While I agree that the statement is pretty definitive, there's still a number of unanswered questions & scenarios that could play out:
- Firstly - it's a trial. Until the trial is proven successful, presumably the chequebook stays in Verizon's pocket.
- Secondly, as Sprint's current review of its deployment of WiMAX illustrates, it's always possible to change direction at a later stage if necessary.
- Verizon is likely to keep (and evolve) its existing 3G EVDO Rev A network irrespective of LTE. Its news release says that it will "continue the expansion" of its existing technologies. Although Rev B isn't getting much traction either, I guess there's scope for a Rev A+ of some sort.
- The big 'swing' factor for UMB continues to be Japanese operator KDDI. If it also backs away from the CDMA family, then its pretty much goodnight for UMB. If it runs with it, then there's possible large scale deployments to follow in places like India or Brazil.
- Another variable is of course SprintNextel, the other big US CDMA operator. Don't forget that it originally trialled Flarion's Flash-OFDM (on which UMB is based, since Qualcomm's acquisition of Flarion), and quite liked it - but felt it wasn't ready for deployment back in 2006. If Sprint backs away from WiMAX (or scales its rollout down), I can't see it necessarily wanting another 3.5G+ technology in the shape of LTE.
- Lastly - it's unclear what might happen if Vodafone & VZW ever parted company.
Essentially, I see convergence between 3GPP and 3GPP2 extending from the core outwards for major carriers:
Stage 1 - Core Network (IMS or something similar), Now
Stage 2 - Radio Access & Transport (aggregating LTE together with HSPA, EVDO, WiFi, TD-SCDMA and maybe WiMAX), around 2011
Stage 3 - Air Interface becomes fully harmonised (excluding things like TD-SCDMA probably), around 2015
That said, the option to create dual-mode CDMA/LTE devices could help Verizon manage multiple networks. And if it did, then it would definitely also create an interesting backdrop for how it treats voice - would it use VoIP on LTE, and circuit on EVDO? Or VoIP everywhere?
UMB is about as similar to CDMA as LTE is; which is to say not at all. 1xEvDO rev A and B, WCDMA, HSDPA/HSUPA are all CDMA based (much to Qualcomm's pleasure and bottom line) but both UMB and LTE are clean breaks; OFDM systems that are broadly similar to mobile WiMAX (other than being FDD, whereas mobile WiMAX is TDD for the moment).
ReplyDeleteYour steps to convergence do seem right, all the systems will converge on all IP core networks. I think you're off base with the notion of ELTE. mobile WiMAX, LTE and UMB pretty much represent the state of the art of air interface technology. There's nothing in the technology pipeline that will supplant them and there's no big driver for unification. The next big phase of radio innovation will come in wireless network architecture, with things like wireless backhaul, micro/pico/femtocells, and hybrid cellular/mesh networks. The air interface is fast on its way to being utility technology (i.e. boring and stable). Instead of unification, you'll just start seeing tri-mode UMB-LTE-WiMAX chipsets that can operate in TDD or FDD. Who needs air interface unification when you have Moore's law!
Incidentally, get ready for the OFDM patent trolls. They're quietly lurking, feeding and growing the lawyers that they'll unleash once 4G networks start to take off. Wi-LAN will be the number one predator.