Part 1. Tech Overview

During the last couple of years, new indoor navigation technologies have started popping up at an ever-increasing pace. Different technologies, standards, manufacturers and brand names get you easily mixed up and confused. To help you navigate through the sea of technologies on offer, we compiled this summary of the major and most popular players in the field.

GPS positioning – Overview

GPS, Global Positioning System, is a navigation system based on GPS satellites in the space. GPS is created and maintained by the USA. A similar system is upkept by Russia under the term “GLONASS” and by China under “Beidou”, and is being deployed by the European Union, known as “Galileo”.

Accuracy: 1-15m
Requirement: GPS/A-GPS chip on the device, GPS turned on (user-controlled)
Availability: Nearly all smartphones (iPhones 3G onwards, all android phones), limited on tablet devices
External hardware required: No
Usability: Outdoors

GPS positioning - Details

GPS positioning functions anywhere in the world, where there is an unobstructed line of sight to four or more GPS satellites. GPS functions poorly indoors, as construction materials weaken the signals and cause reflections. Mobile phones typically feature Assisted GPS, A-GPS. In A-GPS systems, the information from satellites is derived by using network resources, such as mobile network (also known as assistant servers), which significantly decreases the time it takes to get the initial position fix. In addition to outdoor locations, GPS works surprisingly well in indoor locations in wooden buildings in loosely built areas.

Get more info about GPS: https://en.wikipedia.org/wiki/Global_Positioning_System

Wi-Fi positioning – Overview

Wi-Fi positioning takes advantage of the wide availability of wireless access points in urban areas. It is based on measuring the received signal strength from nearby access points. Identifying information of these access points (such as SSID and the MAC address) is compared with a database of known Wi-Fi hotspots and their locations, in order to determine the current location.

There’s systems available from companies like Cisco, who also offer options for calculating the users mobile device position based on WiFi scanning.

Accuracy: 5m – 150m
Requirement: Wi-Fi/ 802.11a/b/g wireless chip on the device, Wi-Fi turned on (user-controlled)
Availability: Nearly all Android smartphones & tablet devices, limited but functional iOS support
External hardware required: WiFi access points at the venue in hand
Usability: Outdoors and indoors, urban areas only

WiFi positioning - Details

Android Location Services periodically checks on your location using GPS, Cell-ID, and WiFi. When your Android phone performs this check, it will send back nearby WiFi access point SSID and MAC address information. Other companies like Apple use similar methods.

Get more info about WiFi positioning: https://en.wikipedia.org/wiki/Wi-Fi_positioning_system

BLE beacons – Overview

Beacons are tiny computer devices with a powerful processor, memory, Bluetooth Smart module, and sometimes temperature and motion sensors. Powered by a coin battery (some plug-in models also exist), they broadcast radio signals through built-in antennas. Beacons transfer signals utilizing Bluetooth Low Energy, BLE, also known as Bluetooth 4.0 or Bluetooth Smart, which is significantly more power efficient than traditional Bluetooth.

iBeacon specification from Apple and Eddystone specification from Google are currently the leading options. Proximi.io supports both specs. There’s also some proprietary specifications available from various vendors.

Accuracy: Recognizes location on three zones: immediate (0-0,5m), near (0,5-2m), far (2-20m), our SDK’s also enable trilateration instead of zones when there’s more than 1 beacon available
Requirement: Bluetooth 4.0 chip on the device, Bluetooth turned on (user-controlled)
Availability: Newest smartphones and tablet devices, such as iPhone 4 onwards, iPad 3 onwards, HTC One series, Samsung Galaxy series, Sony Xperia series. For a full list, see: http://www.bluetooth.com/Pages/Bluetooth-Smart-Devices-List.aspx .
External hardware required: Yes
Usability: Mainly indoors, some weather-proof beacons exist also for outdoors

BLE beacons - Overall operation

Overall Operation

Battery-operating beacons have a typical life span of 2 years. Navigation with beacons is based on the fact that each beacon is identified by unique data transmitted by them, and has a known location in a database.  Beacon broadcast their data for up to 20 metres.

BLE beacons enable Bluetooth-equipped devices to perform different actions when they’re in proximity; however, they don’t really function alone. In case you don’t use any kind of platform, you need to hard-code the interactions within your application or build your own backend. This is where Proximi.io really shines and takes out the complexity of building your own systems.

Get more info about BLE beacons: https://en.wikipedia.org/wiki/Bluetooth_low_energy_beacons

BLE beacons - Hardware

BLE beacon hardware

There’s a large variety of different vendors offering beacon hardware. Usually a beacon consist of a coin battery, a circuit board with integrated chips and also some kind of housing to enclose all the components.

Here’s a list of the most common beacon vendors:

VendorForm factor(s) ProtocolsRetail priceWebsite
Kontakt.ioStand-alone, USB (Beta)iBeacon, EddystoneStarting from $20 a piece (USB)https://kontakt.io
EstimoteStand-alone, stickersiBeacon, Eddystone, PropriotaryStarting from $19 a piece (stickers available for a cheaper price)http://estimote.com/
SensoroStand-alone, USBiBeacon, EddystoneStarting from $15.99 a piece (USB)http://www.sensoro.com/
Radius NetworksStand-alone, key-chain, USBiBeacon, EddystoneStarting from $10 a piece (DOT model)http://www.radiusnetworks.com/
GimbalStand-alone, key-chain, USBiBeacon, Eddystone, propriotaryStarting from $5 a piece (key-chain)https://www.gimbal.com

We’ll update the list as we go so in case you want to have your company listed in here, please drop us a line.

BLE beacons - Protocols

BLE beacon protocols

At the moment there’s two communication protocols leading the way; iBeacon is a Bluetooth 4.0 communication protocol designed by Apple and Eddystone is an open Bluetooth 4.0 protocol from Google.

iBeacon

Beacon standard developed by Apple, released in 2013. iBeacon beacons broadcast tiny packets of data, containing their iBeacon ID and information about the signal strength, so that the mobile device can understand which beacon it hears and how far it is.

iBeacon protocol is officially supported only by iOS, but Proximi.io SDK includes our own implementation of the iBeacon protocol support for Android.

Every iBeacon ID is 20 bytes long and consistst of three sections:

  • UUID (16 bytes)
  • major number (2 bytes)
  • minor number (2 bytes)

Those values are hierarchical. Apple has some recommendations on how to use these values in deployments overall (i.e. common major for a retail chain, individual minor per single store). When you use Proximi.io, you can choose to follow their guidelines or use any of the conventions that fit the best for your deployment.

Eddystone

Open beacon specification developed by Google, released in 2015. It describes several different frame types that may be used individually or in combinations to create beacons that can be used for a variety of applications.

Proximi.io SDK’s include Eddystone support for iOS and Android.

The advertising packet is naturally different when compared to the iBeacon protocol; instead of just one frame Eddystone is designed to support multiple frame types. At the moment there’s four kind of frame types:

  • Eddystone-UID
  • Eddystone-EID
  • Eddystone-TLM
  • Eddystone-URL

Eddystone UID functions in a similar manner as the iBeacon UUID.

Eddystone-EID is designed to give developers control over which clients can make use of their beacon signals. The beacon identifier changes pseudo-randomly in such a way that it can only be resolved to stable information by a resolution service that shares an encryption key with the beacon. Without access to the resolution service, the beacon identifier is of little use.

The TLM format transmits sensor-drived data, currently battery status and device’s temperature.

The URL format allows the beacon to transmit website addresses that can be automatically opened by a browser, without requiring the user to have downloaded a specific app. Currently the only browser that supports this is the iOS version of Chrome.

You check out the most up-to-date descriptions from the Eddystone GitHub repository:

IndoorAtlas – Overview

Geomagnetic navigation has become synonymous with IndoorAtlas, a Finnish IT company that has developed a way to utilize Earth’s geomagnetic variation for indoor navigation. The variation is especially strong indoors in steel and concrete buildings, with each square metre featuring a unique geomagnetic fingerprint. In order to utilize IndoorAtlas, you need to first record the geomagnetic fields in the premise using your own smartphone (for mapping, Android devices are recommended). Using IndoorAtlas with Proximi.io requires you to sign up an account at http://www.indooratlas.com.

Accuracy: under 3m
Requirement: accelerometer, gyroscope and compass
Availability: newest smartphones and tablet devices, such as iPhone 4 onwards, iPad 2 onwards, some HTC One models, Samsung Galaxy S III onwards, some Sony Xperia models.
External hardware required: No
Usability: Indoors (buildings with steel or concrete infrastructure)

About Mika Koskiola

Chief Technology Officer at Proximi.io