Bluetooth® testing solutions

Bluetooth® testing for ubiquitous connectivity

What is Bluetooth®?

Bluetooth® is a short-range wireless technology that enables data communication in personal area networks (PAN). Bluetooth® communication is organized in so-called piconets, which involve one central device and up to seven peripheral devices.

Bluetooth® applies frequency or phase shift keying (FSK/PSK) modulation on 1 or 2 MHz spaced channels in an adaptive frequency hopping (AFH) scheme that operates in the globally available ISM band at 2.4 GHz.

Initial requirements aimed at a data connection that supports certain protocol stack profiles, such as audio streaming or file exchange, based on the so-called basic rate (BR) of up to 1 Mbit/s in an ad-hoc network. Later, in Bluetooth® 2.0, an enhanced data rate (EDR) of up to 3 Mbit/s was specified.

Following the demands for lower power data communication, the Bluetooth® Special Interest Group (SIG) started adopting Bluetooth® Low Energy (LE) technology in Bluetooth® 4.0. This is typically used in central devices to connect with a wide range of wearables, peripherals and IoT devices.

Bluetooth® Classic and Bluetooth® Low Energy

From a physical layer perspective, both Bluetooth® Classic and LE operate in the 2.4 GHz band and apply frequency hopping. There are, however, a few key differences.

Bluetooth® Classic supports basic rate (BR) and enhanced data rate (EDR) modes, both of which use frequency hopping over 79 channels with 1 MHz spacing from 2402 MHz to 2480 MHz. Each mode uses different packet formats and modulation schemes.

Bluetooth® Low Energy (LE) uses 40 RF channels with 2 MHz spacing and includes three primary advertising channels. Bluetooth® 4.0 introduced 1 Msym/s communication (LE 1M) using Gaussian frequency shift keying (GFSK) modulation. Bluetooth® 5.0 introduced two new options to extend the range (LE Coded) as well as an additional mode for higher data rate communication with a symbol rate of 2 Msym/s (LE 2M).

Bluetooth® use cases

Bluetooth® is the dominating technology for short-range, low-power wireless communication, with more than 5 Bn devices shipped every year. The technology is expanding beyond traditional use cases, such as earphones and fitness trackers, to cover new application spaces:

LE Audio: New audio application with better audio quality, broadcasting capabilities and standardized support of hearing aids
Location Services: Bluetooth® direction finding with upcoming features such as highly-accurate distance measurements (HADM) that enable applications like real-time navigation, asset finding and digital keys
Smart home: Bluetooth® mesh and range extension (LE coded) support applications like smart lighting applications, sensor networks and access control, among others
Massive IoT: LE advertising enhancements and large-scale, low-power Bluetooth® networks enable massive use of electronic shelf labels (ESL) for retail and logistics applications. Moreover, low-cost, energy-harvesting or energized Bluetooth® tags have the potential to make ambient IoT a reality.

Bluetooth® test process

Bluetooth® device testing and qualification

Bluetooth® device testing is governed by:

Regulatory compliance for radio operation in the 2.4 GHz band
Compliance with the Bluetooth® specification as part of the Bluetooth® qualification process

The Bluetooth® qualification is driven by the Bluetooth® SIG with the goal of ensuring interoperability and enforcing compliance with related Bluetooth® specifications. Successful qualification is necessary to get the Bluetooth® intellectual property license as well as to apply for related Bluetooth® trademarks.

Bluetooth® qualification testing categories:

Radio and physical layer conformance
Protocol conformance
Profile interoperability conformance

The Bluetooth® SIG has also specified a test mode and interface that should be used to control the implementation under test (IUT) during compliance testing. For Bluetooth® BR/EDR, a radio-based IUT control is specified. This uses the link management protocol (LMP) to control the IUT over the Bluetooth® radio link.

Bluetooth® LE adopts a different approach with out-of-radio test control and uses a dedicated wired interface that can be either a host control interface (HCI) or a 2-wire UART interface.

Besides these standardized test modes and interfaces, there are other test setups applicable. For example, it is possible to control the device under test (DUT) via vendor specific interfaces. There are also solutions that use parts of the Bluetooth® stack to serve different test applications in the product life cycle.

Bluetooth® test solutions from Rohde & Schwarz

The complete Rohde & Schwarz Bluetooth® test solution portfolio has been approved by the Bluetooth® SIG. Our solutions support Bluetooth® BR/EDR and LE, in-line with the Bluetooth® core specification.

In addition, the R&S®CMW wireless communication tester supports Bluetooth® audio testing, WLAN and other non-cellular and cellular technologies. With our unique Bluetooth® test solutions in signaling mode, we stay at the forefront of innovation, enabling Bluetooth® device testing in both connected and over-the-air (OTA) setups.