Designing of cell coverage in light fidelity

The trend of communication has changed and the internet user demands to have higher data rate and secure communication link. Wireless-Fidelity (Wi-Fi) that uses radio waves for communication has been used as an internet access methodology for many years. Now a new concept of wireless communication is introduced that uses visible light for communication and is known as the Light-Fidelity (Li-Fi). Li-Fi attracted the researchers for its vast advantages over Wi-Fi. Wi- Fi is now an integral part of everyday life. In near future, due to scarcity of spectrum, it would be quite difficult to accommodate new users in limited spectrum of Wi-Fi. To overcome this, Li-Fi is a good option because of its infinite spectrum range, as it uses the visible range of the spectrum. Many researchers discussed that Li-Fi is secure when compared to Wi-Fi. But is it really secure enough? Can anybody access hotspot of Li-Fi? Or is there a need to develop a technique that is used to block the unauthorized access? In this research work, a cellular concept is introduced for the Li-Fi usage in order to increase the security. This research presents a flexible and adjustable cell structure that enhances the security of Li-Fi. The coverage area is shown by utilizing the geometrical structure of the cone and the area of the cone can be controlled. A mechanical system is also installed on the roof to control the coverage area of a Li-Fi by moving LED bulb slightly up and down. A mathematical expression for the proposed coverage area of the cell is provided, which is formed on the ground level by a beam of light originating from the source of light. The adjustable and controlled structure provides security benefits to the owner. Finally, the research is backed by its simulation in Matlab

Building energy metering and environmental monitoring - A state-of-the-art review and directions for future research

Buildings are responsible for 40% of global energy use and contribute towards 30% of the total CO2 emissions. The drive to reduce energy consumption and associated greenhouse gas emissions from buildings has acted as a catalyst in the increasing installation of meters and sensors for monitoring energy use and indoor environmental conditions in buildings. This paper reviews the state-of-the-art in building energy metering and environmental monitoring, including their social, economic, environmental and legislative drivers. The integration of meters and sensors with existing building energy management systems (BEMS) is critically appraised, especially with regard to communication technologies and protocols such as ModBus, M-Bus, Ethernet, Cellular, ZigBee, WiFi and BACnet. Findings suggest that energy metering is covered in existing policies and regulations in only a handful of countries. Most of the legislations and policies on energy metering in Europe are in response to the Energy Performance of Buildings Directive (EPBD), 2002/91/EC. However, recent developments in policy are pointing towards more stringent metering requirements in future, moving away from voluntary to mandatory compliance. With regards to metering equipment, significant developments have been made in the recent past on miniaturisation, accuracy, robustness, data storage, ability to connect using multiple communication protocols, and the integration with BEMS and the Cloud – resulting in a range of available solutions, selection of which can be challenging. Developments in communication technologies, in particular in low-power wireless such as ZigBee and Bluetooth LE (BLE), are enabling cost-effective machine to machine (M2M) and internet of things (IoT) implementation of sensor networks. Privacy and data protection, however, remain a concern for data aggregators and end-users. The standardization of network protocols and device functionalities remains an active area of research and development, especially due to the prevalence of many protocols in the BEMS industry. Available solutions often lack interoperability between hardware and software systems, resulting in vendor lock-in. The paper provides a comprehensive understanding of available technologies for energy metering and environmental monitoring; their drivers, advantages and limitations; factors affecting their selection and future directions of research and development – for use a reference, as well as for generating further interest in this expanding research area