MAC protocol employing multiple data rates

• US 6,463,096 B1
• Filed: 06/12/1998
• Issued: 10/08/2002
• Est. Priority Date: 06/12/1998
• Status: Expired due to Term

• Current Assignee: Cisco Systems, Inc.
• Original Assignee: Cisco Systems, Inc.
• Inventors: Raleigh, Gregory G., Pollack, Michael A., Jones, Vincent K.
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Bayard, Emmanuel
• Application Number:
  US09/097,305
• Time in Patent Office: 1,579 Days
• Field of Search: 375/140, 375/141, 375/257, 375/260, 375/295, 375/225, 375/263, 375/265, 370/329, 370/330, 370/327, 370/340, 370/341, 370/337, 370/347, 370/431, 370/436, 370/432, 370/464, 370/468, 370/471, 370/473, 370/475, 455/450, 455/464, 455/509, 455/451, 455/510
• US Class Current: 375/225
• CPC Class Codes: H04J 4/00 Combined time-division and frequency-division multiplex systems H04J13/00 takes precedence ; data transmission H04L5/26; telemetry G08C15/00
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2898 Subscriber equipments DSL modems H04M11/062; cable modems H04L12/2801
• CPC Class Codes: H04L 47/15 in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/788 Autonomous allocation of resources
• CPC Class Codes: H04L 47/801 Real time traffic
• CPC Class Codes: H04L 47/805 QOS or priority aware
• CPC Class Codes: H04L 47/824 Applicable to portable or mobile terminals
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/00 Wireless channel access

Abstract

Method and apparatus for combining high data rate traffic and low data rate traffic on a common transmission medium while maximizing efficient use of available spectrum. Since spectrum is an economically valuable resource and transport of data generates revenue, the present invention directly leads to more profitable network operation. The disclosed systems are applicable to both wired and wireless transmission media. In one embodiment, a bandwidth reservation scheme provides that data rate may be varied so that when a particular data communication device is allocated a frame, it is also assigned a data rate for use in that frame. Because bandwidth usage varies with data rate, the division of available spectrum into channels for use by individual data communication devices may also vary among frames.

Claims

1. In a data communication network, a method for allocating access to a common transmission medium among a plurality of data communication devices comprising:

assigning a transmission frame to a particular data communication device wherein others of said data communication devices do not transmit in said transmission frame;

assigning a data rate for said particular data communication device to employ in said transmission frame; and

transmitting said transmission frame assignment and said data rate assignment to said particular data communication device.

2. The method of claim 1 further comprising:

transmitting an information frame from said data communication device during said transmission frame and at said data rate.

3. The method of claim 1 wherein assigning a data rate comprises:

selecting said data rate from two available data rates.

4. The method of claim 1 wherein assigning a data rate comprises:

selecting said data rate from among at least three available data rates.

5. The method of claim 1 further comprising:

transmitting an access request from said particular data communication device to a hub, said access request indicating an amount of data to be transmitted by said particular data communication device.

6. The method of claim 1 wherein transmitting comprises

transmitting a center-frequency assignment to said particular data communication device.

7. The method of claim 6 wherein said center-frequency assignment is selected based on available transmission quality at a plurality of transmission frequencies.

24. The method of claim 1 further comprising:

assigning a further transmission frame to a data communication device different from said particular data communication device; and

assigning a data rate for said different data communication device to employ in said further transmission frame wherein said particular data communication device and said different data communication device are assigned different data rates.

8. In a data communication network, a method for allocating access to a common transmission medium among a plurality of data communication devices, said method comprising:

receiving access request messages from requesting data communication devices at a hub, said access request messages requesting access to said common transmission medium;

in response to said access request messages, at said hub, allocating access to said common transmission medium in both the frequency and time domain among said requesting data communication devices; and

thereafter

transmitting from said hub to said requesting access devices, instructions for each requesting access device to transmit at particular times and frequencies, and at particular data rates chosen according to said allocating step.

9. A digital communications network comprising:

a plurality of data communications devices transmitting via a common transmission medium; and

a hub receiving signals from said data communications devices via said common transmission medium, said hub comprising;

a bandwidth manager that receives access request messages from requesting data communication devices, said access request messages requesting access to said common transmission medium, and that allocates access to said common transmission medium in both the frequency and time domain among said requesting data communication devices; and

a link supervisor that transmits from said hub to said requesting access devices, instructions for each requesting access device to transmit at particular times and frequencies, and at particular data rates chosen in accordance with allocations by said bandwidth manager.

10. The digital communications network of claim 9 wherein said common transmission medium comprises a wireless medium.

11. The digital communications network of claim 9 wherein said common transmission medium comprises a wired medium.

12. The digital communications network of claim 9 wherein said link supervisor comprises a radio link supervisor.

13. In a digital communications network, a hub comprising:

a receiver that receives signals from said data communications devices via said common transmission medium;

a bandwidth manager that receives access request messages from requesting data communication devices, said access request messages requesting access to said common transmission medium, and that allocates access to said common transmission medium in both the frequency and time domain among said requesting data communication devices; and

a link supervisor that transmits from said hub to said requesting access devices, instructions for each requesting access device to transmit at particular times and frequencies, and at particular data rates chosen in accordance with allocations by said bandwidth manager.

14. The hub of claim 13 wherein said common transmission medium comprises a wired medium.

15. The hub of claim 13 wherein said link supervisor comprises a radio link supervisor.

16. The hub of claim 13 wherein said common transmission medium comprises a wireless medium.

17. The hub of claim 15 wherein said hub further comprises a downstream radio for transmitting signals to said data communication devices.

18. The hub of claim 15 wherein said hub further comprises a plurality of upstream radios for receiving signals from said data communication devices.

19. A data communications device for use in a network, said data communications device comprising:

a bandwidth manager that transmits requests for access to a common transmission medium to a hub; and

a link supervisor that receives medium access instructions from said hub, said medium access instructions specifying data rate, transmission time, and transmission frequency for transmissions to said hub, and that controls transmission of information via said common transmission medium in accordance with said specified data rate, transmission time, and transmission frequency.

20. The data communications device of claim 19 wherein said common transmission medium comprises a wired medium.

21. The data communications device of claim 20 wherein said common transmission medium comprises a wireless medium.

22. The data communications device of claim 21 further comprising:

at least two downstream radios for communicating at selectable data rates.

23. The data communications device of claim 19 wherein said link supervisor comprises a radio link supervisor.

25. In a data communication network, apparatus for allocating access to a common transmission medium among a plurality of data communication devices, said apparatus comprising:

means for assigning a transmission frame to a particular data communication device wherein others of said data communication devices do not transmit in said transmission frame;

means for assigning a data rate for said particular data communication device to employ in said transmission frame; and

means for transmitting said transmission frame assignment and said data rate assignment to said particular data communication device.

26. In a data communication network, apparatus for allocating access to a common transmission medium among a plurality of data communication devices, said apparatus comprising:

means for receiving access request messages from requesting data communication devices at a hub, said access request messages requesting access to said common transmission medium;

means for, in response to said access request messages, at said hub, allocating access to said common transmission medium in both the frequency and time domain among said requesting data communication devices; and

means for transmitting from said hub to said requesting access devices, instructions for each requesting access device to transmit at particular times and frequencies, and at particular data rates chosen according to said allocating step.