Common Issues With Warehouse WiFi & How To Fix Them


Warehouse WiFi can be challenging to get right. We’ve taken a look at some of the most common issues, and what you can do to rectify them.

1: Access Point Locations

Access Points (APs) placed in sub-optimal locations or heights – often both – is one of the most common issues with warehouse WiFi networks. Most Omni-directional (standard) APs will not provide great coverage above certain heights due to their antenna pattern. But in warehouses they are often mounted on the ceilings at heights of 8-16 metres.

Most of the standard type of APs are not designed to be mounted above 4-5 metres. See below (Fig 1) for an example of an Access Point sub-optimally located – in this case, it wasn’t even covering one aisle fully, whereas it should have been able to cover three aisles fully. Fig 2 shows that by moving this Access point to a better position and height we were able to tweak the settings to cover the required three aisles.

Fig 1.

Fig 2.

 

2: Interference

Using omni-directional Access Points on the ceilings also introduces another major issue – interference! If the APs are configured correctly, then this will introduce Co-Channel Interference.

This is because the racking doesn’t quite go to ceiling height, so all the APs can usually see one another. Not good. If they aren’t configured correctly then you’ll get adjacent channel interference - the worst type. So, you create interference & still don’t get the best coverage patterns possible.

 

3: Default settings for Access Points

So, you have a WLAN controller – great. But, what does the controller know, and what can it do? Well, if your initial design is good and you’ve given it some decent parameters to work within, then it can really help your WiFi network run a lot smoother.

But, if your design isn’t optimal & you’ve left everything on the default settings, well – it’s up against it.

Let’s use the Access Points on the ceiling design as an example. All the APs can see each other, so the controller turns down the transmit power to try and lessen interference. But what happens to the coverage on the ground at this point? Yep, you guessed it - it suffers..

This is just one of the many possible issues. So, get this right first time and the rest will only ever be minor tweaks.

 

4: Default settings on the handheld devices

Again, leaving the handhelds on the defaults is a recipe for disaster.

Do you know which band they are using? (2.4GHz or 5GHz) Most are set to AUTO. So, know which band you want them to use (5GHz please). But, your 5GHz coverage may not be good enough, so you have to fall-back to using the 2.4GHz band.

Which standard are they using primarily? Is it 802.11a,b,g,n,ac? You want them using at least 80211n, as that’s when the Multipath stopped being an issue and actually worked in your favour.

Do they roam (move from on AP to the next) correctly? Most handhelds let you change the settings here. But, you need to know your exact per Access Point coverage to really do this correctly. This is where a site survey of your WiFi network really comes into its own.

 

5: Multipath

We mentioned Multipath above, and as we said there – before 802.11n, it can be a major issue. This is even more so in warehouse, logistics & manufacturing environments where signals bounce around even more than usual.

Below is a more in-depth explanation of what Multipath is and why you don’t want to become victim to it, taken from the Certified Wireless Network Administrator study guide:

The bottom line is, make sure your handhelds are 802.n capable and are actually not falling back to 802.11a,b,g standards.

 

6: Incorrect number of Access Points

Not enough – well, this speaks for itself. You get coverage gaps. Or, you don’t have the APs in the correct locations – so it appears as if you don’t have enough.

Too many Access Points – this usually happens when you think you don’t have enough APs, so you just keep adding more in the locations you’re seeing issues. But, this often cause other issues – interference & consequently a poor Signal to Noise Ratio (SnR), which causes handheld devices to dropout.

 

7: Differing Stock Levels & Type

This shouldn’t cause any issues if you’ve designed your WiFi Network correctly, because this would have been taken into account.

But if you haven’t, then you can experience major coverage & interference problems affecting performance.

So, try to get it right during the WiFi site survey and design phase.

If you have an existing WiFi network that is underperforming and would like to know more about how we can help, or discuss a project, then

Please get in touch.

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