Method and apparatus for performing idle handoff in a multiple access communication system

• US 7,006,470 B1
• Filed: 07/27/2000
• Issued: 02/28/2006
• Est. Priority Date: 10/09/1997
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Wang, Jun
• Primary Examiner(s): Jung, Min
• Application Number:
  US09/626,758
• Time in Patent Office: 2,042 Days
• Field of Search: 370/328, 370/329, 370/331, 370/335, 455/436, 455/437, 455/438
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0061 of neighbour cell information
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration

Abstract

In a mobile communication system having a first communication device for communicating with a plurality of second communication devices, a method for performing handoff within the mobile communication system includes transmitting from at least one of the second communication devices to the first communication device a handoff list of second communication devices to which the first communication device is permitted to handoff. A channel assignment message is transmitted from each of the second communications devices in the handoff list. The handoff list includes base stations controlled by a single controller that determines which of the second communication devices transmits the channel assignment message. The base stations on the handoff list have pilot signals and the energy levels of the pilot signals are measured by the first communication device. The measured energy levels are transmitted to the controller and compared by the controller to provide an energy level list of base stations according to the comparing. The energy level list is transmitted to the first communication device and the handoff is performed according to the energy level list.

Claims

1. A method for performing handoff within a mobile communication system, the mobile communication system having at least one first communication device for communicating with a plurality of second communication devices (SCD), comprising the steps of:

(a) transmitting from at least one of the SCDs to the first communication device a handoff list of SCDs to which the first communication device is permitted to handoff when in a system access state; and

(b) transmitting a channel assignment message to the at least one first communication device from each of the SCDs in the handoff list.

2. The method in accordance with claim 1, wherein a channel assignment message transmitted from each SCD in the handoff list includes a channel assignment message to be used only for communicating with the respective transmitting SCD.

3. The method in accordance with claim 1, further comprising the step of transmitting to the first communication device a neighbor list of SCDs that are located in the geographic vicinity of the first communication device.

4. The method in accordance with claim 1, wherein step (b) is followed by the step of performing a handoff of the first communication device from one of the SCDs to another one of the SCDs.

5. An apparatus for performing handoff within a mobile communication system, comprising:

a first communication device (FCD);

a plurality of second communication devices (SCDs) for communicating with the FCD, wherein at least one of the SCDs transmits to the FCD a handoff list of other SCDs to which the FCD is permitted to handoff when in a system access state, and wherein each SCD in the handoff list transmits to the FCD a channel assignment message for communicating with that respective SCD included in the handoff list.