Now a days India’s leading Broadband service provider Bharat Sanchar Nigam Limited (BSNL) is providing internet through ADSL 2+ and VDSL technology which are capable to deliver 16 Mbps & 24 Mbps respectively depending on your broadband plans and of course the line parameters from BSNL CO (Exchange) to your premises. While feedback about these broadband technologies have generally been very positive,

but I’ve been really surprised by the number of people reporting problems including measured speeds that are erratic and/or much lower than expected. On further investigation, I have found that the vast majority of problems have been due to Wi-Fi set-up issues as Wi-Fi puts an extra element in the ‘chain’ between your Internet connection and your devices, sending signals through the airwaves using frequencies that are shared by other Wi-Fi users in the vicinity. Therefore, I am devoting this blog post to the subject of Wi-Fi optimization and that is essential to ensure that you actually get the full speeds that your broadband connection is capable of delivering, and is particularly important for ADSL/ VDSL broadband users.

Wi-Fi Limitations:

Wi-Fi (or WiFi) is a local area wireless computer networking technology that allows electronic devices to network, mainly using the 2.4 gigahertz UHF and 5 gigahertz SHF ISM radio bands. The performance and speed claims from wireless router manufacturers are never achieved in practice because of:

• Interference: Wi-Fi signals (particularly at 2.4 GHz) can be subject to substantial amounts of interference, for example, from neighbors using their own Wi-Fi routers, microwave ovens, security cameras, Bluetooth devices, video senders and cordless phones all of which can cause significant additional interference.
• Legacy equipment: While modern Wi-Fi routers may use the very latest Wi-Fi standards, often the Wi-Fi components in devices already owned by people (such as PCs, notebooks and mobile phones) do not.
• Limited range: Due to the low transmit powers used with Wi-Fi, range is generally very limited. Speeds and performance drop dramatically with distance, particularly if signals have to pass through walls and floors.

Wi-Fi Specification:

Specification	Frequency Band	Data Rate	Remarks
802.11a	5 GHz band	54-Mbps	Greater data rates with less prone to interference
802.11b	2.4 GHz band	11-Mbps	Prone to interference
802.11g	2.4 GHz band	54-Mbps	Prone to interference, superior range
802.11n	2.4 GHz band	100-Mbps	Prone to interference, superior range

2.4 GHz and 5 GHz Wi-Fi and the differences:

There are two separate frequency bands in which Wi-Fi systems can operate: 2.4 GHz and 5 GHz. Wi-Fi routers that can operate in both bands are often termed ‘dual band’ routers. Older Wi-Fi routers tend to work only in the 2.4 GHz band. Bear in mind that even though a new router may be able to operate at both frequencies, some (or all) of your devices may not! Many older devices may only operate at 2.4 GHz.

Each frequency band has its own characteristics, in terms of:

• Interference: where there can be much more interference at 2.4 GHz than 5 GHz
• Range: where 2.4 GHz generally offers superior range, being able to better penetrate floors, ceilings and walls
• Bandwidth: where 5 GHz allows greater maximum data rates to be delivered.

Minimization of interference and overcoming range limitations are two critical aspects of Wi-Fi optimization in order to deliver the highest data rates possible, as will now be discussed.

How to use 2.4 GHz band Wi-Fi Routers Efficiently:

In theory, interference could be avoided if every Wi-Fi access point could use a different frequency. However, the radio spectrum available is extremely limited, making this impossible. The 2.4 GHz Wi-Fi radio spectrum is only 100 MHz wide. While there are 13 channels available, each channel is 20 MHz wide (to deliver adequate data speeds)

so channels actually overlap. This means that a neighbour’s Wi-Fi router operating on channel 9, for example, could interference with your Wi-Fi connections if your router is using channel 7, 8, 9, 10 or 11. There are only three discrete channels (1, 6 and 11) at 2.4 GHz that do not overlap with each other.

Given the state of 2.4 GHz Wi-Fi today, my recommendation is to try to manually select a channel that provides the best performance as many Wi-Fi routers allow manual selection of the channel. You will need to read your router manual for instructions on how to do this.

You can identify the best possible channel either by:

• Manually setting the Wi-Fi channel and alternating slowly between channels 1, 6 and 11 (and assessing the impact on performance)
• Utilising a WiFi scanning application that identifies the Wi-Fi channels in use in the nearby vicinity. Results can help to select the most appropriate channel to use.

The best way, however, to address substantial 2.4 GHz interference issues is to use the less-crowded 5 GHz frequency band instead.

5 GHz usually is much better if all your devices support it:

We strongly recommend that you use the 5 GHz band rather than the 2.4 GHz band as there is currently much less interference for a number of reasons:

• Fewer Wi-Fi routers and devices currently can operate at 5 GHz
• The range of Wi-Fi signal at 5 GHz is greater than 2.4 GHz, meaning that received interference levels are generally lower
• There are more 20 MHz channels available (up to 19), which do not overlap with each other.

Successful operation at 5 GHz obviously requires that your devices have the capability to operate at 5 GHz as well as your Wi-Fi router. If a device does not have 5 GHz capability, it will simply operate at 2.4 GHz. While modern devices such as iPhones and iPads incorporate 5 GHz capability, many devices in existence operate at only 2.4 GHz. In a typical household, there may be a mix of 2.4 GHz and 5 GHz Wi-Fi devices.

In the presence of substantial 2.4 GHz interference, there could be significant differences in the performance of devices in your home. For example, 2.4 GHz-only devices could exhibit huge fluctuations in download speeds whereas 5 GHz devices will deliver much more consistent performance.

While the best situation is to only have 5 GHz-capable devices, most households still have a mix of device capabilities. The easiest way to eliminate 2.4 GHz interference issues is obviously to upgrade as many of your older devices as possible to newer models that incorporate 5 GHz capability, particularly if you use them a lot.

Wi-Fi Optimization Summary:

In summary, here are our top optimization tips:

• Use Ethernet connections wherever you possible can, for example, connecting devices such as set-top boxes and streaming devices, smart TVs, games consoles and PCs.  You should not use Wi-Fi at all for fixed devices.
• Manually select a 2.4 GHz Wi-Fi channel that provides the best performance, choosing one of the following channels: 1, 6 or 11.
• Use a 5 GHz Wi-Fi router, and upgrade as many of your devices as possible to 5 GHz operation. You can upgrade old PCs and notebooks with affordable 5 GHz USB Wi-Fi adapters.
• Operate your 5 GHz Wi-Fi network with a different name to your 2.4 GHz network (to prevent your devices switching to interference-ridden 2.4 GHz operation).
• If you are using a single Wi-Fi router, try to centralise its location in your home to provide good coverage to areas where you use Wi-Fi devices.
• Deploy additional Wi-Fi access points/extenders to enhance coverage, connecting these back to your router using Ethernet cables. Use up to three devices in total (including your Wi-Fi router), and manually set the 2.4 GHz channels to 1, 6 or 11 (without reusing the same channel).