R&D towards the CMS RPC Phase-2 upgrade

High pseudo-rapidity region of CMS muon system is covered only by Cathode Strip Chambers (CSC) and lacks redundant coverage despite the fact that it is a challenging region for muons in terms of backgrounds and momentum resolution. In order to maintain good efficiency for the muon trigger in this region additional RPC are planned to be installed in stations RE31 and RE41. The stations will use RPCs with lower granularity but good timing resolution to mitigate background effects and complete the redundancy of the system. R and D activities will be presented in the talk.