A Look Back at Wireless Implementations

The light went on for Dave Komaromi in a coffee shop. The manager of information technology at Fraser Milner Casgrain LLP was grabbing a quick cup at a Timothy’s downstairs from the national law firm’s downtown Toronto office when his eyes fell on a sign advertising a Wi-Fi hotspot.Komaromi had been thinking about implementing wireless networking, but was concerned about security. Law firms handle sensitive information, and he needed to be very sure he wasn’t exposing it to eavesdropping. He wasn’t sure a wireless network could provide the same level of security as the firm’s wired local-area network (LAN).But that day in the coffee shop in 2004, he realized wireless didn’t have to provide that level of security if Fraser Milner treated it more like a public hotspot than part of its internal network. Komaromi went back upstairs and told his staff: "We are going to create the coffee shop hotspot in the corporate world."That inspiration led to the FMC Hotspot, a service the law firm has now implemented in all of its seven offices. It’s Fraser Milner Casgrain’s answer to widespread security concerns about wireless. Simply put, the law firm set up its wireless network like a public hotspot and requires its staff to use it the same way they would use a public hotspot or a home Internet connection to the office. They connect through virtual private network (VPN) and Citrix Systems, Inc. Presentation Server software.The law firm has used VPNs and Citrix for years so lawyers can connect securely from anywhere, Komaromi says. "When you take in wireless and utilize that same infrastructure, you get to sidestep the security challenge." And for Fraser Milner there’s another benefit – the FMC Hotspot serves clients as well as staff.It’s a pity, Komaromi says, if any businesses today are still shying away from wireless networking because of security concerns, when putting the wireless network outside the corporate firewall and treating it like any other remote access option will at least let them make a start.Hotspot versus Walled AccessAt Concordia University in Montreal, the campus-wide wireless network is also insulated from the university’s core research network. Most students use the wireless net for Internet access, says Andrew McAusland, associate vice-president of instructional and information technology services. Those who need access to the core network through wireless must connect using VPN technology. This wouldn’t work for everyone. Corporate Express Canada Inc., a Mississauga ON-based supplier of office and computer products, installed Wi-Fi networks in its eight distribution centres across Canada over 12 to 15 months starting in 2004. The wireless network allows warehouse staff to track boxes as they load trucks, ensuring that the boxes get on the right trucks and making it easier for warehouse workers and truck drivers to find the boxes. The boxes are bar-coded, as are shelves inside the trucks, and warehouse staff scan both to ensure the boxes are in the right places and to provide printed manifests telling each truck driver where every box is in the truck.You wouldn’t want bar-code scanners operating like laptops on a coffee-shop hotspot. So Corporate Express relies on security built into the 802.11 wireless standard, including Wired Equivalent Privacy (WEP) encryption. You might think that security would be of little concern since the wireless networks are only carrying data about the location of boxes in a warehouse. Not so. "The fact that our wireless network is built as an extension of our corporate network requires that security be extremely tight," says Joseph Mignella, manager of IT business services at Corporate Express Canada. The company doesn’t want rogue wireless users accessing the corporate network via a poorly secured wireless back door.Security has improved since the initial implementation, Mignella says. One step forward was the introduction of Wi-Fi Protected Access (WPA), a standard that provides more secure encryption than WEP.Another improvement Mignella has found helpful makes it easier to change passwords. With some older devices, he says, passwords had to be reset on each access point on the network. Newer technology lets him change the password in one place.If wireless access points don’t broadcast their Service Set Identifier (SSID) codes it’s harder – though not impossible – to connect unless you know the SSID. One precaution Toronto’s Mount Sinai Hospital is taking with a wireless network now partially deployed is not broadcasting SSID codes for private access points. The hospital will offer wireless services to patients and visitors eventually, says Rick Henderson, director of information technology planning and services. These will use separate access points, which will broadcast their SSIDs, but all connections will be routed directly to an authentication and login screen.Just securing the wireless equipment you know you have isn’t the whole story. It is all too easy for users to install their own wireless devices, which they can purchase for less than $50. Often improperly secured, these can be significant security threats. "We are continually going around and disconnecting wireless access points that have been plugged in," says McAusland.Coverage RevealedWhile security has long been a key concern for organizations thinking about building their own Wi-Fi networks, it’s not the only issue. Another crucial aspect is getting the coverage right. Pretty much everyone who has been through it agrees that wireless installations must start with a site survey. This is essentially a two-person job, Komaromi says, where one person walks around with an access point attached to a pole to get it up near the ceiling where it will probably be mounted, while another uses a laptop equipped with software to measure signal strength. Most often a third party, such as the network hardware vendor or a systems integrator, conducts the site survey. Obstacles such as walls and floors affect a wireless signal’s reach, McAusland says. "If you’re going into a new building, you’ve got to wait for the building to be complete before you do your survey." Concrete significantly reduces coverage, and McAusland says glass and chrome make a difference too – "anything that bounces a sound wave off it basically, or reflects it in a way that’s not without distortion."Human bodies affect wireless transmissions as well, McAusland says. "If you have a heavily trafficked area, you’re going to have to adjust your antennas."In Fraser Milner’s case, the large amount of paper involved in the legal profession compounded the issue. "You’re looking at a floor that is basically covered with metal filing cabinets that go from floor to ceiling," he notes. "Those are challenging things to get signals through." In that environment, access points were needed every 50 to 60 feet, he says.Thanks to a proper site survey at the outset, Corporate Express had no initial problems with wireless coverage. Later, though, the physical layout of some centres was changed, and in some cases the way the network was being used changed, exposing gaps in area where coverage hadn’t been needed at first.Any problems Corporate Express has had with changing layouts in its distribution centres pale compared to what Bill McDonald has to deal with. McDonald is director of technology services at the Metropolitan Toronto Convention Centre. A wireless network has covered the entire complex since 2004. Its exhibit halls may be empty one week and occupied by dozens of large, sometimes multi-level booths the next. McDonald’s staff often must make adjustments to compensate for ever-changing obstacles and network usage.Choosing the TechnologyThree versions of the Wi-Fi standard are in use today: 802.11b has a theoretical capacity of 11 Mbps, while 802.11g (which is compatible with 802.11b) and 802.11a (which is not) both operate at up to 56 Mbps. Actual throughput "depends on how many people you have logged on to any one access point," McAusland says. Choosing the right access points also makes a difference. McAusland notes that a cheaper access point may handle only 30 simultaneous users, while a more powerful and costly one would manage 100 without trouble. "You’ve got to figure out what your need is," he says.Access points may be omnidirectional – designed to serve roughly a circular area – or focused in a particular direction. Fraser Milner put four omni-directional Wi-Fi access points in the centre of the floor it occupies in Toronto’s First Canadian Place tower. Around the outside of the floor are unidirectional antennas, aimed parallel to the sides of the building so their strength is concentrated inside the office rather than spreading outside. "We basically have four or five bars (on the Windows graph indicating wireless signal strength) anywhere on our floor," Komaromi says.One bit of good news is that wireless access points seem to be durable. "We don’t have a lot of break-fix," McDonald says. The convention centre does replace older equipment to help keep up with growing demand for wireless capacity, though.McDonald says planning for the future is critical. For instance, he says, running voice over the wireless network will uncover coverage gaps that might never show up with data traffic. Voice is more sensitive than data, he notes, and people will use wireless telephones in areas where they would probably never use computers. "You don’t have to do everything at once," he says, "but you have to have a picture of everything you want to do when you set it up."

A Look Back at Wireless Implementations

News | March 1, 2007

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