Method and apparatus for determining and managing congestion in a wireless communications system
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.
1. A method for use in an access point (AP), the method comprising:
generating a service load indicator that includes:
a best effort (BE) delay field that indicates a representation of: an average access delay for BE frames transmitted during a measurement window, that a BE service is unavailable, or that the average access delay for BE frames is not available;
a background (BK) delay field that indicates a representation of: an average access delay for BK frames transmitted during the measurement window, that a BK service is unavailable, or that the average access delay for BK frames is not available;
a video (VI) delay field that indicates a representation of: an average access delay for VI frames transmitted during the measurement window, that a VI service is unavailable, or that the average access delay for VI frames is not available; and
a voice (VO) delay field that indicates a representation of: an average access delay for VO frames transmitted during the measurement window that a VO service is unavailable, or that the average access delay for VO frames is not available; and
transmitting the service load indicator as part of a single message.
2. The method of claim 1 wherein the measurement window is a predetermined time period.
3. The method of claim 2 wherein the time period is thirty seconds.
4. The method of claim 1 wherein the service load indicator is 4 octets, and the BE delay field, the BK delay field, the VO delay field, and the VI delay field are each a different octet of the 4 octets.
5. The method of claim 4 wherein a value in an octet indicates a scaled representation of an average access delay for a corresponding access category.
6. The method of claim 4 wherein a value in an octet indicates an average access delay greater than a threshold for a corresponding access category.
7. The method of claim 4 wherein a value in an octet indicates that a service for a corresponding access category is unavailable.
8. The method of claim 4 wherein a value in an octet indicates that an average access delay for a corresponding access category is not available.
9. A method for use in wireless station (STA), the method comprising:
receiving, from an access point (AP), a service load indicator as part of a single message, wherein the service load indicator includes:
a best effort (BE) delay field that indicates a representation of: an average access delay for BE frames transmitted by the AP during a measurement window, that a BE service is unavailable, or that the average access delay for BE frames is not available;
a background (BK) delay field that indicates a representation of: an average access delay for BK frames transmitted by the AP during the measurement window, that a BK service is unavailable, or that the average access delay for BK frames is not available;
a video (VI) delay field that indicates a representation of: an average access delay for VI frames transmitted by the AP during the measurement window, that a VI service is unavailable, or that the average access delay for VI frames is not available; and
a voice (VO) delay field that indicates a representation of: an average access delay for VO frames transmitted by the AP during the measurement window that a VO service is unavailable, or that the average access delay for VO frames is not available.
10. The method of claim 9 wherein the measurement window is a predetermined time period.
11. The method of claim 10 wherein the time period is thirty seconds.
12. The method of claim 9 wherein the service load indicator is 4 octets, and the BE delay field, the BK delay field, the VO delay field, and the VI delay field are each a different octet of the 4 octets.
13. The method of claim 12 wherein a value in an octet indicates a scaled representation of an average access delay for a corresponding access category.
14. The method of claim 12 wherein a value in an octet indicates an average access delay greater than a threshold for a corresponding access category.
15. The method of claim 14 wherein a value in an octet indicates that a service for a corresponding access category is unavailable.
16. The method of claim 14 wherein a value in an octet indicates that an average access delay for a corresponding access category is not available.
17. An access point (AP) comprising:
a processor configured to generate a service load indicator that includes:
a best effort (BE) delay field that indicates a representation of: an average access delay for BE frames transmitted by the AP during a measurement window, that a BE service is unavailable, or that the average access delay for BE frames is not available;
a background (BK) delay field that indicates a representation of: an average access delay for BK frames transmitted by the AP during the measurement window, that a BK service is unavailable, or that the average access delay for BK frames is not available;
a video (VI) delay field that indicates a representation of: an average access delay for VI frames transmitted by the AP during the measurement window, that a VI service is unavailable, or that the average access delay for VI frames is not available; and
a voice (VO) delay field that indicates a representation of: an average access delay for VO frames transmitted by the AP during the measurement window that a VO service is unavailable, or that the average access delay for VO frames is not available; and
a transmitter configured to transmit the service load indicator as part of a single message.
18. The AP of claim 17 wherein the measurement window is a predetermined time period.
19. The AP of claim 18 wherein the time period is thirty seconds.
20. The AP of claim 17 wherein the service load indicator is 4 octets, and the BE delay field, the BK delay field, the VO delay field, and the VI delay field are each a different octet of the 4 octets.
21. The AP of claim 20 wherein a value less in an octet indicates a scaled representation of an average access delay for a corresponding access category.
22. The AP of claim 20 wherein a value in an octet indicates an average access delay greater than a threshold for a corresponding access category.
23. The AP of claim 20 wherein a value in an octet indicates that a service for a corresponding access category is unavailable.
24. The AP of claim 20 wherein a value in an octet indicates that an average access delay for a corresponding access category is not available.
25. A wireless station (STA) comprising:
a receiver configured to receive, from an access point (AP), a service load indicator as part of a single message, wherein the service load indicator includes:
a best effort (BE) delay field that indicates a representation of: an average access delay for BE frames transmitted by the AP during a measurement window, that a BE service is unavailable, or that the average access delay for BE frames is not available;
a background (BK) delay field that indicates a representation of: an average access delay for BK frames transmitted by the AP during the measurement window, that a BK service is unavailable, or that the average access delay for BK frames is not available;
a video (VI) delay field that indicates a representation of: an average access delay for VI frames transmitted by the AP during the measurement window, that a VI service is unavailable, or that the average access delay for VI frames is not available; and
a voice (VO) delay field that indicates a representation of: an average access delay for VO frames transmitted by the AP during the measurement window that a VO service is unavailable, or that the average access delay for VO frames is not available.
26. The STA of claim 25 wherein the measurement window is a predetermined time period.
27. The STA of claim 26 wherein the time period is thirty seconds.
28. The STA of claim 25 wherein the service load indicator is 4 octets, and the BE delay field, the BK delay field, the VO delay field, and the VI delay field are each a different octet of the 4 octets.
29. The STA of claim 28 wherein a value in an octet indicates a scaled representation of an average access delay for a corresponding access category.
30. The STA of claim 28 wherein a value in an octet indicates an average access delay greater than a threshold for a corresponding access category.
31. The STA of claim 28 wherein a value in an octet indicates that a service for a corresponding access category is unavailable.
32. The STA of claim 28 wherein a value in an octet indicates that an average access delay for a corresponding access category is not available.