The near-doubling of Long Term Evolution (LTE) users on U.S. networks in the coming days and weeks -- thanks to the iPhone 5 -- could cause localized data congestion and slowdowns that will mostly affect existing users of 4G smartphones and tablets.
Light Reading Mobile caught up with Bill Moore, CEO of RootMetrics, Friday afternoon after the launch of Apple Inc.'s first 4G smartphone to talk about the likely impact of the device on AT&T Inc., Sprint Nextel Corp. and Verizon Wireless's fledgling LTE networks.
(Check out What We Mean When We Say '4G' if you want a refresher on what LTE actually is.)
RootMetrics surveys 3G and 4G network performance, with help from an app that users can install on their own smartphones. Moore says the testing area covers the "top 75 urbanized areas" in the United States.
So what's going to happen with the new iPhone, Bill?
The bad news
Moore estimates there are up to 12 million to 13 million 4G LTE users currently in the U.S., and "they're predicting the iPhone 5 could sell 10 million in the first week," he says.
"That's a lot of new people on 4G all of a sudden. You've got a kind of doubling effect that could occur across the various networks, so that could lead to congestion and slowdowns," suggests Moore. "Plus, LTE users use their phone for data much more than 3G users, so that's going to be a challenge."
He suspects that -- given the still spotty nature of 4G LTE deployments -- any impact will be felt in specific towns or cities rather than nationwide.
"It isn't going to crunch every city. It's going to be localized if it happens," he says "The slowdown would be experienced by people that are already on the network."
That's most likely to be someone with an Android smartphone, as it happens. Verizon, for instance, sold 2.5 million Droids in the second quarter. (See iPhone 5: A 4G Stress Test.)
The mitigating factors
Wireless being the fluid, shared medium that it is, Moore stresses that it is difficult to give any exact predictions about iPhone LTE coverage and problems.
Much, he suggests, depends on how "informed" the average consumer is about 4G LTE and whether they know that Big Red's 370-plus LTE footprint dwarfs its nearest rival in coverage across the U.S. -- although Verizon's pioneering 4G push means its network is also the heaviest loaded LTE network in the U.S. so far.
- If many people switch to Verizon as their 4G provider over AT&T, it could stress some of Verizon's 4G towns and cities.
- If AT&T's users stick by them for LTE and get the traditional iPhone subscriber bump, it could spell trouble for some of that operator's 72 LTE cities. (See AT&T Touts Best-Ever iPhone Sales.)
- Sprint? Moore expects it's least likely to be affected.
The ironic twist
Apple and its carrier partners could be saved by the very success of the iPhone. Apple sold more than 2 million in pre-sales, so shipping dates for many of the devices have been pushed out by two weeks or more.
This could give carriers time to examine the impact of the new iPhone and start to put load-balancing and capacity measures in place to deal with the anticipated influx of data-hungry 4G iPhonistas.
Check out more of our iPhone 5 coverage here.
â€” Dan "Dick Clark" Jones, Site Editor, Light Reading Mobile