GSM rail route optimization This topic has 0 replies, 1 voice, and was last updated 10 years, 4 months ago by AGVA. Viewing 1 post (of 1 total) Author Posts 9th January 2013 at 09:31 #68791 AGVAGuest In our netork we are facing high percentage of Call drop & Blocking for SDCCH as well as TCH. What are the parameter its required to change . Our network is Ericsson GSM 900 band. Author Posts Viewing 1 post (of 1 total) The forum ‘Telecom Design’ is closed to new topics and replies.