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Next Up: Adding Voice to Your Wireless LAN |
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Wireless phone calls are nothing new. Cell phones have been around for decades. Now another flavor of mobile calling -- wireless LAN voice systems that move Voice over IP (VoIP) calls over a company's Wi-Fi network -- is poised to hit the mainstream. A new standard is nearing ratification, and as both Internet telephony and Wi-Fi become more common, businesses are starting to see the value of mixing the two.
In $500 million Deaconess Health System Inc.'s hospital in Evansville, Ind., nurses and physicians are on the move. Nurses page doctors when they need them, but nurses are rarely at their stations long enough to receive the physician's return call. Thus the call goes into voicemail, and a game of phone tag begins. With Deaconess' wireless VoIP system, nurses can take the phones with them and receive calls wherever they are.
But voice over wireless LAN presents some challenges. Wi-Fi is a shared medium, which means that data from multiple users queues up to be transmitted. With many users on the network, voice traffic may line up behind data traffic, resulting in delayed transmissions. When that happens, voice quality plummets and calls can be cut off. Some companies, such as Spectralink Corp., have taken proprietary approaches to wireless voice that give calls priority, thereby increasing the call quality. A new standard under consideration, 802.11e, also takes up the issue.
Hendrick Motorsports Inc. is currently exploring wireless VoIP for use at the racetrack and on its Charlotte, N.C., campus. On campus, engineers rely on voice communications as much as they do on tools like e-mail and instant messaging. As they move between the car shops and office space, they use their cell phones, which increases their wireless bills. Wireless VoIP would curb those bills.
Hendrick is also working on securing the required quality of service on its satellite link so it can extend VoIP to the track on race day. That way, engineers at the track or in the office could reach each other by dialing a four-digit extension.
--J.R.
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Handling Security a Top Concern
Cost and the business case are hardly the only criteria for making wireless a go/no-go decision. The most worrisome concern is often: Will my network be secure?
Security has been a hotly debated issue since late 2000, when Jesse Walker, a security analyst at Intel Corp., published a paper noting vulnerabilities with the encryption protocol Wired Equivalent Privacy (WEP) that was included in the wireless LAN standard. A slew of other researchers and institutions echoed his findings. These flaws kept many businesses away from wireless LANs, even as the IEEE and the Wi-Fi Alliance pushed for better security solutions.
Prior to bringing in a wireless LAN system, Deaconess CIO Neeley also worried about security issues. "Our biggest security concern was how easy it was to drive up and sit out in the parking lot and glean information [from the wireless network]," he says.
Eventually, Neeley was satisfied with the Wi-Fi Protected Access (WPA) encryption for its network, which is included in the 802.11i security standard ratified in July of 2004. The encryption, developed by IEEE, is more complex than WEP and has since been upgraded to Advanced Encryption Standard (AES). The standard also includes new encryption protocols, such as the Temporal Key Integrity Protocol (TKIP), which helps to further decrease the chances of someone using encryption keys they've sniffed off the airwaves.
Today's wireless LANs are also compatible with the 802.1x authentication method, allowing companies to use a myriad of authentication schemes to secure their networks. Hendrick, for example, uses Extensible Authentication Protocol (EAP). A Cisco server authenticates users on the network. Deaconess uses Lightweight Extensible Authentication Protocol (LEAP), a proprietary Cisco approach to authenticating media access control (MAC) addresses. It denies access to any unapproved device that tries to get on the network.
The biggest security threat from wireless LANs may have little to do with over-the-air encryption, says Craig Mathias, principal with Ashland, Mass.-based advisory firm Farpoint Group. Employees used to the convenience of their home wireless networks may bring an access point into work and plug it in, creating a so-called "rogue" access point. All access points come with the security settings turned off, meaning these rogue access points can allow anyone to log on to the corporate network. "You can have a wireless security problem without even having a wireless network," Mathias says.
Networks that scan your airwaves for unapproved devices and block their access have thus become an important asset. Deaconess uses a monitoring system from AirDefense Inc., one of a number of vendors in the RF monitoring space. Besides scanning the airwaves for intruders, attacks and unauthorized access points, such systems can help with configuring access points for optimum performance. "With those three security features, we feel like we have it buttoned down pretty good," CIO Neeley says.
The Evolution Continues
As wireless LAN technology matures, it's becoming easier to manage -- and is fostering a broad range of uses beyond mobility. Switched wireless LAN systems enable centralized management of many access points. A user's location can be tracked by identifying which access point is receiving a signal and triangulating that signal with other access points -- an application gaining use in museums, for example, with visitor handsets that dynamically describe exhibits as the visitor walks past. Voice and video over wireless are also making headway.
Then there's the convergence of cellular and Wi-Fi networks. "With better design, wireless LAN becomes part of a business' overall layout, not something separate," says Gartner's Dulaney.
A raft of new standards is changing the ways in which wireless can be used. For instance, 802.11n increases the throughput of wireless LANs with multiple radios for sending and receiving data by using an approach called multiple input, multiple output (MIMO). Meshed networks that relay information from access point to access point before it hits the wired network allow for greater flexibility in the deployment of a wireless LAN. Another standard on the horizon aims at allowing roaming from access point to access point at high speeds, so people on trains and in cars can use Wi-Fi. Phones that allow roaming between cell networks and Wi-Fi networks have just hit the market.
As the technology speeds along, midmarket CIOs surely will find more ways to use wireless LANs to improve their businesses. Hendrick is working with Cisco to find ways to transmit engine data and other information directly from cars to its wireless LAN network and pit crew. The goal is to ride real-time data, traveling at super speeds over a wireless LAN, past the competition en route to victory.
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