Less than 10 years ago, dot-com was the technology phrase de jour. Business plans, companies and even an economic boom (and bust) were built upon one little dot.
Today, at least in the wireless world, `dot’ has taken on a new meaning.
Dot unites 802 with a variety of trailing numbers and letters that spell out the future of wireless networking. To the untrained eye, what lies behind the dot is nothing more than alphabet soup, but those letters, numbers and occasionally an extra dot all add up to a roadmap for how users will stay connected at all distances.
The IEEE has sponsored four major subsets of the 802 standard that relate to wireless networking. 802.15 addresses short-range wireless transmissions, while 802.11 in its many flavors addresses wireless local area network coverage. 802.16 and 802.20 are newer on the scene, and they aim to address requirements for broadband speeds at greater distances for fixed and mobile usage.
802.15, which has provided fertile ground for a variety of disputes and infighting, encompasses what is known as wireless personal area networks. The standard breaks down into several main versions, including 802.15.1, or Bluetooth; 802.15.3a, or Ultra-Wideband; and 802.15.4, or Zigbee.
Bluetooth, which provides short-range connections between devices like keyboards, computers and headsets, is well established and is widely deployed. The Bluetooth Special Interest Group recently announced plans to cooperate with UWB developers in an effort to incorporate UWB’s higher data rates into the technology’s products.
However, UWB developers themselves are split into two camps that are in a heated battle over which direction the technology should take, a debate that some fear will bog down or even completely derail UWB standards efforts. The WiMedia Alliance Inc., which includes the recently combined WiMedia Alliance and MultiBand OFDM Alliance Special Interest Group, promotes a multi-band approach to UWB. The UWB Alliance supports a single-band approach. Both sides are backed by major vendors and both have pushed forward with product developments, which could make an eventual reconciliation difficult.
ZigBee, which is fairly new, covers industrial, residential and monitoring applications. It also is in a battle of its own with a proprietary technology called Z-Wave.
.11
At about six-years old, 802.11, better known as Wi-Fi, is the granddad of the wireless 802 family. Its first iteration, 802.11b provided speeds up to 11 megabits per second, which at the time was a big accomplishment, said Frank Hanzlik, managing director of the Wi-Fi Alliance.
The standard has gone through several enhancements. The a and g physical layers brought faster speeds to 802.11, up to 54 Mbps, and the up-and-comingiteration further ups the ante to provide speeds greater than 100 Mbps. Other letters symbolize medium access control layers that address security and quality of service upgrades.
Wi-Fi has been widely deployed in homes, enterprises, schools, coffee shops, hotels, convention centers and anywhere else a consumer might to want to check e-mail or surf the Web.
Hanzlik said the technology is moving beyond early adopters into the mainstream and looking forward to the potential for voice, multimedia and even Voice-over-Internet-Protocol-over-Wi-Fi applications. The majority of personal computers today are shipped with Wi-Fi technology included, he said. And the technology is now finding its way into consumer electronics devices and wireless phones, with some first-generation models of cellular/Wi-Fi phones targeted mainly at vertical markets now being introduced, he said.
“There’s a lot of recognition that cellular will never be as fast as Wi-Fi and Wi-Fi will never be everywhere cellular is, so the prospect of having both technologies in one device is exciting,” said Hanzlik.
In addition to providing a complementary service to cellular, Hanzlik said Wi-Fi is also complementary to longer-range wireless metropolitan area network technology outlined in the 802.16 and 802.20 standards.
“There isn’t going to be one wireless technology that does it all,” said Hanzlik. “The reality is devices of the future will have more than one wireless technology inside.”
.16/.20
802.16 breaks down into a few variations of its own, primarily fixed line-of-sight and non-line-of sight versions touted mainly for backhaul and last-mile purposes, and a new mobile version, 802.16e. The mobile version is designed for nomadic, or walking, speeds, said John Kryzwicki, president of TMNG Strategy, which teamed with Bear, Stearns & Co. Inc. last year to assess the markets for the 802.16 and 802.20 broadband wireless standards.
Both 802.16 and 802.20 allow data rates of 1.5 Mbps to 70 Mbps over distances of 2 to 50 kilometers, although Bear Stearns and TMNG noted there is a tradeoff between bandwidth and speed and range. 802.16 targets metro area access, while 802.20 targets wide areas similar to cellular networks.
The 802.16 standard has enjoyed solid vendor support and more than its fair share of hype, driven in part by optimistic revenue predictions. WiMAX got a major boost last month when one if its primary supporters, Intel Corp., released its first WiMAX chip based on the 802.16-2004 version of the standard. A variety of other companies also announced their own WiMAX chips and some carriers have committed to testing the technology.
The WiMAX Forum plans to begin interoperability testing of products this summer with the first certified commercial products expected to hit the market by the end of this year.
802.16e is often said to overlap and compete with 802.20, which itself is named as a competitor to third-generation networks.
802.20, which was created from the get-go as a mobile technology, differs from 802.16 in that among other things it aims to provide high-rate data connectivity at fast traveling speeds. Development work on the standard is in the very early stages.
Flarion Technologies, one of the primary supporters of 802.20, and Nextel Communications Inc. trialed wide-area wireless broadband services in North Carolina using Flarion’s Flash-OFDM technology. Nextel, however, recently announced it plans to halt the network trial.
Whether both 802.16 and 802.20 will survive together is a matter of much debate in the industry.
“How often are you going to need megabit speeds at 70 miles per hour?” asked Kryzwicki about 802.20. In Japan, he said, where a large percentage of citizens commute on high-speed trains, 802.20 technologies may be useful. But in places like the United States where most commuters drive in cars, that type of capability may not be as viable, he said.
“I don’t think you are going to get both 802.16 and 802.20 surviving in developing countries together in a major way,” said Kryzwicki. “You might see some countries go one way and others go the other way. Most people see a stronger future for 802.16, mostly because of its support from Intel. There’s not as big a champion for 802.20.”
