But what I was asking is - are my assumptions correct ? The call flow looks like this [I have skipped some equipment] : ? 2E1 3.6 mbps MS--------->RBS--------------->radio link----------------->GPRS------------------->Internet ? 2E1 3.6 mbps MS<---------RBS<--------------radio link<----------------GPRS<-------------------Internet So, when calculating bandwidth for an end user - several possible calculations arise - assuming the RBS has 3 cells 1) take the two E1s to mean that - 1 is for download, the other is for upload [when there is no congestion] End user will receive = 64kbps * 31 timeslots = 1.984 mbps [not explicitly cos 1mb=1024] But end user is getting a high of 1.6 mbps here - why ? 2) take the two E1s to be shared for both down and upload End user will receive = 64kbps * 31 timeslots * 2 = 3.968 mbps [not explicitly cos 1mb=1024] End user is getting 1.6 mbps because its same scenario or position as the above 3) take that the E1 is divided amongst the 3 cells on an RBS to serve on demand - -and if 1E1 is used for download and the other for upload. So assuming one cell has no user: a) 2/3 * 64 kbps * 31 timeslots = 1.3 mbps or if each cells have at least 1 user b) 1/3 * 64 kbps * 31 timeslots = 661 kbps 4) take the two E1s to be shared for both down and upload and is divided for 3 cells of the RBS So assuming one cell has no user: a) 2/3 * 64 kbps * 31 timeslots * 2 = 2.6 mbps or if each cells have at least 1 user b) 1/3 * 64 kbps * 31 timeslots * 2 = 1.32 mbps ===
From the above results - the results in red are an approximate of what we are getting on the ground.
However, I need to come up with a comprehensive and "almost" true way to calculate the above, in-order to advise appropriately. So based on your experiences, which is the right way to calculate - out of the 4 methods ? These are also microwave links, so take it as same scenario. === How will the increase in users affect these calculations of bandwidth ? I still do not understand the concept of a "dedicated link" when it comes to user distribution - in retrospect - if the customer is getting 3.6 mbps from ISP and he is to distribute to mobile users - are the users really supposed to get 3.6 mbps each - or will this now be divided by the number of active users? Because in theory, each of these users has this 4mbps capable on his 3G/HSDPA card for radio link- and each user has a 3.6 mbps dedicated link to internet on the operator's side. so: is it: 4mbps 3.6mbps user ----------->radio------------------->intenet or is it 4mbps [3.6mbps divided by no. of users] user------------>radio------------------->internet And how does uplink and downlink separate channels to internet affect this ? === I know its a long question - sorry for the time and length. w/r Stephen N.