Wireless access telephone-to-telephone network interface architecture

• US 5,305,308 A
• Filed: 10/29/1992
• Issued: 04/19/1994
• Est. Priority Date: 07/09/1991
• Status: Expired due to Term

• Current Assignee: Windward Corp. (Avaya Incorporated)
• Original Assignee: AT&T, Inc.
• Inventors: Smith, Michael A., Miller, Paul E., Heidebrecht, Richard M., Hearn, Michael L., Mulberg, Alan S., Spencer, Douglas A., Windhausen, Richard A., Kissel, David M., Miller, Richard D., Thompson, John S., Farwell, Charles Y., English, Michael J.
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): BLUM, RUSSELL
• Application Number:
  US07/968,559
• Time in Patent Office: 537 Days
• Field of Search: 370/60, 370/60.1, 370/94.1, 370/94.2, 370/95.3, 370/32.1, 370/85.1, 370/85.9, 379/59, 455/33.1
• US Class Current: 370/335
• CPC Class Codes: H04J 3/0632 Synchronisation of packets and cells, e.g. transmission of voice via a packet network, circuit emulation service [CES] queuing arrangements in packet switching elements H04L49/90; synchronising systems for the synchronous transmission of a pulse code modulated video signal with one or more other pulse code modulated signals H04N7/56
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection

Abstract

A wireless-access communications system, such as a CDMA cellular radio-telephone system (FIG. 2), comprises a packet-switched communications network (202, 207, 201) that interconnects cells (base stations; 202) with each other and with the public telephone network (100). Traffic of individual calls is packetized, and packet-bearing frames (300 in FIG. 7) of a plurality of calls are then statistically multiplexed and frame-relayed through the network to yield the high capacity, efficiency, and speed of traffic transport and handoff required for a CDMA cellular system. At each call processing unit (264 in FIG. 5), individual calls are handled by individual service circuits (602 & 612) which perform speech-processing functions such as coding and decoding, tone insertion, and echo cancellation, and packet-to-circuit-switched-PCM traffic conversion. Processors (602) adapt call processing unit timing to compensate for asynchrony between cells and call processing units and variations in call path transmission delays. Cell-to-cell communications, fixed call path addressing, and packetized control message transfers ensure that the same service circuit handles a call through even multiple soft handoffs (FIGS. 27-29) and efficiently communicates simultaneously with all cells involved in the handoff without involvement of system control entities and negative effect on system call-handling capacity. Both coded (packet-switched) and uncoded (circuit-switched) radio-telephone traffic are accommodated side-by-side. Wherever possible, existing and proven technology and component units are used to achieve low cost and high reliability.

Claims

1. A cell interconnect module for transferring call traffic between cells and a switching system in a radio-telephone communications system, the module comprising:

a packet transmission bus;

at least one time-division-multiplexed (TDM) communications link interface connected to the bus, each for time-division-demultiplexing packets carrying voice call traffic generated by a plurality of radio telephones and received from a cell in incoming time slots of a TDM communications link and transmitting the received demultiplexed packets on the bus, and for receiving on the bus packets carrying voice call traffic destined for radio telephones served by the cell which is connected to the TDM communications link and time-division-multiplexing the received packets into outgoing time slots of the TDM communications link; and

at least one packet communications link interface connected to the bus, each for transmitting on the bus packets received in statistically-multiplexed form from a switching system on a packet communications link, and for receiving on the bus packets destined for the switching system which is connected to the packet communications link and transmitting the received packets on the packet communications link in statistically-multiplexed form.

2. The cell interconnect module of claim 1 wherein

the TDM communications link interfaces and the packet communications link interfaces each frame-relay received packets in both directions of transmission.

3. The cell interconnect module of claim 1 wherein:

each TDM communications link interface time-division-demultiplexes packets carrying compressed call traffic generated by digital radio telephones and received from a cell in first incoming time slots of the TDM communications link, and receives on the bus packets carrying compressed call traffic destined for digital radio telephones and time-division-multiplexes the packets received on the bus into first outgoing time slots of the TDM communications link, and

each packet communications link interface transmits packets on the bus to the at least one TDM communications link interface and receives packets on the bus from the at least one TDM communications link interface; and

the cell interconnect module further comprising

a time-division-multiplexed (TDM) bus defining a plurality of time slots,

at least one first circuit-switching interface means connected to the TDM bus and each for time-slot-interchanging noncompressed call traffic generated by a second radio telephone and received from the cell and carried in second incoming time slots of the TDM communications link into first time slots of the TDM bus, and for time-slot-interchanging noncompressed call traffic destined for the second radio telephone served by the cell and carried in second time slots of the TDM bus into second outgoing time slots of the TDM communications link, and

at least one second circuit-switching interface means connected to the TDM bus and each for transmitting call traffic, received on a circuit-switched communications link, on the TDM bus in the second time slots, and for transmitting call traffic, received on the TDM bus in the first time slots, on the circuit-switched communications link.

4. A switching system for conveying radio-telephone call traffic to and from cells over communications links in a radio-telephone communications system, the switching system being for connection to a plurality of communication channels of a telephone network that is connected to the radio-telephone communications system, each channel for carrying traffic of an individual call, and the switching system including:

a packet transmission bus;

a time-division-multiplexed (TDM) bus defining a plurality of time slots;

a plurality of packet communications link interface means connected to the packet transmission bus and each for receiving from the packet transmission bus packets carrying outgoing voice call traffic destined for radio telephones served by a cell and transmitting the received packets on a packet communications link to the cell in statistically-multiplexed form, and for transmitting on the packet transmission bus packets received in statistically-multiplexed form on the link and each carrying incoming traffic of a voice call from a radio telephone;

a plurality of call-handling means each connected to the packet transmission bus and to the TDM bus, each for handling a different call and responsive to receipt of outgoing voice call traffic of the handled call on the TDM bus in first time slots assigned to the handled call for packetizing the received outgoing call traffic and transmitting the packets at regular intervals on the packet transmission bus, and for receiving at regular intervals on the packet transmission bus packets carrying incoming voice call traffic of the handled call and for depacketizing and transmitting the incoming call traffic on the TDM bus in second time slots assigned to the handled call; and

at least one channel interface means connected to the TDM bus, each responsive to receipt from a communication channel of a telephone network of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the TDM bus in first time slots that are assigned to the call, and responsive to receipt of incoming call traffic of an individual call on the TDM bus in second time slots that are assigned to the individual call for transmitting the received incoming call traffic on the communication channel of the telephone network that carries traffic of that call.

5. The switching system of claim 4 wherein:

each packet communications link interface means transmit and receive packets carrying encoded call traffic; and

each call-handling means include

means responsive to receipt of outgoing call traffic of the handled call on the TDM bus for encoding the received call traffic prior to transmission thereof in packets on the packet transmission bus, and responsive to receipt of packets carrying encoded incoming call traffic for decoding the encoded traffic prior to transmission thereof on the TDM bus.

6. The switching system of claim 4 for use in a radio-telephone communications system wherein a plurality of the cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone,

each call-handling means including:

means responsive to receipt on the TDM bus of outgoing call traffic destined for the one mobile radio telephone, for transmitting packets each carrying a copy of the outgoing traffic of the call to each one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving packets carrying incoming traffic of the call from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, and selecting only one of the received copies of the incoming traffic for transmission on the TDM bus.

7. The switching system of claim 4 for use in a radio-telephone communications system wherein a plurality of the cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone,

each call-handling means including:

means responsive to receipt on the TDM bus of outgoing call traffic of the handled call destined for the one mobile radio telephone for replicating the received outgoing call traffic, packetizing each replica of the outgoing call traffic, and addressing the packets of each replica to a different one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving packets carrying incoming call traffic of the handled call from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, depacketizing the packets received from the different cells, and selecting only one of the depacketized copies of the incoming traffic for transmission on the TDM bus.

8. The switching system of claim 4 wherein:

each packet communications link interface means transmit and receive packets carrying blocks of encoded call traffic; and

each call-handling means include

first means connected to the packet transmission bus for receiving from the packet transmission bus first packets each carrying a block of coded traffic for a call incoming from a radio telephone and for transmitting on the packet transmission bus second packets each carrying a block of coded traffic for the call outgoing to the radio telephone,

second means connected to the first means for depacketizing first packets received by the first means and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic, packetizing the individual blocks to form second packets, and outputting the second packets to the first means,

third means connected to the second means for decoding the blocks of coded incoming call traffic output by the second means to generate an output stream of incoming call traffic, and for coding a received input stream of outgoing call traffic into blocks of coded outgoing call traffic for receipt by the second means, and

fourth means connected to the TDM bus and to the third means for transmitting the output stream of incoming call traffic generated by the third means in first time slots assigned to the call on the TDM bus, and for receiving the input stream of outgoing call traffic in second time slots assigned to the call on the TDM bus and supplying the received stream to the third means.

9. The switching system of claim 4 wherein:

each packet communications link interface means transmit and receive packets carrying blocks of encoded call traffic; and

a plurality of the call-handling means comprise

first means for receiving from the packet transmission bus first packets each carrying a block of coded traffic incoming from radio telephones for any one of a plurality of calls, and for transmitting on the packet transmission bus second packets each carrying a block of coded traffic outgoing to radio telephones for any one of the plurality of calls,

second means connected to the first means for depacketizing first packets received by the first means and each carrying a block of coded incoming call traffic for a different one of the calls and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic each for a different one of the calls, packetizing the individual blocks to form second packets, and outputting the second packets to the first means,

a plurality of third means connected to the second means, each for decoding the blocks of coded incoming call traffic output by the second means for an individual one of the calls to generate an output stream of incoming call traffic for the call, and for coding a received input stream of outgoing call traffic for the individual call into blocks of coded outgoing call traffic for the one call for receipt by the second means, and

fourth means connected to the TDM bus and to the plurality of the third means for transmitting the output streams of incoming traffic of the individual calls generated by the plurality of third means in first time slots of the TDM bus which are assigned to the individual calls and for receiving input streams of outgoing call traffic for the individual calls in second time slots of the TDM bus which are assigned to the individual calls and supplying the received streams to the plurality of the third means.

10. The switching system of claim 4 wherein

each packet communications link interface frame-relays received packets in both directions of transmission.

11. The switching system of claim 4 further comprising:

a plurality of packet communications links each connected to a different packet communications link interface;

a second packet transmission bus;

at least one second packet communications link interface each connected to a packet communications link and to the second packet transmission bus, each for transmitting on the second packet transmission bus packets received in statistically-multiplexed form on the connected packet communications link, and for receiving on the second packet transmission bus packets destined for the connected packet communications link and transmitting the received packets on the connected packet communications link in statistically-multiplexed form; and

at least one time-division-multiplexed (TDM) communications link interface connected to the second packet transmission bus, each for time-division-demultiplexing packets carrying call traffic generated by a plurality of radio telephones and received from a cell in incoming time slots of a TDM communications link and transmitting the received demultiplexed packets on the second packet transmission bus, and for receiving on the second packet transmission bus packets carrying call traffic destined for radio telephones served by the cell which is connected to the TDM communications link and time-division-multiplexing the received packets into outgoing time slots of the TDM communications link.

12. The switching system of claim 11 wherein

each TDM communications link interface time-division-demultiplexes packets carrying compressed call traffic generated by digital radio telephones and received from a cell in first incoming time slots of the TDM communications link, and receives on the second packet transmission bus packets carrying compressed call traffic destined for digital radio telephones and time-division-multiplexes the packets received on the second packet transmission bus into first outgoing time slots of the TDM communications link, and

each second packet communications link interface transmits packets on the second packet transmission bus to the at least one TDM communications link interface and receives packets on the second packet transmission bus from the at least one TDM communications link interface;

and

the switching system further comprises

a plurality of circuit-switched communications links,

a second time-division-multiplexed (TDM) bus defining a plurality of time slots,

at least one first circuit-switching interface means connected to the second TDM bus and each for time-slot-interchanging noncompressed call traffic generated by a second radio telephone and received from the cell in second incoming time slots of the TDM communications link into first time slots of the second TDM bus, and for time-slot-interchanging noncompressed call traffic destined for the second radio telephone served by the cell and carried in second time slots of the second TDM bus into second outgoing time slots of the TDM communications link,

at least one second circuit-switching interface means connected to the second TDM bus and to the circuit-switched communications links and each for transmitting call traffic received on a circuit-switched communications link on the second TDM bus in second time slots assigned to the second circuit-switching interface, and for transmitting on the circuit-switched communications link call traffic received on the second TDM bus in first time slots assigned to the second circuit-switching interface,

at least one third link,

switching means connected to the circuit-switched communications links and to the at least one third link, for interconnecting the circuit-switched communications links with the at least one third link, and

at least one third-link interface means connected to the first TDM bus and each further connected to a different third link, each for transmitting call traffic received on the connected third link on the first TDM bus in third time slots assigned to the third-link interface means, and for transmitting on the connected third link call traffic received on the first TDM bus in fourth time slots assigned to the third-link interface means; and

wherein

each channel interface means is responsive to receipt from a connected channel of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the first TDM bus either (a) in first time slots that are assigned to the call-handling means that are handling the call or (b) in fourth time slots assigned to the third-link interface means whose connected third link carries call traffic of the call, and responsive to receipt of incoming call traffic of an individual call on the first TDM bus either (c) in second time slots that are assigned to the call-handling means that are handling the individual call or (d) in third time slots assigned to the third-link interface means whose connected third link carries call traffic of the call, for transmitting the received incoming call traffic on the connected channel that carries traffic of that call.

13. A radio-telephone-call processing apparatus comprising:

first means for receiving at regular intervals from a packet transmission medium first packets each carrying a block of coded voice traffic for an individual call incoming from a radio telephone and for transmitting at regular intervals on the packet transmission medium second packets each carrying a block of coded voice traffic for the individual call outgoing to a radio telephone;

second means connected to the first means for depacketizing the first packets received by the first means and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic, packetizing the individual blocks to form the second packets, and outputting the second packets to the first means;

third means connected to the second means for decoding the blocks of coded incoming call traffic output by the second means to generate an output stream of incoming call traffic, and for coding a received input stream of outgoing call traffic to generate the blocks of coded outgoing call traffic for receipt by the second means; and

fourth means connected to the third means for transmitting the output stream of incoming call traffic generated by the third means in first time slots that are assigned to the individual call on a time-division-multiplexed medium, and for receiving the input stream of outgoing call traffic in second time slots that are assigned to the individual call on the time-division-multiplexed medium and supplying the received stream to the third means.

14. The apparatus of claim 13 for use in a radio-telephone communications system wherein a plurality of the cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone, wherein

the second means include:

means responsive to receipt from the third means of a block of outgoing call traffic destined for the one mobile radio telephone for replicating the received outgoing call traffic, packetizing each replica of the outgoing call traffic, and addressing the packets of each replica to a different one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving from the first means packets carrying blocks of incoming call traffic from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, depacketizing the packets received from the different cells, and selecting only one of the depacketized copies of the incoming traffic for output to the third means.

15. The apparatus of claim 13 further comprising:

echo-canceling means connected between the third means and the fourth means for canceling echoes of the incoming call traffic from the received input stream of outgoing call traffic.

16. The apparatus of claim 13 further comprising:

fifth means connected between the third means and the fourth means for inserting signals representing tones into the output stream of incoming call traffic generated by the third means.

17. A radio-telephone-call processing apparatus comprising:

first means for receiving from a packet transmission medium first packets for a plurality of calls, the first packets for each individual call being received at regular intervals and each carrying a block of coded voice traffic incoming from a radio telephone for the individual call, and for transmitting on the packet transmission medium second packets for the plurality of calls, the second packets for each individual call being transmitted at regular intervals and each carrying a block of coded voice traffic outgoing to the radio telephone for the individual call;

second means connected to the first means for depacketizing the first packets received by the first means and each carrying a block of coded incoming call traffic for one of the calls and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic each for one of the calls, packetizing the individual blocks to form second packets, and outputting the second packets to the first means;

a plurality of third means connected to the second means, each for decoding the blocks of coded incoming call traffic output by the second means for a different individual one of the calls to generate an output stream of incoming call traffic for the individual one call, and for coding a received input stream of outgoing call traffic for the individual one call to generate blocks of coded outgoing call traffic for the individual one call for receipt by the second means; and

fourth means connected to the plurality of the third means for transmitting the output streams of incoming traffic for the individual calls generated by the plurality of third means in first time slots of a time-division-multiplexed medium, the output stream of incoming traffic for each individual one of the calls being transmitted in ones of the first time slots which are assigned to the individual one of the calls, and for receiving input streams of outgoing call traffic for the individual calls in second time slots of the time-division-multiplexed medium, the input stream of outgoing traffic for each individual one of the calls being received in ones of the second time slots which are assigned to the individual one of the calls, and supplying the received streams to the plurality of the third means.

18. The apparatus of claim 17 for use in a radio-telephone communications system wherein a plurality of the cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone, wherein

the second means include:

means responsive to receipt from the third means of a block of outgoing call traffic destined for the one mobile radio telephone for replicating the received outgoing call traffic, packetizing each replica of the outgoing call traffic, and addressing the packets of each replica to a different one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving from the first means packets carrying blocks of incoming call traffic from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, depacketizing the packets received from the different cells, and selecting only one of the depacketized copies of the incoming traffic for output to the third means.

19. The apparatus of claim 17 wherein

each third means comprises:

fifth means for substituting signals representing tones for selected portions of the output stream of incoming call traffic generated for the individual call.

20. The apparatus of claim 19 wherein

each third means further comprises:

echo-canceling means for canceling echoes of the incoming call traffic for the one call from the received input stream of outgoing call traffic for the one call.

21. A switching system for conveying radio-telephone call traffic to and from cells over communications links in a radio-telephone communications system wherein a plurality of the cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone, the switching system being for connection to a plurality of communication channels of a telephone network that is connected to the radio-telephone communications system, each channel for carrying traffic of an individual call, and the switching system including:

a packet transmission bus;

a time-division-multiplexed (TDM) bus defining a plurality of time slots;

a plurality of packet communications link interface means connected to the packet transmission bus and each for receiving from the packet transmission bus packets carrying outgoing voice call traffic destined for radio telephones served by a cell and transmitting the received packets on a packet communications link to the cell in statistically-multiplexed form, and for transmitting on the packet transmission bus packets received in statistically-multiplexed form on the link and each carrying incoming traffic of a voice call from a radio telephone;

a plurality of call-handling means each connected to the packet transmission bus and to the TDM bus, each for handling a different call and responsive to receipt of outgoing voice call traffic of the handled call on the TDM bus in first time slots assigned to the handled call for packetizing the received outgoing call traffic and transmitting the packets on the packet transmission bus, and for receiving on the packet transmission bus packets carrying incoming voice call traffic of the handled call and for depacketizing and transmitting the incoming call traffic on the TDM bus in second time slots assigned to the handled call, each call-handling means including

means responsive to receipt on the TDM bus of outgoing call traffic destined for the one mobile radio telephone, for transmitting packets each carrying a copy of the outgoing traffic of the call to each one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving packets carrying incoming traffic of the call from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, and selecting only one of the received copies of the incoming traffic for transmission on the TDM bus, and

at least one channel interface means connected to the TDM bus, each responsive to receipt from a communication channel of a telephone network of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the TDM bus in first time slots that are assigned to the call, and responsive to receipt of incoming call traffic of an individual call on the TDM bus in second time slots that are assigned to the individual call for transmitting the received incoming call traffic on the communication channel of the telephone network that carries traffic of that call.

22. A switching system for conveying radio-telephone call traffic to and from cells over communications links in a radio-telephone communications system wherein a plurality of the cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone, the switching system being for connection to a plurality of communication channels of a telephone network that is connected to the radio-telephone communications system, each channel for carrying traffic of an individual call, and the switching system including:

a packet transmission bus;

a time-division-multiplexed (TDM) bus defining a plurality of time slots;

a plurality of packet communications link interface means connected to the packet transmission bus and each for receiving from the packet transmission bus packets carrying outgoing voice call traffic destined for radio telephones served by a cell and transmitting the received packets on a packet communications link to the cell in statistically-multiplexed form, and for transmitting on the packet transmission bus packets received in statistically-multiplexed form on the link and each carrying incoming traffic of a voice call from a radio telephone;

a plurality of call-handling means each connected to the packet transmission bus and to the TDM bus, each for handling a different call and responsive to receipt of outgoing voice call traffic of the handled call on the TDM bus in first time slots assigned to the handled call for packetizing the received outgoing call traffic and transmitting the packets on the packet transmission bus, and for receiving on the packet transmission bus packets carrying incoming voice call traffic of the handled call and for depacketizing and transmitting the incoming call traffic on the TDM bus in second time slots assigned to the handled call, each call-handling means including

means responsive to receipt on the TDM bus of outgoing call traffic of the handled call destined for the one mobile radio telephone for replicating the received outgoing call traffic, packetizing each replica of the outgoing call traffic, and addressing the packets of each replica to a different one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving packets carrying incoming call traffic of the handled call from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, depacketizing the packets received from the different cells, and selecting only one of the depacketized copies of the incoming traffic for transmission on the TDM bus, and

at least one channel interface means connected to the TDM bus, each responsive to receipt from a communication channel of a telephone network of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the TDM bus in first time slots that are assigned to the call, and responsive to receipt of incoming call traffic of an individual call on the TDM bus in second time slots that are assigned to the individual call for transmitting the received incoming call traffic on the communication channel of the telephone network that carries traffic of that call.

23. A switching system for conveying radio-telephone call traffic to and from cells over communications links in a radio-telephone communications system, the switching system being for connection to a plurality of communication channels of a telephone network that is connected to the radio-telephone communications system, each channel for carrying traffic of an individual call, and the switching system including:

a packet transmission bus;

a time-division-multiplexed (TDM) bus defining a plurality of time slots;

a plurality of packet communications link interface means connected to the packet transmission bus and each for receiving from the packet transmission bus packets carrying blocks of encoded outgoing voice call traffic destined for radio telephones served by a cell and transmitting the received packets on a packet communications link to the cell in statistically-multiplexed form, and for transmitting on the packet transmission bus packets received in statistically-multiplexed form on the link and each carrying blocks of encoded incoming traffic of a voice call from a radio telephone;

a plurality of call-handling means each connected to the packet transmission bus and to the TDM bus, each for handling a different call and responsive to receipt of outgoing voice call traffic of the handled call on the TDM bus in first time slots assigned to the handled call for packetizing the received outgoing call traffic and transmitting the packets on the packet transmission bus, and for receiving on the packet transmission bus packets carrying incoming voice call traffic on the handled call and for depacketizing and transmitting the incoming call traffic on the TDM bus in second time slots assigned to the handled call; and

at least one channel interface means connected to the TDM bus, each responsive to receipt from a communication channel of a telephone network of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the TDM bus in first time slots that are assigned to the call, and responsive to receipt of incoming call traffic of an individual call on the TDM bus in second time slots that are assigned to the individual call for transmitting the received incoming call traffic on the communication channel of the telephone network that carries traffic of that call;

wherein

each call-handling means include

first means connected to the packet transmission bus for receiving from the packet transmission bus first packets each carrying a block of coded traffic for a call incoming from a radio telephone and for transmitting on the packet transmission bus second packets each carrying a block of coded traffic for the call outgoing to the radio telephone,

second means connected to the first means for depacketizing first packets received by the first means and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic, packetizing the individual blocks to form second packets, and outputting the second packets to the first means,

third means connected to the second means for decoding the blocks of coded incoming call traffic output by the second means to generate an output stream of incoming call traffic, and for coding a received input stream of outgoing call traffic into blocks of coded outgoing call traffic for receipt by the seconds means, and

fourth means connected to the TDM bus and to the third means for transmitting the output stream of incoming call traffic generated by the third means in first time slots assigned to the call on the TDM bus, and for receiving the input stream of outgoing call traffic in second time slots assigned to the call on the TDM bus and supplying the received stream to the third means.

24. A switching system for conveying radio-telephone call traffic to and from cells over communications links in a radio-telephone communications system, the switching system being for connection to a plurality of communication channels of a telephone network that is connected to the radio-telephone communications system, each channel for carrying traffic of an individual call, and the switching system including:

a packet transmission bus;

a time-division-multiplexed (TDM) bus defining a plurality of time slots;

a plurality of packet communications link interface means connected to the packet transmission bus and each for receiving from the packet transmission bus packets carrying blocks of encoded outgoing voice call traffic destined for radio telephones served by a cell and transmitting the received packets on a packet communications link to the cell in statistically-multiplexed form, and for transmitting on the packet transmission bus packets received in statistically-multiplexed form on the link and each carrying blocks of encoded incoming traffic of a voice call from a radio telephone;

a plurality of call-handling means each connected to the packet transmission bus and to the TDM bus, each for handling a different call and responsive to receipt of outgoing voice call traffic of the handled call on the TDM bus in first time slots assigned to the handled call for packetizing the received outgoing call traffic and transmitting the packets on the packet transmission bus, and for receiving on the packet transmission bus packets carrying incoming voice call traffic of the handled call and for depacketizing and transmitting the incoming call traffic on the TDM bus in second time slots assigned to the handled call; and

at least one channel interface means connected to the TDM bus, each responsive to receipt from a communication channel of a telephone network of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the TDM bus in first time slots that are assigned to the call, and responsive to receipt of incoming call traffic of an individual call on the TDM bus in second time slots that are assigned to the individual call for transmitting the received incoming call traffic on the communication channel of the telephone network that carries traffic of that call;

wherein

a plurality of the call-handling means comprise

first means for receiving from the packet transmission bus first packets each carrying a block of coded traffic incoming from radio telephones for any one of a plurality of calls, and for transmitting on the packet transmission bus second packets each carrying a block of coded traffic outgoing to radio telephones for any one of the plurality of calls,

second means connected to the first means for depacketizing first packets received by the first means and each carrying a block of coded incoming call traffic for a different one of the calls and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic each for a different one of the calls, packetizing the individual block to form second packets, and outputting the second packets to the first means,

a plurality of third means connected to the second means, each for decoding the blocks of coded incoming call traffic output by the second means for an individual one of the calls to generate an output stream of incoming call traffic for the call, and for coding a received input stream of outgoing call traffic for the individual call into blocks of coded outgoing call traffic for the one call for receipt by the second means, and

fourth means connected to the TDM bus and to the plurality of the third means for transmitting the output streams of incoming traffic of the individual calls generated by the plurality of third means in first time slots of the TDM bus which are assigned to the individual calls and for receiving input streams of outgoing call traffic for the individual calls in second time slots of the TDM bus which are assigned to the individual calls and supplying the received streams to the plurality of the third means.

25. A switching system for conveying radio-telephone call traffic to and from cells over communications links in a radio-telephone communications system, the switching system being for connection to a plurality of communication channels of a telephone network that is connected to the radio-telephone communications system, each channel for carrying traffic of an individual call, and the switching system including:

a packet transmission bus;

a time-division-multiplexed (TDM) bus defining a plurality of time slots;

a plurality of packet communications link interface means connected to the packet transmission bus and each for receiving from the packet transmission bus packets carrying outgoing voice call traffic destined for radio telephones served by a cell and frame-relaying the received packets on a packet communications link to the cell in statistically-multiplexed form, and for transmitting on the packet transmission bus received packets that were frame-relayed in statistically-multiplexed form on the link and each carrying incoming traffic of a voice call from a radio telephone;

a plurality of call-handling means each connected to the packet transmission bus and to the TDM bus, each for handling a different call and responsive to receipt of outgoing voice call traffic of the handled call on the TDM bus in first time slots assigned to the handled call for packetizing the received outgoing call traffic and transmitting the packets on the packet transmission bus, and for receiving on the packet transmission bus packets carrying incoming voice call traffic of the handled call and for depacketizing and transmitting the incoming call traffic on the TDM bus in second time slots assigned to the handled call; and

at least one channel interface means connected to the TDM bus, each responsive to receipt from a communication channel of a telephone network of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the TDM bus in first time slots that are assigned to the call, and responsive to receipt of incoming call traffic of an individual call on the TDM bus in second time slots that are assigned to the individual call for transmitting the received incoming call traffic on the communication channel of the telephone network that carries traffic of the call.

26. A switching system for conveying radio-telephone call traffic to and from cells over communications links in a radio-telephone communications system, the switching system being for connection to a plurality of communication channels of a telephone network that is connected to the radio-telephone communications system, each channel for carrying traffic of an individual call, and the switching system including:

a packet transmission bus;

a time-division-multiplexed (TDM) bus defining a plurality of time slots;

a plurality of packet communications link interface means connected to the packet transmission bus and each for receiving from the packet transmission bus packets carrying outgoing voice call traffic destined for radio telephones served by a cell and transmitting the received packets on a packet communications link to the cell in statistically-multiplexed form, and for transmitting on the packet transmission bus packets received in statistically-multiplexed form on the link and each carrying incoming traffic of a voice call from a radio telephone;

a plurality of call-handling means each connected to the packet transmission bus and to the TDM bus, each for handling a different call and responsive to receipt of outgoing voice call traffic of the handled call on the TDM bus in first time slots assigned to the handled call for packetizing the received outgoing call traffic and transmitting the packets on the packet transmission bus, and for receiving on the packet transmission bus packets carrying incoming voice call traffic of the handled call and for depacketizing and transmitting the incoming call traffic on the TDM bus in second time slots assigned to the handled call;

at least one channel interface means connected to the TDM bus, each responsive to receipt from a communication channel of a telephone network of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the TDM bus in first time slots that are assigned to the call, and responsive to receipt of incoming call traffic of an individual call on the TDM bus in second time slots that are assigned to the individual call for transmitting the received incoming call traffic on the communication channel of the telephone network that carries traffic of that call;

a plurality of packet communications links each connected to a different packet communications link interface;

a second packet transmission bus;

at least one second packet communications link interface each connected to a packet communications link and to the second packet transmission bus, each for transmitting on the second packet transmission bus packets received in statistically-multiplexed form on the connected packet communications link, and for receiving on the second packet transmission bus packet destined for the connected packet communications link and transmitting the received packets on the connected packet communications link in statistically-multiplexed form; and

at least one time-division-multiplexed (TDM) communications link interface connected to the second packet transmission bus, each for time-division-demultiplexing packets carrying call traffic generated by a plurality of radio telephones and received from a cell in incoming time slots of a TDM communications link and transmitting the received demultiplexed packets on the second packet transmission bus, and for receiving on the second packet transmission bus packets carrying call traffic destined for radio telephones served by the cell which is connected to the TDM communications link and time-division-multiplexing the received packets into outgoing time slots of the TDM communications link.

27. The switching system of claim 26 wherein

each TDM communications link interface time-division-demultiplexes packets carrying compressed call traffic generated by digital radio telephones and received from a cell in first incoming time slots of the TDM communications link, and receives on the second packet transmission bus packets carrying compressed call traffic destined for digital radio telephones and time-division-multiplexes the packets received on the second packet transmission bus into first outgoing time slots of the TDM communications link, and

each second packet communications link interface transmits packets on the second packet transmission bus to the at least one TDM communications link interface and receives packets on the second packet transmission bus from the at least one TDM communications link interface;

and

the switching system further comprises

a plurality of circuit-switched communications links,

a second time-division-multiplexed (TDM) bus defining a plurality of time slots,

at least one first circuit-switching interface means connected to the second TDM bus and each for time-slot-interchanging noncompressed call traffic generated by a second radio telephone and received from the cell in second incoming time slots of the TDM communications link into first time slots of the second TDM bus, and for time-slot-interchanging noncompressed call traffic destined for the second radio telephone served by the cell and carried in second time slots of the second TDM bus into second outgoing time slots of the TDM communications link,

at least one second circuit-switching interface means connected to the second TDM bus and to the circuit-switched communications links and each for transmitting call traffic received on a circuit-switched communications link on the second TDM bus in second time slots assigned to the second circuit-switching interface, and for transmitting on the circuit-switched communications link call traffic received on the second TDM bus in first time slots assigned to the second circuit-switching interface,

at least one third link,

switching means connected to the circuit-switched communications links and to the at least one third link, for interconnecting the circuit-switched communications links with the at least one third link, and

at least one third-link interface means connected to the first TDM bus and each further connected to a different third link, each for transmitting call traffic received on the connected third link on the first TDM bus in third time slots assigned to the third-link interface means, and for transmitting on the connected third link call traffic received on the first TDM bus in fourth time slots assigned to the third-link interface means; and

wherein

each channel interface means is responsive to receipt from a connected channel of outgoing call traffic of an individual call for transmitting the received outgoing call traffic on the first TDM bus either (a) in first time slots that are assigned to the call-handling means that are handling the call or (b) in fourth time slots assigned to the third-link interface means whose connected third link carries call traffic of the call, and responsive to receipt of incoming call traffic of an individual call on the first TDM bus either (c) in second time slots that are assigned to the call-handling means that are handling the individual call or (d) in third time slots assigned to the third-link interface means whose connected third link carries call traffic of the call, for transmitting the received incoming call traffic on the connected channel that carries traffic of that call.

28. A radio-telephone-call processing apparatus for use in a radio-telephone communications system wherein a plurality of cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone, comprising:

first means for receiving from a packet transmission medium first packets each carrying a block of coded voice traffic for a call incoming from a radio telephone and for transmitting on the packet transmission medium second packets each carrying a block of coded voice traffic for the call outgoing to a radio telephone;

second means connected to the first means for depacketizing first packets received by the first means and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic, packetizing the individual blocks to form second packets, and outputting the second packets to the first means;

third means connected to the second means for decoding the blocks of coded incoming call traffic output by the second means to generate an output steam of incoming call traffic, and for coding a received input stream of outgoing call traffic to generate blocks of coded outgoing call traffic for receipt by the second means; and

fourth means connected to the third means for transmitting the output stream of incoming call traffic generated by the third means in first time slots assigned to the call of a time-division-multiplexed medium, and for receiving the input stream of outgoing call traffic in second time slots assigned to the call of the time-division-multiplexed medium and supplying the received stream to the third means;

wherein

the second means include

means responsive to receipt from the third means of a block of outgoing call traffic destined for the one mobile radio telephone for replicating the received outgoing call traffic, packetizing each replica of the outgoing call traffic, and addressing the packets of each replica to a different one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving from the first means packets carrying blocks of incoming call traffic from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, depacketizing the packets received from the different cells, and selecting only one of the depacketized copies of the incoming traffic for output to the third means.

29. The apparatus of claim 28 further comprising:

echo-canceling means connected between the third means and the fourth means for canceling echoes of the incoming call traffic from the received input stream of outgoing call traffic.

30. The apparatus of claim 28 further comprising:

fifth means connected between the third means and the fourth means for inserting signals representing tones into the output stream of incoming call traffic generated by the third means.

31. A radio-telephone-call processing apparatus for use in a radio-telephone communications system wherein a plurality of cells occasionally simultaneously provide radio-telephone call services to a common one mobile radio telephone, comprising:

first means for receiving from a packet transmission medium first packets each carrying a block of coded voice traffic incoming from radio telephones for any one of a plurality of calls, and for transmitting on the packet transmission medium second packets each carrying a block of coded voice traffic outgoing to radio telephones for any one of the plurality of calls;

second means connected to the first means for depacketizing first packets received by the first means and each carrying a block of coded incoming call traffic for a different one of the calls and periodically outputting individual ones of the carried blocks of coded incoming call traffic, and for periodically receiving individual blocks of coded outgoing call traffic each for a different one of the calls, packetizing the individual blocks to form second packets, and outputting the second packets to the first means;

a plurality of third means connected to the second means, each for decoding the blocks of coded incoming call traffic output by the second means for an individual one of the calls to generate an output stream of incoming call traffic for the call, and for coding a received input stream of outgoing call traffic for the individual call to generate blocks of coded outgoing call traffic for the one call for receipt by the second means; and

fourth means connected to the plurality of the third means for transmitting the output streams of incoming traffic for the individual calls generated by the plurality of third means in first time slots of a time-division-multiplexed medium which are assigned to the individual calls, and for receiving input streams of outgoing call traffic for the individual calls in second time slots of the time-division-multiplexed medium which are assigned to the individual calls and supplying the received streams to the plurality of the third means;

wherein

the second means include

means responsive to receipt from the third means of a block of outgoing call traffic destined for the one mobile radio telephone for replicating the received outgoing call traffic, packetizing each replica of the outgoing call traffic, and addressing the packets of each replica to a different one of the cells that are simultaneously providing the services to the one mobile radio telephone, and further for receiving from the first means packets carrying blocks of incoming call traffic from each one of the cells that are simultaneously providing the services to the one mobile radio telephone, the packets received from different cells each carrying a copy of the incoming traffic, depacketizing the packets received from the different cells, and selecting only one of the depacketized copies of the incoming traffic for output to the third means.

32. The apparatus of claim 31 wherein

each third means comprises:

fifth means for substituting signals representing tones for selected portions of the output stream of incoming call traffic generated for the individual call.

33. The apparatus of claim 32 wherein

each third means further comprises:

echo-canceling means for canceling echoes of the incoming call traffic for the one call from the received input stream of outgoing call traffic for the one call.