Title:
【発明の名称】CDMAハンドオフ方式及びそれを用いた移動通信セルラーシステムとその基地局
Document Type and Number:
Japanese Patent JP3058261
Kind Code:
B2
Abstract:
In a CDMA cellular network where base stations share a common frequency and a first base station has a second frequency in addition to the common frequency, a mobile station receives a pilot signal from the first base station over the second frequency when it has established a connection to it, and transmits a first handoff request when the field strength of the pilot signal drops below a predefined threshold. In response, the first base station returns a change-frequencies command to the mobile station to cause it to switch to the common frequency and receive pilot signals from more than one base station over the common frequency. The mobile station transmits a second handoff request message containing a list of field strengths of the pilot signals. In response, the first base station makes a search through the list of field strengths and returns a handoff command to the mobile station and a connection setup command to a control station if a second base station appropriate for handoff is found. The control station responds to the connection setup command message from the first base station for instructing the second base station to establish a connection to the mobile station. The mobile station responds to the handoff command message from the first base station for instructing the second base station to transmit a connection setup complete message to the control station, which responds to it by instructing the first base station to clear the connection to the mobile station.
Inventors:
Yoshiki Wakisaka
Application Number:
JP13813897A
Publication Date:
July 04, 2000
Filing Date:
May 28, 1997
Export Citation:
Assignee:
NEC
International Classes:
H04W36/00; H04J13/00; H04W36/08; H04W36/18; H04W36/38; H04W76/02; (IPC1-7): H04Q7/22; H04J13/00; H04Q7/28
Domestic Patent References:
| JP6326653A | ||||
| JP7322332A | ||||
| JP8149551A | ||||
| JP4502845A |
Attorney, Agent or Firm:
Yosuke Goto (1 person outside)