iBeacons — Why all the buzz about a 2000 year old technology?

The best known ancient lighthouse is the Pharos of Alexandria, which safely guided ships into the busy harbour more than two millennia ago. The history of the modern lighthouse began around three hundred years ago, with the Eddystone. Improved light sources and optics gave better reliablity and range. And a feature we see in the iBeacon was introduced: The transmission of a code that could uniquely identify the lighthouse from afar.

Lighthouses became increasingly valuable to maritime navigation, and consequently increasingly common. They served a ‘proximity’ role in long distance navigation — coasters could tell how far along the coast they were (but not their precise position) by identifying the coded flashes of a nearby lighthouse. In the same way ships sailing ‘blind’ at night were alerted to nearby maritime hazards.

So far the comparison is clear. iBeacons transmit a coded advertisement that uniquely identifies them. Nearby smartphones can pick up that ‘ping’ and so know that a particular beacon is nearby.

But lighthouses have a further trick up their sleeve. The sensor receiving their optical ‘ping’ is the human eye, which is very good at determing the angle of arrival of the signal, ie. the direction the light is coming from. This can be used to triangulate an absolute position from a number of lighthouses. However iBeacons are Bluetooth beacons, and the smartphone that senses their presence has no way of detecting angles or direction. iBeacons are limited to signaling that the rocks are nearby, but not their direction, leaving them looking a decidedly limited technology.

During the late 20th century lighthouse numbers around the world have fallen. The only obvious reason is that global positioning provided by GPS has become more accurate, more reliable, and more economical. If we can plot a vessel’s exact position on an electronic chart, that’s all we need to know to navigate. The lighthouse becomes superfluous.

So why haven’t lighthouses disappeared completely? The answer is simply that GPS isn’t considered reliable enough. It can be degraded or switched off by the state that operates it. It can easily be jammed over relatively large areas. And in such cases lighthouses would still prove invaluable for ships at sea.

Will lighthouses therefore be with us forever? Definitely not. In the near future many parts of the UK’s coastal waters will have a reliable, complementary back-up to GPS in eLoran. This isn’t a beacon system like lighthouses or iBeacons. It’s a fully-fledged ground-based PNT (positioning, navigation, timing) solution that does what GPS does, but on a local basis, using ground-based radio frequency transmitters. Once this is available, we’ll know with accuracy and reliability exactly where a vessel is. And at that point we don’t need lighthouses.

The corresponding story for iBeacons goes like this. If we know with accuracy and reliablity exactly where a smartphone is, we don’t need iBeacons. At the moment that’s not the case. All smartphones have GPS, but that doesn’t work in urban canyons. And of course it doesn’t work indoors. And it’s not particularly energy-efficient. Lighthouses will have lasted a little over 2300 years before they’re finally redundant. How long will iBeacon’s last?

Galileo, Europe’s answer to GPS, is set to come on stream at the beginning of 2015. Galileo promises better accuracy than GPS, and crucially promises better penetration into buildings for indoor use. When used in combination with GPS and GLONASS, it will provide better reliability through redundancy. It’s sensible to think smartphone manufacturers will quickly integrate Galileo receivers.

eLoran may soon reach a tipping point and become useful for land based positioning and navigation. At which point smartphone manufacturers may look at integrating eLoran receivers.

Other land-based solutions that offer true PNT on a local basis are also becoming available. For instance Locata are trialling their technology on a wider and wider scale, potentially giving smarphones accurate absolute position indoors, over kilometer scale areas.

This may all happen within 5 years. At which point, just like lighthouses, we won’t need iBeacons.

From the invention of the lighthouse, it took very nearly 2000 years to reach mass adoption. And then another 300 years for new technologies to fully eclipse their capabilities. From the announcement of the iBeacon protocol, it may be just 5 years until new technologies render them obsolete. Investing in lighthouses in the early 18th century would have been a good idea. Banking on iBeacons in 2014 may not be such a long term bet.

In the meantime, mass produced bluetooth beacons serve a purpose. Crowd Connected is using signal strengths from iBeacons to determine accurate absolute positions of smartphones in environments where GPS isn’t available, or isn’t accurate enough. Their patent pending system and algorithms are producing GPS-like accuracy from beacon observations alone. But once accurate time-of-arrival measurement is possible (the secret of GPS, eLoran, and Locata type technologies), they won’t be using iBeacons. And nor will you…