Inspired by this post over at the 3G4G wireless blog on VoLGA and VoLTE architecture differences, I reflected a bit on why it has become a bit silent around LTE voice recently. From a VoLGA point of view, maybe it is because there is little more it can prove until the time real LTE mobile devices (not USB sticks) come to the market.
Back in February 2010, VoLGA was demonstrated at the Mobile World Congress in Barcelona as fully functional, using live network equipment. It's here and it's working but until real devices become available, there is nothing more to be shown that could go beyond it. And with closely related UMA (Unlicensed Mobile Access) stacks used in practice today on Nokia, RIM and Samsung devices for Voice over Wi-Fi, I have little doubt that this final piece can be implemented very quickly. Same thing for VoLTE and CS Fallback, they are there on paper and are waiting for devices they can be implemented on.
But once the solutions can be demonstrated in practice, I expect that the competition between them will accelerate again. It's going to be interesting to see if the simplicity, full functionality from day one, fast call setup times and a relatively simple but hyper-important in-call handover from LTE to GSM / UMTS of VoLGA will trump over other solutions.
What I always wonder in all discussions questioning the investment in IMS are the following points:
First: Sticking to VoLGA means to decide for an intermediate investment on the VANC infrastructure because the end of the game will be IMS. AFAIK there are no doubts on this fact even by the VoLGA proponents. If one does not believe in IMS as the end solution then the next question is the business case for maintaining the CS networks in future with revenues going to zero.
Second: Some people always argue to leave voice to the OTT players. They ignore the importance of offering an infrastructure for emergency calls. This will not be done by Google, Skype etc. This is not a technical question of setting up a call on the Internet but of being responsible for reaching the PSAP. Who will be responsible for emergency calls if not the network operator?
Third: If someone believes that only a broadband connection is enough for making users happy, then he should also explain how emergency calls can be guaranteed when other users are clogging the access networks with watching videos. The radio network is and will be a limited resource.
There will be many models for operators in future. If there are going to be 50 billion devices in 2020 there is no need for some to support phones at all – they will be a minority class of connection.
Certainly some operators will deploy IMS, and certainly some will not. GSM and CS networks will be around for at least 20 years more.
There are plenty of other options which could support emergency calling as well, it is not. Black and White picture.
Thanks for your view Dean.
If the CS part of a mobile network will remain in place for such a long time then it makes of course sense to stick to the existing method to provide voice services. It is in the end only a question of the business case.
But I still have some doubts that it is viable to maintain the CS infrastructure for such a long time for a small part of services and revenues.
Franz
We will not be getting $20 LTE phones suitable for prepay users any time soon. Neither will we be transitioning the installed base of GPRS M2M devices quickly, or switching off GSM for inbound roamers.
I’m not expecting mobile PS voice revenues to exceed CS (inc SMS) for an extremely long time – maybe 10 years for the most aggressive operators, maybe 20 for others, if ever.
If you look at the fixed world, the shift to VoIP has taken a very long time indeed – and that’s without the extra challenges of mobility, battery life, radio coverage etc.
Hi all,
thanks for the great discussion so far!
Another thought concerning the legacy CS service: As we go forward, the MSC that used to be a circuit switched monster for some with real circuit switched lines is becoming virtual and fully IP based. In other words, in the not to distant future, the MSC is simply just an IP box sitting in the corner somewhere with a media gateways to connect to the remaining circuit switched world. No reason to get rid of this box, it is doing its job well. And as Dean said, good old GSM will still be with us for quite a while.
Heres a link for more details on the MSC just becoming another IP service box:
http://tinyurl.com/d5wodn
Cheers,
Martin