Wireless Networking: Basic Design Considerations
By Paul Rummery, Securenet Consulting
For
companies who already have or are looking to embrace the cost saving
and productivity boosting provision of mobile and wireless networking
within and around the office, will have to consider the implications
of a significant rise in unmanaged devices roaming and trying to
connect to your network.
By Paul Rummery, Securenet Consulting
You
may already have a pool of managed corporate laptops and mobile
devices, but many CFO's are seeing the cost savings that BYOD or mobile bring
to an organisation, where employees, managers and partners can use
their own personal devices to work from – saving the business
having to invest and provision for mobile working and collaboration.
Basically this means a significant growth in the number of mobile devices that they would to allow and manage access, but to date traditional technologies and solutions are either too costly or simply can not cope with the demand (not only from a bandwidth perspective, but the administration time for setting up, maintaining and managing mobile device access onto your network).
Basically this means a significant growth in the number of mobile devices that they would to allow and manage access, but to date traditional technologies and solutions are either too costly or simply can not cope with the demand (not only from a bandwidth perspective, but the administration time for setting up, maintaining and managing mobile device access onto your network).
This
topic has many layers for consideration, where the actual
implementation of a wireless solution depends on many variables, for
instance, important factors
such as the structural features of your office building, will
be unique to your deployment
– resulting in either a simple or more complex and costly
implementation – in a nutshell, “one size does not fit all”. So
we will touch on some of the key best practises and either address
individual reader problems or concerns, but will no doubt cover key
business solution scenarios in future write ups on this topic.
Considerations: Capacity & Security
Facing
the challenges of supporting the potential number of devices and
device types accessing the network and segmenting users and back end
systems.
Wireless
computer network equipment typically uses radio signals in either a
2.4 GHz range or a 5 GHz range.
A
5GHz network can carry more data than a 2.4 GHz network.
5GHz channel is much cleaner with less interference with 23 non-overlapping channels- 8 times more than 2.4GHz for transmission, which makes it suitable for applications like Video streaming and Gaming which are very sensitive to packet loss and delays.
The ideal would be to implement dual-band AP's, allowing you to maximise the benefits and advantages of both frequency bands.
There
is more bandwidth available in the 5GHz vs 2.4GHz. Being able to
optimise 5GHz is fundamental for achieving optimal wi-fi
performance.
It
is recommended to select the 2.4 GHz if you will be using computers
to access the Internet for simple browsing and email. These
applications do not take too much bandwidth and work fine at a
greater distance.
The
5 GHz has a wider wireless spectrum available compared to the 2.4
GHz, which leads to significantly better performance as the 5 GHz is
commonly used for usage that requires uninterrupted throughput.
That is why it is recommended for media streaming and transferring
music, pictures, and video throughout your home network.
The
wi-fi signal level design criteria typically used for laptops
(nominally 70dBm RSSI) is not sufficient
for tablets and smartphones, especially when they will be deployed in
dense numbers. Since these devices transmit at lower signal levels
and have inferior antennas compared to laptops, networks must be
designed with stronger signal to ensure maximum data rates. Wi-fi
networks for tablet and smartphone support should be designed with a
maximum -65dBm signal strength in BOTH the 5GHz and 2.4GHz bands in
all locations.
Because
of lower transmit power and limited 802.11n data rate support,
tablets and smartphones will typically achieve much lower traffic
throughput performance compared with laptops. More wi-fi radio s are
therefore required to support these devices in a wireless environment
compared to a similar number of laptops, as multiple devices will
share the same radio. A general rule of thumb is to design the
wireless network with enough radios to handle the expected number of
devices at a ratio of 15 per 5GHz radio and 8 per 2.4GHz radio for a
typical office or classroom experience.
Security
considerations around access control and data management are crucial
to plan. IT must focus on the control of the network and data
infrastructure, enabling a seamless user experience and support of
devices. Knowing not only who is on the network but visibility into
what device they are using, and where they are located can feed into
deciding which access polices to enforce for that user's session. For
example using a user identity based access control solution, would
enable a corporate device to receive unrestricted access, yet the
same user with a personal device may only get restricted rights. The
capability exists today to define users and device types against your
corporate policies.
---------------------------------------------------------------------------------------------------------------
WANT TO LEARN MORE? Contact Securenet Consulting
WANT TO LEARN MORE? Contact Securenet Consulting