Beacons or stickers for running race timing?

Hello all - Really just exploring the possibilities here. I’m an avid runner, and race timing solutions currently use RFID and a lot of proprietary hardware. I envision a reverse model from many of the use cases I’ve seen. I see each runner in a race having a beacon or sticker on them, perhaps attached to an ankle strap, and several points along the course having a tablet or other app running that will detect when beacons comes in to range, and display the runner’s location on the course and current speed as measured by the accelerometer. Running races and events have surged in popularity in recent years, and while the largest events offer near-real-time tracking, there are no solutions for smaller events.

A couple of questions I have. I didn’t see the dimensions of Beacons anywhere; size and weight would be a consideration. It’s clear that stickers are smaller, but in order to determine which would be the better option, I would love to know the size of each.

While it isn’t a major concern, I would worry a bit about a person being able to interfere with or broadcast an invalid UUID. I understand these values aren’t currently secured, but can anyone think of a way to mitigate this risk?

I’m curious to hear any feedback you might have before I take the plunge and put together a proof of concept.

Did some measuring and photos for you to get a visual grasp on the size difference:

Stickers would probably be better. On the other hand, stickers have a battery an order of magnitude smaller than that of a beacon, and for most accurate timing you’d need to set it to very high advertising frequency and transmit power, to make sure the packets don’t get lost on the way to the detector (and also taking into account that the running will only be in range of the detector for a short amount of time). So in order to extend the battery life, you’d need to be setting it to these aggressive settings only for the duration of the races, otherwise it’ll run out of juice in a few weeks.

Awesome! Thanks so much for the input. Stickers it is. Traditionally with these types of events, they are timed via an RFID chip handed out by the race timing service, and collected afterwards. So using the stickers, the event would need to change the settings when handing the sticker to the runner, and set them to the most conservative mode when the sticker is returned to maximize battery life.

One other question I would have is how many simultaneous beacons an app could theoretically track at any time. I can envision an event where several hundred runners are within range of an app at once. Since the app would be running on a known piece of hardware, I could control for whether it is active or backgrounded, and would have control over all other settings. When I get further along I could start to test this limit, but if anyone has evaluated the maximums already I would be interested to know. All of this would have to go into a business plan if I get to the point of putting one together.

The limit usually depends on the capabilities of the receiving device. For example, new iPhones have no trouble processing ~150, up to ~200 Bluetooth devices in range at a time. For older devices, with slower processors, it’s usually less. What device do you envision using as a scanner?

Since I would have control over the device I was envisioning a tablet perhaps to start. If the service is successful and gets in to larger events, it would make sense to use a purpose-built device. Everything I’m envisioning is currently handled by RFID scanners, so I have to believe it’s possible to reimplement everything with beacons. The benefit of doing so is that the hardware/software stack for RFID scanners is old, and getting that data to the Internet is quite difficult. Beacons by contrast are exactly the opposite. With the right coverage map it would be possible to “broadcast” a running race in real time on Google Maps using the accelerometer data in the beacons and the GPS coordinates from the receiving device. This opens up a whole new revenue model for these types of events if they can charge for access, or supplement with advertising.


Did you make any progress with this as I am looking to do the same and create an event timing application with stickers?

Hi Neil - I never did get anything implemented around this unfortunately. I did speak with a friend who runs a race timing company and he felt that the issue you would encounter with this type of signal is accuracy of start and end time. Current race timing platforms use a very directed receiver that creates a sort of virtual tape to record when the sensor crosses a very specific point. Beacon antennas are omnidirectional, so in order to get ±0.01-second accuracy for start and finish, you would need to build a custom piece of hardware to capture start and end. It would be very possible to use this tech as a supplement however, to capture more waypoints along the race course (since they don’t have to be as accurate). This way you could provide a more spectator-friendly event, and maybe even ‘live stream’ a race by plotting all the participants along an online map and updating their progress in real time.