HISILICON SEMICONDUCTOR HUAWEI TECHNOLOGIES CO., LTD. Page 1 Jabo 2G Network Equipment Related Voice Quality(Silent Call) Issue Audit Date Count of Silent Call 2013.08.2 3 1541 2013.08.2 4 0 After: Before : Some complaints on silent call(mute)/one way audio received. Suspect Hardware/Transmission issue causing some voice quality issue(incl. silent/one way call) Collected site CDIG log file to identify cells with mute call issue related to equipment(hardware/transmission) in all sites under 17 BSCs in Jabo network. Conducted call testing on site, analyzed BTS /board log and did loopback operation to locate the root cause of mute call. And verified the relation between transmission alarm and mute call issue. Finding 1: Around 1500 times mute call per day recorded in VIP cell BOSTONMD2(site id:24,cellid:180) under BSC Gambir. Confirmed the mute call caused by RF module MRFU faulty. Mute call issue was solved after MRFU board was replaced on 00:00, 24 th , Aug 2013. Problem Background Action Taken Result: Silent call related to equipment issue found in some cells under BSC Gambir and BSC TBS Metro1.