Saturday, 7 November 2009

OneVoice for LTE + IMS : Necessary but not sufficient

EDIT: If you are interested in learning more about the Future of Voice, I am running a series of small-group Masterclasses together with Martin Geddes, as well as providing private internal workshops. Email me at information AT disruptive-analysis DOT com for more details

 This will surprise a few people: I'm actually quite impressed with the announcement the other day about the OneVoice profile for defining an IMS-based approach to voice on LTE. I've now had a chance to read through the full document.

It essentially de-options a lot of the implementation vagueness and distracting flexibility around using IMS for mobile voice, creating a lowest common denominator "Profile" from the existing standards. It strips away a lot of the unnecessary fripperies and boils it all down to what amounts to the minimum set of requirements for basic telephony to work - if you happen to be an operator bought into the IMS world-view, that is.

Exactly two years ago I published a report on VoIPo3G (which included an analysis of the role of VoIP on LTE, HSPA and EVDO). I wrote "Too much emphasis is placed by 3GPP on unproven ‘multimedia’ telephony concepts rather than ‘plain’ VoIPo3G". More than three years ago I wrote another report on IMS-capable handsets (or the lack thereof) in which I wrote "There is little consensus on the answer to the question "What exactly is an IMS phone?""

Well, this document is an IMS-centric take on "Plain VoIPo3G", and it does go a little further in defining the capabilities of an IMS phone. It makes it very clear that "other media types" like video are not essential, for initial deployment at least. There is not a single mention of the word "presence" in the whole document. It talks about AMR codecs and not the "HD" wideband version AMR-WB.

It appears to have taken a long hard look at the unloved MMTel standard for mobile IMS VoIP and turned it into something more practical. It might even make "bare-bones IMS VoIP" a bit cheaper and easier to implement for some of the operators who are skeptical.

All of which is good. -But the problems it addresses have been obvious for at least 2 years, and this announcement is a start of a process and not its end. This document is just a suggestion, not a standard. It will be forwarded to 3GPP and GSMA and other bodies. It's written on a template that *looks* like a standards document, but for now it's just a helpful suggestion from some interested parties. "this specification defines a common recommended feature set and selects one recommended option when multiple options exist for single functionality"

Hopefully, it will become more widely adopted over time - although it will be interesting to see if any changes are made when other companies have their say. Notable major omissions from the roster of participants are NTT DoCoMo, China Mobile, Huawei, ZTE, LG, Apple, RIM, Motorola, Telecom Italia, T-Mobile, Qualcomm, NEC and quite a few others.

Various other commentators have suggested that this means that OneVoice is "One Ring to Rule Them All" (....and in the darkness bind them), spelling the end for Frodo (aka VoLGA), Gollum (CS Fallback) and all the other hobbit-like contenders for Voice on LTE.

I disagree.

OneVoice is necessary but not sufficient. It makes IMS less painful for mobile voice, but it doesn't make it ideal either. It makes interoperable IMS mobile voice less slow to develop, but it doesn't make it fast. It makes it less cumbersome, but doesn't make it elegant. It makes it less costly, but it doesn't obviously make it profitable. It's an important step, but it isn't the whole journey.

When the OneVoice press release came out, I was at the Telco 2.0 conference listening to Vodafone's Internet Services team discussing 360 and commenting on IMS RCS, saying "it was going in the right direction, but taking too long". They also mentioned they might think about putting a VoIP client into 360 at some point. I initially thought Voda's presence in the press release a bit strange given it seems in no hurry to deploy LTE, but on second thoughts I see no downside for them either: simplifying IMS is either neutral or positive for them, depending on which part of the company you talk to.

Either way, OneVoice isn't going to happen ubiquitously, nor overnight. Handset vendors must be breathing a sigh of relief that they *finally* have bits of a specification to work to for IMS handsets. But it's unlikely to be quick to hit the market or be optimised. And the overall business case for mobile operators to deploy IMS is still not exactly pretty, as it offers no obvious new revenue streams. For fixed IMS, there have at least been some decent arguments around cost-savings. But it's far from clear that the mobile IMS spreadsheets have a similar bottom line benefit.

So there is still likely to be a need for an interim solution for several years - as well as something that works on non-IMS LTE operators' networks. CS fallback is a bit of a train-wreck which nobody seems to like. So I think that VoLGA still makes sense for those wanting to make the most of their circuit-switching assets. And Internet-based voice services like Skype or a future "VodaVoIP" may have appeal for the more 2.0-style operators deploying LTE.

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