Call management in a TDMA system through variable packet formatting

• US 6,553,021 B1
• Filed: 11/10/1999
• Issued: 04/22/2003
• Est. Priority Date: 11/10/1999
• Status: Expired due to Term

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Bishop, James William Jr., Emmons, Thomas Peter Jr., Peters, Robert Anthony
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): CONTEE, JOY KIMBERLY
• Application Number:
  US09/437,672
• Time in Patent Office: 1,259 Days
• Field of Search: 370/347, 370/332, 370/335, 370/337, 370/349, 370/252, 370/468, 370/454, 370/443, 370/336, 370/316, 370/328, 455/436, 455/450, 455/452, 455/454, 455/406, 455/408
• US Class Current: 370/347
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters

Abstract

A time division multiple access (TDMA) communications system (20) includes a first TDMA platform (22) for transmitting a call (32) over a circuit switched communication link (36) to a second TDMA platform (24). The call (32) exhibits a first signal type (84) and second signal type (86). A controller (42) establishes a capacity allocation (200) responsive to the first signal type (84) for the communication link (36). When the call (32) exhibits the first signal type (84), the first TDMA platform (22) transmits first packets (111) of the call (32) in a first packet format (113) using the capacity allocation (200), and when the call (32) exhibits the second signal type (86), the first TDMA platform (22) transmits second packets (140) of the call (32) in a second packet format (139) using the capacity allocation (200).

Claims

1. A time division multiple access (TDMA) communications system comprising:

a first TDMA platform for transmitting a call over a communication link, said call exhibiting a first signal type and a second signal type;

a second TDMA platform for receiving said call over said communication link;

means, in communication with said first TDMA platform and said second TDMA platform, for establishing a capacity allocation for said communication link in response to said first signal type, wherein said first TDMA platform transmits said call over said communication link in a first packet format using said capacity allocation when said call exhibits said first signal type, and said first TDMA platform transmits said call over said communication link in a second packet format using said capacity allocation when said call exhibits said second signal type;

wherein a frequency bandwidth and adjacent time slots of a TDMA frame in said frequency bandwidth form said capacity allocation, said first signal type is a real time signal, said second signal type is a data signal, and said first TDMA platform comprises;

a controller;

a first input for receiving said real time signal;

a first multiplexer in communication with said first input and responsive to said controller, said first multiplexer segmenting said real time signal into first signal units and appending a first unique identifier to each of said first signal units to generate first packets of said call in said first packet format, each of said first packets having a first packet size substantially equivalent to one of said adjacent time slots;

a second input for receiving said data signal;

a second multiplexer in communication with said second input and responsive to said controller, said second multiplexer segmenting said data signal into second signal units and appending a second unique identifier to each of said second signal units to generate second packets of said call in said second packet format, each of said second packets having a second packet size substantially equivalent to said capacity allocation; and

a signal output, in communication with a first output of said first multiplexer and a second output of said second multiplexer, for providing said first packets and said second packets of said call to said communication link.

2. A TDMA communications system as claimed in claim 1 wherein said first signal type is a real time signal, and said establishing means assigns frequency bandwidth and allocates adjacent time slots in a TDMA frame of said frequency bandwidth to form said communication link for substantially exclusive use for said call.

3. A TDMA communications system as claimed in claim 1 wherein said second packet size is substantially equivalent to said TDMA frame.

4. A TDMA communications system as claimed in claim 1 wherein said first TDMA platform further comprises:

a channel activity detector in communication with said first input and said controller for detecting silence in said real time signal; and

a switch element responsive to said controller and having a first input in communication with said first output of said first multiplexer, a second input in communication with said second output of said second multiplexer, and a switch output coupled to said signal output, said controller causing said switch element to enable transmission of said second packets over said communication link upon detection of said silence.

5. A TDMA communications system as claimed in claim 4 wherein said controller prevents said switch element from enabling transmission of said second packets over said communication link while said first packets are being transmitted over said communication link.

6. A TDMA communications system as claimed in claim 1 wherein:

said first TDMA platform further comprises;

a first encoder coupled between said first input and said first multiplexer for encoding said real time signal in accordance with a first encoding protocol; and

a second encoder coupled between said second input and said second multiplexer for encoding said data signal in accordance with a second encoding protocol; and

said second TDMA platform comprises;

a receiver input for receiving said first packets and said second packets of said call over said communication link;

a first correlator in communication with said receiver input for detecting said first unique identifier in received ones of said first packets;

a first decoder responsive to said first correlator for decoding said received ones of said first packets in accordance with said first encoding protocol to recover said real time signal;

a second correlator in communication with said receiver input for detecting said second unique identifier in received ones of said second packets; and

a second decoder responsive to said second correlator for decoding said received ones of said second packets in accordance with said second encoding protocol to recover said data signal.

7. In a time division multiple access (TDMA) communications system, a method of managing a call exhibiting a first signal type and a second signal type comprising:

a) establishing a communication link for said call, said communication link being characterized by a capacity allocation responsive to said first signal type;

b) when said call exhibits said first signal type, transmitting first packets of said call over said communication link in a first packet format using said capacity allocation;

c) when said call exhibits said second signal type, transmitting second packets of said call over said communication link in a second packet format using said capacity allocation;

wherein said first signal type is a voice signal, said second signal type is a data signal, and said method further comprises the steps of;

detecting silence in said voice signal when transmitting said first packets of said call over said communication link; and

enabling transmission of said second packets of said call over said communication link during said silence; and

d) wherein said activity a) includes

receiving a request for said call indicating said real time signal;

assigning frequency bandwidth to said call in response to said request;

allocating adjacent time slots of a TDMA frame in said frequency bandwidth to said call in response to said request, said frequency bandwidth and said adjacent time slots forming said capacity allocation.

8. A method as claimed in claim 7 wherein said first signal type is a real time signal, said second signal type is a data signal, and said activity a)further comprises:

determining a first packet size in said first packet format as being substantially equivalent to one of said adjacent time slots; and

determining a second packet size in said second packet format as being substantially equivalent to said capacity allocation.

9. A method as claimed in claim 8 wherein:

said frequency bandwidth includes frequency channels and at least one frequency guard band separating said frequency channels; and

said capacity allocation includes said frequency channels and said at least one frequency guard band.

10. A method as claimed in claim 8 wherein:

said adjacent time slots includes at least one time guard band separating said adjacent time slots; and

said capacity allocation includes said adjacent time slots and said at least one time guard band.

11. A method as claimed in claim 8, wherein:

said frequency bandwidth includes a frequency channel; and

said capacity allocation is substantially equivalent to said TDMA frame in said frequency channel.

12. A method as claimed in claim 8, wherein:

said frequency bandwidth includes frequency channels separated by at least one frequency guard band;

each of said frequency channels includes said adjacent time slots separated by at least one time guard band; and

said capacity allocation is substantially equivalent to said frequency channels, said at least one frequency guard band, said adjacent time slots for each of said frequency channels, and said at least one time guard band.

13. A method as claimed in claim 7 further comprising delaying said activity c) when said activity b) occurs.

14. A method as claimed in claim 7 wherein consecutive TDMA frames of a frequency channel are divided into a sequence of time slots, said first signal type is a real time signal, said second signal type is a data signal, and said method further comprises:

segmenting said real time signal into first signal units prior to said activity b);

appending a first unique identifier to each of said first signal units of said real time signal prior to said activity b) to generate said first packets of said call in said first packet format, each of said first packets having a first packet size substantially equivalent to one of said time slots;

segmenting said data signal into second signal units prior to said activity c); and

appending a second unique identifier to each of said second signal units of said data signal prior to said activity c) to generate said second packets of said call in said second packet format, each of said second packets having a second packet size substantially equivalent to said capacity allocation.

15. A method as claimed in claim 14 further comprising:

encoding said real time signal in accordance with a first encoding protocol prior to said activity b);

encoding said data signal in accordance with a second encoding protocol prior to said activity c);

receiving said first packets and said second packets of said call over said communication link;

detecting one of said first unique identifier and said second unique identifier in received ones of said first packets and said second packets of said call;

when said first unique identifier is detected, decoding said received ones of said first packets in accordance with said first encoding protocol to recover said real time signal; and

when said second unique identifier is detected, decoding said received ones of said second packets in accordance with said second encoding protocol to recover said data signal.

16. A time division multiple access (TDMA) communications system comprising:

a first TDMA platform for transmitting a call over a communication link, said call exhibiting a real time signal and a data signal, and said first TDMA platform including;

a controller;

a first input configured to receive said real time signal;

a first multiplexer in communication with said first input and responsive to said controller, said first multiplexer segmenting said real time signal into first signal units and appending a first unique identifier to each of said first signal units to generate first packets of said call;

a second input configured to receive said data signal;

a second multiplexer in communication with said second input and responsive to said controller, said second multiplexer segmenting said data signal into second signal units and appending a second unique identifier to each of said second signal units to generate second packets of said call; and

a signal output, in communication with a first output of said first multiplexer and a second output of said second multiplexer, for providing said first packets and said second packets of said call to said communication link;

a second TDMA platform for receiving said first packets and said second packets of said call over said communication link; and

means, in communication with said first TDMA platform and said second TDMA platform, for establishing a capacity allocation for said communication link, said establishing means assigning frequency bandwidth and allocating adjacent time slots in a TDMA frame of said frequency bandwidth for substantially exclusive use for said call in response to said real time signal, said frequency bandwidth and said adjacent time slots forming said capacity allocation, said first packets having a first packet size substantially equivalent to one of said adjacent time slots, said second packets having a second packet size substantially equivalent to said capacity allocation;

wherein

when said call exhibits said real time signal, said first TDMA platform transmits said first packets of said call over said communication link using said capacity allocation; and

when said call exhibits said data signal, said first TDMA platform transmits said second packets of said call over said communication link using said capacity allocation.

17. A TDMA communications system as claimed in claim 16 wherein said first TDMA platform further comprises:

a channel activity detector in communication with said first input and said controller for detecting silence in said real time signal; and

a switch element responsive to said controller and having a first input in communication with said first output of said first multiplexer, a second input in communication with said second output of said second multiplexer, and a switch output coupled to said signal output, said controller causing said switch element to enable transmission of said second packets over said communication link upon detection of said silence, and said controller preventing said switch element from enabling transmission of said second packets over said communication link while said first packets are being transmitted over said communication link.

18. A TDMA communications system as claimed in claim 16 wherein:

said first TDMA platform further comprises;

a first encoder coupled between said first input and said first multiplexer for encoding said real time signal in accordance with a first encoding protocol; and

a second encoder coupled between said second input and said second multiplexer for encoding said data signal in accordance with a second encoding protocol; and

said second TDMA platform comprises;

a receiver input for receiving said first packets and said second packets of said call over said communication link;

a first correlator in communication with said receiver input for detecting said first unique identifier in received ones of said first packets;

a first decoder decoding said received ones of said first packets in accordance with said first encoding protocol to recover said real time signal;

a second correlator in communication with said receiver input for detecting said second unique identifier in received ones of said second packets; and

a second decoder responsive to said second correlator for decoding said received ones of said second packets in accordance with said second encoding protocol to recover said data signal.