There is a growing trend towards wireless connectivity today and Bluetooth is the leading medium for paving the way. Bluetooth is a radio based wireless communication technology that was first released in 1999 to replace wired serial communication. The technology has gone through several revisions since then, each time improving on data rate, power consumption, range and robustness. For example, while Bluetooth 1.0 was capable of 1 Mbps transmission rate up to 10 meters range, version 5.2 introduced a flexible data rate. Flexible data rate offers the options to increase range to several hundreds of meters at the cost of data rate reduction, or to increase data rate up to 2 Mbps at the cost of some range reduction.
Among the many differences however, power consumption is probably the most significant one between the earlier versions of Bluetooth (v 1.0 – 3.0) and later versions, called Bluetooth Low Energy (BLE). The former versions are more power hungry and best suited for data-intensive applications that involve exchanging a continuous stream of data at close distance, such as wireless headsets, speakers, printers and large file transfers. On the other hand, BLE utilizes communication by shorter bursts of data with longer or shorter pauses in between. These pauses contribute to power saving and this type of communication is typical to low power sensors often operating on coin cell batteries.
In fact, its low power consumption and suitability with sensors give rise to countless interesting applications. For instance, smart watches and fitness trackers that measure heart rate, movement, temperature, etc, connect via Bluetooth to mobile phones where the measured data is presented to the user in a meaningful way.
Another application is location tracking by smart tags, i.e., small tags that can be attached to wallets, keys, tools, or anything of particular importance. The tag will communicate with a connected mobile phone in order to keep track of the tag’s location. The phone can even give warning in case the tag disappears from the phone’s vicinity.
Bluetooth is especially sought after in medical applications. Such applications typically involve one or more sensors to monitor a patient’s blood pressure, glucose level, EKG or other sensory data. The collected data can be analyzed locally or perhaps forwarded via the Internet where a doctor can monitor the data values.
Benefits of using Bluetooth
BLE is expected to play a huge role in facilitating the Internet of Things (IoT). IoT is a technology where anything can be connected with one another and to the Internet, forming large networks. As the technology expands, it will enable the monitoring and controlling of connected devices from anywhere, by people or by other devices. In a smart home, for instance, one might set some relaxing lighting, convenient temperature, and even put on the right mood of music at home that awaits just the right time before arriving from work.
When it comes to IoT, BLE has several advantages over other wireless protocols. BLE is more energy efficient than Wi-Fi or even ZigBee, which benefits battery powered devices. In comparison with other low power technologies like ZigBee, LoRa or Z-Wave, BLE is also the most widespread one of them as it is present in all modern smartphones. Moreover, as the density of connected devices increases, signal disturbance and interference need to be considered. BLE is the most successful in resisting interference, thus providing the more robust connection in such conditions.
As Bluetooth technology evolves and improves, it gets more and more difficult to decide in advance when or where it absolutely should be avoided. A better approach is to take a case-by-case consideration and test the technology against the specific requirements if possible. BLE has proven itself in applications with requirements for safety, security, range, robustness even in harsh industrial environments, and more.
Om författaren:
Alexandra Hengl, System Developer & Bluetooth Specialist at Avalon Innovation