Apparatus and methods for managing access and update requests in a wireless network

• US 20100002582A1
• Filed: 07/03/2008
• Published: 01/07/2010
• Est. Priority Date: 07/03/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Bienas, Maik, Luft, Achim
• Granted Patent: US 8,259,659 B2
• Time in Patent Office: Days
• US Class Current: 370/230.1
• CPC Class Codes: H04W 74/002 Transmission of channel access control information
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: H04W 74/0841 with collision treatment
• CPC Class Codes: H04W 74/0866 using a dedicated channel for access

Abstract

Methods and apparatus that enable a wireless network to detect and manage impending congestion events caused by a plurality of mobile devices attempting to access the network in a brief space of time. In one embodiment, the network comprises a 3g (UMTS) cellular network, and includes a congestion management and avoidance entity that preemptively triggers a collision mode upon detecting an impending congestion event. This mode advantageously reduces processing burden on the base station by causing the mobile devices (UEs) to halt current access attempts, and invoke a multiple access scheme (e.g., wait a random amount of time before attempting further access attempts). The comparatively early detection and avoidance of collisions reduces the mobile device'"'"'s power consumption, while addressing congestion events early in the wireless communication process so as to maintain optimal network conditions.

Claims

1. A method for reducing network access congestion on a wireless network having a plurality of wireless devices associated therewith, the method comprising:

monitoring a first channel to detect a plurality of requests issued by respective ones of said plurality of wireless devices;

determining when a triggering criterion has been met based at least in part on said monitoring; and

sending a plurality of responses on a second channel to said respective ones of said plurality of devices, said responses imposing a multiple access scheme on subsequent access request messages from said respective ones of said plurality of wireless devices, said multiple access scheme reducing congestion within at least a portion of said network.

2. The method of claim 1, wherein said multiple access scheme comprises staggering of said plurality of subsequent request messages in response to receiving said plurality of response messages.

3. The method of claim 1, wherein said wireless network comprises a UMTS-compliant system, said first channel comprises a RACH channel, said second channel comprises an AICH channel, and said triggering criterion is met at least in part based on the substantially contemporaneous crossing of a geographic boundary of a prescribed number of said wireless devices.

4. The method of claim 1, wherein said act of monitoring occurs periodically during a historically congestive event.

5. The method of claim 4, wherein said historically congestive event comprises a metropolitan area rush hour.

6. The method of claim 1, wherein said wireless network comprises a UMTS-compliant system, and said requests comprise at least one of:

(i) location area (LA) and/or routing area (RA) update requests, or (ii) RRC (connection) requests.

7. The method of claim 1, wherein said wireless network comprises a relay station, and prior to sending said plurality of responses on said second channel, said method further comprises disabling uplink and/or downlink communications at said relay station.

8. The method of claim 7, further comprising setting a timer value and waiting for said timer value to expire prior to re-enabling said uplink and/or downlink communications at said relay station.

9. The method of claim 1, wherein said network comprises a cellular network comprising a base station and a relay station, said relay station being in communication with said base station and at least a portion of said plurality of wireless devices, and said acts of monitoring and sending are performed by said relay station.

10. A computer readable apparatus comprising a storage medium storing at least one computer program, said program comprising a plurality of instructions which, when executed by a processing device:

monitor an access channel of a wireless network to determine a number of wireless devices that intend to issue an access request message; and

send a plurality of negative response messages on a synchronization channel of said wireless network if said number of wireless devices that intend to issue an access request message exceeds a threshold value.

11. The computer readable apparatus of claim 10, wherein said threshold value corresponds to a level of network congestion value that would substantially degrade the operation of said wireless network.

12. The computer readable apparatus of claim 11, wherein said computer readable apparatus comprises a storage device of a relay station within said wireless network.

13. The computer readable apparatus of claim 12, wherein said network comprises a 3G cellular network, said access channel comprises a RACH, said synchronization channel comprises an AICH, and said monitoring of said access channel comprises monitoring for RRC connection or LA/RA update requests from said wireless devices.

14. The computer readable apparatus of claim 12, wherein said method further comprises disabling uplink and/or downlink communications at said relay station if said number of wireless devices that intend to issue an access request message exceeds a threshold value.

15. A congestion-avoidance system for use in a wireless network, the system comprising:

an access node;

a relay station in wireless signal communication with said access node; and

a plurality of wireless devices configured to at least communicate indirectly with said access station via said relay station;

wherein said relay station comprises apparatus adapted to cause delay of a plurality of access request messages to said access station whenever the number of said plurality of wireless devices expected to issue said access request messages exceeds a prescribed criterion.

16. The system of claim 15, wherein said relay station is disposed proximate to a geographic location area/routing area boundary in a cellular network.

17. The system of claim 15, wherein said apparatus adapted to cause a delay comprises logic adapted to issue NACK (no acknowledgement) messages to respective ones of said wireless devices requesting a connection, said NACK causing said wireless devices to invoke said delay on a subsequent request transmission.

18. Apparatus for reducing network access congestion, comprising:

a receiver;

a transmitter;

a processing device; and

a memory;

wherein said memory comprises a computer program having instructions which, when executed by said processing device;

detects when the number of wireless devices that intend to issue an update request message or a random access will meet a given criterion;

receives via said receiver a plurality of requests on an access channel; and

transmits a plurality of negative response messages on a synchronization channel in response to at least a portion of said received requests.

19. The apparatus of claim 18, wherein said apparatus comprises a relay station resident at a geographic location area/routing area boundary in a cellular network.

20. The apparatus of claim 18, wherein said access channel comprises a RACH channel, said synchronization channel comprises an AICH channel, and said given threshold is exceeded when the number of wireless devices that intend to issue an update request message cross a geographic boundary.

21. The apparatus of claim 18, wherein said update request message comprises a location area (LA) and/or routing area (RA) update request.

22. The apparatus of claim 21, wherein said requests comprise radio resource control (RRC) connection requests.

23. The apparatus of claim 18, wherein said update request message comprises a random access.

24. The apparatus of claim 18, wherein said apparatus comprises a relay station that is resident at a mobile environment.

25. A method of operating a cellular communication system so as to avoid simultaneously receiving an excessive number of requests for a service on a first channel, comprising sending a message on a second channel, said message resulting in a staggering of said requests.

26. The method of claim 25, wherein said cellular system comprises a 3G system, said first channel comprises a RACH channel, said second channel comprises an AICH channel, and said excessive number of requests are triggered by the substantially simultaneous crossing of a geographic boundary by a plurality of users of said 3G system.

27. The method of claim 25, wherein said message sent on said second channel is indicative of a collision between two or more of said requests when in fact such requests had no such collision.

28. A method of reducing the power consumption of mobile devices used within a wireless network, said mobile devices each comprising a first protocol and a second related protocol, the method comprising:

receiving requests according to said first protocol from respective ones of said mobile devices; and

issuing responses to said requests according to said first protocol, said issuing causing respective ones of said mobile devices to avoid invoking said second protocol for at least a period of time;

wherein said second protocol would be invoked by said mobile devices but for said issued responses; and

wherein said avoidance of said second protocol causes a reduction in power consumption within said mobile devices as compared to the power consumption associated with operating according to said second protocol.

29. The method of claim 28, wherein said reduction in power consumption within said mobile devices as compared to the power consumption associated with operating according to said second protocol is due at least in part to avoiding multiple request retransmission attempts associated with said second protocol.

30. The method of claim 29, wherein said multiple request retransmission attempts result from collisions occurring between respective ones of said mobile devices that are requesting access to said network.

31. The method of claim 28, wherein said issuing responses is based at least in part on an evaluation of said requests received according to said first protocol.

32. The method of claim 31, wherein said first protocol comprises a channel connection request, and said second protocol comprises a network update request.

33. A method of reducing the power consumption of mobile devices used within a wireless network, said mobile devices each comprising a first protocol and a second protocol, said first protocol having a first power consumption associated therewith, and said second protocol having a second, greater power consumption associated therewith, the method comprising:

receiving a plurality of requests issued by respective ones of said mobile devices according to said first protocol; and

spoofing collisions of said requests by sending responses to said issuing mobile devices that are indicative of a collision;

wherein said spoofing causes said issuing mobile devices to enter an operational mode for at least a period of time that does not utilize said second protocol; and

wherein without said spoofing, said second protocol would be utilized.

34. The method of claim 33, wherein said first protocol comprises a channel connection request, said second protocol comprises a network update request, and said spoofing comprises sending NACK messages indicative of collisions when in fact no such collisions have occurred.