Wireless networks: the winners and losers

The panacea of corporate networking has to be wireless. No messy cabling ducts, no costly upgrades, and should you need to move location, simply pack away all the antennae, PCs and servers and install them in your shiny new offices.

There are two types of wireless network: the ad hoc and the peer-to-peer. Both are based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, with the only difference being that ad hoc networks consist of a central access point from which any PC in range, and with an antenna, can connect to the network.

The peer-to-peer network is a simple point-to-point connection between two computers.

The most crucial thing needed for a wireless network to function is the access point. This is basically a small radio transmitter that is responsible for dispersing the data across a particular area - usually no more than a radius of 150 feet.

For the remote device to pick up this data, it needs a transmitter. Traditionally, a wireless network is based around laptop computers, with the antenna connecting neatly into the PC-card slot. Workstations can be connected through a PCI PCMCIA cradle card.

In the vast majority of cases, the access point is connected to the wired backbone. This allows seemingly unconnected devices to gain quick and easy access to all Lan resources and existing internet connections.

There are two types of access point: software and hardware. The hardware access point is a dedicated device that sits in a strategic place within an office. This is by far the most popular type of device.

The software access point refers to a standard computer that has an antennae installed, but which is loaded up with the necessary gateway software to handle the amount of data coming through from the varied devices.

Why would I want a wireless Lan?
There are many situations where a wireless Lan would be preferable. The most obvious, and probably the most successful, is in the warehousing industry.

A large open space, where employees don't spend much time in any one place, is an ideal environment, as the open space means there would be no problems in coverage.

However, this is not the only situation where a wireless network comes into its own.

"As has always been the case, the majority of wireless networking is deployed building-to-building, and Lan to Lan," said Paul Munnery, managing director at CNP.

"Wireless has generally higher bandwidth and lower cost when compared to either a leased line or laying fibre. In the UK, 60 to 70 per cent of all wireless networks operate building-to-building."

Bernard Picot, managing director at Proxim Europe, said, "A wireless Lan will suit all customers who rely on mobility, temporary installations or significant scalability and flexibility in an office or corporate environment."

Wireless technology is also popular in hospitals. Instead of doing rounds with a clipboard and paper, then manually typing the information into a computer, it could be done on the fly. Not only does this save time and money, but it could also save lives.

IP phones that work over wireless networks can be an ideal solution for hospitals where cell phones are not allowed due to sensitive equipment.

They are also ideal for temporary network installations, as well as tricky installations in old, or even listed, buildings. Of course, the advantage is that should you decide to leave the premises, you can take your network with you.

Not all plain sailing
Although wireless networks seem to be the answer to modern networking needs, they are not without their drawbacks.

Speed is an issue. The original IEEE 802.11 standard specified data rates of up to 2Mbps. The true throughput of only 1-1.5Mbps was often far too low to tempt many network managers away from copper.

The latest standard, however, allows for speeds of up to 11Mbps. Products based on this standard started to ship towards the end of last year.

Again, although a huge improvement over the previous 2Mbps, it still doesn't seem fast enough in a world where 100Mbps is comparatively old hat, and everyone is talking about gigabit ethernet.

In fact, 11Mbps of throughput is ample for the majority of networking needs. It may not provide your users with seamless video conferencing quality, nor will it allow super-users to conduct serious number-crunching tasks over the Lan. For the majority of users, who don't do a lot more than send a few emails, do the odd spreadsheet and a bit of typing, this is more than sufficient.

New standard on its way
Despite this, a new standard that will replace Direct Sequence Spread Spectrum (DSSS) next year will disperse any previously worries about throughput.

"The new OFDM [see box on right] wireless Lan products will operate at 5.3/5.7Ghz and be available from early to mid next year," said Munnery. "Initially delivering up to 54Mbps, and 100Mbps within nine months or so, this will effectively be fast ethernet networking."

Another common problem with wireless networking is interoperability. For such a small market there are a huge number of companies offering wireless products.

Ensuring that all these products are able to interoperate has been causing engineers at IEEE to reach for the headache pills on more than one occasion.

"Interoperability is still not a reality," said Munnery. "Most of the 2.4Ghz wireless Lan manufacturers are telling us they are working towards open interoperability. However, none of them are busting a gut to achieve it. Do not expect interoperability in the short term."

This was a view backed up by Picot. "We feel that scalability is more strategic than basic interoperability. As a response to this concern, we have designed our Harmony product as a modular architecture able to mix several standards," he said.

There are two main issues with interoperability. The IEEE specified two standards for data transmission within the 802.11 standard, known as Frequency Hopping Spread Spectrum and DSSS.

Although both offer the same sort of functionality - and we will not be going into the benefits and pitfalls of each here - there are some interoperability issues between the two.

It may become less of an issue this year, however. The Wireless Ethernet Compatibility Alliance started work earlier this year on the Wi-Fi interoperability standard. Now, any system bearing the Wi-Fi logo is guaranteed interoperable with any other bearing the same mark. However, this is restricted to direct sequence.

The second issue is with roaming. To cover more than one floor in an office block with a wireless Lan, you will need more than one access point. The process of passing from the area of one access point to another is called roaming.

Although vendors will have you believe that there are no issues here, and that roaming is not a problem, this is not necessarily true.

On top of this, there is no official standard within 802.11 to clarify the method used for roaming. It might just be that one vendor's access point will not successfully hand you over to another.

And while we are on the subject of problems, security will always come to the fore as a major issue for companies and users alike. Rightly or wrongly, the public's perception of wireless technology is that it is far less secure than data travelling neatly along a wire.

But this isn't necessarily the case. Although it would be easier to spy on wireless data, it takes far more than simple scanners or short wave receivers to do it. Even if you managed to pick up a signal, then decoding it would be an entirely different matter.

The majority of content that travels the lengths of copper throughout the nation's Lans is not encrypted, but wireless data is. Strong encryption is used on all wireless equipment, and as a result many people believe that it is actually safer than its wired counterpart.

The Bluetooth question
Another wireless standard that has attracted a lot of attention in the press over the last twelve months is Bluetooth.

Although more of a consumer standard, where Bluetooth antennae will be a part of domestic items such as stereos to aid with the home network ideal, it could still be of great interest to the corporate world.

A travelling worker would be able to send email from his laptop via his mobile phone without taking the phone out of his pocket, for example. Although the data rates are slow compared to its 802.11 cousin, it will still be sufficient for its intended purpose.

The worrying thing is that in some quarters, Bluetooth is believed to cause interference with the 802.11 standard.

Surely, with a little forethought, a cutdown version of 802.11 could have been developed for use in the market at which Bluetooth is aimed. As it is, we have conflicting standards offering more or less the same functionality.

A wireless network could be the answer to many problems. Remote workers could arrive at the office, take out a laptop and log directly into the corporate network without the need for cables, outlets or even desks.

Not only that, but 'hot desking' becomes a reality when this is set up. If your company employs several staff that are not always in the office at the same time, you can cut down on the amount of desks and equipment needed by implementing a wireless Lan.Total cost of ownership is greatly reduced, which is certainly something that will please the bean counters upstairs.

As for the future, Munnery said that wireless networking is increasingly taking market share away from conventional cabling. "The future looks very bright indeed," he said.