Advantage of Cell_PCH

[maasricht]

Dear all,

We have 2 vendors in our network. One of them is E/// and the other is NSN.

In E/// side, Cell_PCH State was disabled. And NSN side, it was enabled.

Shall we discuss what is advantage of disable CELL_PCH State?

[rsv12]

Hi, just activate this feature at E also. Nowadays this is very important option , at the beginning of 3G there were some UE that did not work with cell PCH mode. But those UE already have gone and if you do not see any problem in NSN then you do not need to worry about E also. There is many gain in this feature like save RNC resource, less RTT and so on.

[wolverine]

Enabling CELL/URA_PCH is usually introduced with a modification of your CELL_FACH timers. So it becomes a question of what you are comparing it with. CELL_FACH versus CELL_PCH or IDLE versus CELL_PCH.

Against CELL_FACH you are saving battery life for the UE. In fact by adjusting your DRX cycle you can make it the same as IDLE.

Against IDLE, you are saving on RRC signalling (as it takes less messages to transition from CELL_PCH to DCH than IDLE to DCH) and also on latency as it takes less time to transition to DCH from CELL_PCH. On the downside you have cell updates when the UE moves cells (so using URA_PCH might be better) and also the Iu_PS AAL path is kept (between RNC and SGSN) so you might have some capacity issues.

Overall though it is a general understanding that CELL_PCH is a good thing to have in your network.