Page 519 - From GMS to LTE

Bluetooth and Bluetooth Low Energy 505

is Apple. In their proprietary beacon specification the company defines, among other
things, the content of the user data field that can be embedded in the BLE advertising
frames as follows [28]:
A UUID
●
A major and minor version number
●
Transmit power level of the beacon.
●
Further, on their smartphones, Apple offers an application programming interface that
makes this information available to apps. Based on the UUID, devices can find out if the
beacon or beacons they receive have been deployed for one of the installed apps. As an
example, a public transportation company in a city could deploy beacons with their sin-
gle UUID throughout the city and offer their customers an app than will look for beacon
signals with this UUID. By taking the major and minor version number into account,
which can be individually configured for each beacon, the app can further find out at
which venue or part of a venue the user is currently located. By comparing the received
signal strength with the transmit power level advertised by one or more beacons, an app
can then further approximate an indoor location. Based on the position and the beacon’s
identity an app can also interact with a server on the Internet to get further information,
which is then processed and potentially displayed to the user. As an example, museums
could use beacons and an app on mobile devices to interact with their visitors and give
them more background information about the object they are looking at.
Eddystone is a competing beacon solution by Google that is open source for imple-
menters of beacons and software [29]. In addition Google has integrated an Eddystone
API in the closed‐source part of its Android operating system and offers a library for
iOS devices to make it usable across operating system boundaries. The following
beacon formats have been specified:
Eddystone‐UID: Similar to the iBeacon UUID format. An app recognizing UUIDs is
●
required to use the information conveyed by the beacon.
Eddystone‐URL: A compressed URL of a website that can be used without an app
●
directly in the browser. If an Eddystone‐enabled smartphone receives an Eddystone‐
URL beacon broadcast it can notify the user, and the URL that was broadcast can be
directly opened in the browser.
Eddystone‐TLM: The telemetry beacon format can transmit battery status and diag-
●
nostic data about the beacon itself for maintenance staff. TLM notifications are usu-
ally interleaved with other notifications.
Eddystone‐EID: This format sends an ephemeral (temporary) identifier that changes
●
every few minutes to ensure privacy. Tracking a BLE beacon based on the ID it sends
in its advertisement frames is thus not possible. Only devices and apps that possess
the correct Ephemeral Identity Key (EIK) can decode the message and send it to an
app for further processing. This format is useful, for example, for wearable devices, to
prevent a user’s location from being tracked by passive BLE sniffing devices.

7.7.8 BLE and IPv6 Internet Connectivity
Another facet of the Internet of Things (IoT) is the connection of physical things such
as sensors and actuators to the Internet. As BLE is a power‐efficient short‐range
communication protocol, BLE devices require a higher‐layer or even application‐layer
gateway to become accessible via the Internet. An example of how this can be