The short-range wireless connectivity landscape continues to evolve at a rapid pace. Technologies such as Bluetooth®, Wi-Fi, and Ultra-wideband (UWB), which were once focused predominantly on sending and receiving data between devices, are becoming increasingly multi-functional. Most recently, with the introduction of Bluetooth® Channel Sounding, Bluetooth technology has added secure, fine-ranging capabilities to its suite of positioning features to enable true distance awareness.
Bluetooth® Channel Sounding helps support a wide range of use cases that take advantage of highly accurate and secure device positioning, encompassing personal item tracking and digital keys to a whole host of use cases that can benefit from knowing the precise distance between two different Bluetooth® devices. With the massive ecosystem of Bluetooth devices on the market, and the potential for nearly any Bluetooth device to now be accurately located as part of a Find My network, these improvements can help enable a significant acceleration of true distance awareness for connected devices in the years to come.
Bluetooth® Channel Sounding and UWB
There are several wireless technologies on the market that can provide distance measurement capabilities. Each has its own unique benefits and tradeoffs in terms of accuracy, power consumption, latency, range, scalability, ease of deployment, ecosystem enablement, and cost, among many others. The centimeter-level accuracy, ubiquitous availability of Bluetooth smartphones and platform devices, lower chipset costs, lower power consumption, reduced design complexity, and the avoidance of an additional radio could prove compelling enough to leverage standalone Bluetooth® Channel Sounding as an alternative to UWB fine ranging across many distance measurements use cases.
In some application segments, Bluetooth® Channel Sounding will compete with UWB, and in others, they will work directly together to enhance the overall positioning performance. However, it is important to note that different use cases for secure ranging will have different requirements.
While some applications may require UWB’s higher level of precision, for many, this will be overkill, and some OEMs may not be able to justify the cost and complexity of embedding an additional UWB radio onto their device for this sole purpose. For example, if we take the personal tracker use case, there may be little benefit in knowing whether an item is millimeters away versus tens of centimeters or even one meter away, depending on the size of the item. Therefore, some developers may choose to develop a Bluetooth® Channel Sounding solution that provides strong enough performance, strong interoperability, and reduced cost and power consumption, while others may opt for a higher-performance solution with the tradeoff of additional cost and greater power consumption.
In phone-as-key access-control applications, knowing that the user is in sub-meter-level proximity should typically be sufficient for locking and unlocking a door. Today, there are many Bluetooth LE door locks already on the market that leverage the installed base of Bluetooth LE mobile devices for automatic unlocking on approach. Bluetooth® Channel Sounding can provide enhanced security and better user experiences over RSSI by opening only when the user is in closer proximity while avoiding the cost of an additional UWB radio.
Similarly, when tracking a limited number of high-value assets that are within a warehouse, hospital, campus, or industrial environment, distances of between one and five meters can often be sufficient to locate an item efficiently. However, if the item is smaller, such as a tool, having the additional centimeter-level capabilities of Bluetooth® Channel Sounding can be beneficial.