Home Networking at 60 GHz (2014)

The revolution of Information Technology in our lives has started by changing the way we work and continued with the way we entertain, communicate, interact, learn and so on. The wave of digital change has long been at the doorstep of the home to revolutionize our living experience. The initial attempts to get inside with early home automation systems could not be very successful. Their complexity and price tags for the value they offered were not acceptable for the majority of households. The key was the wireless network connectivity that opened the door to change with the convenience of accessing data by any device from anywhere in the home. This convenience has fueled the proliferation of connected devices in the home and made Wi-Fi the preferred technology for home networking. The high bandwidth and QoS demand of advanced multimedia application is challenging the capacity of today's Wi-Fi networks, which is already constrained by the growing number of connected devices and interference of adjacent wireless networks. The potential of improvements on the network capacity is limited by the scarce resources in the conventional frequency bands of unlicensed spectrum. This thesis focused on 60 GHz radio technology to realize multi-gigabit wireless connectivity in home networks since it has a 5 GHz block of globally available bandwidth in the license-free spectrum. The substantial bandwidth comes with a price: heavy attenuation. Radio waves in the 60 GHz band can hardly penetrate through building walls, furniture and human bodies. Therefore, this thesis investigated 60 GHz technology for point-to-point communications in a single room and left the inter-room 60 GHz connectivity to researchers working on Radio-over-Fiber technology. We first characterized the 60 GHz channels in a typical living room environment and generated performance figures with physical layer simulations for several antenna configurations. The results clearly showed the critical importance of directional antennas for 60 GHz communications. In the next stage of the study, we evaluated the reliability of using reflections in maintaining 60 GHz link connectivity when the line-of-sight path is blocked. A large set of 3D ray tracing simulations with various human shadowing and different environment models were performed. Showing that reflections cannot provide fully reliable solution to link blockage, this thesis proposed the use of relaying to improve the quality and robustness of 60 GHz links in the home network. The performance of multiple relaying strategies and configurations was analyzed through analytical and ray tracing studies. The effective application of relaying depends on timely discovery of the neighbors in the network. To shorten the neighbor discovery time with directional antennas in a 60 GHz network, we proposed the Smart Neighbor Discovery strategy that utilizes the location information of the nodes. The inadequacy of current wireless technologies is not the only challenge facing the digital home. Heterogeneity has emerged as a prominent characteristic of the digital home with the increasing number and variety of applications, services and communication technologies supported by the connected devices. The lack of interoperability among these heterogeneous entities has given rise to virtual walls in the digital home by fragmenting it into isolated islands of technologies. This fragmentation in the digital home environment increases the complexity and cost of systems, services and applications while limiting the innovation and user adoption. We approached the fragmentation in the digital home environment at three tiers and proposed Three-tier Integration Model. In the first tier, we focused on the fragmentation in the home networking technologies and proposed the concept of HomeBox, which is a dedicated device with multiple network interfaces. HomeBox is envisioned to provide (I) an open computing platform where the user can deploy applications and services, (II) a communication gateway to bridge devices using different networking technologies, and (III) a coordinator and relaying node that can improve the connectivity of 60 GHz and other wireless technologies. In the second tier, we addressed the fragmentation in the application and service domain and proposed the concept of ADIOSS, which is a conceptual interoperability framework that uses semantic RESTful web services to integrate applications and services. In the third tier, we defined the fragmentation in the market level and proposed the concept of ApS House, which is a digital market place to distribute the applications and services to the home. The main objective of all the concepts in Three-Tier Integration Model is to simplify the application and service lifecycle from development to deployment and usage in the digital home environment. To conclude, we characterize the future digital home as a computing and networking platform that can seamlessly integrate applications and services and interconnect all types of network-enabled devices in On-and-Play fashion with required QoS guarantees. This thesis argues that 60 GHz wireless technology and the proposed Three-tier Integration Model can lower the barriers between this future vision and the current state of the digital home.