Troubleshooting wireless installations

You’ve got wireless equipment, but you’re not getting reliable communications across the wireless links… and you’d like to find out why. Steven Bishop, Engineer and part of the IFSEC Installer Council, offers some advice.

The low cost to install wireless devices makes wireless technology very attractive and it’s become a popular choice for communications infrastructure and signalling.

The savings in time and cabling materials to install a wireless device compared to a wired unit are significant, as the time to install comes down from hours to minutes, and a whole site can be setup with wireless equipment using fewer technicians, or as a DIY install at a much lower cost.

However, wireless technology does come with a risk of unreliability from interference, overlaps in coverage and changes in the wireless signals within the local neighbourhood.

There can be multiple causes of unreliable wireless communications, but one of the more common reasons comes from congestion of the Wireless Spectrum.

Wireless congestion

Sending data across a wireless connection in a congested wireless neighbourhood is like trying to have a conversation in a crowded pub or at a loud dinner party. You can shout to be heard above the din, but when you do raise your voice, your shouts spread out across a wider part of the whole room. This increases the noise levels for everyone else and anyone also talking will raise their own voice.

As the congestion and noise increases in the room, it soon becomes impossible for anyone to hold a conversation. But, if everyone sits close to their partner and whispers into their ear, then the noise in the room drops, congestion falls and all the conversations can carry on without interfering with each other.

What we get from this is that the distance between the speaker and the listener and the volume-level both effect whether we can hold a conversation in a crowded room.

Wireless repeaters

A good example of this effect in action can found it we look at WiFi installations in urban locations.

There is a trend for vendors to try to sell customers extra WiFi repeaters and range extenders, in an attempt to improve the reliability of the customer’s WiFi communications.

These repeaters are designed to be fitted at the mid-point of the signal path between the WiFi End-Points and the WiFi Access-Point, to broaden the coverage area for that WiFi network. But, this also increases the chance of the wireless conversations spreading out and being heard by neighbouring WiFi networks.

So it can create a bit of an ‘Arms-Race’ between neighbours to fit more and more WiFi repeaters. It congests their WiFi with overlapping coverage and it means their WiFi becomes unreliable during peak times at evenings and weekends.

So, what is the solution for wireless connection issues?

The best solution is to reduce the range or distance between the Wireless End-Points and the Access-Point.

You can do this by moving the existing Access-Point into the centre of the required coverage area. Or better yet, you can install multiple Access-Points that each cover a smaller part of the original area. Then, connect each of these Access-Points back to the internet gateway router using a wired connection or a different type of wireless link that doesn’t overlap with your primary wireless equipment.

Writing down the skills to troubleshoot wireless communications is more than can fit into this article, but there are some other basic questions that you can ask yourself.

Has this set of wireless equipment been installed for a while?

• And have you previously been able to get a reliable connection?
• If you have, then it points to a change in the wireless environment of the local neighbourhood.

Is this a new install or upgrade?

• If it is, then it might never have worked reliably. It could be because the Wireless End-Point don’t have enough range to reach the Wireless Access-Point.

Has something changed in the vicinity?

• Has a new piece of unrelated machinery been installed? It could be creating noise in the wireless spectrum.
• Has there been construction work that has made changes to the building? New metalwork, pipes or concrete could now be blocking the path of the wireless signals.
• Has a neighbour added or altered their own system of wireless devices?