Advertisment

WIRELESS LAN: Make Your Enterprise Wireless

author-image
DQI Bureau
New Update

As a senior sales team leader in a financial services firm, Rammaiyah, had to

often move within his office to make presentations with his laptop. Even though

his office - two floors landscaped with tens of cubicles - was well-networked,

he did not have much freedom with mobility. He could get connectivity for his

laptop only in certain locations. This effected his access to real time

information that he often needed to share with his team. That was two months

back. But not any more. Thanks to a wireless local area network (LAN) solution

deployed in his office, Rammaiyah has been able to do what he could not earlier

- roam around freely in the office without worrying for a place to plug in his

laptop. His office now offers connectivity everywhere, even in the office lobby,

courtesy the minus wireless solution that did away with the need to put cables

everywhere.

Advertisment

Why wireless LAN?

Highlights
  • Wireless LANs offer the user

    mobility, speedy and easy installation, flexibility and scalability
  • Limited throughput (5.5 Mbps) rules

    out bandwidth-hungry applications
  • The Wireless Planning and

    Coordination wing (WPC) clearance is needed to deploy W-LAN, more so

    as the frequency band allocated for it is licensed and paid for

The unimportance of wires, one of the most visible attributes

of the traditional wired LAN, is perhaps just one of the many benefits of

wireless LAN. While its cost advantages could be a matter of debate, wireless

LAN definitely offers a number of unquestionable benefits that the ubiquitous

wired LAN cannot. In the highly networked markets of US and Europe, wireless

LANs are popular because of four main reasons - user mobility, speedy and less

cumbersome installation, installation flexibility, and scalability. Many claim

it also entails reduced cost of ownership. But this is true for organizations

that require frequent moves and changes in their LAN set-up. For organizations

with stable set-ups, there would not be a cost advantage involved as wireless

LAN hardware is costlier than those used to deploy a wired LAN.

Advertisment

Not for high bandwidth apps

But deploying wireless LAN is not just about replacing cables

or mobility. It is fine that it would increase employee mobility and that the

organization has a very dynamic network that needs frequent moves and adds or

that the office building does not allow frequent changes in the wiring. But

before you take a decision based on these facts, something more basic would need

an enterprise’s attention - will wireless LAN suit its requirements? The

answer to this question would depend on the type of applications that an

organization runs or would like to run on the LAN. This is important because of

limitations on bandwidth in wireless LAN networks.

Even though theoretically the IEEE 802.11B (the prevalent

wireless LAN standard) is meant to support a 11 Mbps output, in reality not more

than 5.5 Mbps bandwidth is available in wireless LAN. Moreover, in a multi-user

environment, a single user cannot expect to get even this 5.5 Mbps as the

bandwidth is shared with other users. Besides, as the user keeps moving away

from a wireless LAN access hub, the bandwidth output keeps on decreasing.

Naturally, all this rules out high-bandwidth applications. Wireless LAN

throughput is sufficient for applications like electronic mail exchange, access

to shared peripherals like printers, Internet access, and access to multi-user

databases and applications.

Advertisment

The limitations on bandwidth also means that wireless LAN,

despite its other visible advantages, cannot be expected to replace the

traditional wired LAN. In case, an organization does want to replace or go for

wireless LAN completely, it needs to also understand the users who will be

accessing this. If all users were to access it, then the issue clearly becomes

one of what the total bandwidth requirement of the enterprise is and whether the

solution helps achieve that.

W-LAN: Who is It good for?

Wireless LAN is best suited for organizations where the

number of users is less and where mobility is more important than throughput.

Besides, wireless LAN can be and is being used to provide connectivity in hard

to wire places, for example, corridors, lobbies, conference rooms. Wireless LAN

can also be used to provide connectivity in temporary premises, makeshift

offices, site offices etc. Offices which have lots of laptop carrying visitors

too can look for wireless LAN deployment. ‘The decision to deploy wireless LAN

should not be taken just because everyone is talking about wireless but only

when users genuinelyÿ need to compute on the run, from various locations in

your building, or in areas that can’t easily be wired," emphasizes Suresh

Prabhu, service line manager, Cambridge Technology Partners, India.

Advertisment

Pre-deployment spadework

Average cost for a

20-user set-up
  • Acess point cost: Rs 100,000 (approximately)
  • PCMCIA ethernet card cost:

    Rs 17,000 (per user)
  • Spectrum charges: Rs 5,000 (per-user average)

Based on this:

  • The average per-user one-time cost:

    Rs 27,000
  • Recurring cost every year thereafter:

    Rs 5,000

Once a decision has been taken on the deployment of wireless

LAN, the next step should be to approach the Wireless Planning and Coordination

wing (WPC) of the Department of Telecom for spectrum use clearance. This is

because while the frequency band allocated for Wireless LAN operations (2.4 GHz

to 2.4835 GHz) is free for use in most countries outside India, here it is paid.

For first time users, it usually takes three-four months to get a clearance from

WPC as the request has to be first cleared by the Union Home Ministry. However,

an existing user of Wireless LAN can expect to get a clearance in two-three

weeks’ time.

Advertisment

The second important consideration should be the interior

design structure of the site where wireless LAN is going to be set up. Most

wireless LAN systems use RF. And the distance over which RF waves can travel is

not the function of the product alone. It also depends on the propagation path

of RF. Even though RF waves are capable of penetrating most indoor walls and

other physical obstacles, their range of coverage surely depends on the indoor

architecture of the building. In open spaces each wireless LAN access hub can

cover up to 300 feet, while in places with physical barriers-like walls, a hub

could be effective in the range of 130 feet only. This would naturally mean that

access points are placed strategically as such to overcome all physical barriers

inside the building. Otherwise users would not be able to enjoy the advantage of

mobility or roam around freely in a building with their connected laptops.

Cost considerations

The initial investment required for wireless LAN hardware is

on the higher side. One wireless LAN access point costs around Rs 100,000 and a

PCMCIA ethernet card would cost around Rs 17,000.

Advertisment

Typically one access point can support up to a maximum of 20

users in a range up to 130 to 300 feet depending on the internal structure of

the building. Besides these costs, there is the spectrum fee payable to WPC.

While the first user will have to pay Rs 17,500 per year for frequency use,

every other user will have to pay one-fourth of this amount (Rs 4,375) every

year. Given this, currently, the per user cost of setting up a wireless LAN

would be Rs 28,000 per user (one time cost for access point, PCMCIA card and

spectrum charges) and thereafter, a recurring cost of around Rs 5,000 every year

per user on account of frequency use charges. These average costs have been

worked out considering 20 users per access point. The total infrastructure cost

would depend on the number of access points.

Long-term cost benefits could accrue in dynamic environments

requiring frequent moves and changes, as also in businesses where in-building

mobility is highly sought-after.

Security considerations

Advertisment

While it is usually claimed that wireless LANs are more

secure than their traditional wired counterparts, there exist some concerns with

regard to security. There are inherent weaknesses in Wireless Encryption

Protocol (WEP) as defined by IEEE 802.11b, the standard for wireless LANs, and

these weaknesses exist regardless of the length of the encryption key used.

The weakness of most wireless LANs is their use of static WEP

keys shared among user. However, users can now look forward to enhanced wireless

security solutions that offer more sophisticated key management techniques, he

adds. This protocol is only designed to keep casual snoopers at bay and not the

determined ones. There are a number of other technologies that are deployed to

provide security. These include the use of tunneling technology and strong-128

bit encryption and above, layer 2 security through the use of access control

lists to prevent unauthorized people from accessing the network and

authentication mechanisms (for example RADIUS), to verify the identity of the

person before providing access.

Where to get W-LAN solutions

For wireless LAN hardware enterprises can approach such

wireless heavyweights as Cisco, 3com, Intel, Nokia, Enterasys and Ericsson as

also Compaq and Apple. D-Link and Lynksys are the other vendors in this segment.

For implementation, you can consult big names like Cambridge Technology Partners

or upstarts like Tulip Software.

Notwithstanding its limitations, there is no doubt that

wireless LAN has redefined in-building connectivity. And even though it is still

far away from being an effective alternative to wired LANs, attempts are being

made to make wireless LAN more effective in terms of their coverage and

throughput (efforts are on way to get data speeds of 100 Mbps). And if all that

happens, organizations will certainly be relieved of the headache to get their

building wired.

Ravi Shekhar Pandey

/Voice&Data in Delhi

Small, But Growing...

Indian

enterprises are adopting wireless LAN, but hardware costs, limited

applications and policy issues are stifling growth. DQ takes a closer look

The

wireless LAN market in India can best be described as insignificant with

very few deployments. Like most other new technologies, there is a lot of

interest about wireless LAN among probable buyers, too. As far as the

availability of the solutions are concerned, almost all the known vendors

offer their wireless LAN product in the Indian market either directly or

through resellers.

While on the one hand it can be said

that the 802.11b-based wireless LAN is too new a technology for India to

have gained considerable presence, on the other there is no doubt that the

demand has been constrained mainly by factors like high initial cost of

installation, limited application and local regulations."Wireless LAN

segment will grow. However, the early adopters in the market will be those

who either already have wireless approvals for other products or

government organizations, which find it easier to get the regulatory

requirements in place," observes Sayan Ghosh of 3Com India. Besides,

he adds that while many inhibitions across the world result from the issue

of security, in India the main issue arises out of the feasibility and

functionality of the concept and the interoperability with existing

infrastructure and applications.

Patrick Mathias, national manager,

communication sales organization, Intel, lists requirement of approvals

for all sites, per site design and implementation (one design does not fit

all) low bandwidth and multipath interference and near end cross talk as

the most important factors inhibiting the adoption of wireless LAN.

Most potential buyers of wireless LANs

in India are multinational corporations and leading IT namely software

companies. The cost of the wireless LAN products is not a deterrent as it

has been on the free fall and has been more than halved since 1999. The

very high cost of licenses for operating these wireless LAN solutions and

the lengthy procedure involved in getting the different licenses have been

the major roadblocks.

The 5GHz wireless LAN is expected to

gain momentum in the market by 2007 to complement the high-speed wireless

LAN. While installations costs are expected to come down, vendors are

confident that once regulatory issues get sorted out, enterprises will

show eagerness in deploying wireless LAN solutions to leverage all its

advantages.

Advertisment