- This topic has 10 replies, 1 voice, and was last updated 9 years ago by prof.
11th January 2012 at 09:22 #67724profGuest
1. When we say that power control is disabled on BCCH TRX. Does it mean all 8 time slots of BCCH TRX or only 0th time slot?
2. Suppose time slot 6 of BCCH TRX is defined to be TCH. What if this time slot is idle? Will the BTS transmit some dummy data or will it remain silent?
3. Do we have power control enabled in the uplink on BCCH TRX time slots?11th January 2012 at 15:09 #67725pixGuest
1/ it means that the DOWNLINK PC is disabled on ALL the 8 timeslots of the BCCH TRX. The principle is that the BCCH frequency in DL should always be emitted at max power.
2/ it will transmit dummy data at max power (btw, DL DTX is disabled on BCCH TRX as well, for the same reason)
3/ yes, UL PC works the same on all TRX.
pix11th January 2012 at 15:23 #67726BTGuest
2/ The BTS will remain silent in idle mode because there is no communication with the mobile device.12th January 2012 at 09:45 #67727profGuest
Thanks pix and BT.
I see a little debate on my 2nd question. Can there be an agreement?12th January 2012 at 19:49 #67728pixGuest
indeed there is a disagreement… but i hope you know who to trust 😉 i would always tell if i’m not sure about something…
… but here, i know *for sure* the BTS transmits dummy blocks on the BCCH carrier in downlink when there are no actual calls. that’s one of the reason why the bcch frequency needs a “cleaner” frequency planning. And that’s also a reason why BCCH frequency is the one which is NOT hopping in SFH hopping mode.
pix13th January 2012 at 12:19 #67729BTGuest
And how is possible that tracing my phone in idle mode I do not see any dummy data?
What are you using to trace this dummy data?13th January 2012 at 14:16 #67730pixGuest
well, you are actually seeing it : it’s thanks to this “dummy signal” that your ms is able to measure the dl_rxlev(serving) in idle mode, and to measure the dl_rxlev(n) in dedicated mode.
it might not be “dummy blocks” at layer 3, but perhaps just a pure sinus signal. I don’t know those details.
regards14th January 2012 at 10:45 #67731paraHOGuest
I agree with you Pix
GSM 050214th January 2012 at 17:55 #67732pixGuest
give me five !16th January 2012 at 10:30 #67733BTGuest
Yes 🙂16th January 2012 at 10:58 #67734profGuest
thanks you pix/all.