I have stumbled across a blog from Nokia Solutions and Networks Labs today. It compares VoLTE with OTT, and concludes:
"Operator VoLTE beats OTT VoIP in real conditions"
Interesting figures that I am in no position to challenge, but it leaves out a lot I think. Without nagging on the blunt statement I have some thoughts of my own from the top of my head I'd like to share.
My conclusion in short: The concept of VoLTE that they refer to (LTE prioritization, improved battery life due to better implementation of core parts (like VoLTE)) is interesting for operators. Telephony less so however in the future.
I think the argumentation has to come from where we are now: Basic telephony is declining. Basic telephony as a service did not evolve for the last decades. Sure, telephony now always work, yet people consider some OTT applications more suited for an increasing amount of situations. And this is just the beginning: Contextual "OTT communications" in web browsers is just getting started.
By far, the experiences are not always positive and the “fall back to PSTN” is most likely often used, but mostly as last resort. It will not take too long I believe that customer will challenge whether the monthly subscription they pay is worth the last resort option. High quality mobile data networks will only accelerate this.
I think we have to look at it from this angle: Surely if you believe in telephony as it is now, VoLTE does a lot to make you get the same experiences on an LTE connected handset "out of the box". I do not see what the NSN argumentation changes however from the fact that telephony is declining and people prefer better suited alternatives?
VoLTE is not much more than basic, unintegrated, generic telephony.
(yes, I am exaggerating a bit, but I want to make a point, too, and changing my technology hat with a customer hat that statement is not so wrong in fact)
What the article does not also state is that many points are not directly related to VoLTE, but rather LTE as such. I don't claim to be an expert on this, but it is fairly obvious:
- Their first main point is that VoLTE behaves better under load than an OTT application. That is no surprise. That is however not thanks to VoLTE, but LTE bearers. As soon as operators will put their OTT application on dedicated bearers (or the ones from partners) they should achieve equal results. Likewise if VoLTE traffic would be routed over the standard bearer it would equally degrade.
- The second point is battery consumption. Also no surprise, since VoLTE handsets do more in hardware than software for VoLTE and thus require less power. This area is challenged mostly by WebRTC I believe. Once new smartphones have not only telephony codecs, but also high-def “web codecs” such as Opus or VP8/9 inbuilt in hardware (that is happening, Intel and Qualcom both do this) also this problem becomes less relevant.
Interesting to see advances in both aforementioned aspects and how they are actually possible, investigated, tried, and in fact happening in the end.
Bottom line: I think the article is interesting, but the headline rather unsurprising for a Telco vendor. It shows only the best from what they think is the best and the worst from what they think is the worst.
There is so much in the middle where also operators can create real value, while utilizing LTE dedicated bearer concepts as well for example.
They can have a fancy so-called “OTT service” (assuming some general new service, since NSN did not define what they actually mean) or contextual communications service built on WebRTC and in the not too far future (sooner than VoLTE will become mainstream) have a service deliver real value beyond just connectivity to the customer with similar characteristics that are attributed to VoLTE in the article.
All I "read" when coming across VoLTE announcements are "telephony" announcements. "Telephony" can now do this, "telephony" recently launched here, and so on. Great technological achievements, yes.
But when you download tons of to torrents on your DSL line, analog telephony voice quality is also "kept at a good level thanks to (the old CS network's inheritent) Quality of Service (QoS) configuration".
That is not going to save telephony though!
I think the highlight and opportunity that the NSN report did not tell us about is neither in the black or white area (VoLTE vs. "OTT"), but in the grey: #TelcoOTT