At first, VoLTE will be used to deliver "Rich Communications Services" (which look like something similar to what Voice over IP/Video over IP outfits offer today) rather than completely replacing narrowband voice. It will be awhile before Verizon is willing to commit to that, due in part to LTE outages in late 2011.
On the flip side is MetroPC, which has pushed VoLTE as hard as it could.
Then there's Sprint, which will stick to voice over 1x for the foreseeable future, but routes Direct Connect over IP. Sprint's latest DC incarnation seems quite similar to one facet of RCS over LTE.
It's only contiguous with the cellular A block not the B block.. TMO does have the A block B5 themselves. I think Dish will buy it as it will help with coverage even tho B71 will be more useful. I also think I heard the equipment that dish has ordered support N26 Sent from my SM-G975U1 using Tapatalk
Any tower with n71 also has B71 LTE, though the reverse isn't true.
B71 LTE is the longest range tech T-Mobile has, so from a coverage perspective a 4G phone with B71 won't be missing anything. The catch is that in many places the B71 channel is 5 MHz wide, and TMo's B71 deployment is way thinner than Sprint's B26 deployment, so having only 5 MHz hurts more. Though not as bad as having only 5 MHz of PCS.
Now, there are two more factors at play here. First, outside urban areas where Dish etc. grabbed spectrum, T-Mobile has more.to work with, so.performsnce on B71 will be better (unless some rural carrier scooped band 71 up, and some did). Additionally, T-Mobile is touting range improvements for standalone 5G, which launches this quarter, so there is a chance they'll start adding NR-SA n71 cell sites in some rural locations, similar to how they added B71 in some areas they hadn't touched before. In that case your phone wouldn't work.