Point coordinator control passing scheme using a scheduling information parameter set for an IEEE 802.11 wireless local area network

• US 20040105412A1
• Filed: 12/02/2002
• Published: 06/03/2004
• Est. Priority Date: 12/02/2002
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: DOCOMO Communications Laboratories USA, Inc.
• Inventors: Funato, Daichi, He, Xiaoning
• Granted Patent: US 7,356,010 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A communications protocol in a system such as an IEEE 802.11 wireless LAN multi-hop system providing transmission scheduling information is disclosed. The transmission scheduling is formatted within a CF-Poll+Data+SIPS data frame transmitted by the point coordinator (PC) which may be any one of the access point (AP) nodes transmitting in turn as dictated by the scheduling parameters within the scheduling information parameter set (SIPS). The SIPS comprises an offset field, the time left for the presently functioning PC; a delay field, where an AP delays functioning as a PC; and the interval field, the time allowed for an AP to function as a PC. The subsequent scheduling of assigned transmission slots by providing boundaries for the transmission frames through SIPS eliminates collisions resulting from multiple units transmitting simultaneously, thereby supporting interactive media and voice communications on WLAN multi-hop systems.

Claims

1. A wireless local area network (WLAN) protocol for supporting communications in a WLAN, utilizing a CF-Poll+Data+SIPS data frame format for informational packets comprising:

a medium access control (MAC) header further comprising communication control information;

a data block set further comprising informational data associated with the MAC header; and

a scheduling information parameter set (SIPS) further comprising an offset field, a delay field and an interval field associated with the MAC header and the data block set.

2. The communications protocol as in claim 1, wherein the scheduling information parameter set in the CF-Poll+Data+SIPS data frame comprises timing information for client local access points (LAPs) to determine a time that the client LAPs, individually, will function as a point coordinator (PC).

3. The communications protocol as in claim 2, whereby the SIPS offset field contains a time value that reflects a time remaining for an upstream LAP functioning as the PC to continue as the PC.

4. The communications protocol as in claim 2, whereby the SIPS delay field contains a time value reflecting a time that the client LAP delays functioning as the PC after the upstream LAP functioning as the PC terminates the PC function.

5. The communications protocol as in claim 2, whereby the SIPS interval field contains a time value reflecting a durational time that the client LAP functions as the PC.

6. The communications protocol as in claim 1, wherein the LAPs transmit informational packets to mobile terminals within the WLAN.

7. The communications protocol as in claim 1, wherein the communications protocol provides real-time voice and interactive medium data.

8. The communications protocol as in claim 1, wherein the client LAP functions as the PC, further relaying informational packets to downstream LAPs in a multi-hop wireless LAN.

9. The communications protocol as in claim 8, wherein the downstream LAP further relays informational packets to mobile terminals within the multi-hop wireless LAN.

10. The communications protocol as in claim 9, wherein the communications protocol provides real-time voice and interactive medium data.

11. A method of communicating in a wireless local area network (WLAN), wherein a gateway access point (GAP), fixed to a wired network, transmits informational packets that utilize a CF-Poll+Data+SIPS data frame format, while functioning as a point coordinator (PC) to client local area points (LAP) comprising the steps of:

controlling a communication with a medium access control (MAC) header;

communicating data information in a data block associated with the MAC header; and

scheduling the client LAPs function as the PC with a schedule information parameter set (SIPS) comprising an offset field, a delay field and an interval field associated with the MAC header and the data block set.

12. The method as in claim 11, wherein the scheduling step comprises a step of providing a time value in the SIPS offset field that reflects a time remaining for an upstream LAP functioning as the PC to continue as the PC.

13. The method as in claim 11, wherein the scheduling step comprises a step of providing a time value in the SIPS delay field that reflects a time that the client LAP delays functioning as the PC after the upstream LAP functioning as the PC terminates the PC function.

14. The method as in claim 11, wherein the scheduling step comprises a step of providing a time value in the SIPS interval field that reflects the durational time that the client LAP functions as the PC.

15. The method as in claim 11, wherein the LAPs transmit informational packets to mobile terminals within the WLAN.

16. The method as in claim 11, wherein said communicating step provides real-time voice and interactive medium data.

17. The method as in claim 11, wherein the client LAP functions as the PC, further relaying informational packets to downstream LAPs in a multi-hop wireless LAN comprising the steps of:

controlling a communication with a medium access control (MAC) header;

communicating data information in the data block associated with the MAC header; and

scheduling the client LAPs function as the PC with the schedule information parameter set (SIPS) comprising an offset field, a delay field and an interval field associated with the MAC header and the data block set.

18. The method as in claim 17, wherein the scheduling step comprises a step of providing a time value in the SIPS offset field that reflects a time remaining for an upstream LAP functioning as the PC to continue as the PC.

19. The method as in claim 17, wherein the scheduling step comprises a step of providing a time value in the SIPS delay field that reflects a time that the client LAP delays functioning as the PC after the upstream LAP functioning as the PC terminates the PC function.

20. The method as in claim 17, wherein the scheduling step comprises a step of providing a time value in the SIPS interval field that reflects the durational time that the client LAP functions as the PC.

21. The method as in claim 17, wherein the LAPs transmit informational packets to mobile terminals within the WLAN.

22. The method as in claim 17, wherein said communicating step provides real-time voice and interactive medium data.