) * | 1994-02-09 | 1997-12-10 | Motorola Ltd | Method for registration in a communications system |
| FI108098B (en) * | 1994-03-03 | 2001-11-15 | Nokia Networks Oy | Method for controlling a subscriber station, radio system and subscriber station operating on a direct channel |
| SE504044C2 (en) * | 1994-03-29 | 1996-10-21 | Telia Ab | Device for repeaters in radio-based communication system |
| FI98034C (en) * | 1994-05-19 | 1997-03-25 | Nokia Telecommunications Oy | Method of forming a call in a mobile telephone system as well as a mobile telephone system |
| SE513975C2 (en) * | 1994-08-19 | 2000-12-04 | Telia Ab | Repeater and method for DECT systems |
| JP2606613B2 (en) * | 1994-12-28 | 1997-05-07 | 日本電気株式会社 | Data writing method for wireless selective call receiver |
| AU5235596A (en) * | 1995-05-19 | 1996-11-28 | Nec Corporation | Radio paging system using radio selective paging receiver |
| US6132306A (en) * | 1995-09-06 | 2000-10-17 | Cisco Systems, Inc. | Cellular communication system with dedicated repeater channels |
| US5809427A (en) * | 1996-03-28 | 1998-09-15 | Motorola Inc. | Apparatus and method for channel acquisition in a communication system |
| JP3074608B2 (en) * | 1996-06-25 | 2000-08-07 | ミツビシ インターナショナル ゲゼルシャフト ミット ベシュレンクテル ハフツング | Wireless link establishment method |
| US5898679A (en) * | 1996-12-30 | 1999-04-27 | Lucent Technologies Inc. | Wireless relay with selective message repeat and method of operation thereof |
| US6529486B1 (en) * | 1997-04-11 | 2003-03-04 | Transcrypt International/E.F. Johnson Company | Trunked radio repeater communication system |
| US6684080B1 (en) | 1997-05-28 | 2004-01-27 | Transcrypt International/E. F. Johnson Company | Trunked radio repeater communication system including home channel aliasing and call grouping |
| US6374115B1 (en) | 1997-05-28 | 2002-04-16 | Transcrypt International/E.F. Johnson | Method and apparatus for trunked radio repeater communications with backwards compatibility |
| DE19726940C2 (en) * | 1997-06-25 | 2002-07-18 | Littlefeet Inc | Transmitting and receiving device for amplifying the transmission signals between a fixed and a mobile transmitting station and method for operating the channel detection device of a transmitting and receiving device |
| FI973850A (en) * | 1997-09-30 | 1999-03-31 | Nokia Telecommunications Oy | A method for controlling the radio frequency of the radio repeater in a cellular radio network |
| US6141533A (en) * | 1997-11-13 | 2000-10-31 | Motorola, Inc. | Method and apparatus for a mobile repeater |
| JP4192328B2 (en) * | 1999-03-24 | 2008-12-10 | ソニー株式会社 | Wireless transmission method and wireless transmission device |
| US6647244B1 (en) * | 1999-11-16 | 2003-11-11 | The Whitaker Corporation | Wireless vehicular repeater system |
| US7024196B1 (en) * | 2000-06-26 | 2006-04-04 | Motorola, Inc. | Method and apparatus for distributing processing load for decoding radio frequency transmissions |
| US7720484B2 (en) * | 2004-09-02 | 2010-05-18 | Samsung Electronics Co., Ltd. | Proxy translator for extending the coverage area of a wireless network |
| JP2007028176A (en) * | 2005-07-15 | 2007-02-01 | Oki Electric Ind Co Ltd | Communication method and repeating device |
| US20070076645A1 (en) * | 2005-09-30 | 2007-04-05 | Vandrunen Paul J | Signal repeater system |
| US8045982B2 (en) * | 2008-10-17 | 2011-10-25 | Motorola Solutions, Inc. | Methods for site selection in a multi-site communication system |
| US8468412B2 (en) * | 2009-06-19 | 2013-06-18 | Research In Motion Limited | Downlink transmissions for type 2 relay |
| CN102804668A (en) | 2009-06-19 | 2012-11-28 | 捷讯研究有限公司 | Uplink Transmissions For Type 2 Relay |
| WO2012106330A1 (en) | 2011-01-31 | 2012-08-09 | Synchronoss Technologies, Inc. | System and method for host and os agnostic management of connected devices through network controlled state alteration |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT338877B (en) * | 1969-07-23 | 1977-09-26 | Sits Soc It Telecom Siemens | REMOTE INDICATION SYSTEM WITH A NUMBER OF TWO-DIRECTIONAL CHANNELS, EACH OF WHICH ONE IS ONLY USED DURING THE DURATION OF THE CONNECTION BETWEEN AT LEAST TWO TRANSCEIVER-RECEIVING DEVICES |
| US3731203A (en) * | 1970-09-25 | 1973-05-01 | Gte Sylvania Inc | Monitoring circuit and system for detecting signals in a signal transmission system |
| US4056779A (en) * | 1976-04-05 | 1977-11-01 | Motorola, Inc. | Vehicular repeater |
| JPS57178441A (en) * | 1981-04-24 | 1982-11-02 | Nec Corp | Fault detection system of mobile radio communication system |
| JPS617736A (en) * | 1984-06-22 | 1986-01-14 | Nec Corp | Radio relay system |
| US4649567A (en) * | 1985-04-22 | 1987-03-10 | General Electric Company | Dispatch overdialing for inter-group and other added calling/called access to communications channels in a trunked radio communications system |
| US4716407A (en) * | 1985-10-07 | 1987-12-29 | Motorola, Inc. | Trunked communication system true priority channel scan |
| US4726050A (en) * | 1986-02-18 | 1988-02-16 | Motorola, Inc. | Scanning receiver allocation method and apparatus for cellular radiotelephone systems |
| US4882765A (en) * | 1987-05-22 | 1989-11-21 | Maxwell Ray F | Data transmission system |
| US4723264A (en) * | 1987-06-19 | 1988-02-02 | Motorola, Inc. | Signalling method for establishing trunked communication |
-
1989
- 1989-10-24 CA CA002001339A patent/CA2001339C/en not_active Expired - Fee Related
-
1991
- 1991-10-10 US US07/773,755 patent/US5133080A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| US5133080A (en) | 1992-07-21 |
| CA2001339A1 (en) | 1990-06-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2001339C (en) | Repeater for a controlled radio system | |
| US5293638A (en) | Intersystem communication system and method | |
| US4553262A (en) | Communications system enabling radio link access for non-trunked radio units to a multifrequency trunked two-way communications systems | |
| US5058199A (en) | Inter-truncked radio systems bridge protocol | |
| US5179559A (en) | Handoff method for a cellular system | |
| US5369781A (en) | Dispatch communication system with adjacent system signal repeating | |
| EP0390214A2 (en) | Method and apparatus for a distributive wide area network for a land mobile transmission trunked communication system | |
| US5126733A (en) | Location information polling in a communication system | |
| JPH0629910A (en) | Inter radio base station synchronization system | |
| JPH10500815A (en) | Method for establishing a call in a mobile communication system | |
| JP3180346B2 (en) | Single channel remote station relay method | |
| US5561845A (en) | Apparatus and method for preserving coverage in an overlapping coverage area | |
| US5875211A (en) | Multisite radio system with false mobile radio signalling detection | |
| EP0406905A2 (en) | Dual donor booster system | |
| EP0547156B1 (en) | Method and apparatus for establishing voice and tone signalling communication in a trunked system | |
| JPH03231523A (en) | Mobile communication control system | |
| AU634234B2 (en) | Method of establishing communication between independent communication systems | |
| JPS58191542A (en) | Mobile communication controlling system | |
| CA2005638C (en) | Communication system with squelch control | |
| JP2731708B2 (en) | Alternate call connection control method for mobile communication systems | |
| JP2872154B2 (en) | Simplex communication control method for digital mobile communication system | |
| JP3033689B2 (en) | Control channel switching method for PHS base station | |
| EP1304895A2 (en) | Transceivers and method for use in radio communications | |
| WO1999067914A1 (en) | Method of and system for determining arq capability of a base station | |
| JP2770805B2 (en) | Unnecessary channel release method in mobile communication system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed | ||
| MKLA | Lapsed |
Effective date: 19950424 |