WISP Network Insight: The Impact of One Subscriber on an Entire Sector’s QoE

by | June 27, 2017 | Networking

How One Subscriber Can Impact an Entire WISP Network

In a typical WISP network, you have a number of towers with sectors pointing in different directions. These transmit data to subscribers in the direction each sector faces. Individual sectors can serve anywhere from a few subscribers to hundreds.

An important step during installation is testing for signal strength between the sector and the customer’s location. Signal strength can vary depending on the distance and whether there are any obstructions (e.g. trees, buildings) in the path.

Poor signal strength for an individual subscriber or radio means higher latency and packet loss, and lower bandwidth throughput. In other words, the weaker the signal strength for an individual subscriber, the worse the quality of experience (QoE). That got us to wondering. Is there any impact from one subscriber with a poor signal on the other subscribers on that sector?

A Real-World Example with Preseem

Working with a Preseem customer from Washington with over 3,000 subscribers, we were able to test this theory.

WISP Network bandwidth usage example

Preseem snapshot from a real WISP network (client identity and IP addresses hidden), highlighting the impact of one subscriber’s bandwidth usage and high latency on the entire sector’s QoE.

Looking at the image above, specifically between midnight to 1 a.m., we can see that overall bandwidth (downstream bit rate) dropped. Overall latency, however, during the same time range went through the roof (over 200ms). By investigating individual IP addresses, we see that the address ending “.13” shows peculiar behavior and consistently high latency.

Example of high latency on a WISP network

Out of the 10Mb/s total bandwidth on the sector, this customer consumed the most at over 8Mb/s. Also, our customer confirmed that this IP address is located in a zone with poor signal strength and that the subscriber has a high bandwidth plan. Given all this information, we can see that, during that hour, this subscriber single-handedly increased latency for all customers in the same sector. This resulted in poor QoE for everyone.

“One subscriber with poor signal strength and heavy usage of a larger data plan can significantly impact QoE for all other users in the same sector on a WISP network tower.”

What Can WISPs Do About This?

Considering the options we have during signal testing (pre-deployment), you have to ask yourself a question. Do you take this customer on, given that poor QoE for others on the sector will lead to unhappy customers? A similar question arises when a new obstruction causes an existing subscriber to have a poor signal. What can be done?

The potential solutions are:

  • Don’t accept them as a customer
  • Place them on another sector with a different radio frequency
  • Limit their impact by placing them on a lower bandwidth tier

To find out if you have any subscribers reducing QoE for others on the same sector, book a demo with us and we’ll get you started on a 30-day free trial.

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