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Comment by nl | Hacker News Reader

Oh, because ANT+ lets you connect to multiple devices simultaneously. BTLE doesn't let you do that, and it's a pretty big problem.

For example, if you do triathlons ANT+ lets you use a 910XT for the swim & run, and an Edge 500 for the ride without having to re-pair the devices.

This isn't just a theoretical problem: according to a very recent DCRainmaker survey[1] 29% of people use this exact scenario[2].

iOS is bit issue of course, but there are ANT+ dongles and BTLE->ANT+ retransmitters (in the form of a heart rate monitor band). It's worth noting that the Stages power meter does do the dual BTLE and ANT+ transmission thing.

I think ANT+ is going to hang around a lot longer than people think, especially in the field above casual fitness.

[1] http://www.dcrainmaker.com/2013/09/curiositysurvey-different...

[2] http://www.dcrainmaker.com/2013/10/symposium-keynote-present...

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Bluetooth LE uses a client/server (called "central" / "peripheral") model; think of "server" like "web server", typically the client is your smartphone.

I could believe that a single peripheral can't simultaneously connect to multiple centrals (I'm just getting started with BTLE), but the typical pattern is for e.g. the heart rate sensor and smartwatch to both be peripherals of a smartphone.

The first article you reference says: So for folks that may use one device for cycling and another for running, this could cause issues if both devices tried to connect to the heart rate strap at the same time.

As long as you're not cycling and running at the same time, this isn't an issue.

I'm pretty heavily in this field (both as a user and occasional developer). I understand the models pretty well, and BTLE has this wrong, because of their smartphone-centric view of the world.

For casual fitness stuff they can get away with that, but as you get more hard-core it breaks down pretty quickly. After all, Garmin has built a multi-billion dollar business building devices that where a smartphone can handle 90% of the functionality. For that extra 10% you still need an extra device, and that extra 10% is often the rich, passionate end of the market.

Some specific examples:

In a triathlon you are unlikely to take your watch off after the swim when you get on your bike. The HR strap will remain paired to the watch and not your bike display (and given than the swim->bike transition and bike->run transition are often in different locations taking it off isn't realistic either).

People use gym equipment with built in ANT+ displays, but want to record their workouts on their personal devices.

These are both big markets (Garmin/Timex/Sunto/Polar all have specific devices just for them) and BTLE doesn't work in these scenarios.

I wish it did, and I hope they will fix it.

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