Can Wi-Fi do it all?

If Internet enabled a paradigm shift in accessing
Information, then Mobile Internet ushered in a 360 degree change in computer
networking. These radical and dynamic changes in technology and communications
have introduced an era of computing that it vastly different than the scenario
that existed a decade back.


Today the issues that organization and their solution
providers face is not simply about providing access to Internet, it is much more.
The challenge is to provide new age smart devices with reliable, secure and
fast access. To add to all these, you must also remember that majority of these
devices do not have Ethernet ports. So the solution is pretty obvious –


Does Wi-Fi measure up to your expectations?


Almost all mobile communications devices come with Wi-Fi
now – smartphones, tablets and various other new age wireless devices.
Therefore users are making the full use of these devices and stay online
wherever they go. In many cases however it has cause the pain of network
managers –  choking up their companies’ network. These are also leading to
data volumes that exceed network capacity, and RF spectrum that is too crowded
and almost impossible to navigate. But the usage pattern shows no signs of
decrease. Instead users’ expectation for a consistent and ubiquitous wireless
connectivity is rising day by day.


Wi-Fi was initially conceived and developed as a
convenient technology for SOHOs. It was just about Internet access. Wi-Fi was
never meant for density access in large venues, streaming HD videos, SKYPE
calls or video conferencing. But today Wi-Fi is doing all these. Hotels,
hospitals, educational institutes are adopting Wi-Fi and they integrated mobile
devices – tablets, barcode scanners, Wi-Fi phones into their company’s
mission-critical applications. Wi-Fi is no longer just doing simple and
convenient connectivity.


Wi-Fi does have its own issues, the main being erratic
performance from an increasingly noisy spectrum and spotty signal coverage. But
almost all these issues are manageable by advancement of new Wi-Fi technologies
and careful site survey prior to installations. Most importantly, Wi-Fi comes
with most if not all of today’s mobile devices, while Ethernet ports are
vanishing. Wi-Fi therefore has become the most beneficial and cost effective
way to relive strained networks in addition to convenience.


The missing piece of the 802.11n puzzle


IEEE 802.11n standard was ratified in September 2009, and
it was promised to solve all the issues ailing WiFi and bring the bandwidth
comparable to wired networks. But challenge here seems to be how to realize all
the benefits? Owing to lack of knowledge about how 802.11n works, current
implementations are frustrating network managers with poor performance,
unstable client connections and coverage holes.


802.11n is based on Multiple-In-Multiple-Out (MIMO)
technology that leverages many antennas to coherently resolve more information.
An innovative technique called as spatial multiplexing ensures that multiple
independent data streams are transferred simultaneously within one spectral
channel of bandwidth. It significantly increases data throughput as the number
of resolved spatial data streams is increased. Additionally, 802.11n also
doubles the channel width to transmit data.


But the problem is that unless you have explicit
knowledge and control over the RF domain, these techniques are of no use.
Interference or obstacles can corrupt concurrent Wi-Fi signals during
transmission; these can lead to increase in retransmissions, packet loss and


Additionally, using standard di-pole, omni-directional
antennas is never a safe bet for 802.11n implementations. The main issue is
that these antennas transmit and receive signals in all directions, and if
something goes wrong, conventional wireless systems can only decrease their
power or change their RF channel assignment. IT managers find this to be a
highly ineffective and problematic approach due to an increasingly noisy RF


To address these issues, most WLAN vendors advocate:

–   Adding more access points (APs): APs can actually make
things worse by causing more noise and creating co-channel interference that
desecrates spectrum capacity.

–  Lowering AP transmit power: Significantly increasing
802.11n wireless throughput and reliability requires learning about the RF
spectrum as it changes, and adapting Wi-Fi transmissions to the fastest and
cleanest signal path for each packet to reach a given client.

–  Steering clients to a less crowded band: Enterprises must
pay particular attention to new technologies that automate Wi-Fi spectrum
management and provide a more adaptive approach to dealing with RF spectrum
problems such as interference, obstacles, and changing client orientation.


None of the solutions above give you the true benefit of
Wi-Fi. Network managers need to constantly monitor the RF environment with
unidentifiable interference sources from neighbors or compromise the users with
lower performance. Of course adding more access points is the best answer these
WLAN vendors want you to do. Wi-Fi would just become another expensive network
resource and compel you to deal with a lot more of the uncertainties on an
hourly basis. Eventually this will stifle the adoption of mobile Internet and
demoralize enterprise productivity.


Smart Wi-Fi for better throughput


There is a new smarter way to address the performance
issue in a much more elegant way – adaptive antenna technology.  Adaptive
antenna technology run in an array of high-gain, directional antenna elements.
It is controlled by software and is able to overcome the issues ailing Wi-Fi
connectivity owing to poorer implementation. It constantly scans the RF
environment, detect client locations, and transmits Wi-Fi signals where they
are needed. At the same time adaptive antenna technology switch off those
antenna elements most vulnerable to interference, therefore it can reject RF interference.


The built-in client feedback mechanism in these systems
informs them if the Wi-Fi signal being sent to clients is achieving the highest
data rate, best signal-to-noise ratio and lowest amount of packet loss. These
smart antenna arrays can be automatically switched over better signal paths if
something gets in the way between the AP and clients, as they are software



Wi-Fi today is no longer after simply getting access to
the Internet, but it enables you to fully incorporate your enterprise network
and ensure an integrated workplace and personal space usage. Today, it can deal
with the influx of multimedia traffic hitting organizations’ networks from the
users’ new age handheld devices. The changing improvement and maturity of the
technology as well as the evolution from 802.11g to 802.11n enables you to
deliver much more reliable connections because the system can adapt to
environmental changes automatically. As you should be aware- the only thing
constant in the wireless networks is that it is changing constantly. And in
such a dynamic environment, Wi-Fi is always the best bet.



By Manjit Singh, managing director, India & SAARC,
Ruckus Wireless
[email protected]