




I.  The Origins of 4G



A company spokesperson 



Why should customers care?












IV. Conclusions



Comments     Threshold


Some background
By Dwayne Bozworth on 1/10/2011 6:20:14 PM , Rating: 2
Hey Dude. Nice story, too bad there's a few things wrong.

You report that "The origins of the mess began in late 2009, when T-Mobile began upgrading its network to support HSPA+."

This is incorrect. The origins of 4G started in 2002 when T-Mobile US acquired a Texas-based wireless ISP called MobileStar to offer wireless service at major locations such as Starbucks and airports. Within a few months, the service re-launched under the name of "T-Mobile HotSpot" with several thousand additional locations, and a national network, it provided T-1 speeds at local coffee shops and areas with high traffic.

As the WiFi technology evolved, T-Mobile became interested in a technology called MIMO, which was a part of the 802.11n standard. With 802.11n (specifically pre-n) WiFi wireless was able to increase throughput using a technology called spacial coding. They also worked with Siemens who was working on a royalty-free interface called TD-SCDMA.

True LTE is much more than speed. It also uses spacial coding to increase throughput and 4G spells out defined capacity requirements per square mile. It seems this is quickly forgotten. We learned years ago with cable modems that it's of no use if you advertise "up to" speeds. If cell towers are further apart, and won't meet the vanilla December 1, 2010 version of 4G.

Additionally, 4G at 700MHz/800/850MHz can't effectively use MIMO. MIMO requires directionality. Running 4G at lower frequencies is like having a home audio subwoofer- the lower frequencies are not directional and you can stash the subwoofer in a corner or under a table. MIMO works by reflection of signals, similar to a home audio satellite speaker placement.

802.11n took so long because the FCC had to clear spectrum in the higher 5.6GHz range because it required more reflectivity and an unused band.

Developing a network that's loud enough to blast through neighbors walls and uses sub-woofer technology is easy. You just need to have one big subwoofer, and lots of spectrum.

To compare, a 20MHz slice at Clearwire's 2.5GHz can provide 90MB/s Meanwhile, LTE using spectrum at 700MHz seems to tap out at 20-30MB/s.

The bandwidth efficiency means one of two things- The FCC will have to clear up to 300MHz for 800/850MHz to provide the efficiency a 20MHz 2.5GHz can provide, or your established Cellular carriers will have to come clean, start using the idle AWS spectrum they acquired and start a major network build-out, quit primarily depending on the lower frequencies because they are a crutch in 2011. All this will be necessary to match PCS providers spectrum capabilities. Sprint, MetroPCS, Cricket, T-Mobile, will surpass the Cellular providers on 4G.

I imagine 4G has been in the works since 2002, when 802.11n was just a glimmer in the wifi user's eye.

