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Recent advances in the fields of wireless technology and multimedia systems have exhibited a strong potential and tendency on improving human life by enabling smart services in ubiquitous computing environments. This paper investigates a mobile multimedia system through combining various technologies, such as wireless sensor networks, embedded multimedia system and node mobility. In particular, we...
In cooperative networks, a variety of resource allocation problems can be formulated as constrained optimization with system-wide objective, e.g., maximizing the total system throughput, capacity or ergodic capacity, subject to constraints from individual users, e.g., minimum data rate, transmit power limit, and from the system, e.g., power budget, total number of subcarriers, availability of the...
The orthogonal frequency-division multiple access (OFDMA) system has the advantages of flexible subcarrier allocation and adaptive modulation with respect to channel conditions. However, transmission overhead is required in each frame to broadcast the arrangement of radio resources to all mobile stations within the coverage of the same base station. This overhead greatly affects the utilization of...
Traffic engineering (TE) optimizes the performance of a network by analyzing and regulating the data transmission. Traffic engineering with link coloring (TELIC) was proposed to automatically assign LSPs in multi-protocol label switching domain based on bandwidth and class of service attributes. TELIC dynamically assigns colors to links in the network domain on the basis of reservable bandwidth. Different...
In this paper, we propose a cross-layer optimization scheme in which the application layer controls the medium access network (MAC) and physical (PHY) layers in long-term evolution (LTE, from 3rd generation partnership project [3GPP] release 8) to maximize the quality of video streaming services. We demonstrate how to optimize quality using the equi-signal-to-noise ratio (equi-SNR) from the lower...
IEEE 802.16 Wireless Network technology is a hot research issue in recent years. It provides wider coverage of radio and higher speed wireless access, and Quality-of-Service plays an important part in the standard. For mobile multi-hop wireless network, IEEE 802.16j/MR network not only can supply large area wireless deployment, but also can provide high quality network service to mobile users. Although...
The cognitive radio (CR) is evolved as the potential technology to solve the problem of spectrum scarcity and to meet the stringent requirements of upcoming wireless services. CR has two distinct features, the spectrum sensing and the parameter adaptation. The former feature helps the CR to find the vacant spectrum slots/channels in the radio band while the latter mechanism allows it to adjust the...
In this article, we study the coexistence and optimization of a centralized orthogonal frequency-division multiple access-based multiuser cognitive radio (MCR) system which coexists with a cellular primary system (PS). Two different spectrum sharing methods, i.e., the spectrum underlay/overlay, are utilized for different coexistent frameworks, in which, the sharing method is adapted to one of them...
We propose in this article an architecture called trusted timely attacks-tolerating communication architecture (3TCA) designed for mobile multihop relay (MMR) networks. The 3TCA architecture is based on trusted components providing trusted time-related and security-related services along with an intrusion-related service while guaranteeing QoS compensation. 3TCA components are implemented at access...
Satellite is often used as an access network in the Next Generation Networks landscape, where multimedia and real-time services are supported by return channels. However, these satellite return channels are a very limited resource with many terminal stations competing for its use, making its efficient assignation one of the key problems to solve in order to increase network performance. This article...
We consider multi-antenna base stations using orthogonal frequency-division multiple access and space division multiple access techniques to serve single-antenna users. Some users, called real-time users, have minimum rate requirements and must be served in the current time slot while others, called non real-time users, do not have strict timing constraints and are served on a best-effort basis. The...
The development of the advanced wireless access technologies is focusing on the enhancement of mobile user satisfaction in terms of quality of service (QoS). As the number of mobile users increases, the amount of traffic passing through base station (BS) significantly increases so that the preplanned capacity of downlink or uplink can be exceeded from time to time resulting in the degradation of users’...
Dynamic resource allocation scheme is a key component of 3GPP long-term evolution (LTE) for satisfying quality-of-service (QoS) requirement as well as improving the system throughput. In this paper, a buffer-aware adaptive resource allocation scheme for LTE downlink transmission is proposed for improving the overall system throughput while guaranteeing the statistic QoS and keeping certain fairness...
As the wireless sensor networks (WSNs) continue to evolve, it becomes more and more important. Furthermore, no one can deny that quality of services (QoS) is still one of the most important areas in this domain. In this paper, a system for guaranteeing WSN QoS is proposed. The idea of this system is to use the previous individual solutions such as clustering, data prioritization, and data classification...
In this paper, a new model that deploys heterogeneous sensors in 3D wireless sensor networks (WSNs) is proposed. The model handles the two sensing scenarios, single sensing and multiple sensing. The probabilities of intrusion detection in a 3D environment with sensors distributed using Gaussian, uniform, beta, and chi-square are compared. The resultant probabilities values help the WSN security designers...
We investigate the resource allocation dynamics of Coordinated Multi-Point (CoMP) transmissions in a Cloud‘ Radio Access Network (C-RAN) deployment. In this context, we propose a service-aware user-centric scheme that achieves fairness in a multi-point fashion for the downlink. This approach operates in time-frequency and space, assuming a fixed power per transmitter. The scheme adaptively chooses...
This work deals with the analysis of energy efficiency (EE) issues of hybrid automatic repeat request (HARQ) protocols such as Chase combining (CC) and incremental redundancy (IR), in a LTE baseband-based half-division duplex relay-assisted network. The EE performance is highly dependent on delay and circuitry power consumption, i.e., baseband and radio-frequency (RF) parts, and the effects of these...
The Transmission Control Protocol (TCP) is one of the main communication protocols in the Internet, and it has been designed to provide an efficient reaction to packet loss events which are due to network congestion. Congestion is the main cause of losses in wired networks, but in today heterogeneous networks, loss events can also be introduced due to higher error rates on wireless channels, host...
Cloud radio access network is one of the most promising cellular networks for the next generation of mobile networks. The basic idea of cloud RAN (radio access network) is virtualizing and centralizing the intelligent part of the base station, the base band unit, and keeping remote radio heads on cell site enabling a centralized processing and management. Offloading data computation to edge cloud...
Cyber-physical systems (CPSs) connect physical equipment and the information system to realize real-time perception and intelligent control of the equipment. With the rapid development of wireless sensors, wireless sensor networks (WSNs) now play a major role in CPS and have become a focus of research. However, WSNs in CPS face great challenges in ensuring the high reliability and time critical performance...
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