Stable Wireless Network Control Under Service Constraints

We consider the design of wireless queueing network control policies with particular focus on combining stability with additional application-dependent requirements. Thereby, we consequently pursue a cost function based approach that provides the flexibility to incorporate constraints and requirements of particular services or applications. As typical examples of such requirements, we consider the reduction of buffer underflows in case of streaming traffic, and energy efficiency in networks of battery powered nodes. Compared to the classical throughput optimal control problem, such requirements significantly complicate the control problem. We provide easily verifyable theoretical conditions for stability, and, additionally, compare various candidate cost functions applied to wireless networks with streaming media traffic. Moreover, we demonstrate how the framework can be applied to the problem of energy efficient routing, and we demonstrate the aplication of our framework in cross-layer control problems for wireless multihop networks, using an advanced power control scheme for interference mitigation, based on successive convex approximation. In all scenarios, the performance of our control framework is evaluated using extensive numerical simulations.Comment: Accepted for publication in IEEE Transactions on Control of Network Systems. arXiv admin note: text overlap with arXiv:1208.297

VANETs Multipath Video Data Streaming Considering Road Features

Multipath video streaming in Vehicular Ad-hoc Networks (VANETs) is an evolving research topic. The adoption of video transmission in VANETs communication has become essential due to the comprehensiveness and applicability of video data for on-road advertisement and infotainment. Meanwhile, several research studies have considered how to apply and improve the transmission of the video quality. Due to this, the concurrent multipath transmission has been employed in order to achieve load balancing and path diversity, because of the high data rate of the video data.  However, the main nature of the road, which is the pathway for VANET nodes has not been considered explicitly. In this paper, the road features are considered for VANETs multipath video streaming based on the greedy geographical routing protocol. Thus, VANETs Multipath Video Streaming based on Road Features (VMVS-RF) protocol has been proposed. The protocol was compared with an ordinary Multipath Video Streaming (MVS). The result demonstrates that the proposed VMVS-RF protocol outperforms the MVS in terms of Data Receiving Rate (DRR), Structural Similarity (SSIM) index and Packet Loss Ratio (PLR)

Cooperative Coding and Caching for Streaming Data in Multihop Wireless Networks

This paper studies the distributed caching managements for the current flourish of the streaming applications inmultihop wirelessnetworks. Many caching managements to date use randomized network coding approach, which provides an elegant solution forubiquitous data accesses in such systems. However, the encoding, essentially a combination operation, makes the coded datadifficult to be changed. In particular, to accommodate new data, the system may have to first decode all the combined datasegments, remove some unimportant ones, and then reencode the data segments again. This procedure is clearly expensivefor continuously evolving data storage. As such, we introduce a novel Cooperative Coding and Caching (C3) scheme, whichallows decoding-free data removal through a triangle-like codeword organization. Its decoding performance is very close to theconventional network coding with only a sublinear overhead. Our scheme offers a promising solution to the caching managementfor streaming data

Application-Aware Cross-Layer Framework for Wireless Multihop Networks

Current and future mobile and social communications require a rethinking in the development of wireless communication. Optimizing the radio transmission method is not going to scale with the ever increasing user demands. The future internet requires a wireless communication network which can adapt seamlessly to changing environments and service requirements. Especially, service requirements driven by user demand and expanding user device diversity raise a key challenge with respect to content distribution. In this work, research is conducted to improve wireless communication by considering four main aspects: The first aspect is to build a multi layer solution, instead of a conventional single layer solution to achieve higher throughput gains. Here, the physical layer, the medium access layer and the network layer are studied together to utilize capabilities across all these three layers. Thus, a unified graph model is formulated to adapt available mechanisms on the lower three layers in a joint manner. The second aspect is to envision a wireless multihop network which can scale with the increasing number of mobile devices. On the one hand, the number of mobile devices is ever increasing and so is the density of mobile devices in any given network. On the other hand, the requirements and capabilities of mobile devices are becoming more diverse and hence the heterogeneity in a wireless network is growing. This leads to the conclusion that a wireless multihop network is more future proof compared to a wireless network composed only of several base stations. Therefore, the research is focused on wireless multihop scenarios where multiple wireless devices form the network and communication between them occurs over multiple hops. The third aspect is to incorporate different requirements of applications and capabilities of applications. The plethora of applications used in wireless networks come with different sets of requirements, e.g. bandwidth, and capabilities, e.g. adaption of the video quality. Taking into account these requirements and capabilities in addition to a multi layer solution can further increase the performance. In this work, the requirements and capabilities of adaptive video streaming are integrated into an application-aware cross-layer framework. More precisely, scalable video coding and dynamic adaptive streaming over HTTP are integrated into the aforementioned framework. The novel application-aware cross-layer framework adapts network support structures at the network layer, performs resource allocation at the medium access layer, switches between communication types at the physical layer and takes into account the capabilities and requirements of applications, e.g. adaptive video-streaming, at the application layer. The fourth aspect is to utilize aggregation of distributed content, where content is cached over the whole network and can than be aggregated to be consumed by users in the network. Recent research shows promising gains achievable when content is cached at mobile devices, but mostly for single hop wireless networks. Hence, the impact of mobile content caching where popular content is cached and aggregated over multiple devices in a network is investigated in this work. In more detail, a content delivery framework which jointly exploits content already cached at mobile devices as well as switching between mechanisms at the physical layer and the network layer in order to optimally deliver the content to all destinations under changing network conditions is proposed

Data-Centric Multiobjective QoS-Aware Routing Protocol for Body Sensor Networks

In this paper, we address Quality-of-Service (QoS)-aware routing issue for Body Sensor Networks (BSNs) in delay and reliability domains. We propose a data-centric multiobjective QoS-Aware routing protocol, called DMQoS, which facilitates the system to achieve customized QoS services for each traffic category differentiated according to the generated data types. It uses modular design architecture wherein different units operate in coordination to provide multiple QoS services. Their operation exploits geographic locations and QoS performance of the neighbor nodes and implements a localized hop-by-hop routing. Moreover, the protocol ensures (almost) a homogeneous energy dissipation rate for all routing nodes in the network through a multiobjective Lexicographic Optimization-based geographic forwarding. We have performed extensive simulations of the proposed protocol, and the results show that DMQoS has significant performance improvements over several state-of-the-art approaches

Quality-Driven Cross-Layer Protocols for Video Streaming over Vehicular Ad-Hoc Networks

The emerging vehicular ad-hoc networks (VANETs) offer a variety of applications and new potential markets related to safety, convenience and entertainment, however, they suffer from a number of challenges not shared so deeply by other types of existing networks, particularly, in terms of mobility of nodes, and end-to-end quality of service (QoS) provision. Although several existing works in the literature have attempted to provide efficient protocols at different layers targeted mostly for safety applications, there remain many barriers to be overcome in order to constrain the widespread use of such networks for non-safety applications, specifically, for video streaming: 1) impact of high speed mobility of nodes on end-to-end QoS provision; 2) cross-layer protocol design while keeping low computational complexity; 3) considering customer-oriented QoS metrics in the design of protocols; and 4) maintaining seamless single-hop and multi-hop connection between the destination vehicle and the road side unit (RSU) while network is moving. This thesis addresses each of the above limitations in design of cross-layer protocols for video streaming application. 1) An adaptive MAC retransmission limit selection scheme is proposed to improve the performance of IEEE 802.11p standard MAC protocol for video streaming applications over VANETs. A multi-objective optimization framework, which jointly minimizes the probability of playback freezes and start-up delay of the streamed video at the destination vehicle by tuning the MAC retransmission limit with respect to channel statistics as well as packet transmission rate, is applied at road side unit (RSU). Two-hop transmission is applied in zones in which the destination vehicle is not within the transmission range of any RSU. In the multi-hop scenario, we discuss the computation of access probability used in the MAC adaptation scheme and propose a cross-layer path selection scheme; 2) We take advantage of similarity between multi-hop urban VANETs in dense traffic conditions and mesh connected networks. First, we investigate an application-centric routing scheme for video streaming over mesh connected overlays. Next, we introduce the challenges of urban VANETs compared to mesh networks and extend the proposed scheme in mesh network into a protocol for urban VANETs. A classification-based method is proposed to select an optimal path for video streaming over multi-hop mesh networks. The novelty is to translate the path selection over multi-hop networks to a standard classification problem. The classification is based on minimizing average video packet distortion at the receiving nodes. The classifiers are trained offline using a vast collection of video sequences and wireless channel conditions in order to yield optimal performance during real time path selection. Our method substantially reduces the complexity of conventional exhaustive optimization methods and results in high quality (low distortion). Next, we propose an application-centric routing scheme for real-time video transmission over urban multi-hop vehicular ad-hoc network (VANET) scenarios. Queuing based mobility model, spatial traffic distribution and prob- ability of connectivity for sparse and dense VANET scenarios are taken into consideration in designing the routing protocol. Numerical results demonstrate the gain achieved by the proposed routing scheme versus geographic greedy forwarding in terms of video frame distortion and streaming start-up delay in several urban communication scenarios for various vehicle entrance rate and traffic densities; and 3) finally, the proposed quality-driven routing scheme for delivering video streams is combined with a novel IP management scheme. The routing scheme aims to optimize the visual quality of the transmitted video frames by minimizing the distortion, the start-up delay, and the frequency of the streaming freezes. As the destination vehicle is in motion, it is unrealistic to assume that the vehicle will remain connected to the same access router (AR) for the whole trip. Mobile IP management schemes can benefit from the proposed multi-hop routing protocol in order to adapt proxy mobile IPv6 (PMIPv6) for multi-hop VANET for video streaming applications. The proposed cross-layer protocols can significantly improve the video streaming quality in terms of the number of streaming freezes and start-up delay over VANETs while achieving low computational complexity by using pattern classification methods for optimization

Named Data Networking in Vehicular Ad hoc Networks: State-of-the-Art and Challenges

International audienceInformation-Centric Networking (ICN) has been proposed as one of the future Internet architectures. It is poised to address the challenges faced by today's Internet that include, but not limited to, scalability, addressing, security, and privacy. Furthermore, it also aims at meeting the requirements for new emerging Internet applications. To realize ICN, Named Data Networking (NDN) is one of the recent implementations of ICN that provides a suitable communication approach due to its clean slate design and simple communication model. There are a plethora of applications realized through ICN in different domains where data is the focal point of communication. One such domain is Intelligent Transportation System (ITS) realized through Vehicular Ad hoc NETwork (VANET) where vehicles exchange information and content with each other and with the infrastructure. To date, excellent research results have been yielded in the VANET domain aiming at safe, reliable, and infotainment-rich driving experience. However, due to the dynamic topologies, host-centric model, and ephemeral nature of vehicular communication, various challenges are faced by VANET that hinder the realization of successful vehicular networks and adversely affect the data dissemination, content delivery, and user experiences. To fill these gaps, NDN has been extensively used as underlying communication paradigm for VANET. Inspired by the extensive research results in NDN-based VANET, in this paper, we provide a detailed and systematic review of NDN-driven VANET. More precisely, we investigate the role of NDN in VANET and discuss the feasibility of NDN architecture in VANET environment. Subsequently, we cover in detail, NDN-based naming, routing and forwarding, caching, mobility, and security mechanism for VANET. Furthermore, we discuss the existing standards, solutions, and simulation tools used in NDN-based VANET. Finally, we also identify open challenges and issues faced by NDN-driven VANET and highlight future research directions that should be addressed by the research community

Investigating network services abstraction in 5G enabled device-to-device (D2D) communications

The increased demand of data rate by mobile users has led to the evolution of mobile network technologies from the fourth generation to fifth generation (5G). 5G mobile network will support various technologies that will be able to provide low latency, offload traffic and connect vertical industries. Device-to-device (D2D) communications will be used as the underlay technology for 5G network in the offloading of traffic from the cellular network and pushing content closer to the user. With D2D communication, various network services can be implemented to improve spectral efficiency and reduce energy consumption of mobile devices. This paper gives a brief overview of D2D communication and discusses different D2D applications. It proposes a network services abstraction and suggests the mapping of existing studies with the network service abstraction which can be used in the harnessing the development and implementation of D2D communication applications in 5G network. The paper also highlights possible future research for D2D communication in 5G network