The most common complaint we hear from users is “we have warehouse dead spots”. This can range from “we have a dead zone in the back” to “there are dead spots all over the warehouse”. Often, attempts to correct the “warehouse dead spots” have been taken by adding access points, but the problem persists (or gets worse!).
It is true, “Coverage is critical”. Because without good signal, communication may take longer (due to slower data rates), experience retries (from missed or corrupt packets), cause congestion (due to the retires), and result in poor performance. If the signal itself is weak, the solution is likely to improve the quality of the signal (by adding access points, increasing power, doing both, or even possibly making other configuration adjustments).
Ironically, the coverage is often good, and still there are connectivity issues. Adding access points in this situation usually makes the problem worse. You can have too much of a good thing (coverage). Because of the polite nature of WiFi (listen first, then talk) too many access points and their associated communication overhead are likely to cause interference (on adjacent channels) or contention of the medium (same channel), resulting in connectivity problems. However, to users this looks like poor coverage; a dead zone!
So, what is the cure for dreaded warehouse dead spots?
Diagnostics that determine the root cause!
When facing dead zone issues at home, moving the router or getting a booster might be interesting experiments, but in a commercial setting with mission critical work at stake, this shotgun approach can frustrate users, waste time, and even negatively affect productivity.
There are many utilities and apps that can aid in diagnosing the issue(s), with the best (Ekahau, AirMagnet) costing thousands of dollars. Some apps area available for no (or minimal cost). Another option is to hire an expert and have a comprehensive site survey performed. Some access point manufacturers suggest preventative surveys on an annual basis, which can be very cost effective if connectivity issues are costing overtime hours.
Using the tools mentioned above, diagnostics should take less than a day – in most cases. Some of the most common issues we have uncovered during site surveys include:
- Interference from non WiFi devices (especially in the 2.4GHz frequency)
- Adjacent channel interference (a neighboring WiFi device set to an interfering channel)
- Airspace Contention (WiFi devices on the same channel too close together)
- Unauthorized use of WiFi (check the guest or visitor SSID for heavy usage)
- ISP congestion issues (neighbors are competing for the pipe)
- Server utilization (certain times of the day the server CPU is at 100%)
- A large print job (consuming network resources)
- Low powered (weak transmissions from) client devices (iPad, iPhone)
- An area of low signal!
The next time users complain of warehouse dead spots, take the time to do a proper diagnosis before purchasing and installing more access points. A well-tuned and balanced WiFi system will support many users, enhancing productivity and saving labor costs.
Keep in mind that WiFi uses a limited resource / medium, the RF spectrum, to transmit data. This half-duplex medium only allows one user at a time. More APs in the same area “eat up” and “compete for” that limited resource.
Should I add access points?
Filling in the coverage hole will correct for low signal. The challenge, however, is that connectivity issues may exist due to co-channel interference, not necessarily low / weak signal. Adding additional access points without careful configuration consideration may increase co-channel contention and cause more problems!
Email email@example.com or visit us at HEARTLAND-USA.COM for an expert evaluation of your network today!