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BlueHoc, a new project on developerWorks Open Source Zone, provides a simulated Bluetooth environment to allow developers to design applications operating over radio, baseband, and other communication layers.
Back in July, IBM set the ball rolling for Bluetooth development on Linux, by releasing the BlueDrekar protocol stack for Linux, and open-sourcing a driver for the HCI UART transport layer. Now developers have access to BlueHoc, another tool which will help them bring Bluetooth application designs to fruition. The software simulates (1) the lower layers (including radio, baseband, and link layer) of the Bluetooth specification, and (2) an ad-hoc indoor wireless environment consisting of several Bluetooth devices. BlueHoc will thus allow developers to design and test applications in a realistic network environment.
The Bluetooth standard is a short-range wireless communication industry specification that allows portable, personal devices to interact which each other and with other stationary devices. It primarily serves as a replacement for peripheral cables and other short-range wireless technologies like the infrared data access standard (IrDA). However, unlike IrDA, this technology uses the spread-spectrum radio frequency, and therefore supports omnidirectional multiple connections without requiring communicating devices to be in the line of sight.
The BlueHoc simulator presents a software environment consisting of one master Bluetooth device and up to seven devices connected to the hub. The key features include:
The inquiry and paging procedures, which are used for device discovery and connection establishment
Quality of service negotiation at the link level
The physical transport layer and indoor wireless channel
Probable uses of the tool, according to BlueHoc developer Apurva Kumar, include studying the feasibility and performance of various TCP/IP based applications over Bluetooth, studying device discovery and connection establishment delays in Bluetooth, and investigating medium access scheduling (MAC) policies for Bluetooth.
The C++ based simulator has an OTcl interface for configuring the simulator, and a Tk based graphical user interface designed for ease of use.
Although at present BlueHoc is only a simulator, according to Kumar, at a later stage it may be possible to convert the simulation into an emulation and interface it with a live Bluetooth stack. This would allow developers to run real applications on a simulated Bluetooth wireless link and predict their performance under various ad-hoc networking scenarios.
BlueHoc, which is open source, is based on an open source simulator called network simulator, and uses network simulators TCP/IP libraries to enable performance evaluation of TCP/IP-based applications over Bluetooth. As a simulation, Blue Hoc is an approximation of Bluetooth specifications, rather than a certified implementation.
IBM is hoping the release of BlueHoc and other tools for the development of Bluetooth devices will help Bluetooth to avoid the obsolescence that has overtaken IrDA due, say many, to its slow adoption by devicemakers. Using both BlueDrekar, which is an implementation of the higher Bluetooth communication layers, and BlueHoc, which focuses on the lower hardware communication layers, developers have access to tools to help them design Bluetooth software and hardware applications. As yet, however, BlueHoc and BlueDrekar do not interface with one another.
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Wireless
