3. Alphabet Soup - Battle of the Mobile Data Network Standards

Though I don't think I achieved the titled goal of Sunday's session, I came away with a better understanding of the competing standards and their advantages and disadvantages. If you want to learn a little more about the contenders and you're in the mood for a lot of acronyms, read on.

There are three main mobile / cellular wireless network standards: CDMA, TDMA and GSM - each with its own digital data speed transition path. The original system for sending data via cell networks was CDPD (Cellular Digital Packet Data), which actually uses the old 800MHz analog cell standard (AMPS). Though it's slow (19.2kbps max raw data rate) and on its way out, CDPD is still used today because of its wide availability.

CDPD's replacement on TDMA and GSM networks is GPRS (General Packet Radio Service) which typically provides 20 or 30 kbps of useable transfer rate. This is starting to be replaced by EDGE (Enhanced Data Rates for Global Evolution), which AT&T Wireless (now part of Cingular) says will achieve typical data rates of 80-130 kbps. Rollout of EDGE capability on GSM-based networks, which is currently in progress in the US, is expected to be relatively swift, since it involves only a software upgrade.

The step beyond EDGE for the GSM / TDMA camp - UMTS (Universal Mobile Telecommunications System) - seems to merge them with the CDMA world. UMTS incorporates (and is commonly also referred to) as WCDMA (Wideband Code Division Multiple Access) as well as elements of GSM and some additional spectrum for good measure. It's said to support packet data at about 2Mbps, but that will probably change between now and when it starts becoming more real sometime in 2005.

GPRS's competitor in the CDMA world (which in the U.S. is Verizon and Sprint) is called CDMA2000 1X, which according to Seybold's tests can cruise along between 40 and 100 kbps. The next steps for CDMA-based systems were causing the most buzz at the show, both because they were "new news" and because they claim to have superior performance to EDGE.

Verizon announced that it will be spending $1B over the next two years to roll out CDMA2000 1xEV-DO (Evolutionary- Data Optimized) based BroadbandAccess mobile data service in the U.S. to about a third of its customers. The service is already on-line in San Diego and Washington D.C. but costs a stiff $80 / month. It, of course, also provides voice capability, but uses a separate band to do so.

1xEV-DO is a data-only system and tends to grab attention due to its maximum claimed speeds of 2.4 - 4.8 Mbps. But even its typical claimed speeds of 300 - 500kbps are impressive and comparable to those available to many wired DSL subscribers.

The next step in the CDMA data evolutionary chain is CDMA2000 1xEV-DV (Evolutionary- Data Voice), which maintains 1xEV-DO's data speeds but adds packet-based voice capability. Not sure when this one hits the airwaves, given the current focus on 1xEV-DO.