The Research On 2G/3G Interoperability Reselection Optimization And Location Updating

TD-SCDMA/GSM interoperability it mainly includes two aspects:reselection and handover. Reselect is consider as an inter-system cell transition when MS in idle condition; Handover is consider as a inter-system cell transition when MS in active condition.The frequently reselection between TD-SCDMA(following referred to"TD")and GSM network as well as the time delay between each and everyone reselection, during this process, most customers are unreachable,"unreachable"means it can not receive incoming call as it can not receive paging messenger, we will elaborate on some details when we research in reselect delay. In most conditions, the ordinary reselection delay is between 6 seconds to 10 seconds, but it will exceed 20 seconds if we use some imperfection mobile station or with the service of imperfection network, it suggests we can not receive incoming calls in at least 20 seconds.According to statistics,20% of unreachable is caused by reselection delay and location update,in which 20% is caused by severe inter-system time delay.So the severe inter-system reselection time delay is the main aspect which influence of network percentage of call completed, without any doubts, it is an urgent issue with great importance. This composition identify inter-system reselection procedures to three main stages:stay in GSM cell,reading system broadcast messengers,location update and routine update;To each and every stages,we present an improvement plan to shorten the inter-system reselection delay,reduce customer unreachable time during this process;At the end,we look at the principle and protocol of inter-RAT handover,hoping enhance handover completion rate through reducing handover delay. As we analyze token protocol of handover,we know that a whole handover process includes all network,which can be divided into two serial stage,handover preparation and handover executive. In order to improve handover success rate and shorten handover delay,we must shorten token process time.With the development of TD,as we are in the booming market with severe competition,time is not a luxury we have,we must give an impetus to its improvement.