Much of the work on network protocols for the internet of things revolves around forcing square pegs into round holes (as with LTE). But for the short-hop connections between the ‘things’ themselves, Bluetooth has come into its own, rescued from wireless headsets and moving to center stage. Its standards body, the Bluetooth SIG, is determined to keep it there by making enhancements specifically designed for emerging sectors such as wearables and connected cars.
The next major iteration, Bluetooth 4.1, is due out by the end of this year, and its most important change will be the ability to connect wearables and other ‘things’ to the cloud directly, rather than via a hub. This will allow it to link devices which are outside Bluetooth’s 30-meter range via the cloud, creating wider home networks of gadgets, and potentially freeing wearables from their reliance on smartphones for data transfer. A product such as a smartwatch would be able to upload data directly to cloud services without a handset or other hub.
Bluetooth 4.1 will be able to be implemented in equipment such as routers or set-top boxes, which receive Bluetooth data and redirect it to the cloud via a basic embedded software layer rather than a fully-blown OS. An app in the wearable would specify which cloud service to target. For instance, a health monitor could send its findings directly to a cloud-based app, which could then alert medical staff in certain circumstances.
“It’s not only connecting sensors to phones, tablets or hubs, but in essence talking to infrastructure in bigger ways,” said Suke Jawanda, CMO of the Bluetooth SIG. “The scenarios become interesting for remote monitoring and management.”
The 4.1 specification was finalized in December and has two elements. One, the low energy element, was built on Bluetooth Smart (aka Bluetooth LE) for sensors, and sees the radio transmitting small bursts of data at low power. Release 4.1 improves this with smarter timing and improved battery life, and it can cooperate with LTE to avoid interference on near-band transmissions. The second 4.1 element addresses the protocol’s more established use, for continuous data transfers at faster rates in applications such as audio streaming.
Meanwhile, the SIG is also working on security updates to speed acceptance of Bluetooth Smart in connected cars, where it can be used for purposes such as unlocking doors or adjusting heating levels, replacing the tangle of wires inside a vehicle. To reassure carmakers that they will not be allowing a security weakness into their products, the SIG is responding to their concerns with improved security features, under development by the Core Specification Working Group.
As usual with standards, some chip vendors are leaping ahead of the pack. CSR announced its automotive-qualified BLE chips for controlling car body electronics a year ago, saying ‘we won’t be able to wait for the Bluetooth Special Interest Group to come up with new solutions’ but instead added proprietary modifications to the BLE spec.
Qualcomm’s Joel Linsky, who leads the Core Specification Working Group, told EETimes that ‘BLE offers no eavesdropping protection in key exchange today’ and that heavy duty security features would have ‘overburdened the BLE radio’ in most scenarios, but can be added for specific auto-class products. It’s a dilemma which will be increasingly thorny in the internet of things, as vendors weigh the trade-offs between optimal functionality and increasing the cost and power consumption of devices which are so demanding in those areas.