Forward link based rescue channel method and apparatus for telecommunication systems

Abstract

A forward rescue procedure (FRP) for preventing loss of signal and dropped connections between a mobile station and the infrastructure in a wireless telecommunications network is disclosed. The FRP allows wireless systems to recover from forward link failures at the mobile station that would otherwise result in dropped connections. Examples of failure scenarios that can be overcome using the FRP include forward link Layer 2 acknowledgement failures and loss of forward link signal due to a fade that causes loss of signal for a period of time exceeding a threshold value. In response to a potential connection drop situation, a mobile station will autonomously add base station pilot channels to the active set of its rake receiver in order to rescue the connection in danger of dropping. Concurrently, the wireless network infrastructure will initiate transmission on alternative forward link channels that are likely to be monitored by the mobile station during an FRP. If the same channels are monitored by the MS and transmitted on by the infrastructure, the connection in danger of dropping can be rescued.

Description

[0001] This application is a divisional application with the filing date of October 16, 2001, the application number of 200610092492.7, and the title of "Rescue Channel Method and Device Based on Forward Link in Telecommunication System". [0002] Cross References to Related Applications [0003] Embodiments of the present invention claim U.S. Provisional Patent Application Serial No. 60 / 241,268, filed October 17, 2000, entitled "Forward Rescue Procedure," and filed November 14, 2000, entitled Priority of U.S. Provisional Patent Application Serial No. 60 / 248,900 for "Improvement to Rescue Channels Using Dynamic Active Set During Rescue," the contents of which are hereby incorporated by reference for all purposes . technical field [0004] In general, the present invention relates to communication network management and, in one embodiment, to methods of preventing signal loss and disconnection between a mobile station (such as a cellular or PCS phone) and a wireless communicat...

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Problems solved by technology

[0029] Layer 2 acknowledgment failures and forward link fading failures may occur due to excessive frame error rates or burst error rates

However, the proposed rescue procedure based on restarting the connection introduces a lot of interference since the MS is probing to utilize the access channel and requires a lot of power

Furthermore, the proposed reverse-based rescue procedure is only initiated under forward fading conditions, and since the MS transmits before the BS, it is deficient, and this method appears to be less efficient for reasons explained below

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