Combination Of TD-SCDMA And GSM Nerwork Into The Same LAC Investigation

China mobile have the intellectual property TD-SCDMA which is rapidly developing progress. Now TD-SCDMA has following known drawbacks. They are weak signal, high damping decrement, insufficient coverage area. All these impact the network performance and customer experience. In order to mitigate the TD-SCDMA network insufficiency by using mature GSM, China mobile provides bi-module mobile phone with TD-SCDMA and GSM. China mobile subscribers can use GSM network when TD-SCDMA has coverage issue.During the use experience of bi-module user, switch the network impact the customer satisfaction. There are two phases when switching network, retrieval of network broadcast info and location update. Because of failure of residency, service can't work properly. In more detail, terminals are offline and can't out bound during the phase. If there is a downstream broadcast message, because terminal doesn't complete the location update and page message is downstream of the source, terminal can't receive any page message of this call, which impact the user experience of dialing. To shorten the switch delay of TD-SCDMA and GSM, mitigate the inaccessible call by long delay time and improve the customers'satisfaction, it's indispensable to investigate the merge of these two wireless networks.This essay claims the solution of combination of TD-SCDMA and GSM network into LAC network. This combination will omit the bi-network switch process of location update. It will shorten the delay of bi-network selection and improve the customer experience.This essay mainly investigates three areas.1. Modify of Tpbp and RNS page parameters to improve the capability of page performance in TD-SCMDA network, which won't impact the page success ratio or page response delay. This experiment works well on most terminals. The capability of TD-SCDMA network search won't be the problem to integrate the network of LAC sharing network.2. LAC sharing network has less re-selection delay, better accessibility arid reduces the quantity of location update when mutual system operation.3. Combine theory and practice together. Provide the suggestion of user quota to LAC sharing network situation.