LTE中的counter check 的作用是什么？

Counter Check Procedure is always initiated by eNB, by sending "Counter Check" message to UE.

Purpose:
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To instruct UE for checking number of data transmitted/received from/in each DRB.

When:
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Whenever eNB finds the particular COUNT is exceeded than specific value.

Why:
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eNB sends this message if it suspects that new data is introduced by an intruder in any DRB which are used for data transfer between UE and eNB.

Action:
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UE will send Counter Check Response to eNB, by including drb-CountInfoList, drb-Identity, counte-Uplick, count-Downlink IE's corresponding to that specific COUNT value.