Loading Control Methods And Apparatus For Wireless Access Points Of Wireless Local Area Networks In Support Of Legacy Terminals

• US 20080181184A1
• Filed: 01/31/2007
• Published: 07/31/2008
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Kezys, Vytautas Robertas
• Granted Patent: US 7,774,000 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 16/08 Load shedding arrangements
• CPC Class Codes: H04W 52/143 Downlink power control
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Methods and apparatus for use in controlling the loading of wireless access points (APs) in a wireless local area network (WLAN) in support of legacy terminals are disclosed. The WLAN has at least a first AP and a second wireless AP adjacent the first wireless AP. An indication which indicates whether a loading of the second wireless AP is greater than a predetermined threshold is identified. When the indication indicates thai the loading is greater than the predetermined threshold, a first nominal radio frequency (RF) transmission power of the first wireless AP is increased in order to increase a first RF coverage area of the first wireless AP. A second nominal RF transmission power of the second wireless AP is correspondingly reduced in order to reduce a second RF coverage area of the second wireless AP. In response, some of the mobile communication devices initially operating with the second wireless AP are switched to operate with the first wireless AP in order to reduce the loading of the second wireless AP. The techniques may be embodied in a centralized approach where transmission control equipment of the WLAN controls each wireless APs in this manner, or alternatively in a distributed non-centralized approach where each wireless AP acts independently and autonomously in the same or similar manner. Preferably, the techniques do not require the functional requirements of mobile devices to modified and therefore are suitable for use with existing legacy devices.

Claims

1. A method of controlling the loading of wireless access points of a wireless local area network (WLAN) having at least a first wireless access point and a second wireless access point which neighbors the first wireless access point, the method comprising the acts of:

identifying an indication which indicates whether a loading of the second wireless access point is greater than a predetermined threshold;

when the indication indicates that the loading of the second wireless access point is greater than the predetermined threshold;

causing a first nominal radio frequency (RF) transmission power of the first wireless access point to be increased in order to increase a first RF coverage area of the first wireless access point; and

causing a second nominal RF transmission power of the second wireless access point to be reduced in order to reduce a second RF coverage area of the second wireless access point.

2. The method of claim 1, wherein the act of causing the second nominal RF transmission power of the second wireless access point to be reduced causes the loading of the second wireless access point to be reduced.

3. The method of claim 1, wherein the act of identifying the indication comprises the further act of identifying an indication which indicates whether a capacity of the second wireless access point is greater than a predetermined threshold.

4. The method of claim 1, further comprising:

repeating the acts of causing the first nominal RF transmission power of the first wireless access point to be increased and causing the second nominal RF transmission power of the second wireless access point to be reduced.

5. The method of claim 1, which is performed by transmission control equipment coupled in a computer network which includes the WLAN.

6. The method of claim 1, wherein the acts of identifying and causing the second nominal RF transmission power of the second wireless access point to be reduced is performed by the second wireless access point itself.

7. The method of claim 1, wherein the act of causing the first nominal RF transmission power of the first wireless access point to be increased comprises the further act of increasing the first nominal RF transmission power to help achieve a predetermined minimum loading at the first wireless access point.

8. Transmission control equipment for use in controlling the loading of wireless access points of a wireless local area network (WLAN) which includes at least a first wireless access point and a second wireless access point adjacent the first wireless access point, the transmission control equipment comprising:

a network interface for coupling to the WLAN;

one or more processors coupled to the network interface;

the one or more processors being operative to;

identify an indication which indicates whether a loading of the second wireless access point is greater than a predetermined threshold;

when the indication indicates that the loading of the second wireless access point is greater than the predetermined threshold;

cause a first nominal radio frequency (RF) transmission, power of the first wireless access point to be increased in order to increase a first RF coverage area of the first wireless access point; and

cause a second nominal RF transmission power of the second wireless access point to be reduced in order to reduce a second RF coverage area of the second wireless access point.

9. The transmission control equipment of claim 8, wherein the one or more processors are further operative to cause the second nominal RF transmission power of the second wireless access point to be reduced so as to help cause the loading of the second wireless access to be reduced.

10. The transmission control equipment of claim 8, wherein the one or more processors are further operative to identify an indication which indicates whether a capacity of the second wireless access point is greater than a predetermined threshold.

11. The transmission control equipment of claim 8, wherein the one or more processors are further operative to:

repeat the causing the first nominal RF transmission power of the first wireless access point to be increased and causing the second nominal RF transmission power of the second wireless access point to be reduced.

12. The transmission control equipment of claim 8, wherein the one or more processors are further operative to:

monitor a capacity of each of a plurality of wireless APs of the WLAN which include the first and the second wireless APs.

13. The transmission control equipment of claim 8, wherein the one or more processors are further operative to cause the first nominal RF transmission power of the first wireless access point to be increased to be performed prior to the act of causing the second nominal RF transmission power of the second wireless access point to be reduced.

14. The transmission control equipment of claim 8, which comprises a server.

15. A wireless access point (AP) for use in a wireless local area network (WLAN), the wireless AP comprising:

a wireless transceiver for use in communication information between one or more mobile communication devices and the WLAN;

one or more processors coupled to the wireless transceiver;

the one or more processors being operative to;

identify an indication which indicates whether a loading of the wireless AP is greater than a predetermined threshold; and

in response to the indication indicating that the loading of the wireless AP is greater than the predetermined threshold;

cause a nominal radio frequency (RF) transmission power of the wireless AP to be reduced in order to reduce a RF coverage area of the wireless AP.

16. The wireless AP of claim 15, wherein the loading of the wireless AP is reduced as a result of causing the nominal RF transmission power of the wireless AP being reduced.

17. The wireless AP of claim 15, wherein the one or processors are further operative to:

monitor a capacity of the wireless AP which indicates the loading of the wireless AP.

18. The wireless AP of claim 15, wherein the one or more processors are further operative to:

receive a message from a neighboring wireless AP, the message including a capacity of the neighboring wireless AP.

19. The wireless AP of claim 15, wherein the one or more processors are further operative to:

identity an indication which indicates whether a loading of a neighboring wireless AP is greater than a predetermined threshold; and

when the indication indicates that the loading of the neighboring wireless AP is greater than the predetermined threshold;

cause the nominal radio frequency (RF) transmission power of the wireless AP to be increased in order to increase the RF coverage area of the wireless AP.

20. The wireless AP of claim 15, wherein the one or more processors are further operative to:

repeat the causing of the nominal RF transmission power level to be reduced a plurality of times in response to the indication indicating that the loading of the wireless AP is greater than the predetermined threshold.

21. A wireless access point (AP) for use in a wireless local area network (WLAN), the wireless AP comprising:

a wireless transceiver for use in communication information between one or more mobile communication devices and the WLAN;

one or more processors coupled to the wireless transceiver;

the one or more processors being operative to;

identify an indication which indicates whether a loading of a neighboring wireless AP is greater than a predetermined threshold; and

in response to the indication indicating that the loading of the neighboring wireless AP is greater than the predetermined threshold;

cause a nominal radio frequency (RF) transmission power of the wireless AP to be increased in order to increase an RF coverage area of the wireless AP.

22. The wireless AP of claim 21, wherein the loading of the neighboring wireless AP is reduced as a result of causing the nominal RF transmission power of the wireless AP to be increased.

23. The wireless AP of claim 21, wherein the loading of the wireless AP is increased as a result of causing the nominal RF transmission power of the wireless AP to be increased.

24. The wireless AP of claim 21, wherein the one or processors are further operative to:

monitor a capacity of the wireless AP which indicates the loading of the neighboring wireless AP.

25. The wireless AP of claim 21, wherein the one or more processors are further operative to:

receive a message from the neighboring wireless AP, the message including a capacity of the neighboring wireless AP.

26. The wireless AP of claim 21, wherein the indication which indicates whether the loading of the neighboring wireless AP is greater than the predetermined threshold comprises the further act of receiving the indication from the neighboring wireless AP.

27. The wireless AP of claim 21, wherein the indication which indicates whether the loading of the neighboring wireless AP is greater than the predetermined threshold comprises the further act of receiving the indication from transmission control equipment of the computer network.