RACH filter – in a mature network there is a tight co-channels re-use.With this filter you can try to filter out rachs witch ms sended to others co-channels bts. This way in theory you can reduce sdcch assignment failure.(when bts allocate sdcch but nobody ask for it in this cell)
but in practic if real mobile trying to get to bts but you filter out it rach with filter (wrong setting) ms can stay without service until cell reselection(if possible)
MOC case – user have to call twice to reach the network
MTC case – ms can be not reachable from the first attempt.(depends from the number of paging and time between paging) Remember this.
2 way spliter – 3db loss