could you describe exactly what’s happening when the MS is on the SDCCH which is hopping ?
–> in the drivetest : what is the dl rxlev and dl rxqual, what is the BER ? what is the rxlev of the BCCH, just before the sdcch is allocated ? (is there a big diff between rxlev of the bcch and the rxlev of the sdcch ?
–> in your qos tool : what is the main cause of sdcch DROP in those cells ? (we agree that the MS manages to get the SDCCH channel, so it is not a SDCCH Assignment Failure)
–> in your qos tool : do you see many tch drops in those cells ? could you ensure that TCH are established on the “hopping” trx ? (= check that not all calls are located on the bcch trx)
i’m also thinking about another kind of problem : the BSC that handles all those SDCCH timeslots. Are you sure that it is not overloaded ? Did you remap those sdcch on another bsc board, after the replanning ?
please answer each question one by one, don’t miss anything ! 🙂