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Wireless weapons of War

Fri, 03/31/2006 - 7:00pm
Leslie Ellis, Independent Technology Analyst

It seems you can hardly turn around without bumping into yet another flavor of wireless, with yet another multi-company support group behind it, promising yet another way for consumers to get more stuff faster, and without wires.

'Wireless Weapons of War'

In this roundup, we break down 10 of the big names in wireless techniques: Ultrawideband, Bluetooth, WiMax (fixed and mobile), WiBro, WiFi and "the 802.11s," DVB-H, and "the 3Gs."

Here's the big takeaway from the wireless explosion: Without much variation, all of the competing standards bodies and efforts listed below target the same ending: An untethered broadband world, where all of your devices with embedded radios work the way you want them to, regardless of where you are, whose network you're on, what you're trying to do (voice, video, data) or how fast you're moving.

Seem a little unrealistic? Probably. From a cable perspective, the one to watch, of course, is the one Sprint is using: 3G EV-DO, where the "EV-DO" stands for "Evolution Data Optimized." It's also what Verizon is using for its V-CAST broadband services. It matters to cable because of the joint venture Sprint established with Comcast, Time Warner Cable, Cox Communications, and Advance-Newhouse last year.

Know going in that all wireless protocols have one thing in common: They encapsulate. Among other things, they encapsulate IP traffic—which is what makes them useful. They add features in their headers and trailers, which make them more or less useful, depending on the scenario. Much of what's better or worse is "religious," so trying to establish which wireless protocol is "best" usually beelines into technology politics.

Grain of Salt Dept.: We did our best to cut through the clutter of "intended range and speed," vs. reality. Know that actual performance obviously depends on a series of variables, which usually have the impact of either slowing data down, or shortening the intended range. Here's the roundup:

Ultrawideband

Ultrawideband, abbreviated "UWB," is one of three major "short range wireless" networks aimed at eliminating the wire kluge around all our digital stuff. (The other two: Bluetooth, ZigBee.) UWB wasn't designed as a replacement for Bluetooth, Intel says. Instead, it wants to "create a UWB radio that allows for the migration of Bluetooth, USB, and 1394 protocols in such a manner that a single radio can support each of these protocols."

What Spectrum: 3.1–10.6 GHz

What Apps: Short-range "wireless personal area networks," for connectivity between devices—like a laptop with a printer/scanner, or a digital camcorder to an HDTV, or an MP3 player to speakers.

Who's Pushing It: Intel, the MultiBand OFDM Alliance (MBOA), the WiMedia Alliance (www.wimedia.org)

How Far/How Fast: 10 meters/30 feet; 480 Mbps

What's the Spec: IEEE 802.15.3a

Under the Hood: Multi-band OFDM (Orthogonal Frequency Division Multi-plexing)

Bluetooth

Bluetooth is already in the market; many wireless headphones use it, as do wireless headphones in microphones, and PC peripherals.

What Spectrum: Unlicensed 2.4–2.485 GHz

What Apps: Short-range device connectivity

Who's Pushing It: www.bluetooth.com

How Far/How Fast: 10 meters, up to 3 Mbps

Where's the Spec: Bluetooth Web site

Under the Hood: Spread spectrum, frequency hopping, full duplex

Special Notes: The cost per Bluetooth chip is down to $3; it uses 2.4 milliwatts of power (less than most).

WiMax

One of the bigger hype creators of 2005, WiMax is, to some, the death knell for wired broadband services like cable and DSL modems. Proponents say that what WiFi does for your home or office, WiMax does for your subdivision or office park. Detractors say the WiMax spec tries to be too many things to too many people, that it's not backwards compatible to the other variations of the 802.x specification, and that interoperability is going to be a huge issue.

Cable's interest in WiMax lies in its applicability over licensed spectrum. Although few or no operators actually hold any licenses in the WiMax spectral zone, it's a general comfort zone to be in a licensed, and thus controllable, band.

What Spectrum: Licensed and unlicensed 10–66 GHz, and sub 11 GHz

What Apps: Personal, portable broadband, within a metro footprint. Fixed or mobile.

Who's Pushing It: Intel, WiMax Forum (www.wimaxforum.org) and its 300 members (mostly suppliers).

How Far/How Fast: Max cell size of 30 miles; typical cell size of 1.5 to 5 miles; roughly 15 Mbps per cell. Mobility: Connectivity at high vehicular speed (70 mph).

What's the Spec: IEEE 802.16d (fixed); IEEE 802.16e (mobile)

Under the Hood: Multiple channelizations, from 1.5–20 MHz

Other Notes: Issues include backwards compatibility; the realities of range and speed.

WiBro

Short for "Wireless Broadband," WiBro is an adapted version of IEEE 802.16e (mobile WiMAX) developed by and for the Korean marketplace. Services launched in Fall of '05; further launches anticipated this year.

What Spectrum: Licensed 2.3 GHz band

What Apps: Mobile and nomadic broadband

Who's Pushing It: Korea

How Far/How Fast: 4 Mbps/2 Mbps downstream/upstream; 1 km cell radius.

What's the Spec: Based on 802.16e.

Under the Hood: QAM modulation with OFDM for media access

Special Notes: Largely viewed as an accelerator to mobile WiMax (802.16e).

WiFi 802.11N

"WiFi" refers to the variations on the IEEE 802.11 standard, which carries nearly as many one-letter suffixes (a, b, and g) as "on-demand" has prefixes.

There's 802.11a, which runs between 6–54 Mbps on eight to 12 channels in the 5 GHz zone, and can reach about 66 feet.

And there's 802.11b, which runs between 2–11 Mbps on three channels in the 2.4 GHz range, with around a 330-foot max; technologists submit that it's maybe not so good at ignoring the interruptions from the microwave. 802.11g offers speeds up to 54 Mbps, also in the 2.4 GHz zone, but with assorted types of modulation to fend off interference.

And then there's the most recent addition to the WiFi 802.11 soup, intended to increase throughputs. It builds on prior 802.11x formats by adding "MIMO" (Multiple Input/Multiple Output), which increases speeds by using multiple transmitters and receivers. At the chip level, 802.11n has two competing camps: Broadcom, and Intel/Philips.

In early February, the 802.11n group announced that it had approved an amendment to the specification that would lift downstream speeds to a blistering 600 Mbps. The amendment, titled "Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)," will be included as a baseline; a draft is expected by year-end.

According to the WiFi Alliance, an industrial support group for WiFi products, 802.11 is "a family of specifications developed by the Institute of Electrical and Electronics Engineers (IEEE), which define over-the-air interfaces between wireless clients and a base station."

What Spectrum: 5.1–5.3 GHz

What Apps: Wireless local area network (LAN) that supports voice, video, data.

Who's Pushing It: Seekers of municipal WiFi; Boingo; Wifialliance.org.

How Far/How Fast: 100–600 Mbps downstream; as far as 150 miles.

Where's the Spec: www.ieee.org

Under the Hood: "Smart antenna systems," also known as MIMO (see above).

DVB-H

Stands for "Digital Video Broadcast for Handhelds," and is an outgrowth of the DVB-T (Digital Video Broadcast-Terrestrial) system used in European broadcasting. Most commonly mentioned attributes are "time slicing," to save receiver battery life, and forward error correction.

What Spectrum: Digital terrestrial/over-the-air

What Apps: Mobile video

Who's Pushing It: Mostly European digital video broadcasters

How Far/How Fast: Total DVB-T channel capacity is 13.2 Mbps; DVB-H services can live within that channel.

Where's the Spec: DVB-H is not housed in one spec, but in a "family" of specs:

  • The DVB-H system spec is the central spec, and references all the others. Published as European Norm (EN) 302 304.
  • PHY layer spec is inside DVB-T, as an annex.
  • Time slicing and MPE-FEC is in DVB Data Broadcast Spec.
  • Signaling specific to DVB-H is in DVB SI (service info) spec.
  • DVB Implementation Guidelines contain "hints for the use and practical implementation of the standard."

Special Notes: Up to 50 TV streams can be transmitted in a single multiplex, using the same MPEG-2 transport as DVB-T; 1–5 seconds of video is "burst" with each time slice (1–2 Mbps). When the receiver isn't dealing with bursts, it puts the tuner in standby. Bursts are buffered. This provides an estimated 95 percent savings in power consumption (relative to DVB-T receivers).

3G Standard: HSDPA

The "third generation partnership project," or "3GPP," is an aggregated group of standards-setting bodies, tasked with adding advanced features on mobile GSM networks. "HSDPA," one of its broadband efforts, stands for High Speed Downlink Packet Access.

What Apps: Fixed/mobile broadband

Who's Pushing It: Members of 3GPP; mostly cellular industry participants, including Cingular ("Broadband Connect").

How Far/How Fast: Peak of 14 Mbps downstream/2 Mbps upstream; reality more like 3.6 Mbps downstream; Cingular's service promises 400–700 kbps.

Where's the Spec: 3GPP.org

Under the Hood: TDMA, CDMA

3G Standard: EV-DO

"EV-DO" stands for "Evolution, Data Optimized." It's the work of the 3GPP2 (Third Generation Partnership Project #2) effort. Because EV-DO is in wide use by Sprint (212 launched markets), and because Sprint is joint ventured with four major cable operators (Comcast, Time Warner Cable, Cox and Advance-Newhouse), EV-DO is probably the "one to watch," in terms of predictable cable activities.

What Spectrum: The existing cellular/PCS spectrum of participating cellular carriers (Sprint, Verizon).

What Apps: Fixed and mobile broadband with all services—voice, video, data.

Who's Pushing It: Sprint ("Power Vision," "Wireless Broadband"); Verizon ("Broadband Access," "V-Cast"); evdoinfo.com.

How Far/How Fast: 300–400 kbps per user with bursts to 1 Mbps

What's the Spec: Part of the CDMA2000 specs held by 3GPP2.

3G Standard: LTE

"LTE" stands for "Long Term Evolution." Most observers say it's a 2009 thing. Some also refer to it as "Super 3G."

What Spectrum: GSM expansion band

What Apps: Described as an alternative to mobile and fixed broadband

Who's Pushing It: Unclear; T-Mobile is occasionally mentioned.

How Far/How Fast: Peak downstream rate of 100 Mbps (in lab); latency of 20 ms. Intent is 20 Mbps to a mobile phone.

Where's the Spec: Unclear

Under the Hood: Described in limited available information as WiMax-like.

The Support Groups

Because there are so many wireless protocols and standards, and so many vendors and companies behind them, the trend of late is to organize into support groups. Their intent: To rally around a wireless technique, create a "buzz," and serve as an information clearinghouse.

It started in 1999 with the WiFi Alliance (www.wi-fi.org), a 250-member organization focused on, not surprisingly, all variations of the 802.11 specification.

The WiMedia Alliance (www.wimedia.org) arose in 2002 to promote Ultrawideband. It emphasizes "peaceful coexistence with other wireless services"—because UWB was designed to operate with applications stacks developed by the shepherds of 1394, wireless USB, and Bluetooth.

The WiMax Forum, begun in 2001, serves as a support group for everything related to the IEEE 802.16 specifications for fixed and mobile broadband. A major part of its stated intentions is "interoperability."

Conclusion

Like everything else, the answer to the inevitable question—who wins in wireless?—comes down to economics. Of the existing markets—WiFi hot spots, for instance—anything that requires facilities owners to switch out adapters is probably a loser. Why bother, the reasoning goes, unless there's something really significant with the new stuff that I need?

Meanwhile, cable operators continue to figure out how to deal with municipal "overbuilders," such as the cities of Philadelphia and San Francisco, among many others, who plan to build "their own" WiFi networks for citizens.

A growing number of operators are slowly changing their tune on this, from one of seeing Muni WiFi as a competitive threat, to those who view it as a partnership opportunity.

In cable, the wireless story for 2006 probably goes something like this: Watch Sprint and EV-DO for the route toward mobile broadband via the wireless JV; watch for more partnerships with municipalities with WiFi intentions—and let economics and the marketplace pick the winner among the dozens (there are more than what's summarized in this article) of wireless standards options.

Ultimately, the one that is the most interoperable with the others, for the right price, is the one that gets the most customers.

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