Synchronizing data transmission between a wireless network and a wired network

1. A method to synchronize timing of data transmissions between wireless and wired networks using a combined wireless gateway and cable modem, comprising:

sending an indicator prior to a look-ahead time period;

transmitting a poll to a wireless device upon receiving the indicator;

receiving data from the wireless device;

encapsulating the data in a Data Over Cable Service Interface Specification (DOCSIS) format to generate a DOCSIS frame; and

transmitting the DOCSIS frame at a start of a next transmit opportunity to a cable modem termination system (CMTS);

wherein the look-ahead time period is a time period from transmitting the indicator to transmitting the DOCSIS frame.

2. The method of claim 1 , wherein the indicator is a grant synchronization indicator (GSI) that is generated by a DOCSIS application layer based on a timing signal received from a DOCSIS Media Access Control (MAC) layer.

3. The method of claim 1 , wherein the indicator is sent by a DOCSIS application layer to a wireless device application layer within the combined wireless gateway and cable modem.

4. The method of claim 1 , wherein the poll is a contention free (CF) poll of the Institute of Electrical and Electronics Engineers (IEEE) 802.11(e) standard.

5. The method of claim 1 , wherein the next transmit opportunity is a next time slot for transmission of data received from the wireless device; and wherein the next time slot is allotted to the combined wireless gateway and cable modem by the CMTS in a DOCSIS MAP message.

6. The method of claim 1 , further comprising:

determining a round-trip time period, wherein the round-trip time period is the time period from transmitting the indicator to receiving data from the wireless device;

determining a difference between the look-ahead time period and the round-trip time period;

decreasing the look-ahead time period if the difference is greater than a margin time period; and

increasing the look-ahead time period if the difference is less than the margin time period.

7. The method of claim 6 , wherein the increasing comprises: increasing the look-ahead time period for a next transmit opportunity so that the difference is substantially equal to the margin time period.

8. The method of claim 6 , wherein the decreasing comprises: decreasing the look-ahead time for a next transmit opportunity so that the difference is substantially equal to the margin time period.

9. A method to synchronize timing of data transmissions between wireless and wired networks using a cable modem, comprising:

generating an indicator prior to a look-ahead time period;

transmitting a poll trigger to a wireless gateway upon generating the indicator;

receiving data from the wireless gateway;

encapsulating the data in a Data Over Cable Service Interface Specification (DOCSIS) format to generate a DOCSIS frame; and

transmitting the DOCSIS frame at a start of a next transmit opportunity to a cable modem termination system (CMTS);

wherein the look-ahead time period is a time period from generating the indicator to transmitting the DOCSIS frame.

10. The method of claim 9 , wherein the indicator is a Grant Synchronization Indicator and is generated by a DOCSIS application layer based on a timing signal received from a DOCSIS Media Access Control (MAC) layer of the cable modem.

11. The method of claim 9 , wherein the poll trigger is Grant Synchronization Indicator trigger message that is configured to cause the wireless gateway to transmit a contention free (CF) poll to a wireless device.

12. The method of claim 9 , wherein the next transmit opportunity is a next time slot for transmission of data received from the wireless device; and wherein the next time slot is allotted to the combined wireless gateway and cable modem by the CMTS in a DOCSIS MAP message.

13. The method of claim 9 , further comprising:

determining a round-trip time period, wherein the round-trip time period is the time period from transmitting the indicator to receiving data from the wireless gateway;

determining a difference between the look-ahead time period and the round-trip time period;

increasing the look-ahead time period if the difference is lesser than a margin time period; and

decreasing the look-ahead time period if the difference is greater than the margin time period.

14. The method of claim 13 , wherein the increasing comprises: increasing the look-ahead time period so that the difference is substantially equal to the margin time period for a next transmit opportunity.

15. The method of claim 13 , wherein the decreasing comprises: decreasing the look-ahead time so that the difference is substantially equal to the margin time period for a next transmit opportunity.

16. A method to synchronize timing of data transmissions between wireless and wired networks using a wireless gateway, comprising:

receiving a trigger message from a cable modem;

transmitting a poll to a wireless device upon receiving the trigger message;

receiving data from the wireless device;

encapsulating the data in an Ethernet format to generate an Ethernet frame; and

transmitting the Ethernet frame to the wireless device.

17. The method of claim 16 , wherein the trigger message is a contention free (CF) poll of the Institute of Electrical and Electronics Engineers (IEEE) 802.11(e) protocol.

18. The method of claim 17 , wherein the trigger message is based on a look-ahead time Period; and wherein the look-ahead time is a time period between transmitting the trigger message by the cable modem and transmitting a Data Over Cable Service Interface Specification (DOCSIS) frame by the cable modem to a cable modem termination system (CMTS).

19. The method of claim 18 , wherein the DOCSIS frame includes data in the Ethernet frame.