Wireless standards and how they affect your speeds

It is often imperative for organisations to roll out wireless networks that performs at a level that is similar to their wired infrastructure and there are a range of standards that can be used within a wireless LAN. Which standard that is right for you?

The 802.11a standard transmits data at up to 54Mb/s in the 5GHz band, and is generally more popular with businesses than consumers.

The 802.11b standard, which operates on the 2.4GHz wireless spectrum, a very common standard used at public hotspots, is capped at 11Mb/s. The more recent 802.11b+ standard improves the throughput, delivering a data rate of 22Mb/s.

802.11g is a standard that offers transmission over shorter distances at up to 54Mb/s. Networks based on the “g” standard can, however, transmit up to a few kilometres providing there is a clear line of sight.

There are 802.11g based devices available that offer data speeds of up to 108Mb/s. However, it is important to note that such offerings are vendor-specific implementations and may not be compatible with equipment from other vendors.

802.11g equipment is typically backwards compatible with 802.11b equipment, however 802.11b clients accessing the network will impact the speed of access that is possible for 802.11g clients.

There’s also a new emerging standard, 802.11n. Vendors have been shipping what is know as “pre-N” equipment for some time, however Telarus advises caution when purchasing such equipment as it may not support the ratified standard once it is available.

So which standard should you use?

When it comes to deciding on which standard you use, there are some important considerations. The 2.4GHz band (used by 802.11b/g) and the 5GHz spectrums are “unlicensed” which means that anyone can use them potentially increasing traffic.

Fergus Fitzwater (Telarus’ resident wireless expert), 802.11b/g (operating in the 2.4GHz band) is the most common wireless technology. Unfortunately, it is prone to interference from consumer devices like Bluetooth devices and DECT cordless phones that also operate in the 2.4GHz band.

If you are setting up a private wireless LAN for use within your business, 802.11a will probably deliver the best performance due to the fact that there is less interference in the 5GHz band, Fergus says.

Additionally, 802.11a channels are non-overlapping, meaning there is a greater number of channels to choose from if you need to deploy multiple access points.

If there is a requirement for guests (people outside your business) to use your wireless network, you will probably need to use 802.11b/g (operating at 2.4GHz) as the majority of wireless equipment shipped and/or integrated into devices such as laptops and PDA’s (Personal Digital Assistants) is 802.11b/g compatible.

However, the trade-off is that 2.4GHz (as outlined above) is likely to be prone to interference, which may impact the data rate. As such, selecting a channel (or channels if you have multiple access points) that is not overly impacted by interference may be an important consideration.

Fergus says that there are 13 channels available for use on 802.11b and 802.11g networks in Australia. If you are installing multiple access points, there are only three that don’t overlap (channels 1, 7 and 13).

He says that if you are using channels that overlap, the resulting interference will impact the speed of your wireless network and may result in blackspots, so using channels that don’t overlap is highly advisable.

If you’re not sure which standard is best for you, you may want to take advantage of the wireless design and audit service which is being launched soon. If this is of interest, please speak to your Telarus Solutions Engineer or Account Executive.