Remote BSC-MSC and inter-MSC transmission capacity dimensioning

[phunghm]

Dear TX friends,
It's the most important in TX planning that we have to do dimensioning for connections from remote BSCs to MSC, and interconnection between MSCs. Of course the traffic runs on these connections, hence the capacity, depends on how often each call type (intra/inter-BSC/MSC) occur. And this also depends on calling habits, social events, ... Yes, it's statical measurement based-on actual traffic. From the planning phases, we need at least a approximate calculation for the connection dimensioning to make a good performance against traffic congestion.
According to my experience, it's calculated like this:
1. Capacity of connection from a remote BSC to MSC = 1/4 * (Total of capacity from sites upstream to that BSC).
2. Capacity of interconnection between two MSCs = 1/4 * (Total of capacity from BSCs connected to bigger MSC)
For sure, we can use ratio 1/3 instead of 1/4.
I welcome all discussions, comments, and document shares!
Thanks much!

[bentoel]

Dear TX friends,
It's the most important in TX planning that we have to do dimensioning for connections from remote BSCs to MSC, and interconnection between MSCs. Of course the traffic runs on these connections, hence the capacity, depends on how often each call type (intra/inter-BSC/MSC) occur. And this also depends on calling habits, social events, ... Yes, it's statical measurement based-on actual traffic. From the planning phases, we need at least a approximate calculation for the connection dimensioning to make a good performance against traffic congestion.
According to my experience, it's calculated like this:
1. Capacity of connection from a remote BSC to MSC = 1/4 * (Total of capacity from sites upstream to that BSC).
2. Capacity of interconnection between two MSCs = 1/4 * (Total of capacity from BSCs connected to bigger MSC)
For sure, we can use ratio 1/3 instead of 1/4.
I welcome all discussions, comments, and document shares!
Thanks much!

Can u explain to us more detail. How can you get that ratio from you experince dude?

may be u can give us the sample so we can understand furtherer.

Thanks

[phunghm]

Dear Bentoel,

It comes from my statistics survey on operating networks. But we can understand as following:

For 1, TRAU between BSC and MSC, in the most case installed at MSC side. TRAU compresses data with ratio 1/4 (16kbps/64kbps).
For 2, As resulting from my calculation 1/4*1/4 = 1/16 = 6.25% of channel occupation. The ratio is sure for almost the case on operating networks of less than 6%. To save the cost of CAPEX, it always starts at 2%, then add capacity base on the increasing of traffic.


Hope to receive better explanation!


Can u explain to us more detail. How can you get that ratio from you experince dude?

may be u can give us the sample so we can understand furtherer.

Thanks

[phunghm]

And these are additonal steps that should be take into account:
- Total traffic (in Erlang) is offered through the Abis interface of a BSC.
- Define the blocking probability on the Ater interface.
- Apply the Erlang-B formula.
- Calculate the number of traffic channels, Y.
- Find the number of traffic channels that are carried by Ater, e.g. 120.
- Capacity required (in E1) = Y/120.
- Actual capacity planned = capacity required + spare capacity.

[noname]

Dear Phung
For GPRS, and capacity for control every thing, I think them must use.
Pls help me to understand about GPRS and Control everything capacity between BSC and MSC .
RG