Advancements in Bluetooth Technology
The Bluetooth v3.0 standard supports high data rates, while Bluetooth v4.0 incorporates Bluetooth Low Energy (LE) technology, which includes low power consumption in its specifications.New features such as long-range communication and high-precision indoor positioning have been added in Bluetooth v5.0 and later versions.
Bluetooth RF Specifications
The RF specifications of Bluetooth technology are defined as follows.
Bluetooth Technology Protocol Stack
The Bluetooth protocol stack includes various protocols.
The core protocols include the Bluetooth radio, baseband, Link Manager Protocol (LMP), Logical Link Control and Adaptation Protocol (L2CAP), and Service Discovery Protocol (SDP).
The Cable Replacement Protocol includes the Radio Frequency Communication (RFComm) protocol, which is a set of simple transport protocols above the L2CAP protocol, providing up to 60 simultaneous emulated RS-232C serial ports for a single Bluetooth device.This protocol is used directly as an AT command carrier in many telephony-related profiles and also serves as the transport layer for Object Exchange (OBEX) over Bluetooth connections.
The Attribute Protocol (ATT) and Generic Attribute Profile introduced in Bluetooth v4.0 are expected to be used by all low-energy devices.However, note that they can also be used for BR/EDR.
GAP stands for Generic Access Profile.This profile controls Bluetooth connections between devices and determines how to allow interactions between devices using Bluetooth communication and pairing through advertising.Advertising is used to broadcast data via Bluetooth technology to establish connections and transfer data to multiple devices (for example, in the case of Bluetooth beacons).
Bluetooth technology is a packet-based protocol with a central-peripheral structure and a piconet or scatter net architecture.The central connects devices to the network and handles frequency hopping sequences and multiplexing.Bluetooth profiles define the types of data to be transmitted and the services to be used by devices.Standard profiles vary by application, such as smartphones, PC peripherals, audio devices, and wearable terminals.
Any manufacturer wishing to sell Bluetooth products must demonstrate that the product complies with Bluetooth specifications. Testing must be conducted in certified laboratories, including:
The Bluetooth specifications are backward compatible with older versions, and the latest version defines two wireless communication technologies.
BR/EDR and Bluetooth LE have different structures and characteristics.When designing products, one or both technologies can be supported based on application requirements.
Bluetooth Module Testing
Using Anritsu’s MT8852B as an example
Source: Anritsu’s Wireless Connectivity eBook Wireless LAN and Bluetooth Technologies Permeate Our Lives