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Issue of February 2003 
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Networker: WLAN
Wireless LANs becoming imperative

The era of wireless LANs has finally set in. The technology is now mature enough to be put to business or commercial use. by Milind Kamat

Even though wireless LANs are currently more expensive to deploy than their wired counterparts, there are several instances in which a wireless LAN is a better alternative. Here are some examples.

Quick network deployment: Today long-distance fiber backbones are becoming more widespread. The issue is how to distribute this bandwidth easily to the end users, who are distributed across geographies. To some extent, this is being done through mobile service providers (BPL, Airtel, etc.), and through satellite. But a more practical solution is wireless LAN technologies like the 802.11b or 802.11a standards, which have the advantage of speed of installation and commissioning. After the September 11 attacks, companies are finding it imperative to quickly set up LAN and Internet connections, for alternative offices and sites.

Roaming connectivity: With the proliferation of mobile hand phones, the user mindset is shifting towards "always on connections." This is very prominent with top decision makers, especially in the services and hospitality segment. Here, there are two important aspects: one is movement of the objects and movement of the user. Here are two instances to exemplify this. With courier/freight forwarding companies, packages entering and leaving a location need to be tracked. A notebook user on campus wants access to server or network resources, as he moves about. For both these applications, wireless LANs are probably the best alternative.

Public & fun places: There are places like airports, hotels, clubs, etc. where a large number of people gather. They either have a lot of spare time, as they wait for their flights in airport waiting lounges, or come together in clubs. In both situations, information accessible through the Internet is a clear requirement, for which a wireless LAN is the ideal solution.

Difficulty in cable installation: The installation of cables could be hampered for various reasons like getting permission from authorities, non-feasibility of installation in old buildings and ancient monuments, etc. So wireless LAN makes sense here.

High cost of cable installation: In some places the effective cost of cable installation is very high. This may be due to loss of business during that period, or the finishing work needed after that. This is particularly applicable in places like hospitals and hotels.

Secured connection: Wire or fiber is a physical medium and can get damaged. So VSATs are used for long distances. For shorter distances of 10-30 Km, wireless LAN can be a good alternative. This area has become more relevant especially after disaster management gained importance.

LOOK BEFORE YOU LEAP
Before handing over the task to the network designer, the CIO/CTO must really examine basic needs versus inflated requirements. It isn't surprising to see how one wants a desktop PC with minimum memory of 64 MB, and on the other hand be contended with 16-32 KB on a handheld computer. In one way 100 Mbps may not be sufficient, and on the other hand we may be comfortable with 10-20 Kbps of Internet access bandwidth. In fact, one should seriously reconsider the following issues:

  • Is LAN bandwidth getting used efficiently?
  • Is it necessary to "buy & maintain" the entire infrastructure?
  • Can we use the virtual infrastructure maintained by someone?

After we have found the right answers, we can move further.

STRUCTURAL BENEFITS
Moving from wired to wireless has some unforeseen advantages. One is that, given the choice between mobility and bandwidth, the natural human tendency is to go for mobility.

The second advantage is that wireless devices are much more personal. From a budgeting point of view, this would mean that the demand for handhelds, PDAs, notebooks etc. would increase compared to full-fledged desktops.

Now such devices are typically owned by the individual rather than the company. So what wireless does is reduce the need for companies to directly fund the purchase of end-user devices. Companies may initially have to subsidize the purchase of wireless devices by their employees, but in the long run, there will be substantial capex savings.

Another interesting aspect is that temporary workers and business partners can share the wireless fabric, thus extending the reach of the enterprise applications, giving greater control to the enterprise. Yet another benefit is that wireless networks promote thin-client based applications rather than fat-client applications, making it easier to develop and maintain such applications. This further reduces IT budgets. All these factors together can help reduce IT budgets in the long term, even though wireless networks may seem more expensive than their wired counterparts.

VALUE PROPOSITION FOR WIRELESS
To take an analogy, wired versus wireless is like bus versus car. Large bandwidth on the wire is analogous to high capacity of the bus. Bandwidth increase is analogous to increase in speed and frequency of the bus. But can a bus service ever match the convenience of a car? A car gives you the freedom of anytime anywhere mobility, as does wireless technology.

As it stands today, wireless products cannot be compared with the price and efficiency presented by the wired/fiber networks. Hence there has to be a distinct value proposition attached to the wireless solution.

Presently, there are two popular options: 802.11b (11 Mbps shared) and 802.11a (55 Mbps shared). But the advantages presented by high bandwidth (802.11a), are limited to the smaller distance covered. So one has to make a choice: How far vs. How fast?

There seems to be an attractive option of dual-band products supporting both 802.11b and 802.11a standards.

But one has to be extremely careful, as this advantage can be very misleading. For two reasons: the distances covered may totally change as you switch from one standard to the other. Consider this scenario: all users may be connected at 55 Mbps (802.11a), and one mobile user may connect at 11 Mbps (802.11b). In such a scenario, the entire network speed will fall back to 802.11b.

This may lead to total change in design of the wireless network or may demand heavier investments today. It may be a better option to switch over to another standard whenever needed. Frequency approvals in 802.11a frequency band need to be checked carefully.

TECHNICAL AIDS
Site Planning Utilities: Reputed vendors provide site planning aids along with their products. These utilities help in evaluating signal strengths and the bandwidth available at a specific location. A good wireless network can be designed with this information.

Amplifiers & Antenna: To cover larger distances, amplifiers and special antenna support is needed. Single-vendor support for all such accessories eliminates some of the intricate issues.

Power over Ethernet: To cover a specific area or to maintain the deco, the Access Point/Bridges need to be placed at a specific location. Now, there may not be power connection available in the vicinity. In such cases, DC power can be fed thru the CAT-5 Ethernet cable. Devices providing such support are called Power Injectors. Access points/bridges accepting such power over Ethernet should be carefully considered.

CONCLUSION
The time for wireless LANs has come. The technology is now mature enough to be put to business or commercial use. Technical aids are available to ensure that wireless LANs can be implemented effectively and securely.

Besides business productivity benefits, the IT department can also benefit by structural improvements in its applications architecture.

The writer is Country Manager-India, SMC Networks. Send your comments and feedback to milind.kamat@smc-asia.com

 
     
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