LTE at 50 Mbps? Don’t Hold Your Breath

Even though Verizon CTO Dick Lynch tried to stay away from the download-speed numbers game when we spoke to him recently about the company’s plans for Long Term Evolution, you can’t hide from the mainstream tech media’s need for simple figures for long. So it’s not a surprise to see a whole bunch of people taking the “LTE trial speeds of 50-60 Mbps” from Lynch’s presentation at the Mobile World Congress this week and running with that as a projected speed for Verizon’s eventual 4G wireless offering.

Our take? Don’t hold your breath waiting for those kind of speeds.

With the limited amount of spectrum Verizon has available at 700 MHz, a safer guess would be seeing them offering someting in the range of 10-15 Mbps download speeds — not revolutionary, but certainly a magnitude of order better than Verizon’s current pokey 3G offering.

So far, Lynch and Verizon won’t pin down any specifics of their planned deployments. But when they do, the key one to look for is the channel size — specifically, how wide of a channel Verizon will use to pump out that wireless LTE data. There’s a lot of wireless-physics details involved, but a simple rule of thumb is that for best results you want to deploy three equal-sized channels for maximum coverage and minimal interference. Since Verizon only has 20 Mhz of spectrum “depth” in its 700 MHz frequency holdings, the best it can probably hope for is 5 MHz channels — which is a far smaller pipe than the 20 MHz channels used for those 50-60 Mbps tests.

At the very least, Verizon’s aggressiveness on the LTE publicity front seems to have stirred the pot at AT&T, which announced the first tentative dates for its slower-paced LTE rollout. Motorola, which offers some good LTE info on its websites, didn’t get any of the Verizon infrastructure pie, with those deals going instead to Alcatel-Lucent and Ericsson.

The key line from the Verizon press release to remember should be this one:

These field trials have demonstrated download rates of 50 to 60 Mbps peak speeds, though actual average download results will not be determined until the commercial launch of the new Verizon Wireless LTE network.

That will be a number worth waiting to hear.

Leave a Reply