WIRELESS LAN: Make Your Enterprise Wireless



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.

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.

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.

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.

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.

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.

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

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.

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