Method and Arrangement for Allocating a Dedicated Channel in a Cellular Communication System

• US 20070259668A1
• Filed: 04/07/2005
• Published: 11/08/2007
• Est. Priority Date: 04/13/2004
• Status: Active Grant

• Current Assignee: Intellectual Ventures Holding 81 LLC (Intellectual Ventures LLC)
• Original Assignee: Intellectual Ventures Holding 81 LLC (Intellectual Ventures LLC)
• Inventors: Legg, Peter
• Granted Patent: US 8,983,478 B2
• Time in Patent Office: Days
• US Class Current: 455/450
• CPC Class Codes: H04B 7/2656 for structure of frame, burst
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/563 of the wireless resources

Abstract

A dynamic channel assignment scheme for a TDD radio communication system (100) with coexisting dedicated (230; 240) and shared (210; 220) channels has segregated dedicated and shared channel mechanisms. Up to n_{DL—DCH—MAX}/n_{UL—DCH—MAX} dedicated downlink/uplink channel slots are granted, with the remainder of slots for shared channels. These maximum numbers accommodate the needs of conversational and streaming class traffic carried on shared channels. New slots can be claimed for dedicated channels (subject to this maximum) as required, taking the shared channel slot with the smallest timeslot. If the last DCH allocation in a slot is ended, the slot is freed for DSCH/USCH usage. This provides the following advantage(s): uplink algorithm metrics account for intercell interference, the most significant interference source in TDD mode systems, leading to greater capacity; midcall reallocation allows coverage and quality of service to a user to be maintained when a user moves from the centre of the cell to the cell edge; dynamic split between dedicated channel timeslots and shared channel timeslots allows the network to optimise radio resources according to traffic type, leading to an overall higher capacity when the network supports both dedicated channels and shared channels; alignment of the DCH slots across many cells improves the usefulness of measurements for DCA/CAC.

Claims

1. :

A method of allocating a dedicated communication channel in a cellular communication system comprising;

determining a ranking for a plurality of communication channels designated as dedicated channels;

selecting a highest ranked communication channel of the plurality of communication channels as a test communication channel;

performing an allocation feasibility test for the test communication channel; and

if the test communication channel passes the allocation feasibility test, allocating the test communication channel; and

if the test communication channel does not pass the feasibility test, determining if the plurality of communication channels comprises any non-tested communication channels; and

if the plurality of communication channels comprises any non-tested communication channels, selecting the next highest ranked communication channel as the test communication channel and proceeding with the step of performing an allocation feasibility test; and

if the plurality of communication channels does not comprise any non-tested communication channels, re-designating a first communication channel designated as a shared communication channel as a dedicated communication channel.

2. :

The method of claim 1 further comprising selecting the dedicated communication channel as the test communication channel and proceeding with the step of performing the allocation feasibility test.

3. :

The method of claim 1 further comprising re-designating the first communication channel as a shared communication channel in response to a determination of a cease of demand for the first communication channel as a dedicated communication channel.

4. :

The method of claim 1 wherein the re-designation of the first communication channel is subject to a current number of dedicated channels being below a maximum threshold.

5. :

The method of claim 1 comprising performing call admission control.

6. :

The method of claim 1 comprising initializing a communication using the allocated dedicated communication channel.

7. :

The method of claim 1 comprising initiating the allocation of the dedicated communication channel in response to a determination of a mid call reconfiguration detection.

8. :

The method of claim 1 comprising allocating the first communication channel to an existing call and increasing a spreading factor associated with the existing call.

9. :

The method of claim 1 wherein the ranking is in response to intercell interference signals associated with the plurality of communication channels.

10. :

The method of claim 1 wherein the allocation feasibility test comprises testing if a Code Division Multiple Access code is available for the dedicated communication channel.

11. The method of claim 1 wherein the dedicated communication channel is an uplink communication channel and the allocation feasibility test comprises determining a resulting user equipment transmit power and testing if this is below a maximum transmit power threshold for the user equipment.

12. :

The method of claim 1 wherein the dedicated communication channel is an uplink communication channel and the allocation feasibility test comprises determining a resulting interference level for at least one neighbour cell.

13. :

The method of claim 1 wherein the dedicated communication channel is a downlink communication channel and the allocation feasibility test comprises determining a resulting base station transmit power and testing if this is below a maximum transmit power threshold for the base station.

14. :

The method of claim 1 wherein each communication channel corresponds to a time slot.

15. :

The method of claim 1 comprising selecting the first communication channel such that time slots of dedicated communication channels are grouped together.

16. :

The method of claim 1 wherein the first communication channel is designated as a high speed downlink shared channel.

17. :

The method of claim 1 wherein the cellular communication system comprises a UTRA system.

18. :

The method of claim 1 wherein the cellular communication system comprises a 3GPP system.

19. :

An apparatus for allocating a dedicated communication channel in a cellular communication system, the apparatus comprising;

means for determining a ranking for a plurality of communication channels designated as dedicated channels;

means for selecting a highest ranked communication channel of the plurality of communication channels as a test communication channel;

means for performing an allocation feasibility test for the test communication channel; and

means for, if the test communication channel passes the allocation feasibility test, allocating the test communication channel; and

means for, if the test communication channel does not pass the feasibility test, determining if the plurality of communication channels comprises any non-tested communication channels; and

means for, if the plurality of communication channels comprises any non-tested communication channels, selecting the next highest ranked communication channel as the test communication channel and proceeding with the step of performing an allocation feasibility test; and

means for, if the plurality of communication channels does not comprise any non-tested communication channels, re-designating a first communication channel designated as a shared communication channel as a dedicated communication channel.

20. :

The apparatus of claim 19 further comprising means for selecting the dedicated communication channel as the test communication channel and proceeding with the step of performing the allocation feasibility test.

21. :

The apparatus of claim 19 further comprising means for re-designating the first communication channel as a shared communication channel in response to a determination of a cease of demand for the first communication channel as a dedicated communication channel.

22. :

The apparatus of claim 19 comprising means for initializing a communication using the allocated dedicated communication channel.

23. :

The apparatus of claim 19 wherein each communication channel corresponds to a time slot.

24. :

A method of dynamic channel assignment for a TDD communication system, comprising;

allocating, on demand, a channel timeslot for use as a dedicated channel; and

allocating, on cease of demand, the channel timeslot for use as a shared channel.

25. :

The method of claim 24 wherein the plurality of channel timeslots has a dynamically assigned maximum number.

26. :

The method of claim 24 wherein the method is arranged to dynamically assign at least one of A-B;

A at least one uplink channel,

B at least one downlink channel.

27. :

The method of claim 24 wherein the step of allocating a channel timeslot for use as a dedicated channel comprises allocating a timeslot from a plurality of potential timeslots in dependence on intercell interference signals associated with the potential timeslots.

28. :

The method of claim 27 wherein the intercell interference signals are based on interference signal code power and signal to interference ratio associated with a plurality of other cells.

29. :

The method of claim 24 wherein the step of allocating a channel timeslot for use as a dedicated channel comprises;

testing each of a plurality of selected shared channel timeslots for code resource acceptability, transmit power acceptability and intercell interference acceptability; and

if the testing fails selecting a shared channel timeslot with lowest timeslot number and testing the selected shared channel timeslot for transmit power acceptability and intercell interference acceptability.

30. :

The method of claim 24 wherein the;

step of allocating a channel timeslot for use as a dedicated channel comprises allocating to an existing call an additional timeslot and increasing the spreading factor associated with the call.

31. :

An arrangement for dynamic channel assignment in a TDD communication system, comprising;

means for allocating, on demand, a channel timeslot for use as a dedicated channel; and

means for allocating, on cease of demand, the channel timeslot for use as a shared channel.