Computers Today, May 1-15, 1999, Networking; Moving Business

May 1-15, 1999 NETWORKING

WIRELESS LANS
Moving Business

Wireless LANs are releasing business users from their desks, setting them free to roam the floors, offices and conference rooms with their notebooks, while being connected to the network.

By Sudhir Chowdhary

Wireless Lans The big bang of the networked economy has spawned fundamental changes in how corporations conduct business. Corporate staff is no longer defined by where they do their jobs as much as how well they perform their job functions. While such developments have increased productivity and profitability for many corporations, they have also created new demands on the corporate network. A network focussed solely on connecting fixed corporate sites is no longer feasible for many companies. While networking technologies are moving at a rapid pace and offering enormous advanced products, wireless networking technology has identified and secured a market place for itself. Wireless local area network (LAN) components, which let users retain a wireless connection to the network while roaming around a building or campus with a portable computing device, have begun seeing a steady rise in sales because of improving performance, decreasing prices and emerging standards.

Mobile terminals (PDAs), specialised handheld terminals and barcode scanners connected to wireless LANs are being used to significantly increase the profitability of business operations. Mobile data applications are cutting operations costs by increasing the productivity of essential personnels and eliminating unnecessary paperwork. In the healthcare industry, mobile data networks are used to increase productivity and quality. Convenient access to clinical patient information is used to improve promptness, accuracy and productivity of care offered by doctors and nurses. Similary, barcode readers with wireless data links are used to enter the locations and indentification (barcodes) of pallets and boxes. This makes these operations far more efficient due to improved inventory tracking and cost reduction. Result: the market for wireless LANs has been growing rapidly with a 45 percent annual growth rate. Yankee Group, a Boston-based consulting and market research firm says, wireless LANs sales touched $725.4 million by the end of 1998.

At the Crossroads

Why wireless? Lucent Technologies officials say, it is an ideal solution when costs for wire and fibre cable installation and service are too expensive, when cable laying is impractical, when reach is the main consideration, and when high recurring cost and a-point-to-point dedicated link is desired.

HCL Comnet, which distributes Proxim wireless LAN range, believes that wireless LAN products should extend the reach of the existing wired LAN infrastructure, not replace it with a new wireless network infrastructure. According to company officials, "The goal of wireless networking technology should be to make existing LAN equipment and services more productive, not to displace previous investments in wired technology. In this way, wireless LANs can extend and enhance existing LANs, just as cordless telephone technology in homes leverages the wired telephone system."

As a result, like an Ethernet network, a wireless network starts with network interface cards. But these NICs don't have cables, nor do they require a hub. Instead, a user simply attaches the included antenna to each NIC and place it in the highest place possible. Next, install some software and the network is up and running.

With this, not only does a user avoid the hassles of wires and hubs, but enjoys a flexibility offered by no other networking option. A radio frequency wireless network works through walls: one can put machines practically anywhere one wants and move them at his own convenience. A wireless network is also a great choice for those on the move who use a notebook as their primary machine. The most tangible benefit is that one skips the headache of connecting and reconnecting to the network via a docking station or a too-short cable every time one returns to the office.

What Makes a Wireless LAN?

Basically, there are two parts to a wireless LAN solution: the wireless client adapter and the access point. There is the ISA networking adapter for the PCs which offer the ease in setting up the LAN with no cable hassles. The PCMCIA networking adapter (PC card) for the notebooks offer mobility while being connected to the network. This has a major application in the hotel industry (like order registering on the notebook computer instead on the notepads with an automatic process of order processing and billing), hospitals ( doctors/nurses moving to various beds with the patients database already existing in the notebook computer which is connected to the LAN). In the majority of cases, wireless LANs do not replace wired LANs. Instead, they are used to create wireless extensions to wired LANs. To do this, a user needs the second part of a wireless LAN, the access point. An access point is a stationary device that attaches to the wired LAN. An antenna links the wireless clients to the wired LAN via the access point.

Wireless LAN products are available in three different technologies-frequency-hopping spread-spectrum (FHSS), direct-sequencing spread-spectrum (DSSS), and infrared. FHSS and DSSS are spread-spectrum techniques that operate over the radio waves in the ISM (industrial, scientific and medical) bands of the electromagnetic spectrum. The ISM band consists of the 902- to 928-MHz range and the 2.4- to 2.484-GHz range. Infrared operates between the visible part of the electromagnetic spectrum and the shortest microwaves.

One of the main benefits of spread-spectrum wireless LAN technology is roaming. Wireless LAN users can roam the floors without dropping the connection. Once the client software notices a diminishing signal, it searches the domain for the strongest access-point signal and connects to it. All this happens seamlessly without losing connectivity to the file server. Also, security is an important issue. FHSS products are tough to crack as they have multiple security features like data encryption,scrambling and user IDs.

Performance Consistency

A wireless LAN also has its downsides. First, it's considerably slower than Ethernet, topping out at 2 Mbps. The 1- to 2- Mbps throughput promised by many vendors is no match for the 10 Mbps or 100 Mbps wired LANs today. Wireless LANs have significant less bandwidth than wired LANs and should thus not be thought of as a wired LAN replacement. And its performance is not always reliable, receiving range being a limiting factor. Connecting two PCs with the Proxim Symphony will cost $300, connecting a notebook adds another $199, while adding a third desktop PC to the network costs an additional $150.

But the goods news is that wireless LANs are seeing a steady rise in sales thanks to improving performance and decreasing prices. The wireless LANs are freeing business users from their desks, setting them free to roam the floors, offices and conference rooms with their notebooks, all the while connected to the network.

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