Code division multiple access system providing enhanced load and interference based demand assignment service to users

• US 6,069,883 A
• Filed: 04/08/1997
• Issued: 05/30/2000
• Est. Priority Date: 10/05/1995
• Status: Expired due to Term

• Current Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Nanda, Sanjiv, Laha, Subhasis, Ejzak, Richard Paul, Kumar, Sarath, Knisely, Douglas, I, Chih-Lin
• Primary Examiner(s): VU, HUY DUY
• Application Number:
  US08/841,980
• Time in Patent Office: 1,148 Days
• Field of Search: 370/468, 370/465, 370/335, 370/342, 370/441, 370/522, 370/229, 370/230, 370/235, 370/252, 455/450, 455/452, 455/67.1, 455/67.3, 455/63
• US Class Current: 370/335
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 72/541 using the level of interference

Abstract

A code division multiple access system method and apparatus provides for allocation of increased bandwidth to a requesting mobile station. An access controller receives a data burst request (from either a requesting mobile station or from an external network already in connection with the mobile station) requesting a first data rate in excess of the basic data rate B allocated to a mobile station of a first cell. The access controller determines an increased data rate which is to be granted to said mobile station without causing excessive interference at said first cell and at least one adjacent cell and transmits a data burst assignment to a base station of said first cell indicating the increased data rate which has been granted to said mobile station. In another feature, the access controller processes a data burst request received from a mobile station involved in a soft handoff between multiple base stations and negotiates with those base stations for an increased data rate which may be granted to the requesting mobile station. One feature enables additional interactions to further refine the allocation process. A variety of system architectures are also described.

Claims

1. In a code division multiple access system including an access controller and multiple cells, each cell having a base station and multiple mobile stations, a method of allocating bandwidth to a mobile station comprising the steps of:

at the access controller,

receiving a data burst request requesting a first data rate in excess of the basic data rate B allocated to a mobile station of a first cell,

determining an increased data rate which is to be granted to said mobile station without causing excessive interference at said first cell and at least one adjacent cell; and

transmitting a data burst assignment to a base station of said first cell indicating the increased data rate which has been granted to said mobile station.

2. The method of claim 1 wherein the data burst request is a request received from said mobile station requesting an increased data rate over a basic data rate for a reverse link connection to the base station of said first cell.

3. The method of claim 2 wherein the data burst request received from said mobile station includes pilot strength information for the base station of said first cell and a base station of at least one cell adjacent to said first cell and wherein

the access controller uses the received pilot strength information to determine an increased data rate which is to be granted to said requesting mobile station without causing excessive interference at said first cell and said at least one adjacent cell.

4. The method of claim 1 wherein the data burst request is a request received from a network external to the system, already in connection with said mobile, requesting an increased data rate for an forward link connection between said mobile and the base station of said first cell.

5. The method of claim 2 wherein said increased data rate uses multiple basic data rate units, including the original basic data rate unit, each unit using a different CDMA channel and wherein the base station uses a separate channel element for interfacing to each CDMA channel.

6. The method of claim 5 wherein finger tracking information obtained in a channel element used for a CDMA channel of the original basic data rate unit are used by all of the channel elements.

7. The method of claim 1 wherein said increased data rate from the mobile station uses multiple basic data rate units, each unit using a different CDMA channel and wherein the system includes a Packet Processing Element (PPE) for processing all Frame Selection and Distribution (FSD), Encryption (ENC) and Radio Link Protocol (RLP) data for each of the multiple CDMA channels received from a base station.

8. The method of claim 1 wherein said increased data rate for the mobile station uses multiple basic data rate units, each unit using a different CDMA channel and wherein the system includes a Packet Processing Element (PPE) for processing all Frame Selection and Distribution (FSD), Encryption (ENC) and Radio Link Protocol (RLP) data for the original basic data rate CDMA channel and a separate PPE for processing all FSD and ENC data of remaining ones of the multiple CDMA channels.

9. The method of claim 1 wherein said increased data rate from the mobile station uses multiple basic data rate units, each unit using a different CDMA channel and wherein the system includes a Packet Processing Element (PPE) for processing all Frame Selection and Distribution (FSD) and a Interworking Function (IWF) unit for processing all Encryption (ENC) and Radio Link Protocol (RLP) data for each of the multiple CDMA channels.

10. The method of claim 2 wherein power control in any CDMA channel of the reverse link is based on the power control of a basic data rate CDMA channel of the reverse link.

11. The method of claim 4 wherein power control in any CDMA channel of the forward link between the base station of said first cell and said mobile is based on an error rate of the basic data rate CDMA channel forward link.

12. The method of claim 1 wherein when said mobile station is in soft handoff with at least two base stations, burst negotiation occurs between access controller and the base stations, over existing voice and data packet connections.

13. The method of claim 2 wherein said mobile station uses one or more different code masks derived from a basic PN sequence mask for one or more additional codes used to transmit at the increased data rate, the one or more code masks obtained by modifying a known subset of the basic PN sequence mask in accordance with pre-specified rules.

14. The method of claim 4 wherein the base station uses Walsh codes having a pre-specified relationship therebetween for one or more additional Walsh codes used to transmit at the increased data rate.

15. The method of claim 14 wherein the pre-specified relationship is that the Walsh codes are contiguous.

16. The method of claim 1 where the increased data rate allocation is done on a slot basis, each slot including multiple frames of predefined duration.

17. The method of claim 1 wherein following a data burst request received prior to a predetermined interval before the beginning of a slot, each of the at least two base stations determine the increased data rate available at that base station and send an allocation response to the access controller at a predetermined time before said slot.

18. The method of claim 1 wherein the data burst assignment lasts for a predetermined time, and following a continuation request, a new data burst assignment is not transmitted if it is unchanged from the previous data burst assignment.

19. The method of claim 1 wherein the determining step at the access controller is responsive to an allocation response from a base station, where said base station gives priority to data burst continuation requests for a mobile over new data burst requests for a different mobile.

20. The method of claim 1 wherein the determining step at the access controller is responsive to an allocation response from a base station, where said base station allocates resources to data burst requests from different mobiles based on their priority.

21. The method of claim 1 wherein the determining step at the access controller is responsive to an allocation response from a base station, where said base station fairly allocates resources to all data burst requests from different mobiles of equal priority.

22. An access controller for use in a code division multiple access system including multiple cells, each cell having a base station and multiple mobile stations, the access controller comprising,

means for receiving a data burst request requesting a first data rate in excess of the basic data rate B allocated to a mobile station of a first cell,

means for determining an increased data rate which is to be granted to said mobile station without causing excessive interference at said first cell and at least one adjacent cell;

and

means for transmitting a data burst assignment to a base station of said first cell indicating the increased data rate which has been granted to said mobile station.

23. The access controller of claim 22 wherein the data burst request is received from said mobile station and includes pilot strength information for the base station of said first cell and a base station of at least one cell adjacent to said first cell and wherein

the access controller uses the received pilot strength information to determine an increased data rate which is to be granted to said requesting mobile station without causing excessive interference at said first cell and said at least one adjacent cell.

24. The access controller of claim 22 wherein said increased data rate for the mobile station uses multiple basic data rate units, each unit using a different CDMA channel and wherein the system includes a Packet Processing Element (PPE) for processing all Frame Selection and Distribution (FSD), Encryption (ENC) and Radio Link Protocol (RLP) data for each of the multiple CDMA channels received from a base station.

25. The access controller of claim 22 wherein said increased data rate for the mobile station uses multiple basic data rate units, each unit using a different CDMA channel and wherein the system includes a Packet Processing Element (PPE) for processing all Frame Selection and Distribution (FSD), Encryption (ENC) and Radio Link Protocol (RLP) data for the original basic data rate CDMA channel and a separate PPE for processing all FSD and ENC data of remaining ones of the multiple CDMA channels.

26. The access controller of claim 22 wherein said increased data rate for the mobile station uses multiple basic data rate units, each unit using a different CDMA channel and wherein the system includes a Packet Processing Element (PPE) for processing all Frame Selection and Distribution (FSD) and a Interworking Function (IWF) unit for processing all Encryption (ENC) and Radio Link Protocol (RLP) data for each of the multiple CDMA channels.

27. In a code division multiple access system including multiple cells, each cell having a base station and multiple mobile stations, a method of allocating bandwidth to a mobile station in soft handoff with at least two base stations, comprising the steps of:

at an access controller,

receiving a data burst request requesting a first data rate in excess of the basic data rate B allocated to that mobile station;

requesting, in response to the burst request received from the at least two base stations, an increased data rate from the two base stations;

receiving an allocation response from each of the at least two base stations indicating an increased data rate available at that base station;

transmitting a burst assignment from the access controller to the at least two base stations indicating an allocated increased data rate which may be granted to said requesting mobile station, said allocated increased data rate determined from the allocation response received from the at least two base stations.

28. The method of claim 27 wherein the allocated increased data rate does not exceed the minimum of the allocated increased data rates received in the allocation response from the at least two base stations.

29. The method of claim 27 wherein the burst request includes pilot strength information for the at least two base stations.

30. The method of claim 27 further comprising the steps of:

at the access controller, following the allocation response step,

transmitting an allocation request to the at least two base stations indicating an preliminary increased data rate which may be granted to said requesting mobile station, said preliminary increased data rate not exceeding the minimum of the two increased data rates received from the at least two base stations,

receiving a second allocation response from each of the at least two base stations indicating an updated allocated data rate available at that base station, and wherein

the burst assignment of the transmitting step indicates the updated allocated increased data rate which is to be granted to said requesting mobile station.

31. A code division multiple access system including multiple cells, each cell having a base station and multiple mobile stations, the system further comprising

at least two base stations, each including a controller means for controlling the

receiving of a data burst request from a mobile station requesting a first data rate in excess of the basic data rate B allocated to that mobile station;

transmitting of an allocation response to the access controller in response to a received request for an increased data rate from the access controller; and

receiving of a burst assignment from the access controller indicating an allocated increased data rate which may be granted to said requesting mobile station; and

said access controller, for controlling the

requesting, in response to the data burst request received from the at least two base stations, an increased data rate from the two base stations;

receiving of the allocation response from each of the at least two base stations indicating an increased data rate available at that base station; and

transmitting of the burst assignment from the access controller to the at least two base stations indicating said allocated increased data rate which may be granted to said requesting mobile station, said allocated increased data rate not exceeding the minimum of the two increased data rates received from the at least two base stations.