Method and apparatus for handoff control in mobile communications systems

• US 20070177510A1
• Filed: 01/31/2006
• Published: 08/02/2007
• Est. Priority Date: 01/31/2006
• Status: Active Grant

• Current Assignee: Google Technology Holdings LLC (Alphabet Inc.)
• Original Assignee: Motorola Mobility, Inc. (Lenovo Group Ltd.)
• Inventors: Gutowski, Gerald, Natarajan, Kadathur, Boscovic, Dragan
• Granted Patent: US 7,848,241 B2
• Time in Patent Office: Days
• US Class Current: 370/238
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/008357 Determination of target cell based on access point [AP] properties, e.g. AP service capabilities
• CPC Class Codes: H04W 36/00837 Determination of triggering parameters for hand-off
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 92/20 between access points

Abstract

A mobile communications system includes a first base station to service a first set of connections from a first set of mobile communications devices to a communications network. A set of neighboring base stations is in communication with the first base station. In an embodiment of the invention, the first base station prioritizes the first set of connections according to first predetermined criteria and prioritizes the set of neighboring base stations according to second predetermined criteria. The prioritization lists are used in deterministic ways to alleviate potential congestion in backhaul links and optimize the overall performance of system and improved quality of service.

Claims

1. A mobile communications system, comprising:

a first base station to service a first set of connections from a first set of mobile communications devices to a communications network;

a set of neighboring base stations in communication with the first base station; and

wherein the first base station prioritizes the first set of connections according to first predetermined criteria, and prioritizes the set of neighboring base stations according to second predetermined criteria.

2. The mobile communications system of claim 1, wherein in response to a backhaul congestion between the first base station and the network exceeding a first predetermined threshold level, the first base station hands off at least one of the prioritized connections to a base station in the set of neighboring base stations until the backhaul congestion is below a predetermined second threshold level.

3. The mobile communications system of claim 2, wherein the handing off of the at least one prioritized connection is rejected in response to insufficient backhaul availability for the base station in the set of neighboring base stations, a corresponding data field indicating a reason for the rejection.

4. The mobile communications system of claim 1, wherein the first base station comprises a memory device to store a list of the set of neighboring base stations, the list including a set of backhaul measurements and overlay technology corresponding to each base station in the set of neighboring base stations.

5. The mobile communications system of claim 1, wherein the predetermined first threshold level is greater than the predetermined second threshold level.

6. The mobile communications system of claim 1, wherein the first base station comprises a processing device to detect an amount of the backhaul congestion between the first base station and the network.

7. The mobile communications system of claim 1, wherein the first predetermined criteria is selected from a group consisting of:

bandwidth utilization and premium service classification.

8. The mobile communications system of claim 1, wherein a specific neighboring base station of the set of neighboring base stations is selected to receive the at least one handed off connection such that a second backhaul congestion of the specific neighboring base station is below a third threshold level after the handoff.

9. The mobile communications system of claim 1, wherein the second predetermined criteria comprises a detected amount of available bandwidth.

10. A method, comprising:

servicing, at a first base station, a first set of connections from a first set of mobile communications devices to a communications network;

determining backhaul congestion between the first base station and the communications network to provide determined backhaul congestion;

prioritizing the first set of connections according to predetermined criteria in response to the determined backhaul congestion being greater than a first predetermined threshold level to provide prioritized connections; and

handing off at least one of the prioritized connections to a base station in a set of neighboring base stations until the backhaul congestion is below a predetermined second threshold level.

11. The method of claim 10, further comprising storing, at the first base station, a list of the set of neighboring base stations, wherein the list includes a set of backhaul measurements and overlay corresponding to each one of the set of neighboring base stations.

12. The method of claim 10, wherein the predetermined first threshold level is greater than the predetermined second threshold level.

13. The method of claim 10, wherein the predetermined criteria is selected from a group consisting of:

bandwidth utilization and premium service classification.

14. The method of claim 10, further including determining the backhaul congestion based on individual connection identifiers for the first set of connections.

15. The method of claim 10, further comprising selecting a specific neighboring base station of the set of neighboring base stations to receive the at least one handed off connection such that a second backhaul congestion of the specific neighboring base station is below a third threshold level after the handoff.

16. A base station, comprising:

circuitry to service a first set of connections from a first set of mobile communications devices to a communications network;

a memory device to store a list of a set of neighboring base stations; and

a processing device operably coupled to the circuitry and the memory device to detect an amount of backhaul congestion between the base station and the communications network and being configured and arranged to respond to backhaul congestion between the base station and the communications network that exceeds a first predetermined threshold level by prioritizing the first set of connections according to predetermined criteria and handing off at least one prioritized connection to a base station in a set of neighboring base stations until the backhaul congestion is below a predetermined second threshold level.

17. The base station of claim 16, wherein the list further comprises a set of backhaul measurements and overlay corresponding to each base station in the set of neighboring base stations.

18. The base station of claim 16, wherein the predetermined first threshold level is greater than the predetermined second threshold level.

19. The base station of claim 16, wherein the predetermined criteria is selected from a group consisting of:

bandwidth utilization and premium service classification.