Bluetooth®︎ standards & versions
Bluetooth® Classic
- Introduced in Bluetooth® version 1.0
- Bluetooth® Classic versions are backward compatible
- 79 channels with 1MHz bandwidth (2.402 – 2.480 GHz)
- One master, up to 7 slaves
- Time (TDMA) and frequency (FHSS) synchronization done by master
- Slave may send data only if polled by master
- Last enhanced version 3.0. still available but not updated any more
Bluetooth® Low Energy
- Defined from Bluetooth® version 4.0 onwards
- Designed for IoT and battery operated applications
- Bluetooth® LE versions are backward compatible
- 40 channels with 2 MHz bandwidth (2.402 – 2.480 GHz)
- Lower transmitting power
- Mainly short connections (to save battery lifetime)
- Different application roles and profiles: Broadcaster, Observer, Peripheral, Central
Bluetooth® Low Energy
- Generic Attribute Profile (GATT) is a generic “language” between Bluetooth® LE devices
- Custom GATT profiles: Amber SPP-like (Serial Port Profile) e.g. Bidirectional transmission of arbitrary data Bluetooth® Low Energy
- Predefined GATT profilee:
- Battery service profile, e.g.Shares value x in percentage 0% (discharged) - 100% (fully charged)
- Notification service when status changes
- Link loss service: e.g. Alerts after timeout, or link is lost or user alert
Withdrawal: Specifications withdrawn by the Bluetooth® SIG are not maintained and will no longer be available for download on the Bluetooth® public website. Members are not permitted to complete qualifications/declarations for any product using those withdrawn specifications.
If you want to read more find here the whole Product Guide.