IoT networking: Bluetooth and mobile networks: future has multiple nets

IoT networkingMy experience using a consumer IoT tracker device for tracking keyrings shows how IoT networks are constructed
using a combination of Bluetooth, mobile networks and cloud computing networks.  

Bluetooth, a protocol best known for sending audio or keystrokes, is becoming a full-fledged data protocol that offers simplicity while participating in a complex end-to-end IoT system. There are many standards and technologies used for IoT networking.  

In addition to Bluetooth and mobile networks, there are many low-power wide area technologies, such as Narrow-Band IoT (NB-IoT) and Long-Range Wide Area Network (LoRaWAN), and nearby connection alternatives such as NFC or RFID. IoT networking requires a combination of different technologies working in conjunction, depending upon the use case requirements.

An IoT tracking device

I used a Chipolo (Generation 2.5) tracker, but there are similar devices such as Tile or PROTAG Duet. (Note: I received this device as a gift from a third party provider.)

The device is attached to something you don’t want to lose, like a keychain or luggage, and pairs to a smart phone through an app. The app can make the tracker emit a tone to locate it or via geofencing, so if the phone and the device gets too far from each other, it emits an alert on each device. The Android version of the app still has some rough edges but the basic functions work well.

The tracker’s map last known location from the phone’s location services such as GPS is displayed on a web site or the app. The smartphone can be treated as a virtual Chipolo tracking device, so system locates a phones as well as trackers. You can shake the tracker to make a phone ring. (The shake method works without a cell phone or Wi-Fi signal, an alternative to calling a phone or using Find my iPhone/Android Device Manager.)

The last known location is of little use if the tracker location is out of date or if it lost its pairing with a distant phone, but another smart phone running the Chipolo app can participate in the crowd-based network. If I forget a key ring with the tracker in a theater, but it connects someone else with smart phone with a compatible tracking app, the system will notify me where the keys are.

Tracking device & software

This simple device exhibits many characteristics of IoT devices that interface with the physical world. It is a 35 mm by 5 mm disk, uses the Bluetooth Low Energy version 4.0, has replaceable CR2025 button-style batteries with life up to 6 mo., has a range of about 60 m within line of sight, and surprisingly much of their work is done in Slovenia. 

It has 2 sensors: an accelerometer enabling shaking the device to ring phones, and a temperature sensor (it is disabled to save power, but in theory can tell if the device is left outdoors or indoors). 

In comparison, previous generations of baggage locators that weighed more and did not pair to smart phones.

Using a broad network infrastructure

Using this device underscored how IoT works in an ecosystem that uses Bluetooth, mobile networks, and crowd-sourced big data cloud services.

Each component collaborates to deliver the IoT service end-to-end. The tracking device communicates via Bluetooth with the phone acting as an IoT gateway, and the app processes and transmits data through the mobile telecom network to the cloud-based service. The cloud-based service supports a web site to display locations, control the device, share the crowd-sourced tracking data with a network of other Bluetooth connected smart phones.

Supporting the phone’s back-end service is also an GPS system supported by satellites and the cloud-based mapping, similar to Google maps. Launching a similar service without cloud computing and mobile network would have been impractical.

The Bluetooth edge capillary network

The edge of the IoT network are called capillary networks in the same sense of how the circulatory system has arteries, veins and capillaries. It runs many devices limited to low power and long battery life but not needing high bandwidth.

Bluetooth works well in capillary networks because devices do not need to directly connect to the internet and can work with a light network and compute processing. In IoT, a one-size-fits-all view of networking is not needed and the Bluetooth version 4 protocol (Bluetooth Smart) offers choice with:

  1. Low-energy (BLE)
  2. High speed
  3. The classic protocols found in audio headsets

The tracker uses a BLE network at the edge and the app collects the data and transmits it via a mobile network acting as a smartphone IP gateway, or through a conventional Wi-Fi internet gateway.

IoT can use other capillary networks. Devices can construct a peer to peer BLE mesh network, similar to ZigBee, and reduce the number of gateways. Bluetooth 4.2 has added Internet protocol support, enabling use of HTTP directly to a Bluetooth device. Running IP on an IoT make not be for small device trackers, it may work for smart home devices such as thermostats or industrial sensors.

Bluetooth was invented by Ericsson in 1994, a pioneer in mobile communications, and the initial use was for a “personal area network” and found use in for headsets, computer keyboards, mouse and speakers, but IoT will lead to its further adoption since it finds more use cases. 

Early Bluetooth devices were cumbersome, but has improved as it evolved.  Although the protocol originated from a mobile telecom firm, IoT has given both the protocol and telecom firms new growth areas. Bluetooth version 5 has evolved to serve IoT, and telecom companies like Ericsson have focused more attention on IoT, as mobile networks serves as the backbone of IoT networks.

By using Bluetooth to connect to the ubiquitous smart phone, IoT devices like a tracker becomes part of the environment and less of a computer peripheral. This indicates that similar integration may occur in factories, smart homes, or farms.

These IoT systems exhibit an odd dichotomy of simplicity in use, supported by complex back-end systems. Simplicity is derived from the sophistication of the networks and systems that makes it simple to use. Even a simple tracker need complex global mobile network and a cloud computing system, since it shares many characteristics of full-fledged IoT systems.  

There are many technologies striving to address IoT use cases. Bluetooth and mobile are two well-known ones, but there are emerging long-range networks that attempt to bypass local area networking technologies and connect directly the the edge devices. But I hope these examples illustrate how the elements may work together.

In the earlier example, Bluetooth is ideal since smart phones usually have Bluetooth and they act as the gateway to the mobile or local Wi-Fi networks. Thermostats or factory sensors, on the other hand, may have different requirements.

However, as we put more functionality into IoT devices, we also need to be vigilant about its security implications.

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Topics: Internet of Things Networking Enterprise Mobility