小区参数修改引起的小区删建问题

coordination

实际测试中遇到一个问题：修改小区子帧配比触发小区删建，小区删建的时延需要设计好，和终端的处理配合。
有两种可能的选择：
1. 删建时间足够短，删建之后下发寻呼消息指示系统信息改变，终端重新接收系统信息，与网络同步。存在的风险是子帧配比改变很可能会影响到终端PO的改变，终端有可能接收不到寻呼消息。
2. 删建时间足够长，在小区重新建立好之前终端进入脱网，启动重新搜网的过程。根据TS36.133规定，小区删建时间约为15s的延迟就可以保证这一过程。
3. 在只有一个小区或只有一个频点的情况下，为了让终端尽快进入网络，终端应做相应特殊的处理机制，比如启动惩罚定时器，在脱网15s内只搜索当前驻留频点，或类似机制。

4.2.2.1            Measurement and evaluation of serving cell

TheUE shall measure the RSRP and RSRQ level of the serving cell and evaluate thecell selection criterion S defined in [1] for the serving cell at least everyDRX cycle.

TheUE shall filter the RSRP and RSRQ measurements of the serving cell using atleast 2 measurements. Within the set of measurements used for the filtering, atleast two measurements shall be spaced by, at least DRX cycle/2.

If the UE has evaluated in Nservconsecutive DRX cycles that the serving cell does not fulfil the cell selectioncriterion S, the UE shall initiate the measurements of all neighbour cellsindicated by the serving cell, regardless of the measurement rules currentlylimiting UE measurement activities.

If the UE in RRC_IDLE has not found anynew suitable cell based on searches and measurements using the intra-frequency,inter-frequency and inter-RAT information indicated in the system informationfor 10s, the UE shall initiate cell selection procedures for the selected PLMN asdefined in [1].

Table 4.2.2.1-1: Nserv

DRX  cycle length	Nserv  [number of DRX cycles]
0.32	4
0.64	4
1.28	2
2.56	2