China
Africa
Explore chapters and articles related to this topic
Dynamic Network Selection in Wireless LAN/MAN Heterogeneous Networks
Published in Yan Zhang, Hsiao-Hwa Chen, Mobile Wimax, 2007
Olga Ormond, Gabriel-Miro Muntean, John Murphy
The wireless landscape is changing. Influencing factors include deregulation, convergence of the Internet and telecommunications, and continuous evolution of network technologies and terminal capabilities. In home and office settings, wireless broadband networks are a popular alternative to wired networks, because of the ease, speed, and cost-effectiveness with which they can be deployed. At the same time, spoiled by high bandwidth applications, users are becoming more technologically proficient and expect more services at higher quality levels on their wireless devices. The new focus is on users and providing them with quality access to a wide range of services. Offering a positive user experience is central to the success of future wireless networks. The resulting setting is envisioned to be a service-oriented heterogeneous wireless network environment (SOHWNE), as illustrated in Figure 11.1.
5G Mobile Wireless Access and Digital Channeling with RF Over Fiber for Long-Haul 64-QAM Communication
Published in IETE Journal of Research, 2023
Mazin Al Noor, Bal S. Virdee, Karim Ouazzane, Dion Mariyanayagam, Harry Benetatos, Svetla Hubenova
5G is the latest mobile technology that brings greater speed, capacity, and functionality to mobile services, opening new opportunities for consumers, businesses, and public services. Currently, 5G is reusing the spectrum that has previously been used to deliver services such as TV broadcasting and wireless broadband. The physical layer of 5G uses orthogonal frequency-division multiplexing (OFDM) with a typical cell radius of up to 5 miles [5]. 5G like its predecessor, i.e. 4G-LTE, offers wireless and fixed access services and can expand broadband services with mobility to areas, where today no fixed broadband access is feasible because of excessive cost [6]. Moreover, it includes attributes of frequency reuse and flexible bandwidth scalability. Both 5G and 4G-LTE base stations require a lot of energy to transmit signals over 5 km. The path-loss of 5G at 3.5 GHz between a base station (BS) antenna of the height of 30 m and subscriber’s handset height of 2 m is ∼165 dB for the transmission around 4900 m; in 4G-LTE systems, this figure is ∼158 dB [7]. This means a cost-effective solution is needed to overcome transmission costs and signal impairment. RFoF precludes the deficiencies inherent in 5G with the potential to increase the bandwidth and data rate, and to improve the spectral efficiency, thus, raising the broadband, speed between users and between users and BS.
A compact CPW-fed wideband slot antenna with reflector for wireless communication
Published in Electromagnetics, 2019
Amrita Gorai, Bappadittya Roy, G.K. Mahanti
The design is simple because the return loss and AR requirements are achieved without any structural complexities. Reflector position and the material of the reflector are analyzed. The presence of aluminum reflector which has a relative permittivity of 1 enhances the property of circular polarization of the antenna. Circular polarization is also achieved through single feed only. This provides a better reflectivity, better signal transmission strength, robust to phasing issues as signals which are circularly polarized are much better at penetrating and deviating around obstructions because of the reflected signal return in the opposite orientation. The antenna with a size of 20 × 25 mm with the metallic aluminum reflector of the same size is presented. A 3-dB axial ratio bandwidth of 1.18 GHz and impedance bandwidth of 10 GHz is achieved. The gain and radiation patterns of the antenna have been presented. Further optimization of the thickness of the substrate and the aspect ratio of the patch may contribute to wider axial ratio bandwidth and gain. The antenna will be suitable for wireless broadband, medical imaging, radar applications, and other portable wireless applications.
Performance analysis of SLTC-D2D handover mechanism in software-defined networks
Published in International Journal of Computers and Applications, 2019
Hima Bindu Valiveti, Trinatha Rao Polipalli
Figure 3 illustrates the D2D communication based on SDN principles when UE1 and UE2 are connected with single eNodeB under the SDN controller. The policy setting, IP flow, and local routing are governed by the SDN controller. Data traffic can be avoided for using EPC, which is situated with the SDN switches. Decentralized SDN and proxy server are performed with managing the mobility and it can be coordinated with the various Radio Access Technologies. It consists of control plane and data plane and the management tools are situated in the MME of the control plane, which manages the users’ mobility aspects. SDN controller manages the switches, which is connected with proxy server, EPC. EPC is a new Mobile Internet Protocol (MIP)-based core network for LTE, which supports a new requirement of networks to produce true wireless broadband Quality of Experience (QoE). It is very important for end-end IP access services, which can perform delivery of service among LTE.