Method and apparatus for determining and managing congestion in a wireless communications system

• US 20050157676A1
• Filed: 09/13/2004
• Published: 07/21/2005
• Est. Priority Date: 07/23/2003
• Status: Active Grant

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Marinier, Paul, Rahman, Shamim Akbar, Hunkeler, Teresa Joanne, Kwak, Joseph A., Rudolf, Marian, Roy, Vincent, Cave, Christopher, Cuffaro, Angelo, Touag, Athmane, Ali, Ahmed, LaSita, Frank
• Granted Patent: US 8,005,055 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 28/0205 at the air interface dynamic wireless traffic scheduling H04W72/12
• CPC Class Codes: H04W 28/0284 detecting congestion or overload during communication monitoring arrangements H04L43/00
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 72/00 Local resource management
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

An improved method of network management, particularly in the context of standards IEEE802.11 and IEEE802.11k, through two new MAC measurements, with attendant advantages. The two new measurements include WTRU uplink traffic loading measurement, and an AP service loading measurement and is generally applicable at least to layers 1 and 2 as applied to a least 802.11k in the context of OFDM and CDMA 2000 systems, but is applicable to other scenarios as well. A Method for determining and advertising congestion is also provided for a Wireless Local Area Network (WLAN) system. The present invention also introduces a method for managing congestion when congestion is detected. This aspect of the present invention applies primarily to wireless systems that use the Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA) mechanism. The methods are advantageously implemented in selectively configured WTRUs of various forms.

Claims

1. A method for providing channel management in a wireless network, in order to optimize network utilization by both access points (APs) and wireless transmit receive units (WTRUs) capable of wireless communications with each other on wireless channels, comprising:

creating a service load indicator by a first AP for each access category;

advertising the service load indicator to WTRUs within a service range of the first AP; and

selecting an AP by the WTRU based on the service load indicator.

2. The method of claim 1 wherein the service load indicator is an indication of average access delay at the first AP.

3. The method of claim 2 wherein the average access delay is measured in a predetermined time period.

4. The method of claim 3 wherein the time period is thirty (30) seconds.

5. The method of claim 1 wherein the access categories include voice, video, best effort, and background traffic.

6. The method of claim 1 further comprising:

receiving the advertised service load indicator from by a second AP; and

using the advertised service load indicator in deciding disassociation of WTRUs by the second AP.

7. The method of claim 6 wherein the second AP disassociates WTRUs with the second AP where the service load indicator from the first AP is low compared to a service load indicator determined by the second AP.

8. An access point (AP) configured to provide channel management in a wireless network for both access points (APs) and wireless transmit receive units (WTRUs) wherein said WTRUs are capable of wireless communications with the APs over wireless channels, the AP comprising:

a processor configured to calculate a service load indicator for each access category; and

a transmitter configured to advertise the service load indicator to WTRUs within the AP wireless service range whereby WTRUs located within the AP wireless service range of the AP can use the advertised service load indicator to assist in selection of an AP with which to conduct a wireless communication.

9. The AP of claim 8 wherein:

the receiver is configured to receive advertised service load indicators from other APs; and

the processor is configured to use the advertised service load indicators received from other APs to assist in decisions regarding disassociating WTRUs with the AP.

10. A wireless transmit/receive unit (WTRU) configured to provide channel management in a wireless network comprising a plurality of access points (APs) and wireless transmit receive units (WTRUs), the WTRU comprising:

a receiver for receiving a service load indicator for each access category from an AP; and

a processor configured to utilize the service load indicator in selection of an AP with which to conduct a wireless communication.