Hi,

I have been asked to make a proposal for Idirect implementation for a GSM network; we own a 72Mhz tansponder;

i am new to VSAT field and need some help from you guys;

we are having a max traffic of 1800Erl from 63 SCPC remote terminals;

i want to know how much bandwidth will be required(to cater 1800 Erl) with Idirect PCMA enable technology...

Looking forward to your replies....


Regards,

Usama

Hi Usama

1800 Erlangs is about 1829 calls. If you assume that you need at least 24kb for each ignoring all the complex things like timing, overhead, signalling, etc. that means you need  44Mb in each direction.

But its never that simple designing a network. I know that if you speak to your iDirect sales team they will ask all the right questions and help you design a suitable solution. There are a lot of unanswered questions such as link budgets, busy hour, blocking, guard band, etc. still to include in the design.

thanks for your reply :)

i have been able to run this network on almost 68Mhz with SCPC. i cannot put on a decent proposal if at least i can save half of the current utilized bandwidth.

Plus in pakistan we have  5 operators and no one is currently using idirect soultion;

it'll be really helpful if you lemmi know the response of idirect with GSM; KPI wise ... because i ve heard that there are great KPI issues with Idirect when implemented on GSM.

Contact MMTelcom info@mmtelcom.com  or 00 516-608-8464
They have the technology to compact E1 (30 voice) into 128k.

Also, PCMA may work if your uplink and downlink are co-coverage. If so go Comtech with a PCMA canceller.

Best regards, Eric.

Dear Usama,

This is Danish Saleem from iDirect Middle East Region , i support iDirect customer in Pakistan.

it would be great if you can pass me your query to my offical iDirect address i.e. dsaleem@idirect.net or if you can pass me you number i would like to call you and discuss your query.

Thanks
Danish Saleem
System Engineer
iDirect

You cannot use PCMA with a 72mhz transponder..

And no, the PCMA L-Band doesn't work correctly yet.

And Eric is completely correct, if you are going to deploy any type of PCMA, use the Comtech LBC-4000 L to 70 up and down converters.

And make sure you buy the installation services from iDirect, as they will save your skin in a bind when you cannot figure out why things aren't working.

We had the first PCMA deployment with iDirect in the wild, and exclusively run Comtech frequency converters.

Hope this helps..