Code assignment in HS-SCCH less operation mode

• US 8,582,451 B2
• Filed: 08/23/2007
• Issued: 11/12/2013
• Est. Priority Date: 08/23/2007
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Hannu, Hans, Ericson, Mrten, Synnergren, Per
• Primary Examiner(s): Mesfin, Yemane
• Assistant Examiner(s): DAVENPORT, MON CHERI S
• Application Number:
  US12/674,710
• Publication Number:
  US 20110110245A1
• Time in Patent Office: 2,273 Days
• Field of Search: 370/241, 370/252, 370/255, 370/328, 370/335, 370/342
• US Class Current: 370/252
• CPC Class Codes: H04J 13/0077 Multicode, e.g. multiple codes assigned to one user
• CPC Class Codes: H04J 13/16 Code allocation
• CPC Class Codes: H04W 72/0466 the resource being a scrambling code
• CPC Class Codes: H04W 72/52 based on load

Abstract

In a method and a system a good spread of users per code is obtained by providing a value related to the current load for each code in the system. The estimated load value can be used by the network to assign the HS-PDSCH code for users in HS-SCCH less operation, and may also be used in the dynamic transmission process, i.e. which codes are to be used by which user during this and future TTIs. If one code is over a given utilization threshold, where the threshold is set in order to avoid code blocking of VoIP users, enough users can be re-assigned to a different code. In the case that all of the current codes used in the HS-SCCH less operation model are over the utilization threshold, yet another code can be made available for HS-SCCH less operation.

Claims

1. A method implemented by a node in a cellular radio system for assigning codes for users in the system operating in a High Speed Shared Control Channel (HS-SCCH) less mode of operation, the method comprising:

determining the system load generated by a user communicating with the system in a HS-SCCH less operation mode; and

assigning a code for the user in response to said determined system load, wherein said assigning comprises determining, for each available code, the combined system load generated by all users currently assigned to that code and further comprises either;

assigning the user to an available code if the combined system load for that available code plus the system load determined for the user would not exceed a predetermined utilization threshold value;

or

responsive to determining that, for each available code, the combined system load for that available code plus the system load determined for the user would exceed the predetermined utilization threshold value, making another code available and assigning that newly available code to the user.

2. The method of claim 1, wherein assigning a code for the user comprises assigning a High Speed Physical Downlink Shared Channel (HS-PDSCH) code.

3. The method of claim 1, wherein determining the system load generated by a user comprises determining the system load based on one or many of the following parameters:

MAC-hs buffer level;

packet arrival time;

number of re-transmissions;

transmit power usage; and

interference level.

4. The method claim 1, further comprising:

determining if one used code is above the predetermined utilization threshold value.

5. The method of claim 4, wherein, if said one used code is determined to be above the predetermined utilization threshold value, one or more users assigned to that code is reassigned to another code.

6. The method of claim 4, further comprising:

making another code available if all used codes exceed their respective predetermined utilization threshold values.

7. The method of claim 1, further comprising:

continuously or periodically determining the load caused by all users of a particular code and comparing said combined load to the pre-determined utilization threshold value.

8. The method of claim 7, wherein, if a used code is determined to be above the predetermined utilization threshold value, one or more users assigned to that code is reassigned to another code.

9. A node of a cellular radio system operating in a High Speed Shared Control Channel (HS-SCCH) less mode of operation, the node adapted to assign codes for users and comprising:

a load determination circuit configured to determine the system load generated by a user communicating with the system in a HS-SCCH less operation mode, and

a code assignment circuit configured to assign a code for the user in response to said determined system load, by determining, for each available code, the combined system load generated by all users currently assigned to that code and further by either;

assigning the user to an available code if the combined system load for that available code plus the system load determined for the user would not exceed a predetermined utilization threshold value;

or

responsive to determining that, for each available code, the combined system load for that available code plus the system load determined for the user would exceed the predetermined utilization threshold value, making another code available and assigning that newly available code to the user.

10. The node of claim 9, wherein the code assignment circuit is configured to assign a High Speed Physical Downlink Shared Channel (HS-PDSCH) code.

11. The node of claim 9, wherein the load determination circuit is configured to determine the system load based on one or many of the following parameters:

MAC-hs buffer level;

packet arrival time;

number of re-transmissions;

transmit power usage; and

interference level.

12. The node of claim 9, wherein the load determination circuit is further configured to determine if one used code is above the predetermined utilization threshold value.

13. The node of claim 12, wherein the code assignment circuit is configured to re-assign one or more users assigned to said one used code to another code, if said one used code is determined to be above the predetermined utilization threshold value.

14. The node of claim 12, wherein the code assignment circuit is configured to make another code available if all used codes exceed their respective predetermined utilization threshold values.

15. The node of claim 9, wherein the load determination circuit is configured to continuously or periodically determine the load caused by all users of a particular code and compare said combined load to the pre-determined utilization threshold value.

16. The node of claim 15, wherein the code assignment circuit is configured to re-assign one or more users assigned to a code to another code, if that code is determined to be above the pre-determined utilization threshold value.