Query:Micro, Macro Capcity

[Piscean21]

Dear Experts,
I have a question regarding capcity of micro, macro site of configuration S12 & S444 respectively(i.e. Total TRXs in micro site=12 & Total TRXs in macro site=4+4+4=12).

Is the capacity same in both cases???

[redrooster]

There are lots of "if's and but's", however the sites do have the same number of timeslots! The main difference is the fact that the S444 site will require 3 broadcast timeslots (as opposed to the micor site 1). In addtion, the confuguration of the Paging, n x SDCCH timeslots and GPRS could be different.

Not to mentioned the interference / reuse issues in terms of perfomance

Hope that helps.

redrooster

[Piscean21]

If we suppose we have only TCH Channels,no SDCCHs etc.What will be the case then??

[s52d]

If we suppose we have only TCH Channels,no SDCCHs etc.What will be the case then??

Look at Erlang B table.
In order not to have congestion, you need some free TS. more one one 12 TRX cell compared to one 4 TRX cell: but not 3 times more. So, one 12 TRX omni has higher capacity.

Another point: on 4+4+4 you can hardly get equall traffic in every cell. So, one might get congested while other two are not. Again, single 12 is better.

4+4+4 is better on coverage and interference as you use directional antennas.

This story is even more valid for one omni 6 TRXes compared to 2+2+2 (Erlang B table).

Now, with all traffic steering functions of 21 century GSM (direct retry etc) you might make
difference between 4+4+4 and S12 very small: in this case coverage/interference wins.

For GPRS/EDGE S12 is better, no cell changes ;-)

BR
s52d

[cm_rao29]

Also need to be aware the a-bis capacity. config 4/4/4 is max for 1E for the single site. This is by having idle TS for GPRS/EDGE.