CA1189939A - Digital telephone exchange comprising means for processing packet-switched data - Google Patents
Digital telephone exchange comprising means for processing packet-switched dataInfo
- Publication number
- CA1189939A CA1189939A CA000411778A CA411778A CA1189939A CA 1189939 A CA1189939 A CA 1189939A CA 000411778 A CA000411778 A CA 000411778A CA 411778 A CA411778 A CA 411778A CA 1189939 A CA1189939 A CA 1189939A
- Authority
- CA
- Canada
- Prior art keywords
- data
- channel
- packet
- subscriber
- switched data
- 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
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M11/00—Telephonic communication systems specially adapted for combination with other electrical systems
- H04M11/06—Simultaneous speech and data transmission, e.g. telegraphic transmission over the same conductors
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L12/00—Data switching networks
- H04L12/64—Hybrid switching systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
- H04Q11/0428—Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
Abstract
ABSTRACT:
"Digital telephone exchange comprising means for pro-cessing packet-switched data".
Digital telephone exchange comprising a plurality of peripheral control domains PCD which are either con-nected to a digital trunk network DTN or are directly interconnected. Each domain comprises several digital subscriber interface units DSI, a group of digital subscriber sets SS being connected to each interface unit.
The transmission of information over the sub-scriber line is effected in a b-channel for speech (64 kb/s) a b'-channel for circuit-switched data (0/8/64 kb/s) and a .DELTA.-channel for packet-switched data (8/16 kb/s).
The subscriber line interface circuits SLIC
comprise means (166) for identifying the packet-switched data signals and to apply them to a packet processing unit PPU. In this unit the packets are distinguished and firstly signalling information (s) and secondly tele-metry and slow data (t+d'). The separately applied signal-ling information (s) and telemetry data and slow data (t+d') intended for a subscriber line are combined by the packet processing unit to form one packet-switched data signal (.DELTA.) for the subscriber line. In a data unit connected to the trunk network and signals S and (t+d') combined into messages are exchanged between the subscribers without loading the central control unit (CCU) of the telephone exchange.
"Digital telephone exchange comprising means for pro-cessing packet-switched data".
Digital telephone exchange comprising a plurality of peripheral control domains PCD which are either con-nected to a digital trunk network DTN or are directly interconnected. Each domain comprises several digital subscriber interface units DSI, a group of digital subscriber sets SS being connected to each interface unit.
The transmission of information over the sub-scriber line is effected in a b-channel for speech (64 kb/s) a b'-channel for circuit-switched data (0/8/64 kb/s) and a .DELTA.-channel for packet-switched data (8/16 kb/s).
The subscriber line interface circuits SLIC
comprise means (166) for identifying the packet-switched data signals and to apply them to a packet processing unit PPU. In this unit the packets are distinguished and firstly signalling information (s) and secondly tele-metry and slow data (t+d'). The separately applied signal-ling information (s) and telemetry data and slow data (t+d') intended for a subscriber line are combined by the packet processing unit to form one packet-switched data signal (.DELTA.) for the subscriber line. In a data unit connected to the trunk network and signals S and (t+d') combined into messages are exchanged between the subscribers without loading the central control unit (CCU) of the telephone exchange.
Description
33~3 Pi 10 160 'I 3-3~1~82 digital telephone exchange comprising means for processing packet switched data".
The invention relates to a digital telephone exchange comprising a plurality of domains each incorporate in subscriber line interface circuits, each serving to connect a subscriber line o'er which digitized speech signals old data signals are transmitted from and to a digital subscriber set, which data signals are both circuit-switched data signals and packet switched data signals these last-mentioned data signals comprising signaling information, telemetry data and slow data i and, to connect a time division multiplex line per which several signals are transmitted from and to the sub-scriber lines in time~di~ision multiplex, further comprise in a time switching network hazing -terminals for several groups of subscriber lines, terminals for auxiliary units for the signaling information and terminals for a domain interface unit for connection to other domains.
or digital telephone exchanges of the above-described type there is the need to covey, it addition to speech signals, circuit-switched data and packet-switched data from and to the subscriber sets, In practice the following provisions are, for example, taken:
1, a 64 kb/s. b-channel for speech
The invention relates to a digital telephone exchange comprising a plurality of domains each incorporate in subscriber line interface circuits, each serving to connect a subscriber line o'er which digitized speech signals old data signals are transmitted from and to a digital subscriber set, which data signals are both circuit-switched data signals and packet switched data signals these last-mentioned data signals comprising signaling information, telemetry data and slow data i and, to connect a time division multiplex line per which several signals are transmitted from and to the sub-scriber lines in time~di~ision multiplex, further comprise in a time switching network hazing -terminals for several groups of subscriber lines, terminals for auxiliary units for the signaling information and terminals for a domain interface unit for connection to other domains.
or digital telephone exchanges of the above-described type there is the need to covey, it addition to speech signals, circuit-switched data and packet-switched data from and to the subscriber sets, In practice the following provisions are, for example, taken:
1, a 64 kb/s. b-channel for speech
2. a o/8/64 kb/s, channel for circuits itched data, and
3. a 8/16 kb/s delta channel channel) for packet switched data.
The signaling from and to the subscriber sets is usually incorporated in the A -channel.
In practice there is also a need for the trays-mission of telemetry data such as alarm systems for the elderly, meter reading and remote control and slow data for, or example, Teletext and Videotext It has already-been proposed to incorporate these facilities in the ,,' I.
channel. The problem is then encountered that telemetry data and slow data have either a high call rate and a short hold period or a low Cole rate with a very long hold period. Both types of traffic may give rise to congestion in the telephone exchange.
The invention has for its object to provide a novel concept of the digital telephone exchange described in the opening paragraph, it being possible to accommodate the telemetry data and the slow data in the Connally without resulting in congestion in the exchange.
According to the invention, there is provided a digital tote-phone exchange for connecting a plurality of digital subscriber sets to a time division multiplex transmission line, said subscriber sets and time division multiplex transmission line transmitting and receiving circuit switched data signals, and packet switched data signals which include signaling information, telemetry data and slow data, comprising;
a plurality subscriber line interface circuit for connecting each of said plurality of digital subscriber sets to said time division multiplexed transmission line comprising;
means for identifying the packet switched data signals from said subscriber sets;
a packet processing unit connected to receive said identified packet switched data, said unit including means for dividing the packet into signaling information, and into telemetry data and slow data;
means for combining for each subscriber set the signaling information, telemetry data and slow data received from said time division multiplex transmission line to form one packet switched data signal; and means for transmitting telemetry data and slow data to said means for combining from a second assigned channel of said time multiplexed 9~{33.':~
transmission line, and from said processing unit to said second assigned channel of said multiplexed transmission line, and for transmitting said signaling information to said means for combining from a first assigned channel of said time multiplexed transmission line, and from said packet processing unit to said second assigned channel;
said first assigned channel being connected to a central signal processing unit, and said second assigned channel being connected to a packet switched data unit.
The invention will now be further explained by way of example with reference to a block-schematic circuit diagram of a digital telephone exchange using the invention, with reference to the accompanying figures in which:
Figure 1 is a block schematic circuit diagram -pa-I
Pi 10 160 -3- 3~3-1982 of a digital telephone exchange using the invention.
Fig 2 shows an embodiment of' a subscriber line interface circuit for use in the exchange shown in Fig/ 1.
6 the digital telephone exchange to which the invention relates comprises a plurality of peripheral control domains (POD) oil which, the domains 301 and 304 are connected to a digital try network DUN as shown in Fig. 1, In this Figure the domain 301 is shown in greater detail. Digital subscriber sets (SO) are connected to this domain. lye subscriber sets are di~idcd into groups and -each group is connected -to a digital subscriber interface unit (DSI). The two groups of subscriber sets I owe 15 and 49~ owe which are connected to the respective inter-face units 201 and 204 by means of the subscriber lines 401 9 402, r ~416 and 449. D owe are shown in the Figure.
In the interlace units the subscriber lines terminate on subscriber line interface circuits Slicks In the interlace unit 201 whey are the Slicks 101, 102,...1 16 9 The interface units (DSI) of each individual domain (POD) are connected to a peripheral domain time switching network (PUS) via multiple main paths. Thus, in the figure the interface units 201 and 204 are con netted to the time switching network (PUS) via the multi pled main paths 501 and 5040 In addition a signaling auxiliary unit (SWISS
a peripheral domain controller (PDC) and a digital domain interface (DID) are connected to the time switching net ED work (PUS) via one or more-multiplex main paths. The domain interface units (DID) serve as connections to other domains (POD).
The interface units (DID) of different domains (POD) are connected to the digital trunk network DO
I pa multiplex main paths. In the Fuller, -the interface nutted) of the domain 301 is connected to the digital trunk network (DUN) via the multiplex main paths 601 to 60l~, inclusive. For the domain 304 this connection is i I 3 39 pi 160 ~~~ 3-3-1982 effected via main paths such as 6-13.
A central control unit OCCUR which serves inter aria as a central signal processing unit for the signally is connected to the digital trunk network (DUN).
For smaller exchanges the domain interface units (Dyes) may be interconnected directly and connected directly to the central control unit (CCU).
The digital speech signal transmission from subscriber sets (SO) to the exchange and vice errs is effected at a standardized transmission rate of 64 kb/s.
in PAM Norm in a Bunnell of the subscriber lines.
The multiplex main paths such as 501~..504 coy prows for example, thirty-two 64 kb channels and con-sequently have a processing speed of 2.048 kb/sec., designated 2 Mb/sec~ in the further course of the description.
In addition -to speech signals, circuit-switched data streams may be transmitted from the subscriber sets to the exchange and vise versa. This transmission is effected at a standardized transmission rate of o/8/64 kb/sec. in a subscriber line b' channel allocated thereto.
For packet-switched data use is made on a sub-scriber line of a delta channel ( ) with a standardized transmission rate of 8/64 kb/so Inter aria thy telephony signaling signals(s) are accommodated in this -channel. For other forms of data such as telemetry data (t) and "slow" data (d) such as Teletext and View data, they may also be aecommodat-Ed in the channel The peripheral domain controller (PDC) and further interface equipment are then heavily loaded by the slow data traffic, which has a high call rate and a very short holding period or a low call rate and a very long holding period compared with the normal telephone traffic. This may cause congestion for normal telephone traffic.
To obviate this the subscriber line interface circuit (SLIT) is, in accordance with the invention of a construction as shown in Fig. 2 and a packet-switched data Ply 10 l60 -I 3-3-1982 unit (DSU) is connected to -the digital trunk network (DIN). In addition, a data reduction unit (DRY) may be incorporated in the peripheral domain controller (PDC) in order to limit the data traffic to the data unit (DSU) as much as possible The subscriber line interface circuit shown in Fig. 2 comprises in customary manner a line transmission circuit (LO) connected to the subscriber line 401, this line transmission circuit providing the transmission facility for the two-way channels b, d' and .
An adaptation circuit 165 it arranged for adapting the speed between the channels on the telephone __ .
line 401 and the exchange.
The transmission over the subscriber line is effect-Ed in frames in which bits for the channels b, b' and are transmitted in groups.
Complete frames are exchanged between the adaptation circuit 165 and a buffer 1660 The information from the -channel of an incoming frame is identified in the buffer 166 and applied to a packet processing unit (PUP) which comprises means to divide the packets firstly into signaling information (so and secondly into telemetry data and slow data (dot). The unit POW) also comprises means fox combining per subscriber line the signaling information(s) obtained from the time-di~ision multiplex line (main line 501) and telemetry and slow data (ted) into one packet-switched data signal and for the trays-mission of the signaling information (s) from and to a first fixedly assigned channel of the time division mull triplex line (main line 501) of the relevant group of subscriber lines and or the transmission of the telemetry data and the slow data from and to a second fixedly assigned channel of the said time-division multiplex line (main line 501)~
More particularly, the packet processing unit (PUP) comprises a processor (up), for example a Z-8000, a random access memory (RAM) and the controllers us 174~ 175 and 176, for example a Signetics 2652, Pi 10 160 -6- 3-3-1982 mutually interconnected by a bus 177~
to information obtained prom the -channel is split in the mu troller 174 into signaling inform motion (s) and telemetry data and slow data (ted') and stored per -type of information (s) or (ted') in the store (RAM). When the total information of a signaling message(s) has been stored in the store (ROY) the mu-controller 175 investigates whether a special signalizing channel (s), denotes the first charnel, on the main path 501 is free, which channel is represented in the Figures by a broken line. The appearance ox the signalli~g channel (s) on the main path 501 is reported to the controller 175 by a register 170, in which the chclnnel number of the signaling channel (s) is stored. A time-channel counter 171 which counts the channels in a frame which appear on the main path 501 is connected to the register 170. If there is agreement between the channel number in the time channel counter 171 and the channel number in the register 170, and this signaling channel is free, the signaling message stored in the memory (RAM) is fed into this 64 sub signaling channel (s) at a rate of 2 My sea by the controller 1750 Likewise, the total inure formation of a telemetry message (t) and the total in-formation of the slow data message (do) is stored in the (RAM). When a complete telemetry message (t) or a complete slow data message (d') is present in the memory (RAM) the controller 176 investigates whether a second channel specially assigned to telemetry data and slow data (tldl) it tree, which channel is represented in the figures by a dot~and-dash lingo the controller 176 receives the information on the occurrence of the said tot channel from a register 169, which is also connected to the time channel counter 171. The register 169 operates in a similar manner as register 170. When there is agree-mint between the channel number in the time-channel counter 171 and the channel number in the register 169, and the to channel is free, the -telemetry data message (t) and the slow data message (d') stored in the memory (ROY) 10 l60 I 3-3-l982 is fed into this 64 kb(t-~cl') channel at a rate of 2Mb~sec.
The use of the registers such as i69 and 170 render i-t possible to realize a flexible allocation of commons) and (ted') channels on the main path 5010 By extending the number of registers it is possible to allocate several separate (s) and (ted') channels in a flexible marker.
The packet processing I t (PUP) it not only arranged for transmitting in separate channels (s) and to of the main path 501 the signaling information and the telemetry data in combination with the slow data coming from the -charnel of the subscriber lines 9 but this unit is also arranged for assembling the information present in the separate channels(s) and (ted') of the main path 501 intended for the relevant subscriber set into one packet-switched data signal for transmission in the -channel in the subscriber line 401~
For -that purpose the controllers 176 and 175 investigate, at the instants indicated by the registers 169 and 170 of the occurrence ox the (ted') channel and the channel of the main path 501, whether telemetry data or slow data and signaling information are present for the relevant subscriber. If such information occurs the mu controller 175 and 176 9 respectively write this information into the memory (RAM). Under the control of the processor (up) this information is assembled in controller 174 to form packets of (s) (ted') inform motion. As soon as such as packet has been assembled this packet it fed into the A channel of the subscriber lone ~01 by the controller 174 via the frame buffer 166, the adaptation circuit 165 and the line transmission circuit (LO). The speech signals (b) and circuit-switched data (by), respectively which are separated in the buffer 166 are applied to the respective gate circuits 172 and 173 via the respective separate lines b and b'. These gate circuits are controlled by registers 167 and 168 which are both connected to the channel counter 170. random I
PUN 10 owe -8 3-3-1982 charnels of the main path 501 are assigned to the aegis-lens; this is shown in the Figures by means ox a solid line. At the occurrence of the channel of the outgoing annuls on the main path 501 allocated to the speech signals, the gate circuit 172 is open and the speech signal information (b) contained in the frame buffer 166 is applied to this 64 kb channel at a rate of 2 ~b/sec.
Likewise, at the occurrence of a channel (buff the out-going channels on the main path 501 allocated to the circus switched data (by), the gate circuit 173 is open and the data information (by) contained in the buffer 166 is applied to that channel in a similar manner.
At the occurrence of channels belonging to this group of incoming channels on the main path 501, fixedly - 15 adjusted per connection to the relevant subscriber the gate circuits 172 and 173 are open in a correspond-in manner for applying speech signals o'er the line b and circuit-switched data over the line d' from the main path 501 to the buffer 166 at a rate of 2 Mb/sec. via the adaptation circuit 165 and the line transmission circuit LO these speech signals and circuit-switched data are applied to the subscriber line 401 at the associated low bit ratio It should be noted that, instead of connecting it to a gate circuit 173, it is alternatively possible to connect the line b' connected to the buffer 166 to a further mu controller in the packet processing unit (PUP). It is then possible to put the information in the channel of the subscriber line 401 on the special (s) and to channels of the main path 501 and vice versa, if so desired.
As shown in Fig. 1, in this embodiment the channels in Welch (b) and (by) information is present on the main path 501 are switched-through via the peripheral domain time switching network (PUS) to the domain interface unit (DID) where they are interconnected in a one-by-one configuration to channels of a time division multiplex main path 601 which are connected via 99~
Pi lo owe I 3-3-1982 the digital trunk network (DUN) and the time-division multiplex main path 613 to the peripheral control domain 304 for directly exchangiIlg speech signals and circuit-switched data between these peripheral control domains 301 and 304.
The special signaling channel (s) and the special telemetry data and low data channel (ted') are connected in this embodiment, each one individually via the domain time switching network (PUS), to the data reduction unit (DRY) provided in the peripheral domain controller (PDC). This data reduction unit (DRY) is a dynamic multiplexer which concentrates the information present in the special signaling channels (s) of several subscriber interface units (DSI) and applies this con-cent rated signaling information (so to the interface unit DOW) via at least one semi-permanent channel of the time switching network (PUS). From this interface 11n1t (DID) the concentrated signaling information (s) is applied vi at least one special semi-permanent channel in the time-division multiplex main path 601 via the digital trunk network (DUN) to a central signaling processing Nat, not shown in the central control unit CCU of the telephone exchange and processed there. Signaling inure-motion (s) which must be applied to a subscriber interface unit (DSI) by the central control 11n;t OCCUR is applied via the digital trunk network DO the main path 601 and the interface unit (DID) of the peripheral control domain 301 and the peripheral domain time switching network (PUS) to the data reduction unit (DRY) from where this signaling information (s) is distributed. This signaling information (s) is than applied to the relevant main path 501 via the peripheral domain switching network (PUS).
The telemetry data and slow data in the special channels to obtained from several subscriber interface units (DSI) are also concentrated in the data reduction unit (DRY) anal applied to the interface unit (DID) it at least one semi-permanent channel of the time switchiIlg network (PUS). From this interface unit (DID) the I
Pi 10 owe -10- 3-3 19~2 concentrated telemetry data and slow data information (ted') are applied via a-t least one special semi-permanent Shelley in th~time-division multiplex main path 601 via toe digital trunk network (DUN) to the packet-switched data unit (DSU) as processed there.
Telemetry data information and slow data to to be applied to a subscriber interface unit (DSI) by the data unit (DSU) are applied via the digital -trunk network (DUN), thy main path ~01 and the interface unit (DID) of the peripheral domain 301 and the peripheral domain -time switching network (PUS) to the data reduction unit (DOW) where this information (ted') is distributed.
Thereafter it is applied to the relevant main path 501 via the peripheral domain switching network PUS
As will be apparent from the above description the central control unit OCCUR of the telephone exchange does not have the task of processing packet-switched data such as telemetry data (t) and/or low data (do) but these packet-switched data are processed in a separate packet-switched data exchange Thus, congestion in the control unit OCCUR due to these data is prevented from occurring a In addition the signaling information (so and telemetry data information and slow data (t~dl~ are transmitted over separate semi-permanent channels within the telephone exchange. This prevents congestion of speech and signaling information (s) due to telemetry data and slow data (ted') from occurring during this transmission.
Furthermore, because of the provision of a data reduction unit the number of channels required in the time-division multiplex main paths between the mutually interconnected peripheral domain units Pus and the further equipment for transmitting signaling information (s) and telemetry data and slow data to is very small
The signaling from and to the subscriber sets is usually incorporated in the A -channel.
In practice there is also a need for the trays-mission of telemetry data such as alarm systems for the elderly, meter reading and remote control and slow data for, or example, Teletext and Videotext It has already-been proposed to incorporate these facilities in the ,,' I.
channel. The problem is then encountered that telemetry data and slow data have either a high call rate and a short hold period or a low Cole rate with a very long hold period. Both types of traffic may give rise to congestion in the telephone exchange.
The invention has for its object to provide a novel concept of the digital telephone exchange described in the opening paragraph, it being possible to accommodate the telemetry data and the slow data in the Connally without resulting in congestion in the exchange.
According to the invention, there is provided a digital tote-phone exchange for connecting a plurality of digital subscriber sets to a time division multiplex transmission line, said subscriber sets and time division multiplex transmission line transmitting and receiving circuit switched data signals, and packet switched data signals which include signaling information, telemetry data and slow data, comprising;
a plurality subscriber line interface circuit for connecting each of said plurality of digital subscriber sets to said time division multiplexed transmission line comprising;
means for identifying the packet switched data signals from said subscriber sets;
a packet processing unit connected to receive said identified packet switched data, said unit including means for dividing the packet into signaling information, and into telemetry data and slow data;
means for combining for each subscriber set the signaling information, telemetry data and slow data received from said time division multiplex transmission line to form one packet switched data signal; and means for transmitting telemetry data and slow data to said means for combining from a second assigned channel of said time multiplexed 9~{33.':~
transmission line, and from said processing unit to said second assigned channel of said multiplexed transmission line, and for transmitting said signaling information to said means for combining from a first assigned channel of said time multiplexed transmission line, and from said packet processing unit to said second assigned channel;
said first assigned channel being connected to a central signal processing unit, and said second assigned channel being connected to a packet switched data unit.
The invention will now be further explained by way of example with reference to a block-schematic circuit diagram of a digital telephone exchange using the invention, with reference to the accompanying figures in which:
Figure 1 is a block schematic circuit diagram -pa-I
Pi 10 160 -3- 3~3-1982 of a digital telephone exchange using the invention.
Fig 2 shows an embodiment of' a subscriber line interface circuit for use in the exchange shown in Fig/ 1.
6 the digital telephone exchange to which the invention relates comprises a plurality of peripheral control domains (POD) oil which, the domains 301 and 304 are connected to a digital try network DUN as shown in Fig. 1, In this Figure the domain 301 is shown in greater detail. Digital subscriber sets (SO) are connected to this domain. lye subscriber sets are di~idcd into groups and -each group is connected -to a digital subscriber interface unit (DSI). The two groups of subscriber sets I owe 15 and 49~ owe which are connected to the respective inter-face units 201 and 204 by means of the subscriber lines 401 9 402, r ~416 and 449. D owe are shown in the Figure.
In the interlace units the subscriber lines terminate on subscriber line interface circuits Slicks In the interlace unit 201 whey are the Slicks 101, 102,...1 16 9 The interface units (DSI) of each individual domain (POD) are connected to a peripheral domain time switching network (PUS) via multiple main paths. Thus, in the figure the interface units 201 and 204 are con netted to the time switching network (PUS) via the multi pled main paths 501 and 5040 In addition a signaling auxiliary unit (SWISS
a peripheral domain controller (PDC) and a digital domain interface (DID) are connected to the time switching net ED work (PUS) via one or more-multiplex main paths. The domain interface units (DID) serve as connections to other domains (POD).
The interface units (DID) of different domains (POD) are connected to the digital trunk network DO
I pa multiplex main paths. In the Fuller, -the interface nutted) of the domain 301 is connected to the digital trunk network (DUN) via the multiplex main paths 601 to 60l~, inclusive. For the domain 304 this connection is i I 3 39 pi 160 ~~~ 3-3-1982 effected via main paths such as 6-13.
A central control unit OCCUR which serves inter aria as a central signal processing unit for the signally is connected to the digital trunk network (DUN).
For smaller exchanges the domain interface units (Dyes) may be interconnected directly and connected directly to the central control unit (CCU).
The digital speech signal transmission from subscriber sets (SO) to the exchange and vice errs is effected at a standardized transmission rate of 64 kb/s.
in PAM Norm in a Bunnell of the subscriber lines.
The multiplex main paths such as 501~..504 coy prows for example, thirty-two 64 kb channels and con-sequently have a processing speed of 2.048 kb/sec., designated 2 Mb/sec~ in the further course of the description.
In addition -to speech signals, circuit-switched data streams may be transmitted from the subscriber sets to the exchange and vise versa. This transmission is effected at a standardized transmission rate of o/8/64 kb/sec. in a subscriber line b' channel allocated thereto.
For packet-switched data use is made on a sub-scriber line of a delta channel ( ) with a standardized transmission rate of 8/64 kb/so Inter aria thy telephony signaling signals(s) are accommodated in this -channel. For other forms of data such as telemetry data (t) and "slow" data (d) such as Teletext and View data, they may also be aecommodat-Ed in the channel The peripheral domain controller (PDC) and further interface equipment are then heavily loaded by the slow data traffic, which has a high call rate and a very short holding period or a low call rate and a very long holding period compared with the normal telephone traffic. This may cause congestion for normal telephone traffic.
To obviate this the subscriber line interface circuit (SLIT) is, in accordance with the invention of a construction as shown in Fig. 2 and a packet-switched data Ply 10 l60 -I 3-3-1982 unit (DSU) is connected to -the digital trunk network (DIN). In addition, a data reduction unit (DRY) may be incorporated in the peripheral domain controller (PDC) in order to limit the data traffic to the data unit (DSU) as much as possible The subscriber line interface circuit shown in Fig. 2 comprises in customary manner a line transmission circuit (LO) connected to the subscriber line 401, this line transmission circuit providing the transmission facility for the two-way channels b, d' and .
An adaptation circuit 165 it arranged for adapting the speed between the channels on the telephone __ .
line 401 and the exchange.
The transmission over the subscriber line is effect-Ed in frames in which bits for the channels b, b' and are transmitted in groups.
Complete frames are exchanged between the adaptation circuit 165 and a buffer 1660 The information from the -channel of an incoming frame is identified in the buffer 166 and applied to a packet processing unit (PUP) which comprises means to divide the packets firstly into signaling information (so and secondly into telemetry data and slow data (dot). The unit POW) also comprises means fox combining per subscriber line the signaling information(s) obtained from the time-di~ision multiplex line (main line 501) and telemetry and slow data (ted) into one packet-switched data signal and for the trays-mission of the signaling information (s) from and to a first fixedly assigned channel of the time division mull triplex line (main line 501) of the relevant group of subscriber lines and or the transmission of the telemetry data and the slow data from and to a second fixedly assigned channel of the said time-division multiplex line (main line 501)~
More particularly, the packet processing unit (PUP) comprises a processor (up), for example a Z-8000, a random access memory (RAM) and the controllers us 174~ 175 and 176, for example a Signetics 2652, Pi 10 160 -6- 3-3-1982 mutually interconnected by a bus 177~
to information obtained prom the -channel is split in the mu troller 174 into signaling inform motion (s) and telemetry data and slow data (ted') and stored per -type of information (s) or (ted') in the store (RAM). When the total information of a signaling message(s) has been stored in the store (ROY) the mu-controller 175 investigates whether a special signalizing channel (s), denotes the first charnel, on the main path 501 is free, which channel is represented in the Figures by a broken line. The appearance ox the signalli~g channel (s) on the main path 501 is reported to the controller 175 by a register 170, in which the chclnnel number of the signaling channel (s) is stored. A time-channel counter 171 which counts the channels in a frame which appear on the main path 501 is connected to the register 170. If there is agreement between the channel number in the time channel counter 171 and the channel number in the register 170, and this signaling channel is free, the signaling message stored in the memory (RAM) is fed into this 64 sub signaling channel (s) at a rate of 2 My sea by the controller 1750 Likewise, the total inure formation of a telemetry message (t) and the total in-formation of the slow data message (do) is stored in the (RAM). When a complete telemetry message (t) or a complete slow data message (d') is present in the memory (RAM) the controller 176 investigates whether a second channel specially assigned to telemetry data and slow data (tldl) it tree, which channel is represented in the figures by a dot~and-dash lingo the controller 176 receives the information on the occurrence of the said tot channel from a register 169, which is also connected to the time channel counter 171. The register 169 operates in a similar manner as register 170. When there is agree-mint between the channel number in the time-channel counter 171 and the channel number in the register 169, and the to channel is free, the -telemetry data message (t) and the slow data message (d') stored in the memory (ROY) 10 l60 I 3-3-l982 is fed into this 64 kb(t-~cl') channel at a rate of 2Mb~sec.
The use of the registers such as i69 and 170 render i-t possible to realize a flexible allocation of commons) and (ted') channels on the main path 5010 By extending the number of registers it is possible to allocate several separate (s) and (ted') channels in a flexible marker.
The packet processing I t (PUP) it not only arranged for transmitting in separate channels (s) and to of the main path 501 the signaling information and the telemetry data in combination with the slow data coming from the -charnel of the subscriber lines 9 but this unit is also arranged for assembling the information present in the separate channels(s) and (ted') of the main path 501 intended for the relevant subscriber set into one packet-switched data signal for transmission in the -channel in the subscriber line 401~
For -that purpose the controllers 176 and 175 investigate, at the instants indicated by the registers 169 and 170 of the occurrence ox the (ted') channel and the channel of the main path 501, whether telemetry data or slow data and signaling information are present for the relevant subscriber. If such information occurs the mu controller 175 and 176 9 respectively write this information into the memory (RAM). Under the control of the processor (up) this information is assembled in controller 174 to form packets of (s) (ted') inform motion. As soon as such as packet has been assembled this packet it fed into the A channel of the subscriber lone ~01 by the controller 174 via the frame buffer 166, the adaptation circuit 165 and the line transmission circuit (LO). The speech signals (b) and circuit-switched data (by), respectively which are separated in the buffer 166 are applied to the respective gate circuits 172 and 173 via the respective separate lines b and b'. These gate circuits are controlled by registers 167 and 168 which are both connected to the channel counter 170. random I
PUN 10 owe -8 3-3-1982 charnels of the main path 501 are assigned to the aegis-lens; this is shown in the Figures by means ox a solid line. At the occurrence of the channel of the outgoing annuls on the main path 501 allocated to the speech signals, the gate circuit 172 is open and the speech signal information (b) contained in the frame buffer 166 is applied to this 64 kb channel at a rate of 2 ~b/sec.
Likewise, at the occurrence of a channel (buff the out-going channels on the main path 501 allocated to the circus switched data (by), the gate circuit 173 is open and the data information (by) contained in the buffer 166 is applied to that channel in a similar manner.
At the occurrence of channels belonging to this group of incoming channels on the main path 501, fixedly - 15 adjusted per connection to the relevant subscriber the gate circuits 172 and 173 are open in a correspond-in manner for applying speech signals o'er the line b and circuit-switched data over the line d' from the main path 501 to the buffer 166 at a rate of 2 Mb/sec. via the adaptation circuit 165 and the line transmission circuit LO these speech signals and circuit-switched data are applied to the subscriber line 401 at the associated low bit ratio It should be noted that, instead of connecting it to a gate circuit 173, it is alternatively possible to connect the line b' connected to the buffer 166 to a further mu controller in the packet processing unit (PUP). It is then possible to put the information in the channel of the subscriber line 401 on the special (s) and to channels of the main path 501 and vice versa, if so desired.
As shown in Fig. 1, in this embodiment the channels in Welch (b) and (by) information is present on the main path 501 are switched-through via the peripheral domain time switching network (PUS) to the domain interface unit (DID) where they are interconnected in a one-by-one configuration to channels of a time division multiplex main path 601 which are connected via 99~
Pi lo owe I 3-3-1982 the digital trunk network (DUN) and the time-division multiplex main path 613 to the peripheral control domain 304 for directly exchangiIlg speech signals and circuit-switched data between these peripheral control domains 301 and 304.
The special signaling channel (s) and the special telemetry data and low data channel (ted') are connected in this embodiment, each one individually via the domain time switching network (PUS), to the data reduction unit (DRY) provided in the peripheral domain controller (PDC). This data reduction unit (DRY) is a dynamic multiplexer which concentrates the information present in the special signaling channels (s) of several subscriber interface units (DSI) and applies this con-cent rated signaling information (so to the interface unit DOW) via at least one semi-permanent channel of the time switching network (PUS). From this interface 11n1t (DID) the concentrated signaling information (s) is applied vi at least one special semi-permanent channel in the time-division multiplex main path 601 via the digital trunk network (DUN) to a central signaling processing Nat, not shown in the central control unit CCU of the telephone exchange and processed there. Signaling inure-motion (s) which must be applied to a subscriber interface unit (DSI) by the central control 11n;t OCCUR is applied via the digital trunk network DO the main path 601 and the interface unit (DID) of the peripheral control domain 301 and the peripheral domain time switching network (PUS) to the data reduction unit (DRY) from where this signaling information (s) is distributed. This signaling information (s) is than applied to the relevant main path 501 via the peripheral domain switching network (PUS).
The telemetry data and slow data in the special channels to obtained from several subscriber interface units (DSI) are also concentrated in the data reduction unit (DRY) anal applied to the interface unit (DID) it at least one semi-permanent channel of the time switchiIlg network (PUS). From this interface unit (DID) the I
Pi 10 owe -10- 3-3 19~2 concentrated telemetry data and slow data information (ted') are applied via a-t least one special semi-permanent Shelley in th~time-division multiplex main path 601 via toe digital trunk network (DUN) to the packet-switched data unit (DSU) as processed there.
Telemetry data information and slow data to to be applied to a subscriber interface unit (DSI) by the data unit (DSU) are applied via the digital -trunk network (DUN), thy main path ~01 and the interface unit (DID) of the peripheral domain 301 and the peripheral domain -time switching network (PUS) to the data reduction unit (DOW) where this information (ted') is distributed.
Thereafter it is applied to the relevant main path 501 via the peripheral domain switching network PUS
As will be apparent from the above description the central control unit OCCUR of the telephone exchange does not have the task of processing packet-switched data such as telemetry data (t) and/or low data (do) but these packet-switched data are processed in a separate packet-switched data exchange Thus, congestion in the control unit OCCUR due to these data is prevented from occurring a In addition the signaling information (so and telemetry data information and slow data (t~dl~ are transmitted over separate semi-permanent channels within the telephone exchange. This prevents congestion of speech and signaling information (s) due to telemetry data and slow data (ted') from occurring during this transmission.
Furthermore, because of the provision of a data reduction unit the number of channels required in the time-division multiplex main paths between the mutually interconnected peripheral domain units Pus and the further equipment for transmitting signaling information (s) and telemetry data and slow data to is very small
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A digital telephone exchange for connecting a plurality of digital subscriber sets to a time division multiplex transmission line, said subscriber sets and time division multiplex transmission line transmitting and receiving circuit switched data signals, and packet switched data signals which include signalling information, telemetry data and slow data, comprising;
a plurality subscriber line interface circuit for connecting each of said plurality of digital subscriber sets to said time division multiplexed transmission line comprising;
means for identifying the packet switched data signals from said subscriber sets;
a packet processing unit connected to receive said identified packet switched data, said unit including means for dividing the packet into signalling information, and into telemetry data and slow data;
means for combining for each subscriber set the signalling information, telemetry data and slow data received from said time division multiplex transmission line to form one packet switched data signal; and means for transmitting telemetry data and slow data to said means for combining from a second assigned channel of said time multi-plexed transmission line, and from said processing unit to said second assigned channel of said multiplexed transmission line, and for trans-mitting said signalling information to said means for combining from a first assigned channel of said time multiplexed transmission line, and from said packet processing unit to said second assigned channel;
said first assigned channel being connected to a central signal processing unit, and said second assigned channel being connected to a packet switched data unit.
a plurality subscriber line interface circuit for connecting each of said plurality of digital subscriber sets to said time division multiplexed transmission line comprising;
means for identifying the packet switched data signals from said subscriber sets;
a packet processing unit connected to receive said identified packet switched data, said unit including means for dividing the packet into signalling information, and into telemetry data and slow data;
means for combining for each subscriber set the signalling information, telemetry data and slow data received from said time division multiplex transmission line to form one packet switched data signal; and means for transmitting telemetry data and slow data to said means for combining from a second assigned channel of said time multi-plexed transmission line, and from said processing unit to said second assigned channel of said multiplexed transmission line, and for trans-mitting said signalling information to said means for combining from a first assigned channel of said time multiplexed transmission line, and from said packet processing unit to said second assigned channel;
said first assigned channel being connected to a central signal processing unit, and said second assigned channel being connected to a packet switched data unit.
2. The digital telephone exchange of claim 1, further comprising a data reduction unit connected between the second fixedly assigned channels and the packet-switched data unit.
3. The digital telephone exchange of claim 1 wherein said means for transmitting information to and from said assigned channels com-prises;
recording means for recording channel numbers;
a time channel counter;
means for comparing the contents of said time channel counter and of said recording means; and means for initiating transmission of said signalling information and telemetry data and slow data between said assigned channels and said subscriber line interface circuit when said means for comparing indicates said time channel counter and recording means have the same contents.
recording means for recording channel numbers;
a time channel counter;
means for comparing the contents of said time channel counter and of said recording means; and means for initiating transmission of said signalling information and telemetry data and slow data between said assigned channels and said subscriber line interface circuit when said means for comparing indicates said time channel counter and recording means have the same contents.
4. The digital telephone exchange of claim 1 further comprising a time switching network connected between said subscriber line inter-face circuit and said time division multiplex transmission line, said switching network having terminals connected to receive and transmit signals to a signalling auxiliary unit, and to receive and transmit signals to a digital domain interface.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL8104368A NL8104368A (en) | 1981-09-23 | 1981-09-23 | DIGITAL TELEPHONE CONTROL PANEL WITH DEVICES FOR HANDLING PACKAGE-SWITCHED DATA. |
| NL8104368 | 1981-09-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1189939A true CA1189939A (en) | 1985-07-02 |
Family
ID=19838105
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000411778A Expired CA1189939A (en) | 1981-09-23 | 1982-09-20 | Digital telephone exchange comprising means for processing packet-switched data |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4486878A (en) |
| EP (1) | EP0075998B1 (en) |
| JP (1) | JPS5863287A (en) |
| CA (1) | CA1189939A (en) |
| DE (1) | DE3264568D1 (en) |
| NL (1) | NL8104368A (en) |
Families Citing this family (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU570983B2 (en) * | 1983-05-04 | 1988-03-31 | Cxc Corp. | Digital tdm microtelephone system |
| DE3316492A1 (en) * | 1983-05-05 | 1984-11-08 | Siemens AG, 1000 Berlin und 8000 München | CIRCUIT ARRANGEMENT FOR THE SUBSCRIBER CONNECTION IN A SERVICE-INTEGRATING DIGITAL NETWORK (ISDN) |
| DE3316470A1 (en) * | 1983-05-05 | 1984-11-08 | Siemens AG, 1000 Berlin und 8000 München | CIRCUIT ARRANGEMENT FOR A SUBSCRIBER CONNECTION IN A SERVICE-INTEGRATING DIGITAL NETWORK (ISDN) |
| DE3318290A1 (en) * | 1983-05-19 | 1984-11-22 | Siemens AG, 1000 Berlin und 8000 München | TELECOMMUNICATION SYSTEM BOTH FOR STREAM TRAFFIC AND BURST TRAFFIC |
| DE3318814A1 (en) * | 1983-05-24 | 1984-11-29 | Siemens AG, 1000 Berlin und 8000 München | TELECOMMUNICATION SYSTEM BOTH FOR STREAM TRAFFIC AND BURST TRAFFIC |
| DE3319106A1 (en) * | 1983-05-26 | 1984-11-29 | Siemens AG, 1000 Berlin und 8000 München | TELECOMMUNICATION SYSTEM CONNECTED TO AN INFORMATION PROCESSING SYSTEM |
| DE3405011C1 (en) * | 1984-02-13 | 1989-03-16 | Telefonbau Und Normalzeit Gmbh, 6000 Frankfurt | Circuit arrangement for operating two-wire digital connection and/or junction lines on a telecommunications switching system |
| US4596010A (en) * | 1984-05-03 | 1986-06-17 | At&T Bell Laboratories | Distributed packet switching arrangement |
| US4592048A (en) * | 1984-05-03 | 1986-05-27 | At&T Bell Laboratories | Integrated packet switching and circuit switching system |
| GB8425375D0 (en) * | 1984-10-08 | 1984-11-14 | Gen Electric Co Plc | Data communication systems |
| JPH0628361B2 (en) * | 1984-11-27 | 1994-04-13 | 国際電信電話株式会社 | Packet exchange method |
| US4737950A (en) * | 1985-05-31 | 1988-04-12 | Rockwell International Corp. | Multifunction bus to user device interface circuit |
| US4723238A (en) * | 1986-03-24 | 1988-02-02 | American Telephone And Telegraph Company | Interface circuit for interconnecting circuit switched and packet switched systems |
| US4760570A (en) * | 1986-08-06 | 1988-07-26 | American Telephone & Telegraph Company, At&T Bell Laboratories | N-by-N "knockout" switch for a high-performance packet switching system |
| US4754451A (en) * | 1986-08-06 | 1988-06-28 | American Telephone And Telegraph Company, At&T Bell Laboratories | N-by-N "knockout" switch for a high-performance packet switching system with variable length packets |
| US5740156A (en) * | 1986-09-16 | 1998-04-14 | Hitachi, Ltd. | Packet switching system having self-routing switches |
| US6005867A (en) * | 1986-09-16 | 1999-12-21 | Hitachi, Ltd. | Time-division channel arrangement |
| CA1292053C (en) * | 1986-09-16 | 1991-11-12 | Yoshito Sakurai | Time-division channel arrangement |
| US7058062B2 (en) * | 1986-09-16 | 2006-06-06 | Hitachi, Ltd. | Packet switching system having self-routing switches |
| DE3738177A1 (en) * | 1987-11-10 | 1989-05-18 | Siemens Ag | INTERMEDIATE NODE FOR THE INTERMEDIATE OF DATA SIGNALS TRANSMITTED IN DATA PACKAGES |
| CA1278121C (en) * | 1987-12-23 | 1990-12-18 | Michael H. Reichmann | Data communication system |
| JPH0612912B2 (en) * | 1988-07-26 | 1994-02-16 | 株式会社大興電機製作所 | Remote monitoring system in ISDN |
| FR2637751A1 (en) * | 1988-10-07 | 1990-04-13 | Trt Telecom Radio Electr | INFORMATION REWARDING DEVICE FOR TRANSMITTING INTO OUTSTANDING TIME MULTIPLEX INFORMATION FROM MULTIPLEX ASYNCHRONOUS INPUT TEMPORALS |
| US5058111A (en) * | 1989-06-19 | 1991-10-15 | Oki Electric Industry Co., Ltd. | Subscriber line interface circuit in a switching system |
| FI83007C (en) * | 1989-10-05 | 1991-05-10 | Nokia Data Systems | Digital data transfer system |
| CH680101A5 (en) * | 1989-12-19 | 1992-06-15 | Alcatel Str Ag | |
| DE4205554C1 (en) * | 1992-02-24 | 1992-12-24 | Siemens Nixdorf Informationssysteme Ag, 4790 Paderborn, De | |
| JP2596346B2 (en) * | 1993-11-29 | 1997-04-02 | 日本電気株式会社 | LAN connection device |
| JP3247540B2 (en) * | 1994-05-12 | 2002-01-15 | 株式会社日立製作所 | Packetized communication device and switching device |
| CA2883494C (en) | 2012-08-31 | 2021-08-24 | 3M Innovative Properties Company | Multi-functional compositions comprising a hydrophilic silane |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS585541B2 (en) * | 1978-05-08 | 1983-01-31 | 富士通株式会社 | Packet transmission method |
| JPS6038064B2 (en) * | 1980-01-28 | 1985-08-29 | ケイディディ株式会社 | Line packet complex switching method |
| FR2475827B1 (en) * | 1980-02-13 | 1987-05-29 | Dauphin Jean Louis | TIME DIVISION DIGITAL SWITCHING SYSTEM FOR MICROPHONE VEHICLES SPEAKING AND PACKET DATA |
| JPS577656A (en) * | 1980-06-17 | 1982-01-14 | Nec Corp | Packet and circuit combined exchange system |
| US4408323A (en) * | 1981-06-29 | 1983-10-04 | Bell Telephone Laboratories, Incorporated | Processor facilities for integrated packet and voice switching |
-
1981
- 1981-09-23 NL NL8104368A patent/NL8104368A/en not_active Application Discontinuation
-
1982
- 1982-08-16 US US06/408,339 patent/US4486878A/en not_active Expired - Fee Related
- 1982-09-20 CA CA000411778A patent/CA1189939A/en not_active Expired
- 1982-09-20 JP JP57163791A patent/JPS5863287A/en active Granted
- 1982-09-22 DE DE8282201178T patent/DE3264568D1/en not_active Expired
- 1982-09-22 EP EP82201178A patent/EP0075998B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5863287A (en) | 1983-04-15 |
| US4486878A (en) | 1984-12-04 |
| EP0075998B1 (en) | 1985-07-03 |
| JPH0552119B2 (en) | 1993-08-04 |
| NL8104368A (en) | 1983-04-18 |
| DE3264568D1 (en) | 1985-08-08 |
| EP0075998A1 (en) | 1983-04-06 |
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