Method and a network node for controlling output uplink and downlink power levels in a mobile communications system

• US 8,908,635 B2
• Filed: 05/23/2007
• Issued: 12/09/2014
• Est. Priority Date: 05/23/2007
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Boncz, Lars, Olsson, Andreas
• Primary Examiner(s): SMARTH, GERALD A
• Application Number:
  US12/593,931
• Publication Number:
  US 20100074227A1
• Time in Patent Office: 2,757 Days
• Field of Search: 370/331
• US Class Current: 370/331
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/40 during macro-diversity or soft handoff
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

The present inventions relates to a method and a network node for controlling an output uplink power level of a mobile station and for controlling an output downlink power level of a target base station in a target cell of a mobile communications system. The method comprises receiving at the network node a message indicating that a handover of the mobile station from an originating cell to the target cell is completed; and commanding the target base station to use an initial output downlink power level and the mobile station to use an initial output uplink power level, wherein the initial output downlink power level and the initial output uplink power level are based on at least previous power control levels used a time after previous handovers were completed between the originating cell and the target cell.

Claims

1. A method for controlling an output uplink power level of a mobile station and controlling an output downlink power level of a target base station in a target cell of a mobile communications system, the method comprising:

receiving, at a network node of said mobile communications system, a message indicating that a handover of said mobile station from an originating cell to said target cell, is completed;

commanding, after reception of said message, said target base station to use an initial output downlink power level where said initial output downlink power level is determined responsive to one or more previous output downlink power levels used by the target base station to communicate to one or more other mobile stations after their handovers were completed between said originating cell and said target cell; and

commanding, after reception of said message, said mobile station to use an initial output uplink power level where said initial output uplink power level is determined responsive to one or more previous output uplink power levels used by one or more other mobile stations to communicate to the target base station after their handovers were completed between said originating cell and said target cell,

where said initial output downlink power level and said initial output uplink power level are further based on a timing advance value between the mobile station and the target base station,

wherein the timing advance value is determined responsive to the distance between the mobile station and the target base station.

2. The method according to claim 1 where said initial output uplink power level and said initial downlink power level are further based on a received level of downlink signal strength of the target base station, measured before said handover between the originating cell and the target cell was executed.

3. The method according to claim 1 where said initial output downlink power level and said initial output uplink power level are further based on a path loss in said target cell.

4. The method according to claim 1 where the initial output downlink power level the target base station is to use is commanded by said network node in a base station power control command message.

5. The method according to claim 1 where the initial output uplink power level the mobile station is to use is commanded by said network node, in a mobile station power control command message.

6. The method according to claim 1, further comprising:

storing, by said network node, said previous power control levels used at a time after previous handovers between said originating cell and said target cell, in a database;

further storing, in said database, previous power control levels used at a time after previous handovers of one or more different mobile stations between cells in said mobile communications system; and

accessing said database to retrieve the previous power control levels used after previous handovers of one or more different mobile stations between cells in said mobile communications system for use in determining the initial output uplink power level for use by the mobile station.

7. A method for controlling an output uplink power level of a mobile station and controlling an output downlink power level of a target base station in a target cell of a mobile communications system, the method comprising:

receiving, at a network node of said mobile communications system, a message indicating that a handover of said mobile station from an originating cell to said target cell, is completed;

commanding, after reception of said message, said target base station to use an initial output downlink power level where said initial output downlink power level is determined responsive to one or more previous output downlink power levels used by the target base station to communicate to one or more other mobile stations after their handovers were completed between said originating cell and said target cell; and

commanding, after reception of said message, said mobile station to use an initial output uplink power level where said initial output uplink power level is determined responsive to one or more previous output uplink power levels used by one or more other mobile stations to communicate to the target base station after their handovers were completed between said originating cell and said target cell,

where said initial output downlink power level is lower than or equal to an output downlink power level used by said target base station during said handover of one or more different mobile stations and said initial output uplink power level is lower than or equal to an output uplink power level used by said mobile station for initial signaling said target cell during said handover of one or more different mobile stations,

where said output uplink power level used by said mobile station for initial signaling in said target cell during said handover is equal to a maximum assigned output uplink power level after previous handovers of one or more different mobile stations, and said output downlink power level used by said target base station during said handover is equal to a maximum allowed output downlink power level after previous handovers of one or more different mobile stations.

8. A network node, of a mobile communications system, for controlling an output uplink power level of a mobile station and controlling an output downlink power level of a target base station in a target cell of said mobile communications system, said network node comprising:

a receiver configured to receive a message indicating that a handover of said mobile station from an originating cell to said target cell is completed; and

circuitry configured to command, after reception of said message, said mobile station to use an initial output uplink power level, where said initial output uplink power level is determined responsive to one or more previous output uplink power levels used by one or more other mobile stations to communicate to the target base station after their handovers were completed between said originating cell and said target cell; and

wherein the circuitry configured to command is further configured to command, after reception of said message, said target base station to use an initial output downlink power level, where said initial output downlink power level is determined responsive to one or more previous output downlink power levels used by the target base station to communicate to one or more other mobile stations after their handovers were completed between said originating cell and said target cell,

where said initial output downlink power level and said initial output uplink power level are further based on a timing advance value between the mobile station and the target base station,

wherein the timing advance value is determined responsive to the distance between the mobile station and the target base station.

9. The network node according to claim 8 where said initial output uplink power level and said initial downlink power level are further based on a received level of a downlink signal of the target base station, measured before said handover between the originating cell and the target cell was executed.

10. The network node according to claim 8 where said initial output downlink power level and said initial output uplink power level are further based on a path loss in said target cell.

11. The network node according to claim 8 wherein the circuitry configured for commanding further commands, using a base station power control command message, said target base station to use the initial output downlink power level.

12. The network node according to claim 8 where wherein the circuitry configured for commanding further commands, using a mobile station power control command, said mobile station to use the initial output uplink power level.

13. The network node according to claim 8 where said network node is a base station controller BSC in said mobile communications system.

14. The network node according to claim 13 is further operable, in an inter-BSC handover, to inform, by an originating BSC, a target BSC, of a measured downlink signal strength of the target base station.

15. A network node, of a mobile communications system, for controlling an output uplink power level of a mobile station and controlling an output downlink power level of a target base station in a target cell of said mobile communications system, said network node comprising:

a receiver configured to receive a message indicating that a handover of said mobile station from an originating cell to said target cell is completed; and

circuitry configured to command, after reception of said message, said mobile station to use an initial output uplink power level, where said initial output uplink power level is determined responsive to one or more previous output uplink power levels used by one or more other mobile stations to communicate to the target base station after their handovers were completed between said originating cell and said target cell; and

wherein the circuitry configured to command is further configured to command, after reception of said message, said target base station to use an initial output downlink power level, where said initial output downlink power level is determined responsive to one or more previous output downlink power levels used by the target base station to communicate to one or more other mobile stations after their handovers were completed between said originating cell and said target cell,

where said initial output downlink power level is lower than or equal to an output downlink power level used by said target base station during said handover of one or more different mobile stations and said initial output uplink power level is lower than or equal to an output uplink power level used by said mobile station for initial signaling in said target cell during said handover of one or more different mobile stations,

where said output uplink power level used by said mobile station for initial signaling in said target cell during said handover is equal to a maximum assigned output uplink power level after previous handovers of one or more different mobile stations, and said output downlink power level used by said target base station during said handover is equal to a maximum allowed output downlink power level after previous handovers of one or more different mobile stations.

16. A non-transitory computer-readable medium having instructions stored thereon, which are executable by a computer system, configured to control an output uplink power level of a mobile station and configured to control an output downlink power level of a target base station in a target cell of a mobile communications system, the instructions comprising:

instructions configured to receive a message indicating that a handover of said mobile station from an originating cell to said target cell, is completed;

instructions configured to command, after reception of said message, said target base station to use an initial output downlink power level where said initial output downlink power level is determined responsive to one or more previous output downlink power levels used by the target base station to communicate to one or more other mobile stations after their handovers were completed between said originating cell and said target cell; and

instructions configured to further command, after reception of said message, said mobile station to use an initial output uplink power level where said initial output uplink power level is determined responsive to one or more previous output uplink power levels used by one or more other mobile stations to communicate to the target base station after their handovers were completed between said originating cell and said target cell,

where said initial output downlink power level and said initial output uplink power level are further based on a timing advance value between the mobile station and the target base station,

wherein the timing advance value is determined responsive to the distance between the mobile station and the target base station.