This chapter introduces some of the new and emerging wireless communications technologies. We also discuss some of the new wireless technologies that are expected to materialize in the future due to demand from end users, and therefore advances in research into new technologies. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay5G5G (also known as fifth generation wireless systems, or beyond 4G, or beyond mobile communication technologies beyond 2020) is one of the upcoming buzzwords for the world of mobile communication of the future. It can be seen as a user-centric network, as opposed to the operator-centric approach seen in 3G and the service-centric approach in 4G. 5G is not yet detailed in any particular specification in any official document from any telecommunications standards body. However, 5G terminals are expected to be software-defined radios capable of using access to several wireless networks simultaneously. It is expected that they will be able to download and incorporate new modulation and error control schemes into use, and should also be able to stitch together different data streams from different technologies (so-called multimodal MTs). The network will be the party responsible for managing user mobility, while MT will make the final choice between different wireless network providers for a given service. Furthermore, larger wireless spectrum allocations, highly directional beamforming antennas on both MT and BS, longer battery life, lower probability of network outage, much higher bit rates in larger portions of the wireless coverage area, lower infrastructure costs and greater aggregate capacity for many concurrent users in both licensed and unlicensed spectrum (Wi-Fi and cellular) are expected from 5G in a paper by Li et al. (2009). The article also predicts that 5G backbone networks will transition from copper and fiber to millimeter wave wireless connections. In the article by Tombaz, Västberg and Zander (2011) the authors analyzed the design limitations for future very high capacity wireless access systems, as well as their impact on the overall system architecture. Traditional mobile systems have been limited primarily by available bandwidth, but moving forward, high-capacity data systems will be increasingly constrained by energy and infrastructure costs. Some fundamental assumptions and expectations for future wireless infrastructures can be summarized as:It is not only the energy cost, but also the total cost of the access network, that is strongly influenced by the number of network BSs. If the energy cost is high, the total cost will be minimized for dense BS implementations. In high-density scenarios, the idle power of BSs and backhaul will increase as a significant factor. The cost of energy is also highly dependent on the amount of spectrum available. Significant savings in both energy and infrastructure costs can be achieved if more spectrums are made available. Optimizing MT power consumption is vital in current devices and will remain a key factor in the future as well, as As battery technologies improve very slowly compared to the evolution of other technologies or MTs that use the Internet to a large extent, improvements in Web caching techniques can also bring significant energy savings due to the decrease in the need for network access. An alternative solution to relying on BSs for Internet access is to use.