During the early state of TD-LTE network

the voice service is using CSFB method

which has the main defect of long time delay. In 2014 the time-delay of Shijiazhuang TD-LTE network is 11.08 seconds

through a detailed analysis of CSFB signaling processto fi nd out the followingfour categoriesparameters whichcan be optimized

such as non-critical signaling switches

TCH immediate assignment

UE inactivity timer

called selective authentication.wecompared and found out the shorten of the CSFB delay effect is obvious

by summarizing the results of optimization

comprehensive adjustment of network parameters.The time delay of Shijiazhuang TD-LTE network has been reduced to 10 seconds in 2015. The optimizing effect is signifi cant and effectively improve the network operating quality and customer perception.