Reducing access latency while protecting against control signaling data processing overload

• US 20080242301A1
• Filed: 04/02/2007
• Published: 10/02/2008
• Est. Priority Date: 04/02/2007
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Karlsson, Jonas B., Osterling, Kristian J., Andersson, Peter
• Granted Patent: US 7,773,991 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 76/30 Connection release
• CPC Class Codes: H04W 92/20 between access points

Abstract

A control signal data processing load associated with mobile terminals currently having a connection with a radio access network is regulated. The connection is terminated when the control processing cost for maintaining the connection exceeds the benefit of maintaining the connection to achieve shorter access latency. A connection activity level is determined for current connections between multiple mobile terminals and a base station. A current data processing load in the base station associated with the mobile terminal control signaling is calculated. A decision is made whether one or more of the mobile terminals is likely to request a handover of its respective connection to a neighboring base station. Based on the current load, the likelihood of requesting handover of the respective connection, and the connection activity level determined for the respective connection, a decision is made whether to terminate the respective connection.

Claims

1. A method for regulating a data processing load for control signaling associated with mobile terminals currently having a connection with a base station in a radio access network, comprising:

determining a connection activity level for current connections between multiple mobile terminals and the base station;

determining whether one or more of the mobile terminals is likely to request a handover of its respective connection to a neighboring base station; and

determining whether to terminate the respective connection based on the likelihood of handover being requested for the respective connection and the connection activity level determined for the respective connection.

2. The method in claim 1, wherein each mobile terminal having a connection with the base station is in a connected state in which the radio access network is aware of a cell in which the mobile terminal is currently located, the mobile terminal is authenticated, and the mobile terminal is assigned a local data packet routing address, and

wherein each mobile terminal that does not have a connection or has terminated connection is in an idle or disconnected state in which the radio access network is aware of a paging area much larger than the cell in which the mobile terminal is currently located, the mobile terminal is not authenticated, and the mobile terminal is not assigned a local data packet routing address.

3. The method in claim 1, further comprising:

determining a current data processing load in the base station that is associated with the mobile terminal control signaling;

comparing the current data processing load to a load threshold; and

determining whether to terminate the respective connection based on the likelihood of requesting handover of the respective connection, the connection activity level determined for the respective connection, and the load comparison.

4. The method in claim 3, further comprising:

informing one or more neighboring base stations when the current data processing load exceeds a threshold to deter the handover requests from the one or more neighboring base stations.

5. The method in claim 3, further comprising:

classifying the connection activity level for current connections as more active or less active, and

terminating the respective connection when the respective connection is classified as less active and the connection is causing control processing load or is likely to cause control processing load.

11. The method in claim 1, wherein the activity level of a connection is determined based on a time of a most recent data transmission over that connection.

12. The method in claim 1, wherein maintaining the respective connection achieves shorter access latency.

6. The method 5, further comprising:

if the determined load does not exceed a first threshold, designating the current load level for the base station as normal;

if the determined load exceeds a first threshold but is less than or equal to a second higher threshold, designating the current load level for the base station as loaded; and

if the determined load exceeds the second threshold, designating the current load level for the base station as congested.

7. The method in claim 6, further comprising:

if the base station load level is normal, sending a normal message to one or more neighboring base stations indicating that the base station can accept a handover request of a mobile terminal connection from the one or more neighboring base stations;

if the base station load level is loaded, sending a loaded message to the one or more neighboring base stations; and

if the base station load level is congested, sending a congested message to the one or more neighboring base stations.

8. The method in claim 7, further comprising:

if the base station load level is loaded or congested, rejecting handover of a less active connection from a neighboring base station.

9. The method in claim 8, further comprising:

if the base station load level is loaded or congested, accepting handover of a more active connection from a neighboring base station and terminating a less active connection being currently handled by the base station.

10. The method in claim 6, further comprising:

receiving a load state from a neighboring base station;

evaluating handover information for a connection likely to request hand over to the neighboring base station;

if the load state in the neighboring base station is other than normal, terminating the connection likely to request hand over to the neighboring base station if that connection is less active.

13. Apparatus for regulating a data processing load associated with control signaling associated with mobile terminals currently having a connection with a base station in a radio access network, comprising electronic circuitry configured to:

determine a connection activity level for current connections between multiple mobile terminals and the base station;

determine whether one or more of the mobile terminals is likely to request a handover of its respective connection to a neighboring base station; and

determine whether to terminate the respective connection based on the likelihood of handover being requested for the respective connection and the connection activity level determined for the respective connection.

14. The apparatus in claim 13, wherein each mobile terminal having a connection with the base station is in a connected state in which the radio access network is aware of a cell in which the mobile terminal is currently located, the mobile terminal is authenticated, and the mobile terminal is assigned a local data packet routing address, and

wherein each mobile terminal that does not have a connection or has terminated connection is in an idle or disconnected state in which the radio access network is aware of a paging area much larger than the cell in which the mobile terminal is currently located, the mobile terminal is not authenticated, and the mobile terminal is not assigned a local data packet routing address.

15. The apparatus in claim 13, wherein the electronic circuitry is further configured to:

determine a current data processing load in the base station that is associated with the mobile terminal control signaling;

compare the current data processing load to a load threshold; and

determine whether to terminate the respective connection based on the likelihood of requesting handover of the respective connection, the connection activity level determined for the respective connection, and the load comparison.

16. The apparatus in claim 13, wherein the electronic circuitry is further configured to:

inform one or more neighboring base stations when the current data processing load exceeds a threshold to deter the handover requests from the one or more neighboring base stations.

17. The apparatus in claim 14, wherein the electronic circuitry is further configured to:

classify the connection activity level for current connections as more active or less active, and

terminate the respective connection when the respective connection is classified as less active when the current data processing load exceeds a threshold.

18. The apparatus in claim 17, wherein the electronic circuitry is further configured to:

designate the current load level for the base station as normal if the determined load does not exceed a first threshold;

designate the current load level for the base station as loaded if the determined load exceeds a first threshold but is less than or equal to a second higher threshold; and

designate the current load level for the base station as congested if the determined load exceeds the second threshold.

19. The apparatus in claim 18, wherein the electronic circuitry is further configured to:

send a normal message to one or more neighboring base stations indicating that the base station can accept a handover request of a mobile terminal connection from the one or more neighboring base stations if the base station load level is normal;

send a loaded message to the one or more neighboring base stations if the base station load level is loaded; and

send a congested message to the one or more neighboring base stations if the base station load level is congested.

22. The apparatus in claim 17, wherein the electronic circuitry is further configured to:

receive a load state from a neighboring base station;

evaluate handover information for a connection likely to request hand over to the neighboring base station; and

terminate the connection likely to request hand over to the neighboring base station if that connection is less active and if the load state in the neighboring base station is other than normal.

23. The apparatus in claim 13, wherein the electronic circuitry is further configured to determine the activity level of a connection based on a time of a most recent data transmission over that connection.

20. The apparatus in claim 20, wherein the electronic circuitry is further configured to:

reject handover of a less active connection from a neighboring base station if the base station load level is loaded or congested.

21. The apparatus in claim 20, wherein the electronic circuitry is further configured to:

accept handover of a more active connection from a neighboring base station and terminate a less active connection being currently handled by the base station if the base station load level is loaded or congested.