Like all major technological advancements, Bluetooth has evolved to become much more than was initially planned, both in terms of features and sheer numbers of Bluetooth compatible devices. The specification has gone through a number of revisions to accommodate growing requirements in the fast-paced world of Internet of Things (IoT) development:
Which Version is Right for Me?
From 4.0 to 5 we have seen a steady advance in the capabilities and scalability of this tech.
For Bluetooth developers who want to provide more wide-ranging connectivity in their designs, Version 4.2, later built upon by Bluetooth 5, offers two ways to do so, dependent on whether connecting over existing IPv4 systems or moving on to next-generation IPv6 networks.
Internet Protocol Support Profile. The addition of the Low Power Wireless Personal Area Networks (6LoWPAN) specification to the Internet Engineering Task Force (IETF) IPv6 standard means that the number of addresses available for the IoT will be all but inexhaustible. In addition, every wirelessly connected thing will have its own unique address, enabling it to be connected to the Internet directly without going through an intervening gateway or server.
Bluetooth Smart Internet Gateways via GATT. In the future, all Internet access will be via IPv6. Currently, however, with the exception of most wireless phone vendors and some of the major Internet service providers, the majority of ISPs still use older IPv4 protocols. So developers have two choices: either make use of the IPv6 access available on mobile platforms such as Android to access other external 6LoBTLE connections, or find an alternative means that can work over the older IPv4 systems.
In Version 4.2’s Smart Internet Gateways, Internet connections are no longer performed on a sensor-by-sensor or app-by-app basis. With this new capability, mapping GATT to Internet HTTP connections is largely straight-forward and standardized across all sensor accesses to services and data. Using Bluetooth GATT capabilities such as the HTTP Proxy Service (HPS) and RESTful APIs will further facilitate the connectivity of Bluetooth Smart devices with the Internet.
With the release of Bluetooth 5, we see a transformative update that increases wireless range and allows for broader more flexible capabilities without the loss of energy or security advances from Bluetooth 4.2. Bluetooth 5 is also updated to help prevent potential interference from other wireless technologies ensuring that Bluetooth devices coexist within the global IoT environment like never before.
Bluetooth Mesh. A new topology released recently, Bluetooth Mesh allows for advances in communication over previous Bluetooth LE topologies. Mesh is based off a flooding network, meaning that each individual node can send messages out in a web pattern whereas previous topologies relied on a star point to point pattern that utilized a single node broadcasting outwards.
Mesh provides downward compatibility with devices that support GATT this includes all Bluetooth versions after 4.0. However, Bluetooth 5 has unique features that optimize it for usage with the mesh network. One such feature, advertising packet, has the device submit a transmission in an address free packet. This improves privacy and reduces power consumption by transmitting fewer bites. A second feature of Bluetooth 5 related to Mesh is that it allows for multiple sets of data to be advertised concurrently. This means concurrent advertising can be set up for both proxy nodes and relay nodes.
Bluetooth mesh is a fascinating addition to the IoT and it ensures that older versions remain a viable option while being optimized for usage with Bluetooth 5. For more knowledge on Bluetooth Mesh here.
Enhancing Bluetooth Privacy and Security
For most of the time Bluetooth has been available to build wireless IoT systems, an ongoing effort has been made to continually improve the security and privacy of transmitted data. The introduction of advertising packets in Bluetooth 5 coupled with two upgrades introduced in Version 4.2, LE Secure Connections and LE Privacy, have helped to make Bluetooth a safer and more reliable component of the IoT.
LE Secure Connections. Until now, the fundamental building block of Bluetooth security has been Secure Simple Pairing, where device connections are made only after the generation and distribution of several encryption keys: one short-term key (STK) and three long-term keys for link layer encryption and authentication (LTK), connection signature resolution (CSRK) and identity resolution (IRK).
Bluetooth 4.2 offers developers heavy duty, industrial-strength security. For key management, it adds asymmetric Elliptic Curve Cryptography (ECC) with FIPS-recommended elliptic curves. It also uses FIPS’s approved AES-CCM cryptography for message encryption. The result is strengthened link-layer security between neighboring devices that protects wireless links against such things as passive eavesdropping, and in some cases, Man-in-the-Middle (MITM) attacks.
LE Privacy. Version 4.0 Bluetooth has supported frequent changing of device private addresses to limit the ability of hackers to track devices over time and extract useful information. To enable a Bluetooth device to establish a connection, private addresses are generated using the identify resolution key (IRK) shared during the device bonding process.
Bluetooth 4.2 adds LE Privacy, which manages private address resolution in controller devices as well as in a host device, and also supports white-listing of private addresses at the controller level. In addition to ensuring greater privacy, this reduces the frequency of waking up the host device, thus reducing overall power consumption.
Other power management enhancements. Version 4.2 featured an increase in maximum transmit power modes for BLE Power Class 1 from +10 to +20 dB. This allows many Bluetooth designs to be implemented without the need for an external power adapter, which can offer both cost as well as board space savings to end users.
Bluetooth 5 moves Bluetooth low energy a step closer to becoming the foundation for IoT technology, by lowering energy while providing faster speeds, effortless connectivity and powerful security derived from Bluetooth 4.2. Bandwidth can be decreased to achieve up to 4x the range while keeping power requirements down. This range can be tuned to the designer’s specifications allowing for a wide range of power saving applications.
Higher Performance/Greater range
In Version 4.2, Bluetooth packet capacity was increased by almost 10 times compared with the Bluetooth 4.1 (from 27 bytes to 251 bytes). Bluetooth 5 has increased this broadcasting message capacity 800% from Bluetooth 4.1. The major boost in broadcast messaging capacity will further propel the deployment of beacons and effortless location and navigational services for home automation, industrial and retail markets through robust and reliable connections. Bluetooth 5’s advances in beacon and location capabilities are staggering for the IoT when you consider that more than 371 million Bluetooth enabled beacons are projected to ship by 2020.
These advances allow for smart city infrastructure development, emergency response applications, smarter airport navigation all of which are being boosted by Bluetooth 5’s capability to send custom information unhindered by connection or application barriers.
In addition, data range in Bluetooth 5 has quadrupled from Bluetooth 4.2. Longer range allows for whole-house coverage for smart home applications including lighting, door locks and security systems. Improved data range also advances mesh networks allowing for improved stability and reduction in network congestion by complementing or preplacing current ad hoc scatternet configurations.
Bluetooth 5 has made a significant boost in data speed, from 1 Mbps to 2Mbps. Doubling speed provides faster data transfers while optimizing responsiveness and lowering latency, for the everyday user and critical situations of security and medical devices.
Bluetooth 5 has made device-to-device communications as well as connections over the Internet more efficient, and allows for more frequent firmware updates and faster uploads of sensor data logs to a smartphone, the cloud or some intermediate location on an ISP provider's servers or routers.
The Future is here: Bluetooth 5
Bluetooth 5 is revolutionizing the IoT experience by addressing the issues surrounding range and download speeds to produce simple and effortless interactions between connected devices. Bluetooth 5 produces IoT solutions that allow flexibility in range, speed and security for a variety of environments and end products. Through increased speed and range, Bluetooth 5 lays the groundwork for Bluetooth audio and more connected homes, buildings and outdoor realities.
Bluetooth 5 is estimated to sell 13.9 billion products by 2020. 1 in every 3 wireless products that ships in 2020 will include Bluetooth technology. 2 of every 3 consumers already prefers Bluetooth technology in their personal devices.
Because the Internet of Things is growing rapidly and expanding to a size and into applications not even conceived of a few years ago, developers can expect continuing enhancements and extensions to Bluetooth and other wireless protocols at even greater frequency. So far, Bluetooth 5 has set the standard in speed, range, data and wireless coexistence for the IoT.