The Internet of Things (IoT) is becoming a household concept, and Bluetooth low energy (BLE) – specifically Bluetooth 5 – is likely to be a key enabling technology. The growing IoT will rely on multiple wireless technologies, with the choice depending on the use case. For connectivity between small, low-power IoT devices, there are two broad scenarios.
Low-power Wide Area Networks (LPWANs)
LPWANs are wide-area networks where network providers supply base station infrastructure covering large geographic areas, such as cities or countries. This includes traditional Mobile Network Operators (MNOs) running networks in licensed bands, as well as new IoT-related technologies such as LTE Cat M1 or Narrowband IoT (NB-IoT). We also see LPWANs such as LoRa, Sigfox and RPMA that run in unlicensed bands and are often set up by other operator types, including private entities or public entities, such as a city.
Low-power Local Area Networks (“LPLANs”)
These local networks can cover one or more buildings and are typically connected to Wide Area Networks through gateways or routers. The gateways might be using an LPWAN technology, or be connected directly to wired internet infrastructure. LPLANs include short-range radio networks such as 802.15.4 (ZigBee, Thread etc.), Wi-Fi and Bluetooth. There are also numerous proprietary wireless technologies in use.
Blending LPLAN and LPWAN
Looking ahead, LPWANs and LPLANs will continue to co-exist to support the IoT. Many use cases will have combinations, where some devices are connected to an LPWAN directly and others to an LPLAN, which is then connected to the WAN via a gateway.
For example, if there are several sensors or devices in a building, it may be unnecessary or undesirable to connect them all to an LPWAN. The devices may need to interact with one another directly, so passing data through a remote server would add complication and latency. In another scenario, the sensors or devices may generate a lot of data, which needs to be aggregated or filtered before being sent to the internet through the WAN.
Bluetooth becomes a network-oriented technology
The initial use cases for Bluetooth BR/EDR and the first generation of BLE focused on connecting a few pieces of equipment to a mobile device. Today’s Bluetooth is opening up new possibilities, while still taking advantage of its current ecosystem of phones, tablets, laptops and the like.
This expansion started when Bluetooth 4.1 enabled transmission of data directly on the link level, which in turn enabled the definition of support for IPv6 over Bluetooth, using 6LoWPAN. While this wasn’t widely adopted, it indicated that Bluetooth was becoming more network-friendly. Bluetooth 4.2 added features that enabled further network-oriented use cases.
Introducing Bluetooth 5
Even more interesting are the features of the recently released Bluetooth 5. This new version of the standard enables a feature toolbox for tailoring the technology to the requirements of various use cases. For instance, should throughput be more important than range, Bluetooth 5 enables a 2 Mbit/s physical layer, compared to the 1 Mbit/s speed of Bluetooth 4.x. On the other hand, if range is more important, Bluetooth 5 can offer up to four times the range of Bluetooth 4.2. The enhanced broadcasting and multi-casting capabilities given by the Advertisement Extension also enable new use cases compared to older versions of Bluetooth.
Bluetooth mesh will also be released soon, enabling several nodes to be available in the same network. This is quite a departure from what earlier Bluetooth versions were aiming for. Mesh also helps increase the range to cover large areas, where older Bluetooth had issues. The first version of Bluetooth mesh is based on Bluetooth 4.0 or later, but not yet Bluetooth 5. However, work is on-going to look at how the new Bluetooth 5 capabilities and other proposed enhancements can make Bluetooth mesh even more efficient. Several current and future Bluetooth 5 features are tailored for improved mesh abilities. This includes ideas on how to enable IPv6 on top of Bluetooth mesh.
With the planned and future developments of Bluetooth, networking capabilities will be greatly improved, making the technology even better for IoT applications.
Bluetooth chipsets push in the same direction
The latest Bluetooth chipset releases are pushing to take advantage of the networking capability improvements. Several chipsets support higher radio output power and better radio sensitivity. These developments, in combination with new longer-range features enabled in the Bluetooth standard, will improve the way the technology can be used in scenarios where long range has previously been an issue.
A perfect blend
The new features added to Bluetooth 4 and 5, the forthcoming mesh capability and new Bluetooth chipsets with better output power and sensitivity will together enable a variety of new IoT applications, where networking capabilities and range are of key importance.