IPC분류정보
국가/구분 |
United States(US) Patent
등록
|
국제특허분류(IPC7판) |
|
출원번호 |
US-0795113
(2004-03-05)
|
등록번호 |
US-7336953
(2008-02-26)
|
우선권정보 |
KR-10-2003-0014643(2003-03-08) |
발명자
/ 주소 |
- Kim,So Hyun
- Koo,Chang Hoi
- Son,Jung Je
|
출원인 / 주소 |
- Samsung Electronics Co., Ltd.
|
대리인 / 주소 |
|
인용정보 |
피인용 횟수 :
67 인용 특허 :
1 |
초록
▼
A broadband wireless access communication system in which a subscriber station (SS) sends a serving base station (SBS) a handover request to neighbor base stations (NBSs) having a CINR satisfying a handover condition, in response to a handover scan request message, and performs the handover to a par
A broadband wireless access communication system in which a subscriber station (SS) sends a serving base station (SBS) a handover request to neighbor base stations (NBSs) having a CINR satisfying a handover condition, in response to a handover scan request message, and performs the handover to a particular NBS that transmits a handover response. The SBS transmits the handover scan request message to the SS, sends a handover connection request to NBSs in an order determined by CINRs reported from the SS, and sends, to the SS, information on a particular NBS upon receiving a handover connection response with ACK information from the particular NBS. The particular NBS determines whether it can support handover of the SS, in response to the handover connection request, and sends the handover connection response with the ACK information to the SBS, if it can support handover of the SS.
대표청구항
▼
What is claimed is: 1. A method for performing a handover of a subscriber station at a request of a serving base station in a broadband wireless access communication system including the serving base station for providing a service to the subscriber station and a plurality of neighbor base stations
What is claimed is: 1. A method for performing a handover of a subscriber station at a request of a serving base station in a broadband wireless access communication system including the serving base station for providing a service to the subscriber station and a plurality of neighbor base stations being adjacent to the serving base station, the method comprises the steps of: receiving information on the neighbor base stations from the serving base station; measuring carrier-to-interference and noise ratios (CINRs) of frequency bandwidth signals from the neighbor base stations based on the information about the neighbor base stations; receiving a handover scan request message from the serving base station; transmitting to the serving base station a handover request message including information about the measured CINRs of the selected neighbor base stations satisfying a predetermined handover condition, in response to the handover scan request message; receiving, from the serving base station, a handover response message including information on at least one particular target base station among selected neighbor base stations, said at least one particular base station capable of supporting the handover of the subscriber station among the neighbor base stations; and performing the handover from the serving base station to one of the at least one target base stations; wherein the predetermined handover condition comprises a first handover condition, in which a CINR of a particular neighbor base station should not remain less than a minimum CINR for a maximum holding time and a second handover condition, in which a CINR of a particular neighbor base station should remain greater than a measured CINR of the serving base station for a minimum holding time. 2. The method of claim 1, wherein the information about the neighbor base stations is included in a downlink message received from the serving base station. 3. The method of claim 1, further comprising the step of stopping the CINR measurement on neighbor base stations with CINRs not satisfying the first handover condition, among the measured CINRs of the neighbor base stations. 4. The method of claim 1, wherein the handover request message is transmitted to the serving base station along with the CINRs of the neighbor base stations, a quality of service (QoS), and a bandwidth. 5. A method for performing a handover by a serving base station in a broadband wireless access communication system including the serving base station for providing a service to a subscriber station and a plurality of neighbor base stations being adjacent to the serving base station, the method comprising the steps of: (a) transmitting information on the neighbor base stations to the subscriber station; (b) transmitting a handover scan request message for handover request to the subscriber station, if a handover of the subscriber station is required; (c) receiving a handover request message including carrier-to-interference and noise ratios (CINRs) of the neighbor base stations from the subscriber station in response to the handover scan request message; (d) sorting the neighbor base stations in order determined by the received CINR levels; (e) sequentially sending a handover connection request to the neighbor base stations in the sorted order; and (f) transmitting information on at least one particular neighbor base station among the neighbor base stations to the subscriber station upon receiving a handover connection response including ACK (Acknowledgement) information from the particular neighbor base station in response to the handover connection request, said at least one particular base station capable of supporting the handover of the subscriber station among the neighbor base station; wherein step (e) comprises sending the handover connection request to the neighbor base stations according to an order beginning with a neighbor base station corresponding to a highest CINR to a neighbor base station corresponding to a lowest CINR, until the handover connection response including the ACK information is received. 6. The method of claim 5, further comprising the step of receiving a handover request from the subscriber station, including measured CINRs of the neighbor base stations, a quality of service (QoS), and a bandwidth. 7. The method of claim 6, wherein the handover connection request is transmitted to the neighbor base stations including the QoS and the bandwidth by the subscriber station. 8. The method of claim 5, wherein the information about the at least one particular neighbor base station includes an identifier and a carrier frequency of the particular neighbor base station. 9. The method of claim 5, further comprising the step of transmitting a handover connection confirm message to the at least one particular neighbor base station, upon receiving the handover connection response message including the ACK information from the particular neighbor base station. 10. The method of claim 5, further comprising the step of releasing a link connected to the subscriber station, after transmitting the information about the particular neighbor base station. 11. A broadband wireless access communication system comprising: a subscriber station for transmitting a request for a handover to at least one neighbor base station having a carrier-to-interference and noise ratio (CINR) satisfying a handover condition, in response to a handover scan request message, and performing the handover to a particular neighbor base station of the at least one neighbor base stations that transmits a handover response in response to a handover request; a serving base station, which is currently in communication with the subscriber station, for receiving the request for the handover, transmitting the handover scan request message to the subscriber station, if handover of the subscriber station is required, sending a handover connection request to the neighbor base stations in an order determined by CINRs reported from the subscriber station, and sending, to the subscriber station, handover information, upon receiving a handover connection response including ACK (Acknowledgement) information; and a particular neighbor base station from the at least one neighbor base stations for determining whether it can support the handover of the subscriber station, in response to the handover connection request, and sending the handover connection response including the ACK information to the serving base station, if it can support the handover of the subscriber station; wherein the handover condition comprises a first handover condition, in which a CINR of the particular neighbor base station should not remain less than a minimum CINR for a maximum holding time and a second handover condition, in which a CINR of the particular neighbor base station should remain greater than a measured CINR of the serving base station for a minimum holding time. 12. The broadband wireless access communication system of claim 11, wherein CINR measurement on neighbor base stations with CINRs not satisfying the first handover condition among the measured CINRs of the neighbor base stations, is suspended. 13. The broadband wireless access communication system of claim 12, wherein the subscriber station sends the handover request to the serving base station, if at least one of the measured CINRs of the at least one neighbor base stations is higher than a predetermined threshold and a CINR of the serving base station. 14. A broadband wireless access communication system comprising: a serving base station for transmitting information on the neighbor base stations to the subscriber station, transmitting a handover scan request message to the subscriber station, if a handover of the subscriber station is required, receiving a handover request message including carrier-to-interference and noise ratios (CINRs) of the neighbor base stations from the subscriber station in response to the handover scan request message, sorting the neighbor base stations in order determined by the received CINR levels, sequentially sending a handover connection request to the neighbor base stations in the sorted order, transmitting information on at least one particular neighbor base station among the neighbor base stations to the subscriber station upon receiving a handover connection response including ACK (Acknowledgement) information from the particular neighbor base station in response to the handover connection request, said at least one particular base station capable of supporting the handover of the subscriber station among the neighbor base stations, and sending the handover connection request to the neighbor base stations according to an order beginning with a neighbor base station corresponding to a highest CINR to a neighbor base station corresponding to a lowest CINR until the handover connection response including the ACK information is received. 15. The broadband wireless access communication system of claim 14, wherein the serving base station receives a handover request from the subscriber station, including measured CINRs of the neighbor base stations, a quality of service (QoS), and a bandwidth. 16. The broadband wireless access communication system of claim 15, wherein a connection request, including the QoS and the bandwidth is transmitted to the neighbor base stations by the subscriber station. 17. The broadband wireless access communication system of claim 14, wherein the information about the particular neighbor base station includes an identifier and a carrier frequency of the particular neighbor base station. 18. The broadband wireless access communication system of claim 14, wherein the serving base station transmits a handover connection confirm message to the particular neighbor base station, upon receiving the handover connection response message including the ACK information from the particular neighbor base station.
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