Method for performing handover by considering quality of service in broadband mobile communication system and system for providing the same

• US 8,169,967 B2
• Filed: 03/18/2008
• Issued: 05/01/2012
• Est. Priority Date: 03/30/2007
• Status: Active Grant

• Current Assignee: Korea University Industrial & Academic Collaboration Foundation, Samsung Electronics Co. Ltd.
• Original Assignee: Korea University Industrial & Academic Collaboration Foundation, Samsung Electronics Co. Ltd.
• Inventors: Lee, Chang-Hyun, Ko, Sung-Jea, Oh, Yun-Je, Park, Tae-Sung, Park, Jeong-Rok, Choi, Jeong-Seok, Joo, Young-Hun, Kim, Hye-Soo, Chae, Kyung-Ho
• Primary Examiner(s): Pwu, Jeffrey
• Assistant Examiner(s): Esmaeilian, Majid
• Application Number:
  US12/050,341
• Publication Number:
  US 20080240043A1
• Time in Patent Office: 1,505 Days
• Field of Search: 370/331
• US Class Current: 370/331
• CPC Class Codes: H04W 36/26 by agreed or negotiated communication parameters
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data

Abstract

A system and method for performing a handover of a mobile station (MS) by considering Quality of Service (QoS) in a broadband mobile communication system. The method can include the steps of: receiving information about one or more neighbor base stations and reception strengths for the neighbor base stations from a Serving Radio Access System (RAS) currently communicating with the MS; extracting a value of a specific field from the received information about the neighbor base stations; combining the extracted value of the specific field with the reception strengths to thereby obtain combined values, and selecting a maximum value among the combined values; and transmitting a handover (handoff) request message to a base station corresponding to the selected maximum value. The system includes an MS that analyzes information about neighbor stations received in a Mobile Neighbor Base-station Advertisement (MOB_NBR_ADV) message to select a target RAS.

Claims

1. A method for performing a handover of a mobile station (MS) in a broadband mobile communication system, the method comprising:

(a) receiving information about respective neighbor base stations and reception strengths for the respective neighbor base stations from a Serving Radio Access System (RAS) currently communicating with the MS;

(b) extracting a value of at least one specific field from the received information about the neighbor base stations, said information including a base station utilization level;

(c) combining the extracted value regarding base station utilization level of the neighbor base stations with respective reception strengths of the neighbor base station to obtain respective combined values, the method of combining favoring higher reception strength and lower utilization level, wherein the utilization level provides a greater contribution to the combined value than the reception strength; and

(d) selecting a maximum value from among the combined values in step (c);

(e) selecting a base station corresponding to the selected maximum value from the neighbor base stations; and

(f) transmitting a handover request message to the selected base station.

2. The method of claim 1, wherein the information about the neighbor base stations comprises a Mobile Neighbor Base-station Advertisement (MOB_NBR_ADV) message.

3. The method of claim 1, wherein the information about a utilization level of said base station of said one or more neighbor base stations is determined by a frequency of use of said base station and a number of users.

4. The method of claim 2, wherein the at least one specific field is allocated in the MOB_NBR_ADV message and is included within a Scheduling Service Supported field for representing a class of QoS that a given base station can support.

5. The method of claim 2, wherein the at least one specific field is allocated in the MOB_NBR_ADV message and is included within a Scheduling Service Supported field for representing a class of QoS that a given base station can support.

6. The method of claim 4, wherein the at least one specific field comprises three bits.

7. The method of claim 4, wherein the at least one specific field comprises more than three bits.

8. The method of claim 1, wherein the at least one specific field comprises at least one bit.

9. The method of claim 1, further comprising the step of receiving a handover indication message from the Serving RAS.

10. The method of claim 1, further comprising:

monitoring a number of users and a state of a utilization of neighbor base stations by a current base station;

collecting and generating information about neighbor base stations, including the monitored information; and

transmitting the generated information about the neighbor base stations to at least one mobile station according to a predetermined period.

11. The method of claim 10, wherein the information about neighbor base stations corresponds to a MOB_NBR_ADV message.

12. The method of claim 11, wherein the MOB_NBR_ADV message includes status information in a specific field regarding utilization of a base station of the neighbor base stations.

13. The method of claim 12, wherein the specific field is allocated in the MOB_NBR_ADV message is included within a Scheduling Service Supported field for representing a class of QoS that a predetermined base station can support.

14. The method of claim 13, wherein the specific field comprises of three bits.

15. A system for providing a handover in a broadband mobile communication system, comprising:

an MS for;

receiving information about one or more neighbor base stations and respective reception strengths of said one or more neighbor base stations,

extracting a value of a specific field from the received information, the value being associated with a utilization level of a corresponding one of the one or more neighbor base stations, and

determining a handover to a base station from among the neighbor base stations said determining comprising;

combining the utilization level with a reception strength of a corresponding neighboring base station to obtain a combined value for each neighbor base station, said combined value formulated to favor high reception strength and low utilization, wherein the utilization level provides a greater contribution to the combined value than the reception strength;

selecting the base station having a maximum combined value as a base station to handover to; and

a Serving Radio Access System (RAS) for;

monitoring a number of users and a utilization level of said one or more neighbor base stations,

collecting and generating information about said one or more neighbor base stations by using the monitored information, and

transmitting the generated information about said one or more neighbor base stations to the MS according to a predetermined period.

16. The system of claim 15, wherein the information about said one or more neighbor base stations corresponds to information contained in a Mobile Neighbor Base-station Advertisement (MOB_NBR_ADV) message.

17. The system of claim 16, wherein information about the utilization level of a base station of said one or more neighbor base stations is included in the specific field within the MOB_NBR_ADV message.

18. The system of claim 17, wherein the information about the utilization level of the base station of said one or more neighbor base stations is determined by an amount of usage of the base station and a number of users.

19. The system of claim 17, wherein the specific field is allocated in the MOB_NBR_ADV message and is included within a Scheduling Service Supported field for representing a class of QoS that a predetermined base station can support.

20. The system of claim 18, wherein the specific field is allocated in the MOB_NBR_ADV message and is included within a Scheduling Service Supported field for representing a class of QoS that a predetermined base station can support.

21. The system of claim 19, wherein the specific field comprises three bits.