Have you considered a wireless site survey to determine the best possible coverage and speeds? Let's look at why this is a critical step for any enterprise deployment involving
cellular routers and wireless connectivity, as well as some important tips for success.
Cellular network connectivity has become ubiquitous and powers much of the IoT world today. Cellular carriers have optimized data plans to be able to provide customers with the best rates, with protection from overages, and leveraging private networks to secure those devices. It’s almost certain that a cellular device customer has contracted with a particular cellular carrier to provide coverage for all of their devices, across hundreds or thousands of locations. But what happens when that carrier isn’t the most optimal carrier at every location? This is where a wireless site survey can help.
Because of most people’s experience with personal cell phones, and the ubiquity of cellular coverage, we have all had experience trying to get coverage in various locations. In other words, you may actually be informally doing a wireless site survey in your personal life, whether you've moved around a store or an outdoor space looking for the best connection to load a website or video, check your grocery list on your phone from the back of the store, or send a text from somewhere inside a venue - perhaps even knowing that if you can switch to another carrier network you'll be able to connect.
In the enterprise space, it's the job of an IT team to handle these concerns, with questions like:
- How can dozens of employees all use the same cellular connection at the same time?
- Will the performance of the network be able to support that need when it needs to scale?
- Where should cellular routers be located within a store to provide the stocking team with connectivity for their tablets to perform their inventory work?
But, can't they just go around the building with their cell phones to find the best connection? Let's explore.
Why Do I Need a Wireless Site Survey?
Cellular connectivity is a wireless technology, which means it uses radio frequency to send data communications. There are a number of factors that play a part in how well the device's cellular connectivity will perform:
- Interference
- Broadcasting power
- Which radio frequencies are being used
- Which frequencies the antennas installed on the devices can listen to
- How radio waves propagate through the air
- How materials can block or weaken that signal
Additionally, cellular carriers have varying functionality, range, and locations where their networks function optimally. Let's look at three key terms that help to understand how things work behind the scenes:
- Reference Signal Received Power (RSRP): RSRP is how “loud” the signal is
- Reference Signal Received Quality (RSRQ): RSRQ is how “clear” the signal is
- Signal to Noise Ratio (SNR): SNR is how much other “noise” there is in the area
All of these affect whether one carrier is better than another in a given area. A carrier whose network operates in a higher frequency of RF range is more impacted by things like concrete, rebar, and even modern windows. Lower frequency RF ranges penetrate through those things more easily.
As various carriers have bought up licensing rights from the FCC for RF ranges, the same carrier may not operate on the same frequency across the entire country, or potentially across a single area of a country. All of these items combined will affect the throughput (speed) on a given carrier at any location. A wireless site survey can help determine the best carrier for the area.
How Digi Professional Services Can Help
Digi’s Professional Services team has worked with hundreds of Digi customers, and has frequently encountered situations where one carrier has better performance than another carrier due to various reasons, including location of cell towers, available frequency bands and their varying abilities to penetrate buildings, as well as available power outlets, antenna placement and locations.
Case Study: A Wireless Site Survey Saves the Day
In one use case, Digi Professional Services recently worked with a national retail provider who had a critical security event taking down their primary wired network, and our team was contacted to provide a Digi cellular solution to get their locations back up and running. A particular cellular carrier was selected, SIM cards installed, devices delivered to stores, devices installed by store managers and most stores were up and running and had a decent experience with the network connectivity provided.
However, there were several locations with suboptimal performance. Digi’s Professional Services team was deployed to go onsite and perform wireless site surveys with multiple carrier options. The team then selected the carrier that was receiving the best network performance and installed that carrier’s SIM card into the device. The team also assisted in helping relocate devices for more optimal cellular coverage and helped to align antenna placement to receive the best signal possible. After the team’s visits, those locations with suboptimal performance were running on a different cellular carriers’ network than previously, but now with optimal performance to allow the employees at that location to get their work done.
What Should I Consider for Optimal Cellular Connectivity?
Here are some tips and tricks learned by the Professional Services team over the years that may prove useful to you.
- Coverage maps: Carrier network coverage maps have a lot of useful data, but until you have a device at a location, it’s impossible to know what local impacts you may experience from things like building materials.
- Antenna selection: Most Digi devices do come with a default set of antennas, but it may be possible that those antennas are not the greatest fit for the location. Things like directional antennas or mounting external antennas with long leads to connect to the device are options to have in one’s bag of tools. Contact us if you need guidance.
- Carrier comparison: Verify the carrier performance, and check contracts with more than a single cellular carrier and have SIM cards from them all on hand, in case one carrier does prove to provide better performance than another.
- Network performance tools: Have an easy way to run network performance testing to compare the results between different carriers.
- Battery-operated devices for site selection: Use a device with a battery powered option, so you can walk around a location with the device to find the most optimal location, before connecting power to a wall outlet can greatly assist the speed in finding the most optimal location.
- Antenna installation: Always connect the maximum number of antennas supported by the cellular device.
Armed with these tips, it is easier to ensure that your cellular device installation goes smoothly and that your device will have the most optimal possible performance. However, getting installation teams trained and familiar with these aspects may not be easy. Digi’s Professional Services team offers services for performing site-surveys, on site troubleshooting and training options to assist you in any way possible to ensure that you have the greatest success with Digi International’s cellular devices.
If you need any of these services, reach out to Digi’s Professional Services team at professional.services@digi.com and request a quote today!
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