Cell Data on a Single Channel

Posted by Sam Churchill on

Orange, a large cellular carrier in Europe and subsidiary of France Telecom, has begun a technical and marketing trial of the IPWireless UMTS TDD (TD-CDMA) system, in Lille, France. It will be used to test enterprise high data rate services.

The IPWireless system uses UMTS (cellular) frequency, but instead of a paired band (FDD) it uses an unpaired band (TDD) for data.

Orange will use its WCDMA-based network for the trial, which will assess the coexistence of TDD and FDD networks. Other factors to be assessed include coverage area, network capacity and number of simultaneous users per carrier.

UMTS TDD is a data-only network which means cellular providers must gamble that removing a voice channel for data-only services, won’t hurt the revenue stream (from multiple voice calls).

IPWireless provides TD-CDMA chipsets, software, and reference designs in its Developer’s Kit. Their half-pound modem is housed in a robust, cast-metal enclosure with internal electronics contained on both sides of an eight-layer-buildup circuit board. The product is powered by two processors: an Intel Xscale (PXA255AOC), which likely handles the upper layers of the TD-CDMA stack, and a baseband processor made by Philips.

Jeda Technologies says it has the world’s first single baseband solution that supports all TD-SCDMA, GSM, and GPRS cellular standards.

The Global UMTS TDD Alliance is created and supported by members of the UMTS TDD community. UTStarcom is providing UMTS TDD for a UK Broadband network trial and with Optus in Australia while Moving Media may lower the high cost of dedicated lines to cell towers. Toyko is trialing TD-CDMA technology. IPMobile has built three cell-sites inside Tokyo metropolitan area with subscribers using both PCMCIA cards and modems with USB interfaces. TD-CDMA is optimized for data traffic and Internet usage. Only one frequency is used for both up and downstream transmission.

China may opt to use its own home-grown 3G standard TD-SCDMA, developed by Chinese companies and Siemens. Siemens and Huawei Technologies are developing the TD-SCDMA. TD-SCDMA can use a single (simplex) channel for voice and data. It adds a syncronization element and was adopted by the ITU and is now one of three legitimate “3G” standards.

Intel and Korea’s LG will work together to harmonize 802.16e and WiBro. The 802.16e standard will incorporate a thousand or more COFDM carriers, providing more rugged data links and mobile handoff. The higher upstream data channel of WiBro/802.16e could have advantages for VoIP, just as new revisions of EV-DO and HSPDA have for cellular operators.

Verizon’s chief technology officer, Dick Lynch has said a VoIP offering could be launched in the 2008 or 2009 timeframe after it upgrades its 3G network to 1xEV-DO Revision A. EV-DO Revision A will upgrade existing EV-DO systems based on the earlier Release O standard and boost upstream rates to 1.8 Mbit/s, making VoIP feasible on EV-DO. Same deal with HSPDA.

Related DailyWireless articles include; UMTS TDD: The Other Broadband Standard, Siemens and Huawei developing TD-SCDMA, and Unwired in Maui.

Posted by Sam Churchill on Thursday, March 31st, 2005 at 7:01 am .

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