Communication system employing multiple handoff criteria

• US 20060159051A1
• Filed: 03/20/2006
• Published: 07/20/2006
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: English, Sean
• Granted Patent: US 7,505,436 B2
• Time in Patent Office: Days
• US Class Current: 370/332
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

Disclosed herein is a communication system which manages guarantee of service (GOS) requirements for various users while efficiently managing backhaul network traffic and optimizing overall system capacity. In one aspect, armed handoff is used to transmit forward link data from a single base station to a particular mobile station as long as certain minimum requirements are met, such as minimum data throughput, minimum data rate, and GOS requirements. If these criteria are not met, soft and softer handoff can be employed to transmit forward link data from one or more base stations to a particular mobile station until the conditions for armed handoff are met. In another aspect, the test to add a base station sector to the active set differs based on whether other sectors of that base station already exist in the active set. The test is less stringent when a sector is not the first of its base station to enter the active set, and more stringent when it is the first.

Claims

1. A system controller, communicatively connected to a plurality of base stations and a mobile station, comprising:

a processor for maintaining data queues for the mobile station'"'"'s forward traffic data in those base stations contained in the mobile station'"'"'s active set; and

wherein the system controller receives a message directing more than one base station to transmit data simultaneously on their respective forward traffic channels and directs the respective base stations accordingly.

2. A base station, communicatively connected to a base station controller, a plurality of other base stations, and one or more mobile stations, comprising:

a transmitter for transmitting pilots and code channels comprising a forward traffic channel; and

a receiver for receiving messages from a mobile station;

wherein the base station receives, and transmits in response, to a message directing it to transmit data on its forward traffic channel;

wherein the base station receives from a mobile station and delivers to the base station controller a message directing more than one base station to transmit simultaneously on their respective forward traffic channels; and

wherein the base station transmits accordingly under direction of the base station controller.

3. A mobile station which communicates with a plurality of base stations, the base stations communicatively connected to a base station controller, comprising:

a diversity receiver configured to measure respective signal qualities of the pilots;

a processor configured to produce a signal quality standard, prepare a message directing one of the base stations to transmit data on its respective forward traffic channel when the quality of the pilot of the one base station equals or surpasses the standard, and prepare a message directing more than one base station to transmit data simultaneously on their respective forward traffic channels when the quality of a single pilot of any of the base stations does not equal or surpass the standard; and

a transmitter configured to transmit the message to the system controller via the plurality of base stations.