关于Radio contact lost with the MS

yiweialive

最近在工作中看到Radio contact lost with the MS
但是不了解这个出现的原因，只知道是bssgp协议层
求高手解答。。。

admin

是在哪一层的log里看到了这个信息呢？或者有抓包吗？

yiweialive

bssgp层的信令

persign

看该消息的详细解码，即Radio-cause值，3GPP中关于该参数的解释如下，详见3GPP TS 48018 7.3 Radio Status procedure节：
A BSS and an MS radio interface communication status may change due to the following:
1)        the MS goes out of coverage and is lost;
        This condition is signalled by setting the Radio Cause value to "Radio contact lost with MS".
2)        the link quality is too bad to continue the communication;
        This condition is signalled by setting the Radio Cause value to "Radio link quality insufficient to continue communication".
……
Conditions 1) and 2) indicate that attempts to communicate between an MS and an SGSN via this cell should be suspended or abandoned. An SGSN shall stop sending LLC-PDUs to the cell for the MS.
可见，Radio contact lost with the MS指示的是移动终端所处位置不在覆盖区域内，也即是说终端当时所处位置存在弱覆盖或者未覆盖的情况。

warren

通常“Radio Contact Lost with the MS”被认为是无线侧原因导致客户上网异常，但是也有出现过核心网SGSN的单元负荷高原因产生该错误码的情况。因此在排除核心网侧高负荷等原因外，通常该错误码定位为无线侧问题。