The principal benefit of all wireless local area networks, or WLANs, is flexibility. Like a wired network, a WLAN will connect a PC to the internet or other PCs but, unlike an ordinary network, a WLAN works through the air, through walls and through ceilings.

This means a WLAN can provide connectivity in places that have previously posed problems. Examples include portable buildings, sleepouts, annexe buildings across roads, or historic buildings. A WLAN will allow all of these sites to be “wired up” without digging trenches, drilling holes in walls, laying cables or installing sockets.

On the smallest scale, a wireless network can very easily allow a small businesses owner to work with a laptop PC anywhere in their home or office, from the lounge or a deck for example, not just that dingy back room where the internet connection happens to enter the building. Almost as simply, larger businesses can set up a limited wireless connection wherever it is going to be most useful, for example in a meeting room or boardroom. Not only is this convenient for users but it will also save on the cabling and installation costs of setting up multiple local area network access points.

1) The basics
At the most simplest level, just two main components are required to set up a WLAN. First a wireless access point, also known as a base station, which is the ‘transmitter’ part of the network. Second, each user or ‘receiver’ of the network, will need to have a wireless network adapter fitted to their computers. These days, all but the most low-end laptop computers have wireless capability built-in as standard, but it is easy to retro-fit a wireless network card or an external USB adaptor into older computers.

A laptop card, available from Xtra or from high street electronics retailers such as Dick Smith Electronics, costs as little as $60, while an external adaptor, which conveniently plugs into a computer’s USB socket, costs about $80. An increasing number of other portable devices such as PDAs and some mobile phones are WiFi capable and therefore able to log on to a wireless network.

A wireless access point such as the D-Link G604T wireless router, as supplied by Xtra as part of its Wireless Network Kit, links a broadband internet connection with one or more wireless-enabled PCs or laptops. Wireless routers are also available from retailers but if you are setting up or changing an internet connection it could be worth talking to your ISP. For example Xtra provides its Wireless Network Kit for just $99.95 to new broadband subscribers instead of the usual price of $199.95.

2) Wireless standards
Wireless networking equipment is generally based on two wireless standards in common use. The newer 802.11g standard works at speeds around five or six times faster than the earlier standard 802.11b. Generally speaking it’s a good idea if the wireless card in your PC or laptop is of the same standard as the access point, but all modern notebooks and most access points will support both standards.

In practice, an access point based on 802.11b will deliver data to one user at the rate of up to 5-6 Mbps (megabits per second) while an 802.11g network will achieve speeds of up to 25-30 Mbps. However these speeds will be reduced as more users log on to the network or with increasing distance from the access point. A single access point can accommodate up to a dozen or so users depending on the intensity of their traffic.

3) Range and siting
As a rule of thumb the maximum range for a single access point is about 100 metres. However the range can be adversely affected by obstructions like iron girders or thick concrete walls, or even atmospheric conditions in a similar manner to television reception.

In homes or small offices, the wireless access point is usually connected directly to the phone/broadband jack, but in larger buildings access points are commonly installed as extensions to wired networks, so they can be connected at some distance from a server by conventional network cable.

4) Multiple access points
The question of siting becomes more complex when multiple access points are added to allow the wireless network to cover an entire building, a campus, or even a city district.

Paull Wilson, mobility marketing manager at HP, says the starting point for all larger wireless network projects is a site survey. This is a specialist job involving testing the local factors affecting wireless range and specifying the access point sites which will provide the required coverage most efficiently.

Just like a wired network, the larger a wireless network gets the more back end infrastructure is required to manage traffic and channel the bandwidth to users. Companies such as Cisco and Netgear supply a wide range of specialist routers and hubs for this purpose.

5) Hotspots
A ‘hotspot’ is a wireless network that is available to the public or visitors, either on a free or paid for basis. One of the best known examples in New Zealand are the hotspots provided by the Starbucks coffee shop chain, and they are also commonly found at airport lounges. The Starbucks hotspots are operated by Telecom, and access is enabled either by entering a pre-paid voucher code or an Xtra log in or account number. One of the main advantages of providing a hotspot is to attract or better serve customers with laptops or other wireless access devices such as PDAs and WiFi smart phones.

According to Wilson at HP, which helped to develop the Starbucks hotspot billing system, hotspots do not pose any extra technical challenges compared with ordinary wireless networks. Also, as publicly available networks can be run completely separately from other networks, there are no security problems. However developing a billing system can be costly, so businesses setting up a hotspot should consider carefully whether it’s worth charging for the service.

6) Security
It’s important to think about security with any network but according to IBM’s Northern integrated technology services manager Verdon Kelliher, it’s probably the key issue when you are setting up a corporate scale wireless network. The main potential threats to wireless networks at all levels are bandwidth theft or hacking by unauthorised users, and electronic eavesdropping. At the SOHO scale, the first of these risks is more likely, but unauthorised log ons by your neighbour’s kids are easily prevented when the network is first set up. Wireless routers can be set up to only grant access to one or more identified PCs or by a password for example.

These days, all wireless access points also provide basic protection against eavesdropping by Wired Equivalent Privacy (WEP) encryption which means it is very difficult for hackers to decipher any traffic on the network. However publicly quoted companies, government agencies or any organisation dealing with market sensitive data would be wise to consider using specialist services such as IBM’s Manage 24, which provides around the clock monitoring of wireless network users and traffic.

7) The business case
Wireless networks offer many advantages over ordinary wired networks but they are predominantly ‘soft’ rather than ‘hard’ benefits.

Once established a wireless network results in lower network support costs when new users are set up on the network or moved, and it can also lead to more efficient or collaborative working practices. Wireless networks tend to be as popular with employees as they are with senior executives and so there is also a staff retention argument for installing one.

In terms of hard cash the initial cost of wireless network hardware is higher than for a wired LAN but this must be offset against cheaper cabling and installation costs. In some cases a wireless network can provide connectivity where it would be difficult or very costly by any other means.

For more information visit the Mobile Business Research Pavilion

September 2006

By Michael Foreman