## 2 Background  
The growth of IoT has been exponential in recent years, with the number of connected devices expected to reach 75.44 billion by 2025, according to a report by Statista [12]. As a result, there has been a proliferation of devices that use different wireless communication technologies to communicate with each other. Some of the most widely used wireless interfaces in IoT include Z-Wave, ZigBee, Wi-Fi, 4G-LTE, and IR. Z-Wave is a wireless communication protocol specifically designed for home automation that operates in the 800-900 MHz frequency range and has a range of up to 100 m [13]. ZigBee, on the other hand, is a low-power wireless communication protocol that uses the IEEE 802.15.4 standard and is designed for low data rate applications, with a range of up to 70 m [2]. It provides a mesh network that supports a wide range of applications, including home automation, lighting control, and remote sensing. Wi-Fi is a ubiquitous wireless communication protocol that operates on the 2.4 GHz and 5 GHz frequency bands and has a range of up to 100 m [14]. Additionally, 4G-LTE is a mobile communication protocol that operates on the cellular network and has a range of several kilometers [15]. Finally, IR is a wireless communication technology that uses infrared radiation to transmit signals and has a range of up to 10 m.  
Infrared (IR) is a line-of-sight wireless communication technology that uses infrared light to transmit signals. It is extensively used in consumer electronics, such as televisions and remote-control devices. Furthermore, various sensors are also used in IoT applications. Motion sensors detect changes in movement and are used in security and home automation applications. Temperature sensors measure the environment temperature and are used in HVAC and weather monitoring applications. Luminance sensors measure brightness and are used in lighting control and energy management applications. Humidity sensors measure the moisture content in the air for environmental monitoring and control applications. Vibration sensors measure mechanical vibrations for machinery monitoring and maintenance applications. UV sensors measure ultraviolet light levels for environmental monitoring and control applications. Energy sensors measure the energy consumption of devices in energy management applications. Switch sensors are used to control the state of devices and are widely used in home automation applications. In addition to the individual applications of various sensors, many IoT applications utilize a combination of sensors through the use of sensor fusion techniques. Sensor fusion is the process of combining data from multiple sensors to improve accuracy and provide a more comprehensive view of the environment being monitored. Examples of established IoT applications of sensor fusion include smart occupancy detection [16], smart healthcare [17], and smart transportation [18]. These applications demonstrate the benefits of combining multiple sensor inputs and the potential for more advanced IoT systems. The use of multiple wireless communication technologies in IoT devices poses challenges for interoperability and integration. Therefore, the need for testbeds that can handle the diversity of IoT devices and communication technologies has become increasingly important. Testbeds provide a controlled environment for testing and evaluating IoT systems, enabling researchers and developers to identify and address issues related to interoperability, security and reliability. This paper presents an IoT testbed that integrates different wireless interfaces and sensors in an open architecture using the openHAB platform. The open architecture of the testbed is essential to enable the integration of different wireless interfaces and sensors, which are often proprietary and use different communication protocols. By using an open platform like openHAB, the testbed can accommodate a wide range of devices and protocols, and facilitate the development of new IoT applications and services.