how to calculate number of A-links and factors it depends on

[kahnoie]

I would like to know more about A-link calculation and what are the factors affecting it.


Regards,
Amit
agarwalamit081@gmail.com

[ghassen]

which A-link you mean A interface is it ??

[kahnoie]

Yes. I meant the links on A-interface.
Which all are the factors to be considered?
1. number of BSCs
2. number of TRXs
3. Traffic capacity

Can you explain with an example please on dimensioning A-interface links?

Thanks
Amit

[ghassen]

Yes. I meant the links on A-interface.
Which all are the factors to be considered?
1. number of BSCs
2. number of TRXs
3. Traffic capacity

Can you explain with an example please on dimensioning A-interface links?

Thanks
Amit

i added a thx by mistake whatever it doesn't matter so it depend of the trafic needed here i mean the number of trx and number of SS7 links needed for signaling each subslot from Asub interface will be mapped into one full time slots in the A interface

[sachinsatija_in]

Is it about Ainterface links?

[kahnoie]

No,
It is about factors to be considered while choosing a particular vendor? I mean how can be different vendors be evaluated in terms of technical performance of BTS and BSCs except for their supported capacity?

[maahsan]

1 A-link will carry approximately 30erlang traffic.

[seedweb]

I would like to know more about A-link calculation and what are the factors affecting it.


Regards,
Amit
agarwalamit081@gmail.com

i dont know it，but i want to learn it with u！

[kahnoie]

Thanks you maahsan. But how do you conclude that one E1 is 30 Er traffic? I know that there will be 30 TS for the users but each TS doesnt necessarily correspond to 1 Er traffic.
For example: A network has 100 BTS (S333) --> 300 TRX --> 2400 channels. There are again multiplexed on the Abis interface and presumably there could be 60 E1 connected to the BSC (assuming some of the microwave links are nested). If user traffic is 25 mE how much will be the traffic coming into the BSC (assuming 20K subscribers). and how many A-links need to be connected from the BSC to MSC for such a scenario?

[maahsan]

Thanks you maahsan. But how do you conclude that one E1 is 30 Er traffic? I know that there will be 30 TS for the users but each TS doesnt necessarily correspond to 1 Er traffic.
For example: A network has 100 BTS (S333) --> 300 TRX --> 2400 channels. There are again multiplexed on the Abis interface and presumably there could be 60 E1 connected to the BSC (assuming some of the microwave links are nested). If user traffic is 25 mE how much will be the traffic coming into the BSC (assuming 20K subscribers). and how many A-links need to be connected from the BSC to MSC for such a scenario?

Actually, when 1500 channels are trunked the trunking efficiency is almost 1. For your case, each cell with 3 TRX will have an erlang capacity of 13.18 erlang approx. So for 100 such sites the erlang capacity required is 3954 erlangs. And to carry 3954 erlang traffic, you will need 3913 channels on A-links. which amount to almost 130 links. But offcourse, that is the max capacity you are going to need on A-link and you will need only a percentage of this in real world scenario.