“iBeacon” or “BLE Tag”? Clearing up some terms.
In a recent webinar we did together with Bluetooth SIG (get the slides here — sign up for our next webinar on our roadmap here) an important question came up: why do we call some things “Beacons” and other “Tags” even though they are both powered by Bluetooth Low Energy?
That is a good question!
Let’s have a look at the where these words come from.
From the Oxford Dictionary:
A beacon is “a light or other visible object serving as a signal, warning, or guide at sea, on an airfield, etc.”
Notice that the beacon is stationary while the planes and boats move. How does the plane know where it is? It knows the location of the beacon and can thereby determine its own location and figure out whether it will run into a cliff or hit the landing strip head on.
Now — what’s a tag?
Again, the Oxford Dictionary:
A tag is “a label attached to someone or something for the purpose of identification or to give other information.”
In the context of location, how would you know where a tag is?
Well, first imagine a tag that sends out a message in regular intervals. Next, a fixed device receives the message. Now, if you know that this fixed device is in a room and hears the message of the tag… well, then you also know where the tag is.
Gateway, Reader or Receiver — what are their roles?
All these devices basically perform the same function. First, they listen to messages sent from the tag. In other words, they’re “reading” or “receiving” the messages. This requires these devices to speak the same language as the tag. For example, passive or active RFID, Infrared, Bluetooth or WiFi.
Now, it’s nice that the Gateway, Reader or Receiver knows when they receive the message from a tag. But, if you need to stand next to the device in order to figure out which tag is being heard, the entire system would be pretty pointless.
That is where function number two comes into play: relaying the information received to the internet. This is where the word “Gateway” comes from though it usually applies to Readers and Receivers as well.
To sum up: step one — listen to devices; step two — relay that information to the internet or a local server.
Now, because we know where the Reader, Receiver or Gateway is and we can deduce which tag is closest to the Reader, Receiver or Gateway. Because the Reader, Receiver or Gateway is connected to the internet, we can now use this data however we like.
Are they “beacons” or “tags”?
Technically, a beacon is a device broadcasting a message using Bluetooth Low Energy. The name “beacon” originates from Apple who launched the “iBeacon” protocol.
These devices were intended to act as, well, “beacons” providing context to mobile phones. Apple is pretty good at marketing, so the name stuck. Otherwise they might as well have been called “Eddystones” after Google’s protocol.
When the beacon is fixed and the receiver (the mobile phone) is mobile, then the term is appropriate. Typical applications are for example indoor navigation where the beacons guide the user via the mobile phone.
Disruption, Disruption, Disruption
Importantly, there is nothing inherent in Bluetooth Low Energy that requires a fixed device. In fact, the opposite is true: because of the low power consumption, good range and ability to transmit sensor, data Bluetooth Low Energy lends itself to usage a tag.
Attached to an item or a person coupled with a Gateway, Bluetooth Low Energy tags can provide critical information about the location, temperature, and possible acceleration of the underlying asset.
In fact, this is why Bluetooth Low Energy tags will be truly disruptive in IoT. For the full theory, check out my article: Bluetooth Low Energy and RFID: Applying Disruption Theory.