Hi Klaus, I work for a company called Smile Communications based in Johannesburg, South Africa (although legally registered in Mauritius) and we are a startup mobile comms company focussing on providing low cost voice and messaging services to underserved (bottom of the pyramid) customers across Africa. We have spectrum and operator licenses in Uganda, Tanzania, Nigeria & DRC thus far and are trying to acquire more as we go along. We launched in Uganda 18 months ago by rolling out our own Wimax network and fixed-wireless wimax/voip phones. We are now looking at rolling out in our other licensed countries. We built an entire voice/messaging stack integrating over 40 different open source projects using an SOA methodology. We have now decided that with the slow uptake of Wimax voice handsets (in fact, no uptake :( ) we will now roll out LTE in our spectrum instead. This necessitates us to move our architecture from something slightly proprietary (although it is all based on SIP) to obey the IMS/VoLTE specifications. Following our previous approach, we want to build the end to end IMS/OSS/BSS architecture in as cost effective manner as possible. We live by the motto that our customers make a decision to either eat lunch or make a phone call with the money they have at any given time - we want to make our calls as affordable as possible and hence keep our Capex and Opex costs as low as possible. We also want to have great flexibility and be able to make changes quickly without needing to call on product vendors. At the same time our motto is provide back to the community - hence us publishing all the stuff we are going to do SR ;) Cheers Jason On Thu, Apr 21, 2011 at 4:41 PM, Klaus Darilion < klaus.mailinglists(a)pernau.at&gt; wrote: