Bluetooth Versions And Profiles
The SIG is continually modifying and updating the Bluetooth specification to keep up with demand and new technologies. Early access to these updated specifications, extended to the two top tiers of SIG members, can make a large difference in the time-to-market of consumer devices, and therefore long-term profits and market positioning of a company.
For consumers, upgrades to the Bluetooth standard introduce many benefits—greater security, more functionality (as with the enhanced data rate addition, and then the Bluetooth Low Energy specification for wearables), improved power consumption and paring reliability. All versions are backwards compatible, and the flagship features of each version are considered optional.
Bluetooth 1.x was plagued with a number of implementation and security problems, and is now obsolete. Bluetooth 2.x opened the gates to mass adoption of the standard, improved interoperability, and quick-pairing, and it introduced the Enhanced Data Rate capability. Bluetooth 3.x tacked on a High Speed feature by adding support for a lower layer link protocol where all Bluetooth capabilities could be run from an alternate radio in the device, like Wi-Fi. Finally, Bluetooth 4.x introduced Low Energy support for devices like wearables and smart sensors with very low data overhead.
A Bluetooth profile is a set of pre-determined capabilities and a customized stack, determined by the type of operation intended. Profiles make it much easier to design for, implement and manage the very wide variety of Bluetooth operations needed for an application. For example, a car with Bluetooth capability would most commonly only implement the Hands Free Profile, containing a very customized protocol stack, but not implement the Serial Port Profile. Meanwhile, a sensor used for laboratory measurements would only implement the Serial Port Profile for collecting data, but would completely ignore the Audio/Video Remote Control Profile.
As of this writing, there are more than 33 profiles listed in the latest Bluetooth specification, and it allows for the addition of many more—as many as required for each new application class that may emerge in the coming years.
Certain profiles are usually implemented by all Bluetooth devices. For example, the Generic Access Profile (GAP) forms the basis of all other profiles and determines how two Bluetooth devices establish a connection. Other profiles are more specific, for example the Health Thermometer Profile (HTP) that facilities protocols for medical device data exchange.
Profile and device-specific APIs are a key element of many Bluetooth profiles, and implement the customized methods by which the protocol layers may interact.