求教：一个关于RRC 和PDCP的问题？

在RRC（TS36331）中讨论了establish/re-establish/reconfigure PDCP entity, 其中establish/re-establish 过程比较容易理解，在PDCP协议中也有描述，但是，reconfigure过程却很含糊，有人知道如何reconfigure PDCP entity吗？

回复 3# 的帖子
你这段内容有点过时了，如果使用了full configuration是可以重配置RLC mode的。

For SRBs a choice is used to indicate whether the RLC configuration is signalled explicitly or set to the values defined in the default RLC configuration for SRB1 in 9.2.1.1 or for SRB2 in 9.2.1.2. RLC AM is the only applicable RLC mode for SRB1 and SRB2. E-UTRAN does not reconfigure the RLC mode of DRBs except when a full configuration option is used, and may reconfigure the UM RLC SN field size only upon handover within E-UTRA or upon the first reconfiguration after RRC connection re-establishment.

RRC connection reconfiguration
在reconfigure PDCP/RLC entity过程中，ENB会不会改变DRB的传输模式，比如从AM改为UM或AM该为UM？(注意是reconfiguration,不是reestablishment.)

回复 2# 的帖子
找到一些关于DRB reconfig的说明， 基站不会reconfig DRB 传输模式
见RRC协议（36331）
RadioResourceConfigDedicated information element
rlc-Config
For SRBs a choice is used to indicate whether the RLC configuration is signalled explicitly or set to the values defined in the default RLC configuration for SRB1 in 9.2.1.1 or for SRB2 in 9.2.1.2. RLC AM is the only applicable RLC mode for SRB1 and SRB2. E-UTRAN does not reconfigure the RLC mode of DRBs, and may reconfigure the UM RLC SN field size only upon handover within E-UTRA or upon the first reconfiguration after RRC connection re-establishment.

我觉得reconfigure主要是用来支持S1的E-RAB Modification过程的