Method and apparatus for scanning signals of neighboring base station in broadband wireless communication system

• US 8,837,378 B2
• Filed: 10/31/2007
• Issued: 09/16/2014
• Est. Priority Date: 10/31/2006
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Sung, Ki-Won
• Primary Examiner(s): Taha, Shaq
• Application Number:
  US11/982,203
• Publication Number:
  US 20080101294A1
• Time in Patent Office: 2,512 Days
• Field of Search: 370328-338, 370349-352
• US Class Current: 370/329
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

An apparatus and method for scanning signals of a neighboring Base Station (BS) in a broadband wireless communication system is provided. In the broadband wireless communication system, a scanning method of a serving base station includes: receiving information on a frequency use status of a neighboring base station from an upper network entity; and after determining a recommended scan frequency by using the received information, transmitting a scanning response message including the recommended scan frequency.

Claims

1. A scanning method of a serving base station in a broadband wireless communication system, the method comprising:

transmitting, by the serving base station, a MOB_SCN_FREQ_REQ message to inquire about a frequency use status of a neighboring base station having a plurality of downlink frequencies to an upper network entity;

receiving, by the serving base station, a MOB_SCN_FREQ_RSP message comprising information on the frequency use status of the neighboring base station from the upper network entity;

determining, by the serving base station, at least one recommended scan frequency among the plurality of downlink frequencies based on the frequency use status of the neighboring base station; and

in response to receiving a MOB_SCN_REQ message from a mobile station, transmitting, by the serving base station to the mobile station, a MOB_SCN_RSP message that includes the at least one recommended scan frequency determined based on the frequency use status to the mobile station.

2. The method of claim 1, wherein the MOB_SCN_RSP message includes at least one piece of recommended scanning frequency information as long as the neighboring base station does not refuse a scanning request of the mobile station.

3. The method of claim 1, wherein the recommended scan frequency indicates a downlink center frequency.

14. The method of claim 1, wherein the at least one recommended scan frequency is determined taking into consideration that a Mobile Station (MS) does not scan a specific frequency assignment (FA) in the following cases:

when the intra-FA handover has a priority and the inter-FA handover is used for the purpose of load balancing;

when a specific FA is dedicated to be used only for Multicast &

Broadcast Service (MBS) or a MBS service is frequently used;

when a traffic load of a specific FA is currently significantly high in a neighboring cell; and

when a specific FA cannot be used according to a network operation.

16. The method of claim 1, wherein the MOB_SCN_RSP message comprises at least one Recommended_Scan_Frequency field storing the at least one recommended scan frequency.

17. The method of claim 1, the information on the frequency use status includes at least one each traffic load of the plurality of downlink frequencies.

4. A scanning method of a mobile station in a broadband wireless communication system, the method comprising:

transmitting a MOB_SCN_REQ message to a serving base station;

receiving a MOB_SCN_RSP message that includes at least one recommended scanning frequency from the serving base station, wherein the at least one recommended scanning frequency among a plurality of downlink frequencies is determined based on a frequency use status of a neighboring base station having the plurality of downlink frequencies, the frequency use status received by the serving base station in a MOB_SCN_FREQ_RSP message from an upper network entity in response to a MOB_SCN_FREQ_REQ message; and

performing scanning by referencing to the at least one recommended scanning frequency included in the MOB_SCN_RSP message.

5. The method of claim 4, wherein the MOB_SCN_RSP message includes at least one piece of recommended scanning frequency information as long as a neighboring base station does not refuse a scanning request.

6. The method of claim 4, wherein the recommended scanning frequency indicates a downlink center frequency.

7. A base station apparatus for performing scanning in a broadband wireless communication system, the apparatus comprising:

a message processor configured to extract information on a frequency use status of a neighboring base station having a plurality of downlink frequencies from a MOB_SCN_FREQ_RSP message received from an upper network entity;

a frequency allocation determining unit configured to determine at least one recommended scan frequency among the plurality of downlink frequencies based on the frequency use status of the neighboring base station;

a message generator configured to generate a MOB_SCN_RSP message that includes the at least one recommended scan frequency determined based on the frequency use status, in response to receiving a MOB_SCN_REQ message from a mobile station; and

a controller configured to transmit to the upper network entity a MOB_SCN_FREQ_REQ message that inquires the frequency use status of the neighboring base station.

8. The apparatus of claim 7, wherein the MOB_SCN_RSP message includes at least one piece of recommended scanning frequency information as long as the neighboring base station does not refuse a scanning request of the mobile station.

9. The apparatus of claim 7, wherein the frequency allocation information indicates a downlink center frequency.

15. The apparatus of claim 7, wherein the a frequency allocation determining unit determines the at least one recommended scan frequency taking into consideration that a Mobile Station (MS) does not scan a specific frequency assignment (FA) in the following cases:

when the intra-FA handover has a priority and the inter-FA handover is used for the purpose of load balancing;

when a specific FA is dedicated to be used only for Multicast &

Broadcast Service (MBS) or a MBS service is frequently used;

when a traffic load of a specific FA is currently significantly high in a neighboring cell; and

when a specific FA cannot be used according to a network operation.

10. A broadband wireless network comprising a plurality of base stations, each of the plurality of base stations operable to scan in the broadband wireless network, wherein each base station of the plurality of base stations comprises:

a message processor configured to extract information on each frequency use status of a plurality of neighboring base stations having a plurality of downlink frequencies from a MOB_SCN_FREQ_RSP message received from an upper network entity;

a frequency allocation determining unit configured to determine at least one recommended scan frequency among the plurality of downlink frequencies based on the frequency use statuses of the neighboring base stations;

a message generator configured to generate a MOB_SCN_RSP message that includes the at least one recommended scan frequency determined based on the frequency use statuses, in response to receiving a scanning request message from a mobile station, and wherein the generated MOB_SCN_RSP message is transmitted to the mobile station; and

a controller configured to transmit to the upper network entity a MOB_SCN_FREQ_REQ message that inquires the frequency use statuses of the neighboring base station.

11. The broadband wireless network of claim 10, wherein the MOB_SCN_RSP message includes at least one piece of recommended scanning frequency information as long as the neighboring base station does not refuse a scanning request of the mobile station.

12. A mobile station apparatus for performing scanning in a broadband wireless communication system, the apparatus comprising:

a transmitter configured to transmit a MOB_SCN_REQ message to a serving base station;

a receiver configured to receive a MOB_SCN_RSP message that includes at least one recommended scanning frequency from the serving base station, wherein the at least one recommended scanning frequency among a plurality of downlink frequencies is determined based on a frequency use status of a neighboring base station having the plurality of downlink frequencies, the frequency use status received by the serving base station in a MOB_SCN_FREQ_RSP message from an upper network entity in response to a MOB_SCN_FREQ_REQ message; and

a controller configured to perform scanning by referencing to the at least one recommended scanning frequency included in the MOB_SCN_RSP message.

13. The apparatus of claim 12, wherein the MOB_SCN_RSP message includes at least one piece of recommended scanning frequency information as long as a neighboring base station does not refuse a scanning request.