Adaptive transmission in multi-access asynchronous channels

• US 20050111477A1
• Filed: 07/02/2004
• Published: 05/26/2005
• Est. Priority Date: 02/26/1999
• Status: Active Grant

• Current Assignee: Global Communications Investment LLC
• Original Assignee: Jerry W. Sessom, Wael Hani Ghanma
• Inventors: Ghanma, Wael Hani, Sessom, Jerry W.
• Granted Patent: US 7,719,981 B2
• Time in Patent Office: Days
• US Class Current: 370/445
• CPC Class Codes: H04L 12/4035 in which slots of a TDMA packet structure are assigned based on a contention resolution carried out at a master unit TDM/TDMA multiplex systems per se H04J3/1694; hybrid switching systems H04L12/64
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]

Abstract

A hybrid transmission cycle (HTC) unit of bandwidth on a shared transmission medium is defined to include an adaptive, time division multiplexing transmission cycle (ATTC), which is allocated in portions sequentially among all participating network entities, and a residual transmission cycle (RTC), which is allocated in portions, as available, to the first network entity requesting access to the shared medium during each particular portion. The ratio of logical link virtual channels, or D-Channels, to data payload virtual channels, or B-Channels, within the ATTC is adaptive depending on loading conditions. Based on transmission profiles transmitted on the D-Channels during the ATTC, each network entity determines how many B-Channels it will utilize within the current HTC. This calculation may be based on any decision network, such as a decision network modelling the transmission medium as a marketplace and employing microeconomic principles to determine utilization. The ratio of the duration of the ATTC segment to the duration of the RTC segment is also adaptive depending on loading conditions, to prevent unacceptable latency for legacy network entities employing the shared transmission medium. During the RTC, utilization of the shared medium preferably reverts to IEEE 802.3 compliant CSMA/CD transmission, including transmissions by HTC-compliant network entities.

Claims

1. A method of communication over a shared transmission medium, comprising:

defining a transmission cycle having a first portion and a second portion which are alternately repeated;

allocating a part of the first transmission cycle portion to each of a plurality of network entities employing the shared transmission medium; and

allocating parts of the second transmission cycle portion as available to network entities employing the shared transmission medium based on primacy of requests for access to the shared transmission medium.

2. The method of claim 1, wherein the step of defining a transmission cycle having a first portion and a second portion which are alternately repeated further comprises:

defining an adaptive time-division multiplexing transmission cycle portion and a residual transmission cycle portion.

3. The method of claim 1, wherein the step of allocating a part of the first transmission cycle portion to each of a plurality of network entities employing the shared transmission medium further comprises:

allocating a logical link channel within the first transmission cycle portion to each network entity employing the shared transmission medium and participating in a communication protocol apportioning the first transmission cycle portion among all participating network entities in an ordered sequence of participating network entities.

4. The method of claim 1, wherein the step of allocating a part of the first transmission cycle portion to each of a plurality of network entities employing the shared transmission medium further comprises:

allocating zero or more data payload channels within the first transmission cycle portion to each network entity employing the shared transmission medium and participating in a communication protocol apportioning the first transmission cycle portion among all participating network entities.

5. The method of claim 4, wherein the step of allocating zero or more data payload channels within the first transmission cycle portion to each network entity employing the shared transmission medium and participating in a communication protocol apportioning the first transmission cycle portion among all participating network entities further comprises:

allocating data payload channels to each participating network entity based on loading conditions.

6. The method of claim 1, wherein the step of allocating a part of the first transmission cycle portion to each of a plurality of network entities employing the shared transmission medium further comprises:

allocating parts of the first transmission cycle portion to each of a subset of network entities employing the shared transmission medium without allocating any part of the first transmission cycle portion to network entities employing the shared transmission medium without participating in the communication protocol.

7. The method of claim 1, wherein the step of allocating parts of the second transmission cycle portion as available to network entities employing the shared transmission medium based on primacy of requests for access to the shared transmission medium further comprises:

allocating access to the shared transmission medium to network entities employing the shared transmission medium as requested with network entities backing off upon collision detection.

8. The method of claim 7, wherein the step of allocating parts of the second transmission cycle portion as available to network entities employing the shared transmission medium based on primacy of requests for access to the shared transmission medium further comprises:

allocating access to the shared transmission medium during the second transmission cycle portion in compliance with the IEEE 802.3 to any network entity regardless of whether that network entity participates in a communication protocol apportioning the first transmission cycle portion among all participating network entities.

9. The method of claim 1, wherein the step of allocating parts of the second transmission cycle portion as available to network entities employing the shared transmission medium based on primacy of requests for access to the shared transmission medium further comprises:

allocating access to the shared transmission medium to IEEE 802.3 compliant network entities.

10. A communication structure, comprising:

a device capable of being selectively coupled to a shared medium and transmitting on the shared medium; and

a communication protocol governing transmission on the shared medium by the device, the communication protocol;

defining first and second transmission cycles which are alternately repeated;

allocating portions of the first transmission cycle to the device and to each other device coupled to the shared medium and participating in the communication protocol for transmission on the shared medium; and

allocating portions of the second transmission cycle based on primacy of requests to any device coupled to the shared medium and requesting access to the shared medium.

11. The communication structure of claim 10, further comprising:

the shared medium; and

at least one other device in addition to the device connected to the shared medium and participating in the communication protocol for transmissions on the shared medium.

12. The communication structure of claim 11, further comprising:

at least one device connected to the shared medium and not participating in the communication protocol.

13. The communication structure of claim 10, wherein the device is a data processing system.

14. The communication structure of claim 10, wherein the device is a telephone.

15. The communication structure of claim 10, wherein the device is a data processing system and further comprising:

a plurality of other devices, each selected from the group consisting of a data processing system and a telephone, each connected to the shared medium, and each participating in the communication protocol for transmissions on the shared medium; and

at least one device connected to the shared medium and not participating in the communication protocol.

16. A computer program product within a computer usable medium, comprising:

instructions for detecting a first transmission cycle on a shared medium;

instructions, responsive to detection of the first transmission cycle on the shared medium, for joining a communication protocol allocating portions of transmission time on the shared medium during the first transmission cycle to each entity participating in the communications protocol;

instructions for attempting to transmit during a second transmission cycle following the first transmission cycle upon detecting the shared medium to be idle; and

instructions for backing off upon detection of a collision while attempting to transmit during the second transmission cycle.

17. The computer program product of claim 16, wherein the instructions for detecting a first transmission cycle on a shared medium further comprise:

instructions for detecting a logical link layer data frame being transmitted on the shared medium and identifying a number of entities participating in the communication protocol.

18. The computer program product of claim 17, wherein the instructions for joining a communication protocol allocating portions of transmission time on the shared medium during the first transmission cycle to each entity participating in the communications protocol further comprise:

instructions for assuming an identifier one greater than the number of entitied participating in the communication protocol.

19. The computer program product of claim 17, wherein the instructions for attempting to transmit during a second transmission cycle following the first transmission cycle upon detecting the shared medium to be idle further comprise:

instructions for attempting an IEEE 802.3 compliant transmission during the second transmission cycle.

20. The computer program product of claim 17, further comprising:

instructions for monitoring the shared medium for repetition of the first and second transmission cycles;

instructions for transmitting a logical link layer data frame identifying payload data frame requirements during each repetition of the first transmission cycle; and

instructions for attempting IEEE 802.3 compliant transmission, as needed, during each repetition of the second transmission cycle.