March 23, 2006



Beyond Wi-Fi

Multiple antennae MIMO and ultra wideband may be just the technology ticket for fast and media-furious activities.
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In the 1960s classic movie The Crowded Sky, a fighter jet and a passenger-filled commercial airliner race toward each other miles above the Earth in what will eventually be a catastrophic meeting. The film sent chills through audiences, as it dramatically and fictionally detailed just how little room there is, and how scant the margin for error, even in something as expansive as the sky.

Hollywood executives probably won’t rush to make a movie about the increasingly crowded airwaves and number of collisions happening every day in your typical wireless office environment. However, the IT types in most medium to large companies are taking a hard look at such things as collision management, multi-level authentication, access pathways and bandwidth rationing—especially as 802.11 wireless LANs are used to support a variety of data and voice applications that were not necessarily a part of the original installation and deployment plan. They are also dealing with a lot more wireless network types and the applications that make use of them than they ever did in the past.

One technology that is creeping (as opposed to sweeping) through a lot of companies right now is voice over Internet Protocol, or VoIP, which basically involves using a wired or wireless system to conduct voice communications that in many cases augment or replace traditional telephone services. In most cases, VoIP is cheaper and more manageable than traditional phone service since local and long distance calls are channeled over the Internet and administrators for even the smallest companies can control user access and features through a Web-based portal. VoIP technology can also be smoothly integrated into existing applications, such as customer relationship management packages and e-mail systems. There are also relatively secure and nearly free VoIP services, such as Skype, that add instant messaging and basic team collaboration tools to the mix.

Cost Not a Deciding Factor

Oddly enough, however, it is not cost-savings alone that is driving the adoption of VoIP into most businesses and corporate call centers, according to a report just released by The Yankee Group. In a survey of more than 1,000 contact center managers, the research group discovered that most companies make the switch from traditional packet-switched phone systems to non-traditional VoIP due to application needs and not the resulting reduced costs in infrastructure and operation. This includes small and medium business users, who were highlighted as early adopter front-runners in the report “VoIP in Contact Centers Is Inevitable but Not Imminent.”

Many users are looking at VoIP as a limited-range solution, as opposed to a replacement for conventional telephone services. For example, Palmetto Health, a not-for-profit healthcare collaborative based in South Carolina, presently uses localized VoIP and wireless 802.11 networks to provide voice communications for doctors and nurses at the group’s three hospitals and combined 1,300-bed capacity. Healthcare personnel use Cisco Systems handsets and a Bluesocket secure wireless network to communicate with each other, confer with colleagues and engage in wireless conference calls right from a patient’s bedside.

Other hospitals throughout the country rely on 802.11 wireless networks and VoIP systems that make use of tiny Star Trek-like badges, developed by Vocera Communications, that can be pinned on a lapel and used hands-free by doctors and others in the operating room or interacting with patients and staff.

As companies make more use of VoIP and other systems that depend on reliable and secure wireless systems, and quality of service becomes a mandate, solutions will evolve that are specifically designed to juggle many users and operate in congested or RF signal–bloated areas. One solution that is quickly moving from trend to widely accepted technology involves the use of multiple “smart” antennae and radios on each wireless access point. Commonly known as MIMO (multiple input, multiple output), the technology transmits simultaneously to streams to provide fast and reliable 802.11 wireless services. Some manufacturers are even taking this approach a step further and developing MIMO-enhanced controllers and gateways that work with dumb APs, which are deliberately overlapped in a wireless network to provide near-100 percent coverage.
This is not a bad approach, but it may create some problems on the client side, as devices must be adapted to new communications architectures, says Ben Guderian, director of marketing for Spectralink, a developer of Wi-Fi handsets for enterprise applications. “You have to be careful that you are not trading off how fast you can do a hand-off, security and re-authentication in order to get higher and higher capacity,” he warns.

Going Wide for Wireless

MIMO technology and Wi-Fi–based VoIP are not the only wireless activities residing in your typical enterprise neighborhood. Many companies already make use of a variety of short-range wireless technologies to wirelessly send files to local printers, transmit PowerPoint presentations to a wireless-enabled LCD projector and synchronize PDAs and smartphones on the fly. Most of this is accomplished via Bluetooth, and in some cases near-field radio technology alternatives are available from Philips Electronics, Sony and others that make use of the 13.56MHz frequency range to zap information over a distance of a few centimeters. Like “old school” line-of-sight infrared communications, near-field technology is inherently secure since you almost have to touch devices to make a data transfer, which means you are probably looking directly at the person with whom you are swapping data.

One technology that could prove to be the four-lane superhighway of enterprise wireless is ultra wideband (UWB), which is a high-bandwidth low-power alternative that transmits over a limited range (6 to 13 feet) and is now used mostly for military and government applications. The technology differs from Wi-Fi, Bluetooth and other limited-range communications architectures since it works across a wide range of frequency spectrums by transmitting a series of very narrow and low power pulses. This pulsed data operation means that UWB theoretically creates less interference than conventional narrowband radio solutions and delivers wire-like performance in an indoor wireless environment. This makes the technology ideal for multimedia-rich consumer applications and enterprise applications involving the high-speed transfer of video and media-rich signals.

Despite the technology’s natural tendencies to not disrupt other communications architectures and systems, it has come under some scrutiny, as government officials and others questioned the possible health implications of high-bandwidth communications bouncing all over the office and creating possible interference with other devices that operate in and around the same frequencies (such as aircraft communications). However, earlier this year the Federal Communications Commission gave approval to the WiMedia Alliance—a UWB standards and development group—to sell indoor and handheld UWB equipment.

UWB Finding Its Own Level

The IEEE’s 802.15.3a task group was also scheduled to meet to decide on a specification for UWB, with the choices being the WiMedia’s architecture or a technology structure developed by the competing UWB Forum, which demonstrated a variety of UWB devices for consumers at the Consumer Electronics Show (CES) in Las Vegas.

The first wave of UWB devices will consist of such consumer devices as wireless media centers, high-definition televisions and media-capable cell phones (at CES, for example, members in one UWB Forum demonstrated a cellular phone capable of wirelessly transferring MP3 files and digital photos taken with the phone to a laptop). However, companies like Alereon, XtremeSpectrum and others pioneering the field are looking into enterprise applications—especially those involving machine-to-machine and remote-sensing systems.

For example, prototype UWB systems have been used to sense the height of liquid surfaces within closed tanks and keep an eye on the waterline of cargo ships to warn if things are suddenly not on an even keel. Because of its ground-penetrating capabilities, UWB has also been used to sense the presence of pipes and tunnels and has even played a role in public safety by sensing the position of people within a building during hostage situations.

Of course, the enterprise applications of UWB have little in common with those more at home in an episode of Fox’s 24 than in the white collar world. As office and even remote applications become more media-capable and the demand for converged video and data systems increases, companies will start taking a serious look at UWB and other non-conventional wireless approaches, says Greg Caltabiano, COO of Soma Networks, a company that specializes in providing “last mile” broadband wireless solutions. “UWB can give conventional wireless some competition in this space,” he points out.
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