System and method for controlling wireless lan bandwidth allocation

• US 20050174973A1
• Filed: 07/31/2003
• Published: 08/11/2005
• Est. Priority Date: 08/02/2002
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Xu, Shugong, Kowalski, John, Kandala, Srinivas, Ohtani, Yoshihiro
• Granted Patent: US 7,414,986 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/287 when the channel is in stand-by
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A system and method are provided for controlling bandwidth allocation in a wireless local area network (wLAN). The method comprises: expressing device bandwidth allocations in terms of a time base; in response to expressing the bandwidth allocation in terms of a time base, monitoring network communications; and, measuring the allocated bandwidths. The method may further comprise: establishing polling schedules in response to the time-based bandwidth allocation; and, de-energizing devices in response to the polling schedules. Expressing device bandwidth allocations in terms of a time base includes establishing: an inter-transmission opportunity (TXOP) interval; and, a TXOP jitter. These fields are supplied in the IEEE 802.11e transmit specification (TSPEC). Then, de-energizing devices in response to the polling schedule includes disengaging transmission and receiving functions in the minimum TXOP intervals between polling events, where the minimum TXOP interval is the inter-TXOP interval minus the TXOP jitter.

Claims

1. In a wireless local area network (wLAN), a method for controlling bandwidth allocation, the method comprising:

expressing device bandwidth allocations in terms of a time base;

in response to expressing the bandwidth allocation in terms of a time base, monitoring network communications; and

,

measuring the allocated bandwidths.

2. The method of claim 1 further comprising:

in response to expressing the bandwidth allocation in terms of a time base, establishing polling schedules; and

,

de-energizing devices in response to the polling schedules.

3. The method of claim 2 wherein expressing device bandwidth allocations in terms of a time base includes establishing:

an inter-transmission opportunity (TXOP) interval; and

,

a TXOP jitter.

4. The method of claim 3 wherein establishing an inter-TXOP interval and a TXOP jitter includes establishing a transmit specification (TSPEC) communication with inter-TXOP interval and a TXOP jitter fields.

5. The method of claim 4 wherein expressing device bandwidth allocations in terms of a time base includes establishing a TSPEC communication with fields including:

a minimum TXOP duration;

a nominal TXOP duration; and

,

a maximum TXOP duration.

6. The method of claim 5 wherein expressing device bandwidth allocations in terms of a time base includes:

a first station (STA) requesting permission to communicate traffic information at a second bandwidth, with a second STA, where the second bandwidth is defined as a first desired bandwidth plus a surplus bandwidth allowance;

a hybrid controller (HC) relaying the request to the second STA,

the second STA transmitting a response, including a first STA allocation to communicate with the second STA at the second bandwidth;

the HC relaying the response to the first STA; and

,

the method further comprising;

the first STA transmitting traffic information to the second STA through a wireless medium at the second bandwidth.

7. The method of claim 6 wherein establishing polling schedules in response to expressing the bandwidth allocation in terms of a time base includes:

the HC establishing a polling schedule; and

,

in response to the polling schedule, the HC sending a poll to the first STA; and

,

wherein the first STA transmitting traffic information to the second STA through a wireless medium at the second bandwidth includes the first STA transmitting in the TXOP durations derived from the TSPEC.

8. The method of claim 7 wherein monitoring network communications in response to expressing the bandwidth allocation in terms of a time base includes the HC monitoring first STA traffic channel TXOP durations, the PHY data rate within the TXOPs, and the intervals between TXOPs;

and,

wherein measuring the allocated bandwidths includes the HC calculating the ratio of transmitted bits (TXOP duration x PHY data rate) to TXOP intervals for the first STA.

9. The method of claim 8 wherein de-energizing devices in response to the polling schedule includes de-energizing devices in the TXOP intervals between polling events;

and,

the method further comprising;

saving device power in response to de-energizing the devices.

10. The method of claim 9 wherein de-energizing the devices in the TXOP intervals between polling events includes the first STA disengaging transmission and receiving functions in the minimum TXOP intervals, where the minimum TXOP interval is equal to the inter-TXOP interval minus the TXOP jitter.

11. In a wireless local area network (wLAN), a method for saving portable device power, the method comprising:

expressing device bandwidth allocations in terms of a time base;

in response to expressing the bandwidth allocation in terms of a time base, establishing polling schedules; and

,

de-energizing devices in response to the polling schedules.

12. In a wireless local area network (wLAN), a method for saving portable device power, the method comprising:

expressing device bandwidth allocations in terms of a time base;

in response to expressing the bandwidth allocation in terms of a time base, establishing station (STA) transmission schedules; and

,

de-energizing STAs in response to the transmission schedules.

13. The method of claim 12 further comprising:

in response to expressing the bandwidth allocation in terms of a time base, establishing polling schedules;

polling the STAs in response to the polling schedules; and

,

wherein establishing station (STA) transmission schedules includes establishing transmission schedules in response to the polling.

14. In wireless local area network (wLAN) system for controlling bandwidth allocation, the system comprising:

at least one station (STA), each STA having a wireless port to communicate information in a bandwidth allocation expressed in terms of a time base; and

,

a hybrid coordinator (HC) having a wireless communications port to monitor the STA communications and measure the allocated STA bandwidths.

15. The system of claim 14 wherein the HC establishes and polls a communicating STA using polling schedules responsive to the time-based bandwidth allocation;

and,

wherein the communicating STA de-energizes devices in response to the polling schedules.

16. The system of claim 15 wherein the STA communicates in a bandwidth allocation expressed in terms of a time base having an inter-transmission opportunity (TXOP) interval and a TXOP jitter.

17. The system of claim 16 wherein the STA communicates in a time base having an inter-TXOP interval a TXOP jitter, in response to receiving a transmit specification (TSPEC) communication with inter-TXOP and TXOP jitter fields.

18. The system of claim 17 wherein the STA receives a TSPEC communication with a minimum TXOP duration field, a nominal TXOP duration field, and a maximum TXOP duration field.

19. The system of claim 18 further comprising:

a first station (STA) with a wireless communications port requesting permission to communicate traffic information at a second bandwidth, where the second bandwidth is defined as a first desired bandwidth plus a surplus bandwidth allowance;

wherein the HC includes a second STA with a station management entity (SME), the HC relaying the request from the first STA to the second station SME, the second STA SME transmitting a response to the first STA via the HC, including an allocation to communicate with the second STA at the second bandwidth; and

,

wherein the first STA transmits traffic information to the second STA at the second bandwidth.

20. The system of claim 19 wherein the HC, in response to establishing a polling schedule, sends a poll to the first STA;

and,

wherein the first STA transmits in the TXOP durations derived from the TSPEC.

21. The system of claim 20 wherein the HC monitors first STA traffic channel TXOP durations, the PHY data rate within the TXOPs, and the intervals between TXOPs, and measures the allocated bandwidth by calculating the ratio of transmitted bits (TXOP duration x PHY data rate) to TXOP intervals.

22. The system of claim 21 wherein the first STA de-energizes in the TXOP intervals between polling events, and saves power in response to de-energizing.

23. The system of claim 22 wherein the first STA disengages transmission and receiver functions in the minimum TXOP intervals, where the minimum TXOP interval is equal to the inter-TXOP interval minus the TXOP jitter.

24. A wireless local area network (wLAN) system for saving portable device power, the system comprising:

a hybrid coordinator (HC) having a wireless communications port for polling using polling schedules established in response to a time-based bandwidth allocation; and

,

at least one station (STA), each STA having a wireless port to communicate information in the allocated bandwidth and de-energizing transmission and receiver functions in response to the polling schedules.