In recent years, cellular voice networks have transformed into powerful packet-switched access networks for both voice communication and Internet access. Evolving Universal Mobile Telecommunication System (UMTS) networks and first Long Term Evolution (LTE) installations now deliver bandwidths of several megabits per second to individual users, and mobile access to the Internet from handheld devices and notebooks is no longer perceived as slower than a Digital Subscriber Line (DSL) or cable connection. Bandwidth and capacity demands, however, keep rising because of the increasing number of people using the networks and because of bandwidth-intensive applications such as video streaming. Thus, network manufacturers and network operators need to find ways to continuously increase the capacity and performance of their cellular networks while reducing the cost.
标签： BRINGING NETWORKS Beyond and 3G 4G
上传时间： 2020-05-26
上传用户：shancjb
The surge of mobile data traffic forces network operators to cope with capacity shortage. The deployment of small cells in 5G networks is meant to reduce latency, backhaul traffic and increase radio access capacity. In this context, mobile edge computing technology will be used to manage dedicated cache space in the radio access network. Thus, mobile network operators will be able to provision OTT content providers with new caching services to enhance the quality of experience of their customers on the move.
上传时间： 2020-05-26
上传用户：shancjb
Since the telephone was invented in the late nineteenth century, there has been a steady development of telephone services, and the number of subscribers has con- tinuously increased. One of the most revolutionary developments in telephone serv- ice in the late twentieth century was the introduction of the cellular variety of mobile phone services.
标签： Engineering Capacity Systems CDMA
上传时间： 2020-05-26
上传用户：shancjb
Multiple-Input Multiple-Output (MIMO) systems have recently been the subject of intensive consideration in modem wireless communications as they offer the potential of providing high capacity, thus unleashing a wide range of applications in the wireless domain. The main feature of MIMO systems is the use of space-time processing and Space-Time Codes (STCs). Among a variety of STCs, orthogonal Space-Time Block Codes (STBCs) have a much simpler decoding method, compared to other STCs
标签： Orthogonal Space-Time Processing Complex
上传时间： 2020-05-26
上传用户：shancjb
The recent developments in full duplex (FD) commu- nication promise doubling the capacity of cellular networks using self interference cancellation (SIC) techniques. FD small cells with device-to-device (D2D) communication links could achieve the expected capacity of the future cellular networks (5G). In this work, we consider joint scheduling and dynamic power algorithm (DPA) for a single cell FD small cell network with D2D links (D2DLs). We formulate the optimal user selection and power control as a non-linear programming (NLP) optimization problem to get the optimal user scheduling and transmission power in a given TTI. Our numerical results show that using DPA gives better overall throughput performance than full power transmission algorithm (FPA). Also, simultaneous transmissions (combination of uplink (UL), downlink (DL), and D2D occur 80% of the time thereby increasing the spectral efficiency and network capacity
标签： Full-Duplex Cells Small
上传时间： 2020-05-27
上传用户：shancjb
The first Third Generation Partnership Project (3GPP) Wideband Code Division Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005 there were 100 open WCDMA networks and a total of over 150 operators having frequency licenses for WCDMA operation. Currently, the WCDMA networks are deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is expected to be available in the near future. 3GPP has defined the WCDMA operation also for several additional bands, which are expected to be taken into use during the coming years.
标签： HSDPAHSUPA Access Speed Radio UMTS High for
上传时间： 2020-05-27
上传用户：shancjb
To meet the future demand for huge traffic volume of wireless data service, the research on the fifth generation (5G) mobile communication systems has been undertaken in recent years. It is expected that the spectral and energy efficiencies in 5G mobile communication systems should be ten-fold higher than the ones in the fourth generation (4G) mobile communication systems. Therefore, it is important to further exploit the potential of spatial multiplexing of multiple antennas. In the last twenty years, multiple-input multiple-output (MIMO) antenna techniques have been considered as the key techniques to increase the capacity of wireless communication systems. When a large-scale antenna array (which is also called massive MIMO) is equipped in a base-station, or a large number of distributed antennas (which is also called large-scale distributed MIMO) are deployed, the spectral and energy efficiencies can be further improved by using spatial domain multiple access. This paper provides an overview of massive MIMO and large-scale distributed MIMO systems, including spectral efficiency analysis, channel state information (CSI) acquisition, wireless transmission technology, and resource allocation.
标签： Large-scale Antenna Systems
上传时间： 2020-05-27
上传用户：shancjb
An optical fiber amplifier is a key component for enabling efficient transmission of wavelength-divisionmultiplexed(WDM)signalsoverlongdistances.Eventhough many alternative technologies were available, erbium-doped fiber amplifiers won theraceduringtheearly1990sandbecameastandardcomponentforlong-haulopti- caltelecommunicationssystems.However,owingtotherecentsuccessinproducing low-cost, high-power, semiconductor lasers operating near 1450 nm, the Raman amplifiertechnologyhasalsogainedprominenceinthedeploymentofmodernlight- wavesystems.Moreover,becauseofthepushforintegratedoptoelectroniccircuits, semiconductor optical amplifiers, rare-earth-doped planar waveguide amplifiers, and silicon optical amplifiers are also gaining much interest these days.
标签： Propagation Light Media Gain in
上传时间： 2020-05-27
上传用户：shancjb
Mobilenetworkoperatorswillmeetmanychallengesinthecomingyears.Itisexpectedthatthe numberofpeopleconnected,wirelineandwireless,willreachfivebillionby2015.Atthesame time, people use more wireless services and they expect similar user experience to what they can now get from fixed networks. Because of that we will see a hundred-fold increase in network traffic in the near future. At the same time markets are saturating and the revenue per bit is dropping.
标签： Self-Organising Networks LTE
上传时间： 2020-05-27
上传用户：shancjb
Fordecades,microwavelineofsight(LOS)linkshavebeenoneofthebasictechnolo- gies used to build telephone networks. Until 1980, the fast rollout of high capacity transport networks and deployment of links in areas with challenging geographic characteristics could not be understood without this technology.
上传时间： 2020-05-28
上传用户：shancjb
