System and method for channel allocation in a multi-band wireless network

• US 20030064727A1
• Filed: 06/26/2002
• Published: 04/03/2003
• Est. Priority Date: 10/02/2001
• Status: Active Grant

• Current Assignee: Quanta Computer
• Original Assignee: Quanta Computer
• Inventors: Lin, Yi-Bing, Tsai, Hsien-Ming
• Granted Patent: US 6,954,645 B2
• Time in Patent Office: Days
• US Class Current: 455/449
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 72/563 of the wireless resources
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Disclosed is a system and method for channel allocation in a multi-band wireless network. The system includes microcell base stations, at least one macrocell base station, a mobile station, and a channel allocation center. When the mobile station makes/receives a call or executes a handover, the channel allocation center uses repacking on demand (RoD) scheme to allocate a radio channel of either a macrocell base station or a microcell base station to the mobile station. RoD has the following steps. First, a microcell channel is trying to be allocated if available. If no microcell channel is available, a macrocell channel is then trying to be allocated. Third, if no macrocell channel is available, repacking is performed to execute a handover of another mobile station'"'"'s call from the macrocell to another microcell, and to allocate a reclaimed macrocell channel to the mobile station. Otherwise, no repacking call is available and the mobile station is blocked or forced terminated. By the invention, call blocking probability and call handover rate of the mobile stations in the multi-band wireless network can be reduced, and thus users'"'"' satisfaction can be enhanced.

Claims

1. A system for channel allocation in a multi-band wireless network, comprising:

a plurality of microcell base stations, providing a plurality of microcell channels;

a macrocell base station, providing a plurality of macrocell channels, wherein the radio coverage of the macrocell base station is overlaid with that of the microcell base stations;

a mobile station, capable of making and receiving a call by using a channel from the microcell channels and the macrocell channels; and

a channel allocation center, capable of performing repacking on demand (RoD) scheme for allocating a first one of the macrocell channels and the microcell channels to a first one of the mobile stations for a call.

2. The system according to claim 1, wherein the channel allocation center starts the RoD scheme when the mobile station attempts to make a call.

3. The system according to claim 1, wherein the channel allocation center starts the RoD scheme when the mobile station attempts to receive a call.

4. The system according to claim 1, wherein the channel allocation center starts the RoD scheme when the mobile station executes a handover from a current base station to a new base station.

5. The system according to claim 1, wherein the RoD scheme comprising:

determining whether there are any idle radio channels provided by one of the microcell base stations for the mobile station;

if so, allocating an idle radio channel provided by a first one of the microcell base stations to the mobile station, and then ending the scheme;

if not, proceeding to the following steps;

determining whether there are any idle radio channels provided by the macrocell base station for the mobile station;

if so, allocating an idle radio channel provided by the macrocell base station to the mobile station, and then ending the scheme;

if not, proceeding to the following steps;

determining whether there are any available repacking candidates in the macrocell base station for the mobile station;

if so, selecting a repacking candidate and executing a handover of the repacking candidate from the macrocell base station to the microcell base station of the repacking candidate, and allocating the macrocell channel reclaimed from the repacking candidate to the mobile station, and then ending the scheme;

if not, proceeding to the following step; and

ending the scheme if no idle radio channel is available.

6. The system according to claim 5, wherein the repacking candidate is randomly selected from available repacking candidates by the channel allocation center.

7. The system according to claim 5, wherein the repacking candidate is selected from available repacking candidates by the channel allocation center, wherein the microcell base station of the selected repacking candidate has a maximum number of idle radio channels among those of the available repacking candidates.

8. The system according to claim 5, wherein the repacking candidate is selected from available repacking candidates by the channel allocation center, wherein the selected repacking candidate is generated from a mobile station with the slowest speed among other mobile stations that generate the available repacking candidates.

9. The system according to claim 1, wherein the channel allocation center is capable of detecting high-speed mobile stations and using repacking on demand for high-speed mobile stations (RoD-H) scheme to allocate one of the macrocell channels and microcell channels to a high-speed mobile station.

10. The system according to claim 9, wherein the channel allocation center performs the RoD-H scheme when the high-speed mobile station is trying to make a call.

11. The system according to claim 9, wherein the channel allocation center performs the RoD-H scheme when the high-speed mobile station is trying to receive a call.

12. The system according to claim 9, wherein the channel allocation center performs the RoD-H scheme when the high-speed mobile station executes a handover from a current base station to a new base station.

13. The system according to claim 9, wherein the RoD-H scheme comprises:

determining whether any idle radio channels are available in the macrocell base station of the high-speed mobile station;

if so, allocating an idle macrocell channel to the high-speed mobile station and then ending the scheme;

otherwise, proceeding to the following step;

determining whether any repacking candidates of slow-speed mobile stations exist in the macrocell base station of the high-speed mobile station;

if so, selecting a repacking candidate of a slow-speed mobile station, executing a handover from the macrocell base station to the microcell base station of the repacking candidate of the slow-speed mobile station, allocating a reclaimed macrocell channel to the high-speed mobile station and then ending the scheme;

otherwise, proceeding to the following step;

determining whether any idle radio channels are available in the microcell base station of the high-speed mobile station;

if so, allocating an idle microcell channel to the high-speed mobile station and then ending the scheme;

otherwise, proceeding to the following step;

determining whether any repacking candidates of another high-speed mobile station exist in the macrocell base station of the high-speed mobile station;

if so, selecting a repacking candidate of a first high-speed mobile station, executing a handover from the macrocell base station to the microcell base station of the repacking candidate of first high-speed mobile station, allocating a reclaimed macrocell channel to the high-speed mobile station and then ending the scheme;

otherwise, proceeding to the following step; and

ending the scheme if no idle radio channel is available for the high-speed mobile station.

14. The system according to claim 13, wherein the repacking candidate is randomly selected from available repacking candidates by the channel allocation center.

15. The system according to claim 13, wherein the repacking candidate is selected from available repacking candidates by the channel allocation center, wherein the microcell base station of the selected repacking candidate has a maximum number of idle radio channels among those of the available repacking candidates.

16. A method for channel allocation of a mobile station in a multi-band wireless network, the method comprising the steps of:

determining whether any idle radio channel provideds by the microcell base station of the mobile station are available;

if so, allocating an idle radio channel of the microcell base station to the mobile station and then ending the method;

otherwise, proceeding to the following steps;

determining whether any idle radio channel provided by the macrocell base station of the mobile station is available;

if so, allocating an idle radio channel of the macrocell base station to the mobile station and then ending the method;

if not, proceeding to the following steps;

determining whether any repacking candidates exist in the macrocell base station of the mobile station;

if so, selecting a repacking candidate, executing a handover from the macrocell base station to the microcell base station of the selected repacking candidate, and allocating a reclaimed radio channel in the macrocell base station to the mobile station and then ending the method;

if not, proceeding to the following step; and

ending the method if no idle radio channel is available for the mobile station.

17. The method according to claim 16, wherein the method is to be performed when the mobile station is trying to make a call.

18. The method according to claim 16, wherein the method is to be performed when the mobile station executes a handover from the current base station to a new base station.

19. A method for channel allocation of a high-speed mobile station in a multi-band wireless network, the method comprising the steps of:

determining whether any idle radio channels are available in a macrocell base station of the high-speed mobile station;

if so, allocating an idle macrocell channel to the high-speed mobile station and then ending the method;

otherwise, proceeding to the following step;

determining whether any repacking candidates of slow-speed mobile stations exist in the macrocell base station of the high-speed mobile station;

if so, selecting a repacking candidate of slow-speed mobile stations, executing a handover from the macrocell base station to the microcell base station of the repacking candidate, allocating a reclaimed macrocell channel to the high-speed mobile station and then ending the method;

otherwise, proceeding to the following step;

determining whether any idle radio channel are available in the microcell base station of the high-speed mobile station;

if so, allocating an idle microcell channel to the high-speed mobile station and then ending the method;

otherwise, proceeding to the following step;

determining whether any repacking candidates of other high-speed mobile stations exist in the macrocell base station of the high-speed mobile station;

if so, selecting a first repacking candidate of another high-speed mobile station, executing a handover from the macrocell base station to the microcell base station of the first repacking candidate, allocating a reclaimed macrocell channel to the high-speed mobile station and then ending the method;

otherwise, proceeding to the following step; and

ending the method if no idle radio channel is available for the mobile station.

20. The method according to claim 19, wherein the method is to be performed when the high-speed mobile station is trying to make a call.

21. The method according to claim 19, wherein the method is to be performed when the high-speed mobile station executes a handover from the current base station to a new base station.