THE design and the optimization of video communications over wireless networks is attracting a lot of attention from both academia and industry. The main challenge is to enhance the quality of service (QoS) support in terms of packet loss rate, end-to-end delay Distortion-Fair Cross-Layer Resource Allocation for Scalable Video Transmission in OFDMA Wireless Networks and minimum guaranteed bit-rate, while providing fairness where needed. The cross-layer approach, i.e., the exchange of information among different layers of the system, is one of the key concepts to be exploited to achieve this goal. Distortion-Fair Cross-Layer Resource Allocation for Scalable Video Transmission in OFDMA Wireless Networks In beyond-3G and 4G wireless system orthogonal frequency division multiple access (OFDMA) has been selected as a key physical (PHY) layer technology to support a very flexible access with high spectral efficiency. In order to exploit the available temporal, frequency and multi-user diversity, Distortion-Fair Cross-Layer Resource Allocation for Scalable Video Transmission in OFDMA Wireless Networks and to provide a given level of QoS, suitable adaptive resource allocation and scheduling strategies have to be implemented. Opportunistic schedulers, as for instance, proportional fair (PF) and maximum signal-to-noise ratio (SNR) schedulers, take advantage of the knowledge of the channel state information (CSI) in order to maximize the spectral efficiency. However, with these schedulers, the final share of throughput often results unfair, especially for the cell-edge users which suffer of data-rate limitations due to high Distortion-Fair Cross-Layer Resource Allocation for Scalable Video Transmission in OFDMA Wireless Networks path-loss and inter-cell interference. In real-time streaming the mismatch between the allocated PHY layer rate and the rate required by the delay-constrained application may cause the loss of important parts of the streams, which significantly degrades the end-user quality of experience (QoE). The provision of acceptableQoE to every user is enabled by the use of a scheduler at the medium access control (MAC) layer which delivers a fair throughput, according to specific utilities and constraints defined by the application. Moreover, the presence of an optimized source rate adaptation technique at the application (APP) layer becomes crucial to improve stability, to prevent buffer Distortion-Fair Cross-Layer Resource Allocation for Scalable Video Transmission in OFDMA Wireless Networks overflow and to maintain video play-back continuity. Rate adaptation is enabled by the use of video encoders that support multiple layers which can be sequentially dropped, thereby providing a graceful degradation. One of the most promising tool is the H.264 Advanced Video Coding (AVC) standard with scalable extension, also known as Scalable Video Coding.

AS the advance of wireless communication techniques, wireless networks have become universal and novel applications have proliferated in various fields such as mobile auctions, military command and control, distance education and intelligent Reliable Multicast with Pipelined Network Coding using Opportunistic Feeding and Routing transportation systems. In these applications, multicast is a key mechanism developed to disseminate information from a single source to multiple destinations. It has attracted significant efforts to improve its performance in wireless environment with different metrics including throughput, delay, energy efficiency, etc. Traditionally, in order to facilitate routing protocol design, an ideal wireless network model is used with the assumption that the wireless transmission links are lossfree. In reality, transmission failures would happen because the quality of wireless links is affected or even jeopardized by Reliable Multicast with Pipelined Network Coding using Opportunistic Feeding and Routing many factors like collisions, fading or environmental noise . Therefore, a new model for wireless networks with lossy links should be considered in the multicast protocol design, especially for some applications in adverse environment such as wireless sensor networks in the wilds. Recently, cooperation between nodes is proposed to improve the multicast performance in lossy wireless networks. Reliable Multicast with Pipelined Network Coding using Opportunistic Feeding and Routing When a node fails to receive a packet from its direct upstream node, other neighboring nodes that have successfully received it can cooperatively feed the packet to this node. Such opportunistic routing (OR) strategy at each receiver, like ExOR , is referred as forwarder-cooperation in this paper. Later, MORE is proposed to simplify the coordination by combining forwarder-cooperation and intra-session network coding. Reliable Multicast with Pipelined Network Coding using Opportunistic Feeding and Routing It has shown great advantages in increasing the network throughput and simplifying protocol design by eliminating the coordination between nodes. Unfortunately, the multicast in MORE is not efficient since excessive forwarders may be evolved in data dissemination, which would incur serious MAC contention and degrade the multicast performance. Moreover, the batch-by-batch policy makes the protocol susceptible to the “crying baby” problem, which is pointed out in [ and solved by a round-robin batch scheduling. However, the proposed algorithm Pacifier in is not energy-efficient since substantial number of useful packets may be flushed away during frequent batch scheduling over the whole network. Furthermore, its privilege for data dissemination to the destinations with good connections from source would lead to serious unfairness in throughput.

WIRELESS mesh networks (WMNs) have emerged in recent years as a promising communication paradigm toward the cost-effective deployment of all-wireless network infrastructures [1]. Several operators have started usingWMNs as a valuable technology to Efficient and Truthful Bandwidth Allocation in Wireless Mesh Community Networks provide broadband Internet access in urban and rural areas, where the low return on investments cannot cover all costs to deploy more expensive wired solutions. With the aim of further reducing the overall maintenance costs and maximizing the profit, WMN operators have been fostering the deployment of wireless mesh community networks (WMCNs) . In WMCNs, a group of independent mesh routers owned by different individuals forms or extends a WMN to Efficient and Truthful Bandwidth Allocation in Wireless Mesh Community Networks enhance the broadband connectivity, whose availability can be shared with other users not directly involved in the management of the community network. In this context, we envision a marketplace scenario where an operator may lease the bandwidth of its wireless access network to a subset of customers in order to increase the network coverage of its WMN and provide access to other residential users through the customers’ mesh client devices. Efficient and Truthful Bandwidth Allocation in Wireless Mesh Community Networks The customers1 who manage these mesh clients pay the network operator to exploit the access bandwidth, while they are rewarded directly by the residential users they serve. Note that both the operator and the customers gain from this agreement since the former can lease the bandwidth of itsWMN, savingmanagement andmaintenance costs, while the latter can earn money by subleasing the purchased bandwidth to other residential users. Efficient and Truthful Bandwidth Allocation in Wireless Mesh Community Networks Finally, the residential users that would not have been covered by the WMN operator (because of low payoffs) obtain a better Internet service. Efficient and Truthful Bandwidth Allocation in Wireless Mesh Community Networks The proposed marketplace would therefore contribute to overcome the Digital Divide problem, improving the economical efficiency of public-private wireless partnerships like those analyzed in. In order to be an attractive solution, the aforementioned bandwidth market managed by theWMN operator needs convincing allocation and payment mechanisms that should act as incentives for customers to participate and subscribe to the service.

OUTAGE probability is an important performance metric for wireless networks operating over fading channels . It is commonly defined as the probability that the signalto interference-plus-noise ratio (SINR) drops below a given threshold. Outage Probability in Arbitrarily-Shaped Finite Wireless Networks The analysis of the outage probability and interference in wireless networks has received much attention recently . For the sake of analytical convenience and tractability, all the aforementioned studies and many references therein assumed infinitely large wireless networks and often used a homogeneous Poisson point process (PPP) as the underlying model for the spatial node distribution. Outage Probability in Arbitrarily-Shaped Finite Wireless Networks A homogeneous PPP is stationary i.e., the node distributionis invariant under translation. This gives rise to locationindependent performance, statistically the network characteristics such as mean aggregate interference and average outage probability as seen from a node’s perspective are the same for all nodes. Mathematical tools from stochastic geometry have been applied to obtain analytical expressions for the outage probability in infinitely large wireless networks ,. Outage Probability in Arbitrarily-Shaped Finite Wireless Networks The outage analysis in infinite wireless networks has also been extended to wireless networks with the Poisson cluster process as well as to coexisting networks sharing the same frequency spectru. In practice, many real-world wireless networks comprise a finite number of nodes distributed at random inside a given finite region. The boundary effect of finite networks gives Outage Probability in Arbitrarily-Shaped Finite Wireless Networks rise to non-stationary location-dependent performance, i.e., the nodes located close to the physical boundaries of the wireless network experience different network characteristic as compared to the nodes located near the center of the network. As a result, the modeling and performance analysis of finite wireless networks requires different approaches as opposed to infinite wireless networks. For example, when a finite number of nodes are independently and uniformly distributed (i.u.d.) inside a finite network, a Binomial point process (BPP), rather than a PPP, provides an accurate model for the spatial node distribution . Outage Probability in Arbitrarily-Shaped Finite Wireless Networks Unlike infinite wireless networks, deriving general results on the outage probability in finite wireless networks is a very difficult task because the outage performance depends strongly on the shape of the network region as well as the location of the reference receiver. In this work, we would like to investigate whether there exist general frameworks that provide easy-to-follow procedures to derive the outage probability at an arbitrary location in an arbitrarily-shaped finite wireless network.

A Cognitive radio network (CRN) is formed by advanced radio devices, which observe the radio environment for a suitable band, employ an intelligent agent for decision-making, and a frequency-agile radio that can be tuned to a wide range of frequency bands and eventually A Spectrum-aware Clustering for Efficient Multimedia Routing in Cognitive Radio Sensor Networks operate on an intelligently selected band. Motivated by the spectrum utilization and regulation issue for exclusive use by the licensed or primary users, it brings a revolutionary change in this new paradigm by introducing a new class of unlicensed or secondary users who can share the spectrum opportunistically without interfering with the primary users. A Spectrum-aware Clustering for Efficient Multimedia Routing in Cognitive Radio Sensor Networks This new paradigm has also been investigated for wireless sensor networks (WSNs) to enjoy the potential benefits of cognitive radios, thus forming cognitive radio sensor networks (CRSN). CRSN can be utilized in many different application scenarios, for instance, intelligent transportation system , industrial monitoring, surveillance , smart grids , etc. Dynamic spectrum access plays a key role to mitigate the noisy spectrum bands and eases the reconfiguration of spectrum usage. Wireless multimedia A Spectrum-aware Clustering for Efficient Multimedia Routing in Cognitive Radio Sensor Networks sensors have been realized for monitoring and intelligent transportation in public transport vehicles, train. However, the spectrum utilization issues for multimedia delivery in vehicular networks have not been addressed adequately. The lack of established infrastructure, network dynamics, constrained spectrum access privileges along with the unpredictable band opportunity, and the nature of the wireless medium offer an unprecedented set of challenges in supporting demanding applications over CRSN. A Spectrum-aware Clustering for Efficient Multimedia Routing in Cognitive Radio Sensor Networks Thus, supporting multimedia applications of traditional WMSNs over CRSN presents many key issues, which are not dealt in its counterpart wireless multimedia sensor network. The varying capacity of wireless links in CRSN deteriorates the performance of a routing protocol in achieving end-to-end delay bound. The strict delay constraint is usually compensated by setting a suitable playout deadline to take into account the underlying network bottlenecks. Thus, by setting appropriate deadline in conjunction with playout time, the multimedia routing protocol should address the significant variation in delay and jitter to ensure the persistent quality of service for multimedia applications.

NOWADAYS, the spectrum-sliced elastic optical networking based on the optical orthogonal frequency-division multiplexing (O-OFDM) technology has attracted intensive research interests as it can improve the spectral efficiency of the optical layer significantly Dynamic p-Cycle Protection in Spectrum-Sliced Elastic Optical Networks with flexible bandwidth allocation. Unlike the wavelength-division multiplexing (WDM) networks that operate on discrete wavelength channels with a bandwidth of 50 or 100 GHz, the O-OFDM networks groom the capacities of a few narrow-band subcarrier channels (frequency slots) that are spectrally contiguous and achieve high-speed data transmission over them. Dynamic p-Cycle Protection in Spectrum-Sliced Elastic Optical Networks Hence, by adjusting the number of assigned frequency slots (FS’) to each lightpath, O-OFDM networks can allocate optical spectrum with a finer granularity and agile bandwidth management for different network applications can be achieved. To this end, people refer the optical networks based on the O-OFDM technology as elastic optical networks (EONs) . Dynamic p-Cycle Protection in Spectrum-Sliced Elastic Optical Networks Previously, researchers have investigated the routing and spectrum assignment (RSA) of lightpaths intensively for realizing efficient service planning and provisioning in EONs . However, most of these studies did not consider how to setup Dynamic p-Cycle Protection in Spectrum-Sliced Elastic Optical Networks lightpath connections with protection or restorability. It is known that in optical networks, the amount of service disruption and data loss caused by a network-related outage can be huge , because a single optical fiber can carry over 20 Tb/s transmission capacity . Meanwhile, natural disasters and other factors can trigger unpredictable failures of network elements and make network survivability a serious issue . Dynamic p-Cycle Protection in Spectrum-Sliced Elastic Optical Networks In EONs, a link failure may lead to more severe service disruption due to the higher data-rate provided by the supper-channels. Therefore, it is not only important but also necessary to study the protection schemes for EONs, and the network operators need to implement them to ensure certain service availability for the lightpath connections. The authors of proposed an SPP scheme for EONs, which was called elastic separateprotection- at-connection and could realize spectrum sharing by using first-fit to assign working traffic and last-fit to assign backup traffic.