Soft-TDMA for wireless ad-hoc networks

1. A method of scheduling packets received from a higher layer packet source for transmission from a network device onto a medium shared with at least one contending network device where access to the medium is controlled by a medium access protocol, the method comprising:

obtaining medium history information associated with the medium;

determining, in the network device, a transmission schedule that provides for periodic opportunities to transmit a packet from the network device, the transmission schedule minimizing contention with transmission from the at least one contending network device by taking into account the medium history information associated with the medium;

providing, to a medium access controller in the network device that operates in accordance with the medium access protocol, at least some of the packets based on the determined transmission schedule; and

transmitting, from the network device, packets output from the medium access controller, wherein the transmission schedule comprises a time alignment parameter and a time period parameter, wherein the at least some of the packets are provided to the medium access controller based in part on the time alignment parameter and the time period parameter.

2. The method of claim 1 , wherein the time period parameter is based on a reception time period at which packets are received from the higher layer packet source.

3. The method of claim 1 , wherein the time alignment parameter is based on a transmission duration allowance parameter and on the medium history information.

4. The method of claim 1 , wherein the medium history information includes received signal strength information.

5. The method of claim 1 , wherein the time alignment parameter is based on an extended transmission duration allowance parameter and on the medium history information, wherein the extended transmission duration allowance parameter includes a plurality of time offsets and the time alignment parameter is based on a selection of one of the plurality of time offsets.

6. The method of claim 1 , further including modifying the transmission schedule by adjusting the time alignment parameter to reduce a time gap between a transmission from the network device and a transmission from the at least one contending network device.

7. The method of claim 1 , further including:

obtaining updated medium history information associated with the medium; and

modifying, in the network device, the transmission schedule based at least in part on the updated medium history information associated with the medium.

8. The method of claim 7 , wherein obtaining updated medium history information is conducted upon a determination that contention has occurred on the medium with the one or more of the at least one contending network device.

9. The method of claim 1 , wherein a plurality of transmission schedules are determined and utilized by the network device for transmission of the packets from the higher layer packet source.

10. A network device configured to schedule packets received from a higher layer packet source for transmission by the network device onto a medium shared with at least one contending network device where access to the medium is controlled by a medium access protocol, the network device comprising:

a memory;

a transmitter coupled to the memory; and

a processor coupled to the memory and to the transmitter and configured to:

obtain medium history information associated with the medium;

determine a transmission schedule that provides for periodic opportunities to transmit a packet from the network device, the transmission schedule minimizing contention with transmission from the at least one contending network device by taking into account the medium history information associated with the medium;

provide, to a medium access controller that operates in accordance with the medium access protocol, at least some of the packets based on the determined transmission schedule; and

transmit, from the transmitter, packets output from the medium access controller, wherein the transmission schedule comprises a time alignment parameter and a time period parameter, wherein the at least some of the packets are provided to the medium access controller based in part on the time alignment parameter and the time period parameter.

11. The network device of claim 10 , wherein the time period parameter is based on a reception time period at which packets are received from the higher layer packet source.

12. The network device of claim 10 , wherein the time alignment parameter is based on a transmission duration allowance parameter and on the medium history information.

13. The network device of claim 10 , wherein the medium history information includes received signal strength information.

14. The network device of claim 10 , wherein the time alignment parameter is based on an extended transmission duration allowance parameter and on the medium history information, wherein the extended transmission duration allowance parameter includes a plurality of time offsets and the time alignment parameter is based on a selection of one of the plurality of time offsets.

15. The network device of claim 10 , wherein the processor is further configured to modify the transmission schedule by adjusting the time alignment parameter to reduce a time gap between a transmission from the network device and a transmission from the at least one contending network device.

16. The network device of claim 10 , wherein the processor is further configured to:

obtain updated medium history information associated with the medium; and

modify, in the network device, the transmission schedule based at least in part on the updated medium history information associated with the medium.

17. The network device of claim 16 , wherein the updated medium history information is obtained upon a determination that contention has occurred on the medium with the one or more of the at least one contending network device.

18. The network device of claim 10 , wherein a plurality of transmission schedules are determined and utilized by the network device for transmission of the packets from the higher layer packet source.

19. A non-transitory storage medium which stores computer instructions readable by a processor of a network device to implement functions for scheduling packets received from a higher layer packet source for transmission by the network device onto a medium shared with at least one contending network device where access to the medium is controlled by a medium access protocol the functions comprising

obtaining medium history information associated with the medium;

determining, in the network device, a transmission schedule that provides for periodic opportunities to transmit a packet from the network device, wherein the transmission schedule minimizes contention with transmission from the at least one contending network device by taking into account the medium history information associated with the medium;

providing, to a medium access controller in the network device that operates in accordance with the medium access protocol, at least some of the packets based on the determined transmission schedule; and

transmitting, from the network device, packets output from the medium access controller, wherein the transmission schedule comprises a time alignment parameter and a time period parameter, wherein the at least some of the packets are provided to the medium access controller based in part on the time alignment parameter and the time period parameter.

20. The non-transitory storage medium of claim 19 , wherein the time period parameter is based on a reception time period at which packets are received from the higher layer packet source.

21. The non-transitory storage medium of claim 19 , wherein the time alignment parameter is based on a transmission duration allowance parameter and on the medium history information.