When most British 4G LTE cellular networks were in the planning and pre-rollout stage, I remember having a conversation with a carrier network engineer and talking about the the different technologies (2G, 3G and 4G) and how the carriers would likely favour 2G and 4G networks. The rationale here is that 2G is great for handling calling and texting and that whilst the latest DC-HSPA 3G radio technology was "as fast as matters compared with LTE," it didn't have anything like the same capacity so would be swapped out. I could see the logic behind this, but the UK market felt four years behind the USA, so in the absence of plentiful LTE coverage it seemed just a pipe dream. Now eighteen months later and after an especially aggressive LTE rollout, my smartphone has plentiful 4G coverage. We have increasing discussion of voice over LTE networks across different carriers such that with a little more development, 2G and 4G combination networks would work for many customers.
We are seeing the first signs of this from Verizon Wireless thanks to the investigations of Milan Milanovic, the sort of chap who various around an industrial spectrum analyzer. Milan discovered last month that Verizon had shut down their 1,980 MHz / 1,990 MHz, 3G EV-DO network in the Manhattan area. But earlier in the week, Milan noticed that these frequencies now contained Verizon's LTE coverage all over Manhattan, but nothing in Brooklyn and Queens. The masts are only transmitting at a very low level and Internet connection speeds are very slow, so Verizon appear to be still in the testing stage. Indeed, GigaOM contacted Verizon and a spokeswoman confirmed that Verizon is testing LTE in the PCS band, but would not go into the detail of the locations. I've seen other reports of this band being repopulated with LTE in the Cleveland area thanks to the SG4U website. Verizon also reiterated that as far back in 2011, the company highlighted that they would likely shut down 3G networks and move across to 4G LTE technology. It's only been three years and we are already seeing this!
It's important that we don't get too excited about this, because whilst somewhere close to 80% of Verizon's traffic is now transferred across 4G networks, only 60% of their total devices in use today have a 4G radio. It means that the network will need to maintain a level of 3G coverage at each (or at least most) cell sites. Coming back to the UK networks, the proportion of 4G handsets is much, much lower; we are still some way behind the US market when it comes to LTE coverage and consumer penetration. It remains to be seen how each of the carriers handles the transition but Verizon appear to have shut down their upper-band 3G network at Manhattan to make way for 4G LTE. Longer term, with the adoption of VoLTE technologies, I expect to see the carriers aiming towards getting all traffic on their highly efficient LTE network. 2G will remain as a backup technology and 3G will likely be shut down.