SAN JOSE, Calif. Chip designers for cellular and WiMax networks are sharpening their pencils on plans for 700 MHz support after getting new guidance from the Federal Communications Commission (FCC) on the spectrum last week. A race is on to determine who will have what chips with what performance dynamics ready when new spectrum owners start planting towers as early as February 2009.
Qualcomm is working to characterize its current and future CDMA technologies for 700 MHz with initial chips shipping next year. WiMax players are doing the same. And the proponents of the Long Term Evolution version of cellular are still finishing their specification.
"One of the things I lose sleep over is whether the technology road maps will slip, and I will have to deploy an interim solution before one of these 4G technologies is ready," said Stagg Newman, chief technology officer for Frontline Wireless, a startup that hopes to buy some of the new spectrum rights.
"I'm really glad I don't have to choose a technology for 4-6 months," said Newman, recalling his experience years ago making a similar choice between CDMA and TDMA vendors for a US cellular provider.
"Both of them slipped their dates by several years and their capacity wasn't anything like what they promised," recalled Newman. "The industry has gotten better at delivering since then, but it is still not very good about hitting dates," he added.
Cellular chip and systems makers have to jump plenty of hurdles to have products ready for deployment in February 2009. They will be applying to cellular networks broader use of the OFDMA (orthogonal frequency division multiple access) technology than it has ever seen, as well as using broader swaths of spectrum than ever before (up to 11 MHz) to carry signals.
They must do this in a relatively constrained 700 MHz where some transmit and receive channels will be separated by as little as 12 MHz. Developers typically use spacing of as much as 30 MHz.
"This is one of the more complex bands," said Peter Carson, senior product manager of next-generation cellular chips at Qualcomm CDMA Technologies.
The 700 MHz band will carry two-way broadband networks for commercial and public safety applications as well as high-powered digital TV broadcast for services such as Qualcomm's MediaFlo mobile TV network. The FCC is still refining the rules on how all those services will work providing much new detail in its latest ruling just last week.
"We did a first round of analysis [of the Qualcomm chip- designs] based on a lot of assumptions about the regulations," said Carson. "Now we are doing a second round of analysis based on the ruling that came out Friday. We expect to be able to be more specific in a month or two with more details, figures of merit and qualitative analysis," he added.
More rulings may be yet to come. For instance, companies such as Frontline expect to file petitions for reconsideration, called recons, asking for changes in the most recent rulings, said Newman. "Usually there are no major changes with the recons," said Newman, a former chief technology officer at the FCC.
For its part, Qualcomm plans to ship a quad-band chip set supporting 700 MHz for its exiting EVDO Rev A and B technology in time to enable systems launches for the expected deployments starting in 2007. A similar chip set for its next-generation REV C technology, also called Ultra Mobile Broadband (UMB), should be ready by June 2009 at the latest.
The Qualcomm Rev A technology promises peak physical layer data rates of 3.1 Mbits/s down to a terminal and 1.8 Mbits/s up from a terminal. The Rev B technology has a capability to support three such channels, and the Rev C boosts theoretical peak bandwidth to as much as 40-80 Mbits/s.
Qualcomm says all the chips sets will consists of three primary parts—a single chip CMOS transceiver, a baseband chip and a power amplifier.
For its part, Frontline is tracking LTE, UMB and WiMax closely. "The final decision of what technology we will use will be based on the state of health of the technology and the ecosystem supporting it," said Newman.
"Once someone has bought the spectrum and has their check books out, vendors will start developing these systems in earnest," Newman said. That should come by March 2008, he added.