## 4 Wired HAN  
At present, there are many traditional and non-traditional transmission infrastructures such as telephone lines, electronic wiring, unshielded twisted pairs, coaxial cables, and optical fibers. A widely adopted power line communications technology named HomePlug uses the already available home electricity wiring infrastructure to communicate; it is mainly used for high-speed wired communication applications (e.g., multi-stream entertainment networking) and has a developed set of standards [54]. Ethernet is a family of computer networking technologies for LANs and metropolitan area networks (MANs). It is a common and widely adopted technology that offers a vast range of data rates (10 Mbps-1 Gbps) or optical fibres (as high as 10 Gbps) [55]. This technology uses a shared interface present in various parts of household equipment, such as printers, laptops, game consoles, servers, and audio-video (AV) equipment. Ethernet might not be the best option for connecting all the equipment and devices in the HAN (especially appliances) as a result of the power requirements and high cost, but perhaps the most important issue is with the need for separate wiring back to a central point. X10 is an international and open industry standard that utilizes power line cabling for signalling and control of home devices in which the signals include brief radio frequency (RF) bursts of digital information. Yet, it suffers from some issues such as incompatibility with installed wiring and appliances, limited functionality, interference, excessive attenuation of signals between the two live conductors, slow speeds, lack of encryption, and frequent loss of commands [54]. Administered by the KNX Association, KNX is a standardized (EN 50090, EN 50090) OSI-based network communications protocol designed for smart buildings. KNX is the improved replacement and enhanced version of three previous standards: BatiBUS, the European Home Systems Protocol (EHS) and the European Installation Bus (EIB or Instabus). All KNX installation devices are linked together by a dual wire bus--the most usual form of installation, consequently permitting them to exchange data [56]. The individual bus devices function is established by their project planning and can be adapted and modified at any time. KNX allows three bus topologies: line, star and tree, and can be mixed when needed, but it doesn't allow ring topologies. The tree topology has advantages over remaining ones in certain cases when a large network is required [57]. KNX contains a wireless physical layer (PHY) called KNX-RF and along with home automation networks, the basic PHY technology of KNX-RF is also utilized for the transmission of metering information between smart meters in Europe [58]. Other development by KNX Association is KNX IP--the name of the IP protocol when it is utilised as a pure KNX communication medium. Thus, KNX IP devices communicate with each other exclusively via KNX IP [59]. My companies have been involved in development of a system that integrates powerline products with the already-established KNX system configuration. Thus, through powerline gateway it is possible for the system to receive and send information, events and commands to and from the electrical bus [60,61]. Insteon it defines a mesh topology composed of RF and power line links and it addresses X10 limitations while maintaining backward compatibility with X10. Insteon is a solution specifically developed for home automation and its devices can be power-line only or RF-only, or can support both forms of communication. All Insteon devices are peers, signifying that each device can transmit, receive, and repeat any message of the Insteon protocol, without requiring a routing software or master controller [49]. Local Operating Networks (LON, LonWorks) is a sensor/control networking technology that covers a wide range of applications.