It's time to tune in to wireless LANs

The hour has come for wireless LANs as falling prices and improving technology are making them attractive solutions - sometimes...

The hour has come for wireless LANs as falling prices and improving technology are making them attractive solutions - sometimes more cost-effective than cabling - in a range of network implementations.

Wireless LAN technology is cheaper than ever. A few years ago users would have paid around £350 for an 802.11 wireless LAN card. An 802.11b card today from Cisco typically costs £140.

To get started users need to buy a wireless Access Point as well as a wireless LAN card. The Access Point is a device that provides several wireless users with a physical link into the corporate network. The wireless LAN card is used in a notebook PC or handheld computer to connect users to a corporate LAN.

No cables required
Network firm Avaya sees a major area for deployment of wireless LANs being implementations where cables for traditional LANs are difficult, or prohibitively expensive to install. Another major area is campuses where LANs within different buildings can be connected together more cost effectively than by using network cables.

Tim Reilly, principal solution specialist at Avaya, says: "For small and medium sized business users wireless technology can be a cost-effective and tidy solution." For example, in a small business or environment with 10 people per office "users do not need structured cabling to their desktop PCs". The set-up for a branch office would simply require a wireless Access Point that talked to a router connecting the branch office to headquarters.

Another application area for wireless networks is as an extension of the hard-wired LAN. This is popular with health authorities, allowing hospitals to deploy carts kitted out with a wireless PC to provide doctors and nurses with access to medical records at a patient's bedside. Wireless solutions are also heavily used in retail for stock-taking using mobile terminals equipped with bar-code scanners.

The chance to boost employee productivity is another big selling point for wireless LANs, according to Martin Cook, business development consultant for mobile technology at Cisco. Last year a study by the company found wireless LANs delivered a 20% improvement in productivity. "It is possible to measure the number of minutes an employee is disconnected from the network during their working day," Cook points out. Coffee breaks, external meetings and working at a different site all involve staff being disconnected from their LAN. With a suitably equipped notebook PC a user could be given constant access to the network via wireless LAN technology.

Difficulties with wireless
If this sounds like a good idea, users should look before they leap on to the wireless bandwagon. The first issue concerns evolving standards. The two main wireless standards being touted are 802.11b and 802.11a. Devices that use 802.11b are compatible and widely available. This is based on 2.5GHz wireless technology and supports network speeds up to 11Mbps. To achieve higher network speeds users need to opt for the 802.11a specification which is not compatible with 802.11b. This is based on 5GHz technology and provides 54 Mbps network bandwidth. Some experts feel 802.11a is not ready yet.

Vincent Vermeer, business development manager at 3Com, says: "802.11a needs a completely different Access Point." This is because 802.11b is based on 2.5GHz technologies, incompatible with the 5GHz technology used in 802.11a.

A related issue that wireless users may encounter is bandwidth. According to Vermeer, while 11Mbps is the theoretical network speed of 802.11b, 5 Mbps is the bandwidth available to users. Once a few users have connected to an access point this bandwidth can quickly be consumed. To maintain a high network speed users need to deploy extra Access Points.

Users who need faster wireless networks can also move to the 802.11a specification. But there is a problem. "To take full advantage of 802.11a users need three or four times as many Access Points as 802.11b," says Vermeer.

Wireless technology has certainly arrived. The killer application - where wireless access points are installed in public places - may be some way off, but users can extend their internal LANs with wireless technology today. In certain areas, such as in schools, hospitals, retail and where it is necessary to link nearby buildings, wireless technology is fast becoming the preferred network technology.

Case study: Counting students
Following an inspection by the Office for Standards in Education (Ofsted), Great Barr sixth form college in Birmingham realised it had to make dramatic improvements to sixth form pupil attendance which was below 80%.

Dick Frank, operations manager at Great Barr, says the problem lay with the way the student attendance was being taken. He said that the school checked attendance twice a day, at morning and afternoon registration. But this did not take into account the more flexible structure in the sixth form where pupils would attend classes but not necessarily go to morning registration.

The answer was to register the attendance for sixth form students during classes. This would involve a portable computer for capturing class registration data that could then be passed into the school's registration system called Sims.

"We had a choice of PDA or notebook PC," Frank explains. In the end the school chose notebooks because they offered greater flexibility and gave staff access to Microsoft Office 2000 - as well as providing the portable attendance registration system (PAR) developed by Tasc, a bespoke software development house.

During the initial rollout of the system Frank used second-hand Compaq Armada notebooks running Windows 98, Office 2000 and the registration software. Each was configured with a 3Com wireless LAN card. Having built one machine, he cloned the set-up and rolled it out to 85 sixth-form teachers.

Frank used 14 100Mbps 3Com Access Points to connect the whole caboodle to the wireless LAN. He says the technology has enabled Great Barr to improve its Ofsted-verified attendance figures from 80% last year to "above 94%".

This year Great Barr plans to extend the rollout of the PAR system to the rest of the school.

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