Retail Wi-Fi Networks – Are You Making These 8 Mistakes?
Retail Wi-Fi Networks – steps to improve performance and reliability
Retail Wi-Fi networks are often required to operate in very hostile radio frequency (RF) environments. Retail outlets often depend on their Wi-Fi networks to trade or attract customers so it is essential to do everything possible to improve reliability and performance. You should also consider the impact of your retail Wi-Fi network on your neighbours Wi-Fi networks. The RF environment may well be mostly out of your control but there are measures you can take to ensure you are getting the best from your Wi-Fi investment while living harmoniously with your neighbours. The good news is, if you are responsible for a chain of retail outlets, once you have a set of installation and configuration rules for your Wi-Fi, you can duplicate them across the estate.
1) Misunderstanding the meaning of noise
Noise is one of the most important parameters in wireless networking and possibly the least understood. Most of us associate wireless noise as being hiss, crackle and pops (for example). But noise is anything other than the signal we want to receive at that given time. If you are in a busy bar and you are talking to your friend, you will have to ‘tune in’ to their voice because you will have countless other conversations going on in the background. As far as your conversation with your friend is concerned, all of the other conversations are noise.
Noise comes in many forms, including microwave ovens, mobile phones, fluorescent lights, radar, electric motors, the list goes on. However, there are two noise sources that are often overlooked: noise from APs in other retail outlets wireless networks, and noise from access points within your own network. They may be valid AP to wireless client communications but they will be noise to every other device other than the device (AP or client) sending the data and the device receiving the data.
2) Believing your neighbours are friendly
Retail outlets are rarely in locations on their own. Their neighbours are also likely to have Wi-Fi networks. If the outlet is in a shopping centre or shopping mall the centre owners are also likely to have their own W-Fi network for staff and customers. This results in areas awash with RF in the Wi-Fi bands. Imagine standing in the middle of Twickenham stadium when England have just scored a try and trying to have a quiet conversation with a friend standing a few metres away. That is what it is like for your hand-held devices when they are trying to communicate with their associated wireless access point.
In the vast majority of installations every access point in the area are transmitting at full power, SHOUTING TO BE HEARD above all of the other access points. I already mentioned above that anything other than the radio frequency signal from the device the access point is listening to at that time is noise. With every access point on full power the noise levels are far higher than they need to be. Having said this, we can rarely do anything about this other than refusing to join the shouting match.
3) Accepting local wireless configuration rules without question
Some shopping centres try and impose rules on their retail tenants by issuing a Wi-Fi design guide. In principle this is a very good idea but the document has to be kept up to date with wireless technology and developments. The examples I have seen have been several years out of date and as a result create more problems than they solve. In addition to this, these documents tend to address each retail outlet as an individual entity (which again, is OK in principle) but they rarely take an holistic approach. Sometimes there is an opportunity missed to get this right for all tenants and the shopping centre. If you are being asked to adopt these rules for your wireless network I would always recommend getting a second opinion, any move away from a standard build is likely to have implications on your PCI compliance.
4) Allowing your customer Wi-Fi network to have a detrimental effect on your business retail Wi-Fi network
Many stores are providing customer Wi-Fi access as a value add. There is certainly huge potential for stores engaging in price matching allowing customers to check against online stores. Many modern retail outlets are either steel fabricated or reinforced concrete units serving as an effective Faraday cage to mobile signals so Wi-Fi may be the only option. Given that some retail environments are extremely challenging to Wi-Fi it may be wise to ensure all of your business Wi-Fi services are running effectively before introducing customer access.
5) Adding wireless Access Points to overcome performance issues.
It is easy to make the mistake of adding more APs when you are experiencing performance issues. However, the transmitted signals from each AP are noise to the surrounding APs even within your own network. I have seen Access Points in shopping centres seeing over 130 other APs on the same network – that is 130 sources of noise!
6) Installing wireless Access Points in poor locations
Access Point location can be critical in a retail environment. Careful positioning of your APs can reduce their susceptibility to interference from other APs. The recent tendency for open plan store fronts within enclosed shopping centres makes positioning even more critical both for your own benefit and to be kind to your neighbours.
7) Failing to use the building materials in your favour
Do not rule out using parts of the building structure as a partial shield from other APs. If the building has visible supporting steel works in the ceiling, these may be used to shield your APs from interference from external APs and other APs within your own network.
8) Continuing to support legacy devices
Maintaining support for legacy devices such as 802.11b can be the downfall of your network in heavily congested environments. This can have a massive impact on noise susceptibility to the point where the entire network fails. Unless you have a specific need for legacy support, it is safer to remove it.
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