Channel reuse patterns in a mobile communications system

• US 6,497,599 B1
• Filed: 08/04/1999
• Issued: 12/24/2002
• Est. Priority Date: 03/01/1999
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Johnson, Eric N., Comeau, Adrien A., Barany, Peter A., Kularatna, Shavantha
• Primary Examiner(s): Nguyen, Lee
• Assistant Examiner(s): Nguyen, Simon
• Application Number:
  US09/368,591
• Time in Patent Office: 1,238 Days
• Field of Search: 455/422, 455/446, 455/447, 455/449, 455/450, 370/330, 370/321, 370/343, 370/348, 370/442, 370/468, 370/480, 370/345
• US Class Current: 455/447
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning

Abstract

A mobile communications system having a plurality of cells, with each cell being divided into a number of sectors. Each sector is allocated one of a corresponding number of channels of different frequencies. In addition, a plurality of time groups are defined, and a channel reuse pattern is provided that is based on both channel frequencies and time groups. In one arrangement, a 1/3 channel reuse pattern is provided to carry traffic signals in the system. For control signals, which are more susceptible to interference, a higher effective channel reuse pattern (e.g., 3/9 or 4/12) based on both frequency and time is employed.

Claims

1. A method for use in a mobile communications system having a plurality of cell segments, comprising:

allocating a plurality of channels each having a predetermined frequency to carry signals;

defining a plurality of time groups;

providing a channel reuse pattern for the plurality of cell segments that is based on both channel frequencies and time groups;

providing a frame having a plurality of time slots; and

assigning time slots for carrying control signaling, wherein the time slot for carrying control signaling in any one time group is separated from the time slot for carrying control signaling in any other time group by at least one time slot.

2. The method of claim 1, further comprising synchronizing base stations in the cell segments so that the plurality of time groups are aligned in time in the cell segments.

3. The method of claim 2, wherein the synchronizing includes aligning the time slots in the cell segments.

4. The method of claim 3, further comprising providing a multiframe having a plurality of frames to carry control and data signals, wherein the synchronizing includes aligning the frames in the cell segments.

5. The method of claim 2, wherein N channel frequencies are provided, the method further comprising allocating a different channel frequency to each cell segment in a cluster of N cell segments.

6. The method of claim 5, wherein defining the time groups include defining M time groups, and wherein providing the channel reuse pattern includes providing an effective M/(M*N) channel reuse pattern.

7. The method of claim 5, wherein three channel frequencies are provided, and wherein defining the time groups includes defining three time groups and providing the channel reuse pattern includes providing an effective 3/9 channel reuse pattern based on the three carrier frequencies and the three time groups.

8. The method of claim 5, wherein three channel frequencies are provided, and wherein defining the time groups includes defining four time groups and providing the reuse pattern includes providing an effective 4/12 channel reuse pattern based on the three carrier frequencies and the four time groups.

9. The method of claim 1, further comprising allocating each cell segment a combination of a channel frequency and a time group so that all adjacent cell segments are allocated different time groups to reduce adjacent channel interference.

10. The method of claim 1, further comprising:

carrying control signals and data traffic signals using the plurality of channels; and

providing a second channel reuse pattern for the data traffic signals that is based on the channel frequencies but not the time groups.

11. The method of claim 9, comprising providing a 1/3 channel reuse pattern for the data traffic signals and an effective 3/9 or 4/12 channel reuse pattern for the control signals.

12. The method of claim 1, wherein providing the channel reuse pattern includes defining a cluster of cell segments each assigned a different combination of frequencies and time groups.

13. The method of claim 1, wherein assigning the time slots for carrying control signaling comprises assigning odd time slots but not even time slots for carrying control signaling.

14. The method of claim 13, wherein the frame has time slots TN0, TN1, TN2, TN3, TN4, TN5, TN6, and TN7, and wherein assigning the odd time slots comprises assigning time slots TN1, TN3, TN5, and TN7.

15. The method of claim 1, wherein assigning the time slots for carrying control signaling comprises assigning even time slots but not odd time slots for carrying control signaling.

16. The method of claim 15, wherein the frame has time slots TN0, TN1, TN2, TN3, TN4, TN5, TN6, TN7, and wherein assigning the even time slots comprises assigning time slots TN0, TN2, TN4, and TN6.

17. An apparatus for use in a mobile communications system having a plurality of cell segments, comprising:

an interface unit adapted to communicate with the plurality of cell segments over a wireless link, wherein data and control signaling are carried by a frame having plural time slots over the wireless link; and

a system controller adapted to define a channel reuse pattern for the cell segments, the channel reuse pattern being based on a plurality of allocated carrier frequencies and a plurality of time groups,

the system controller adapted to assign different time slots in respective time groups for carrying control signaling, the time slot of any one time group for carrying control signaling separated from the time slot of any other time group for carrying control signaling by at least one time slot.

18. The apparatus of claim 17, wherein the system controller is adapted to define a cluster of cell segments, each cell segment in the cluster having a different combination of carrier frequencies and time groups.

19. The apparatus of claim 17, wherein the system controller is adapted to define a higher effective channel reuse pattern for the cell segments than is available based on the number of carrier frequencies.

20. The apparatus of claim 17, wherein the system controller is adapted to provide packet-switched communications over the wireless link.

21. The apparatus of claim 17, wherein the system controller is adapted to control communications with N channel frequencies over the link and to define M time groups to provide an effective M/(M*N) channel reuse pattern.

22. The apparatus of claim 21, wherein the channel reuse pattern includes a 4/12 channel reuse pattern.

23. The apparatus of claim 21, wherein the channel reuse pattern includes a 3/9 channel reuse pattern.

24. The apparatus of claim 17, further comprising a second system controller adapted to control communications over a second wireless link.

25. The apparatus of claim 24, wherein the second wireless link includes carriers that are separate from the carriers of the first wireless link.

26. The apparatus of claim 24, wherein the first system controller is adapted to provide packet-switched communications over the first wireless link.

27. The apparatus of claim 24, wherein the second system controller is adapted to provide circuit-switched communications over the second wireless link.

28. The apparatus of claim 17, wherein the system controller is adapted to assign even time slots but not odd time slots for carrying control signaling in the respective time groups.

29. The apparatus of claim 17, wherein the system controller is adapted to assign odd time slots but not even time slots for carrying control signaling in the respective time groups.

30. An article including one or more machine-readable storage media containing instructions for controlling communications in a mobile communications system, the instructions when executed causing a controller to:

allocate a plurality of channels each having a predetermined frequency;

define a plurality of time groups;

provide a channel reuse pattern based on the predetermined channel frequencies and time groups;

provide a frame having a plurality of time slots; and

assign time slots for carrying control signaling, wherein the time slot for carrying control signaling in any one time group is separated from the time slot for carrying control signaling in any other time group by at least one time slot.

31. The article of claim 30, wherein assigning the time slots for carrying control signaling comprises assigning odd time slots but not even time slots for carrying control signaling.

32. The article of claim 30, wherein assigning the time slots for carrying control signaling comprises assigning even time slots but not odd time slots for carrying control signaling.

33. An apparatus for use in a mobile communications system having a plurality of cell segments, comprising:

a station including a transceiver adapted to communicate with plural mobile units in a cell segment using a wireless carrier having a selected one of a plurality of frequencies; and

the station further including a controller adapted to communicate signals on the carrier in a selected one of a plurality of time groups, the controller communicating signals in a channel reuse pattern based on the plurality of frequencies and time groups in which the station is assigned a channel defined by one of the frequencies and time groups,

the controller adapted to perform packet-switched communications with the plural mobile units using the assigned channel,

wherein the wireless carrier carries data and control signaling in a frame having plural time slots, and wherein the controller is adapted to communicate control signaling in one of the time slots based on which time group the station is assigned,

the time slot for carrying control signaling in each frame in the respective time groups separated from each other by at least one time slot.

34. The apparatus of claim 33, further comprising one or more additional stations each having a transceiver adapted to communicate using one or more additional carriers of predetermined frequencies different from the first frequency, the one or more additional stations each assigned to selected ones of the plurality of time groups.

35. The apparatus of claim 34, the stations each including a synchronization circuit to time synchronize all the stations.

36. The apparatus of claim 33, wherein the assigned channel is shared by the plural mobile units for performing the packet-switched communications.

37. The apparatus of claim 33, wherein the time slots for carrying control signaling include even time slots but not odd time slots in the frame.

38. The apparatus of claim 33, wherein the time slots for carrying control signaling include odd time slots but not even time slots in the frame.

39. A method for communicating in a mobile communication system having a plurality of cells, each cell having plural cell sectors, comprising:

providing a plurality of carriers each having a predetermined frequency to carry signals;

allocating a plurality of time groups;

staggering communications of signals across the time groups to create a channel reuse pattern based on the plurality of predetermined frequencies and time groups to provide a higher effective reuse pattern than available from the number of frequencies,

wherein, within each cell, the cell sectors are assigned different frequencies from each other and different time groups from each other; and

providing frames each having plural time slots to carry data and control signaling,

wherein time slots for carrying control signaling in respective time groups are separated from each other by at least one time slot.

40. The method of claim 39, wherein the time slots for carrying control signaling include even time slots but not odd time slots in the frame.

41. The method of claim 39, wherein the time slots for carrying control signaling include odd time slots but not even time slots.