The concept of smart cities emerged few years ago as a new vision for urban development that aims to integrate multiple information and communication technology (ICT) solutions in a secure fashion to manage a city’s assets. Modern ICT infrastructure and e-services should fuel sustainable growth and quality of life, enabled by a wise and participative management of natural Resources to be ensured by citizens and government. The need to build smart cities became a requirement that relies on urban development that should take charge of the new infrastructures for smart cities (broadband infrastructures, wireless sensor networks, Internet-based networked applications, open data and open platforms) and provide various smart services and enablers in various domains including healthcare, energy, education, environmental management, transportation, mobility and public safety.
標(biāo)簽： Enablers Cities Smart for
上傳時(shí)間： 2020-05-25
上傳用戶：shancjb
Wireless penetration has witnessed explosive growth over the last two decades. Accordingly, wireless devices have become much denser per unit area, resulting in an overcrowded usage of wireless Resources. To avoid radio interferences and packet collisions, wireless stations have to exchange control messages to coordinate well. The existing wisdoms of conveying control messages could be classified into three categories: explicit, implicit, or hybrid.
標(biāo)簽： Transmission Attachment Networks Wireless in
上傳時(shí)間： 2020-05-26
上傳用戶：shancjb
Cognitive radio has emerged as a promising technology for maximizing the utiliza- tion of the limited radio bandwidth while accommodating the increasing amount of services and applications in wireless networks. A cognitive radio (CR) transceiver is able to adapt to the dynamic radio environment and the network parameters to maximize the utilization of the limited radio Resources while providing flexibility in wireless access. The key features of a CR transceiver are awareness of the radio envi- ronment (in terms of spectrum usage, power spectral density of transmitted/received signals, wireless protocol signaling) and intelligence.
標(biāo)簽： Cognitive Wireless Network
上傳時(shí)間： 2020-05-26
上傳用戶：shancjb
The General Packet Radio Service (GPRS) allows an end user to send and receive data in packet transfer mode within a public land mobile network (PLMN) without using a permanent connection between the mobile station (MS) and the external network during data transfer. This way, GPRS opti- mizes the use of network and radio Resources (RRs) since, unlike circuit- switched mode, no connection between the MS and the external network is established when there is no data flow in progress. Thus, this RR optimiza- tion makes it possible for the operator to offer more attractive fees.
上傳時(shí)間： 2020-05-27
上傳用戶：shancjb
There is a phenomenal burst of research activities in mobile cloud computing systems, which extends cloud computing functions, ser- vices, and results to the world of future mobile communications applications, and the paradigm of cloud computing and virtualization to mobile networks. Mobile applications demand greater Resources and improved interactivity for better user experience.
標(biāo)簽： Mobile Cloud Computing Systems
上傳時(shí)間： 2020-05-30
上傳用戶：shancjb
Theartofcomputationofelectromagnetic(EM)problemshasgrownexponentially for three decades due to the availability of powerful computer Resources. In spite of this, the EM community has suffered without a suitable text on the computational techniques commonly used in solving EM-related problems. Although there have been monographs on one particular technique or another, the monographs are written for the experts rather than students. Only a few texts cover the major techniques and dothatinamannersuitableforclassroomuse.Itseemsexpertsinthisareaarefamiliar with one or a few techniques but not many seem to be familiar with all the common techniques. This text attempts to fill that gap.
標(biāo)簽： Electromagnetics Techniques Numerical in
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
Rapid growth of wireless communication services in recent decades has created a huge demand of radio spectrum. Spectrum scarcity and utilization inefficiency limit the development of wireless networks. Cognitive radio is a promising tech- nology that allows secondary users to reuse the underutilized licensed spectrum of primary users. The major challenge for spectrum sharing is to achieve high spectrum efficiency while making non-intrusive access to the licensed bands. This requires in- formation of availability and quality of channel Resources at secondary transmitters, however, is difficult to be obtained perfectly in practice.
標(biāo)簽： Opportunistic Spectrum Sharing
上傳時(shí)間： 2020-05-31
上傳用戶：shancjb
In a cellular communication system, a service area or a geographical region is divided into a number of cells, and each cell is served by an infrastructure element called the base station through a radio interface. Management of radio interface related Resources is a critical design component in cellular communications.
標(biāo)簽： Management Resource Radio
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
The radio spectrum is one of the most precious Resources which must be managed to ensure efficient access for the wireless communication services which use it. The allocation and management of spectrum are administered by the regulatory authorities. Traditionally, spectrum allocation is carried out exclusively of its use in large geographic areas and assigning frequency bands to specific users or service providers is proved to be inefficient. Recently, substantial knowledge about dynamic spectrum access scheme has been accumulated to enable efficient spectrum sharing.
標(biāo)簽： Management Spectrum Access and
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
Once upon a time, cellular wireless networks provided two basic services: voice telephony and low-rate text messaging. Users in the network were separated by orthogonal multiple access schemes, and cells by generous frequency reuse patterns [1]. Since then, the proliferation of wireless services, fierce competition, andthe emergenceof new service classes such as wireless data and multimediahave resulted in an ever increasing pressure on network operators to use Resources in a moreefficient manner.In the contextof wireless networks,two of the most common Resources are power and spectrum—and, due to regulations, these Resources are typically scarce. Hence, in contrast to wired networks, overprovisioning is not feasible in wireless networks.
標(biāo)簽： Maximization Nonconvex Wireless Utility Systems in
上傳時(shí)間： 2020-06-01
上傳用戶：shancjb
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