Going to Great Lengths With the Imp and WiFi

July/23/13

WiFi performance is incredibly important to us because it is one of the cornerstones of the Electric Imp connectivity solution. It is so important, in fact, that prior to releasing the first imp last year, we spent hundreds of hours tuning the antenna to ensure the best possible performance.

For us, WiFi performance is analogous to the way a car fanatic treats an automobile. If you’re into your car and spend lots of time tuning it, at some point you want to take it out to run the quarter mile.

To that end, we recently put the Imp WiFi range to the ultimate test, and are excited to share the results with you.

In the early days of Electric Imp, a successful imp WiFi test meant walking out of our office and maintaining a signal all the way to the auto parts store next door, a distance of about 91 meters (300 feet) - quite a milestone back then. More recently, at an Electric Imp hackathon we achieved a WiFi range just shy of 121 meters (400 feet) before running out of room - but still had enough margin to believe we could do even better.

Fast forward to the field trip we ventured out on in May.

Bounded by hills to the west and urban density to the east, the first challenge was finding an uninterrupted and lightly trafficked straight stretch of road for a long range test near our office in Los Altos, California. Like the car fanatic looking for someplace to run the quarter mile, we spent hours searching Google Earth and driving around to scout sites. We finally found an ideal location just north in Redwood City.

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On one end of the road, we set up a enterprise grade WiFi router with built-in LTE Internet connection. Our test device used a solder-down Imp module (imp002) running off of 4 AA batteries. Then, armed with a smartphone to collect GPS and signal strength data, we began walking and walking… and walking… until we could no longer see the access point through the heat haze. Finally, at an astonishing 790 meters (2,591 feet), nearly half a mile, the signal finally dropped.

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Most people think of WiFi range in terms of the size of their homes. So, to achieve almost a half mile of range, we were extremely pleased - and incredibly proud - by what we accomplished. Based on our hackathon results, we thought we would attain 340 meters (1000 feet) at the maximum, but clearly exceeded that by some distance. This test demonstrated that the Imp can perform at an extremely wide range and that the Electric Imp WiFi solution is more than up to the task of providing reliable connectivity.

As you can see, distance matters - to us and, presumably, to you too - which is why we spend as much time as possible testing and optimizing the performance of the Imp so it consistently delivers what you’re asking it to do.

Brandon Harris
Senior Systems Engineer