This post is a quick follow up to a previous post on LTE smartphones at CES. In the post I came to the conclusion that unlike for CDMA operators, it doesn’t make a lot of sense for GSM/UMTS operators to go for LTE smartphones until they have a solid voice over LTE implementation. By solid, I mean good quality, a fast call setup time, proper integration into the UI of the smartphone and handover to GSM/UMTS when running out of LTE coverage.
There are several solutions such as CS fallback, which I think won’t be acceptable due to the increase in call setup time, IMS VoLTE which requires a complex core network addition and is nowhere on the horizon and of course Voice over LTE via GAN, or VoLGA for short. VoLGA is based on the 3GPP Generic Access Network (GAN) extension that replaces the GSM or UMTS radio network with IP over Wi-Fi. The solution has been deployed by a number of network operators for several years now and although it hasn’t found much traction it could be the very key to LTE on smartphones in the 3GPP world.
With recent announcements of GAN now being available on Android phones and some network operators shipping and upgrading such phones, that’s the best starting point you could possibly wish for as a GSM/UMTS operator planning to go for LTE.
Think about it, let a smartphone maker put an LTE chip into a GSM/UMTS smartphone in a similar way as is now happening for CDMA smartphones. However, instead of having two radios active at the same time, put the Android GAN Client on the device that uses Wi-Fi or LTE as an IP network to connect back to the operator’s core network to offer voice, SMS, etc.
That way, with next to no effort at all, GSM/UMTS network operators using GAN today and thus already having a GAN gateway in place will be able to offer LTE smartphones with proper voice service once they launch LTE. A bit of extra effort is required to make the handover to GSM/UMTS of an ongoing voice call. But really, that’s a piece of cake compared to making other solutions work. So who are those network operators being Voice over LTE ready, whether they have already considered it or not? According to smart-wi-fi.com that’s Orange France, T-Mobile US, Rogers, Cincinnati Bell, TeliaSonera and Orange UK.
The list is not very long but that doesn’t matter a lot. Practically all GSM/UMTS network operators that are not on the list can quickly get smartphones with LTE and voice service as well and hit the ground running. What they need in addition is a GAN / VANC controller in the core network and the experience to run GAN / VoLGA. But those network operators mentioned above are proof that it’s working.