A delay‐centric parallel multi‐path routing protocol for cognitive radio ad hoc networks

In this paper, we develop a delay‐centric parallel multi‐path routing protocol for multi‐hop cognitive radio ad hoc networks. First, we analyze the end‐to‐end delay of multi‐path routing based on queueing theory and present a new dynamic traffic assignment scheme for multi‐path routing with the objective of minimizing end‐to‐end delay, considering both spectrum availability and link data rate. The problem is formulated as a convex problem and solved by a gradient‐based search method to obtain optimal traffic assignments. Furthermore, a heuristic decentralized traffic assignment scheme for multi‐path routing is presented. Then, based on the delay analysis and the 3D conflict graph that captures spectrum opportunity and interference among paths, we present a route discovery and selection scheme. Via extensive NS2‐based simulation, we show that the proposed protocol outperforms the benchmark protocols significantly and achieves the shortest end‐to‐end delay. Copyright © 2015 John Wiley & Sons, Ltd.     

A group-based data-driven approach for data synchronization in unstructured mobile P2P systems

This paper addresses the problem of data consistency on mobile peer-to-peer (MP2P) systems (or MP2P networks). The considered MP2P system is based on a mobile ad-hoc network, where the energy and connectivity on the mobile devices are limited. Since different mobile nodes may store copies of shared information, data synchronization on an MP2P system becomes crucial and challenging due to frequent disconnection and change on network topology caused by node mobility. We propose an effective approach to improving the performance of data synchronization with a dynamic inverted data indexing structure and group-based data-driven consistency management. The proposed approach can effectively synchronize the data items without using a central cache node in each group (or cluster) and perform well in terms of the coverage of successfully synchronized nodes and the number of redundant messages. Last, the proposed approach is validated through extensive simulation experiments.     

Extending P2PMesh: topology‐aware schemes for efficient peer‐to‐peer data sharing in wireless mesh networks

Wireless mesh networks (WMNs) have emerged as a promising technology that provides low‐cost broadband access to the Internet for fixed and mobile wireless end users. An orthogonal evolution in computer networking has been the rise of peer‐to‐peer (P2P) applications such as P2P data sharing. It is of interest to enable effective P2P data sharing in this type of networks. Conventional P2P data sharing systems are not cognizant of the underlying network topology and therefore suffer from inefficiency. We argue for dual‐layer mesh network architecture with support from wireless mesh routers for P2P applications. The main contribution of this paper is P2PMesh: a topology‐aware system that provides combined architecture and efficient schemes for enabling efficient P2P data sharing in WMNs. The P2PMesh architecture utilizes three schemes: (i) an efficient content lookup that mitigates traffic load imbalance at mesh routers; (ii) an efficient establishment of download paths; and (iii) a data transfer protocol for multi‐hop wireless networks with limited capacity. We note here that the path establishment and data transfer schemes are specific to P2P traffic and that other traffic would use routes determined by the default routing protocol in the WMN. Simulation results suggest that P2PMesh has the potential to improve the performance of P2P applications in a wireless multi‐hop setting; specifically, we focused on data sharing, but other P2P applications can also be supported by this approach. Copyright © 2011 John Wiley & Sons, Ltd.     

Link stability‐aware reliable packet transmitting mechanism in mobile ad hoc network

To guarantee the QoS of multimedia applications in a mobile ad hoc network (MANET), a reliable packet transmitting mechanism in MANET is proposed. In this paper, we introduce an effective link lifetime estimation scheme. According to the current network topology and corresponding estimated link lifetime, the end‐to‐end connection is established adaptively in the best effort manner. Consequently, utilizing the network coding method the relay node combines and forwards the packets on the working path. Furthermore, to keep the balance between the gain in reliability and the amount of redundant packets, the time for sending the redundant packets on the backup path is determined for the link stability intelligently. Simulations show that our mechanisms can provide reliable transmissions for data packets and enhance the performance of the entire network, such as the packet delivery ratio, the end‐to‐end delay and the number of control messages. Copyright © 2011 John Wiley & Sons, Ltd.     

Low end‐to‐end delay fuzzy networking protocol for mobile wireless sensing

Because of the practical limitations of the energy and processing capabilities, the deployment of many Wireless Sensor Networks (WSN) is facing two main challenges of increasing network lifetime and reducing End to End Delay (EED) which become critical when the nodes are mobile and use non‐rechargeable energy sources. One way to help to extend network lifetime is using fuzzy logic in a form of artificial intelligence. To this end we propose a new routing protocol for using mobile WSNs, which holds the nodes in an equal level of energy and decreases energy dissipation of the network. An optimum path is selected based on the cost of each node to increase network lifetime. In order to lessen EED, we also attempt to design a novel zoning‐scheme for the network area. In this scheme, zonation is dynamic and works based on the Data Link (DL) position. The simulation result shows a significant improvement in lifetime and EED by proposed protocol compared with existing protocols. Copyright © 2016 John Wiley & Sons, Ltd.     

SDN‐based fault‐tolerant on‐demand and in‐advance bandwidth reservation in data center interconnects

Geographically distributed data centers are interconnected through provisioned dedicated WAN links, realized by circuit/wavelength–switching that support large‐scale data transfer between data centers. These dedicated WAN links are typically shared by multiple services through on‐demand and in‐advance resource reservations, resulting in varying bandwidth availability in future time periods. Such an inter‐data center network provides a dynamic and virtualized environment when augmented with cloud infrastructure supporting end‐host migration. In such an environment, dynamically provisioned network resources are recognized as extremely useful capabilities for many types of network services. However, the existing approaches to in‐advance reservation services provide limited reservation capabilities, eg, limited connections over links returned by the traceroute over traditional IP‐based networks. Moreover, most existing approaches do not address fault tolerance in the event of node or link failures and do not handle end‐host migrations; thus, they do not provide a reliability guarantee for in‐advance reservation frameworks. In this paper, we propose using multiple paths to increase bandwidth usage in the WAN links between data centers when a single path does not provide the requested bandwidth. Emulation‐based evaluations of the proposed path computation show a higher reservation acceptance rate compared to state‐of‐art reservation frameworks, and such computed paths can be configured with a limited number of static forwarding rules on switches. Our prototype provides the RESTful Web service interface for link‐fail and end‐host migration event management and reroutes paths for all the affected reservations.     

Distributed Routing Based on Minimum End‐to‐End Delay for OFDMA Backhaul Mobile Mesh Networks

In this paper, an orthogonal frequency division multiple access (OFDMA)‐based minimum end‐to‐end delay (MED) distributed routing scheme for mobile backhaul wireless mesh networks is proposed. The proposed scheme selects routing paths based on OFDMA subcarrier synchronization control, subcarrier availability, and delay. In the proposed scheme, OFDMA is used to transmit frames between mesh routers using type‐I hybrid automatic repeat request over multipath Rayleigh fading channels. Compared with other distributed routing algorithms, such as most forward within radius R, farthest neighbor routing, nearest neighbor routing, and nearest with forwarding progress, simulation results show that the proposed MED routing can reduce end‐to‐end delay and support highly reliable routing using only local information of neighbor nodes.     

Reliability-oriented ant colony optimization-based mobile peer-to-peer VoD solution in MANETs

Mobile peer-to-peer (MP2P) has emerged as a state-of-the-art technology for video resource sharing in mobile ad-hoc networks (MANETs), building on the advantages of P2P data exchange and providing a feasible solution for large-scale deployment of media streaming services. Fast search for video resources and low maintenance overhead of overlay networks to support the mobility of nodes are key factors in MP2P video on demand solutions. In this paper, we propose a novel reliability-oriented ant colony optimization (ACO)-based MP2P solution to support interactivity for video streaming in MANETs (RACOM). RACOM makes use of highly innovative algorithms such as the peer status-aware mechanism and peer-centric overlay maintenance mechanism to support high-efficiency video resource sharing. The peer status-aware mechanism includes the user reliability measure model which is used to identify the peers having reliable playback status in order to find stable potential resource suppliers and a new ACO-based prediction model of playback behavior which provides the accurate prediction of playback content in the future to ensure the smooth experience and optimize the distribution of resources. In order to balance the fast supplier discovery and low maintenance overhead, RACOM makes use of peer-centric overlay maintenance mechanism composed of the time window-based detection strategy and encounter-based synchronization strategy to reduce the maintenance overhead of reliable peers, obtain quasi real-time status of peers and support the mobility of mobile nodes. Simulation results show how RACOM achieves higher hit ratio, lower seek delay, lower server stress, lower peer load and less overlay maintenance overhead in comparison with another state of the art solution.     

Service‐oriented 5G network architecture: an end‐to‐end software defining approach

With the ever‐increasing mobile demands and proliferation of mobile services, mobile Internet has penetrated into every aspect of human life. Although the 4G mobile communication system is now being deployed worldwide, simply evolving or incrementally improving the current mobile networks can no longer keep the pace with the proliferation of mobile services. Against this background, aiming to achieve service‐oriented 5G mobile networks, this article proposes an end‐to‐end software defining architecture, which introduces a logically centralized control plane and dramatically simplifies the data‐plane. The control plane decomposes the diversified mobile service requirements and, correspondingly, controls the functions and behaviors of data‐plane devices. Consequently, the network directly orients towards services, and the devices are dynamically operated according to the service requirements. Therefore, the proposed architecture efficiently guarantees the end‐to‐end QoS and quality of experience. The challenges and key technologies of our architecture are also discussed in this article. Real traces‐based simulations validate the performance advantages of proposed architecture, including energy efficiency and the whole performance. Copyright © 2015 John Wiley & Sons, Ltd.     

A survey and comparison on overlay‐underlay mapping techniques in peer‐to‐peer overlay networks

Peer‐to‐peer (P2P) overlay networks were developed initially for file sharing such as Napster and Gnutella; but later, they have become popular for content sharing, media streaming, telephony applications, etc. Underlay‐unawareness in P2P systems can result in suboptimal peer selection for overlay routing and hence poor performance. In this paper, we present a comprehensive survey of the research work carried out to solve the overlay‐underlay mapping problems up till now. The majority of underlay‐aware proposals for peer selection focus on finding the shortest overlay routes by selecting nearest nodes according to proximity information. Another class of approaches is based on passive or active probing for provision of underlay information to P2P applications. Some other optimizations propose use of P2P middleware to extract, process, and refine underlay information and provide it to P2P overlay applications. Another class of approaches strive to use ISPs or third parties to provide underlay information to P2P overlay applications according to their requirements. We have made a state‐of‐the‐art review and comparison for addressing the overlay‐underlay mismatch in terms of their operation, merits, limitations, and future directions.     

A fairness adaptive TDMA scheduling algorithm for wireless sensor networks with unreliable links

Wireless sensor networks consist of a large number of wireless sensor nodes that organize themselves into multihop radio networks. With different link quality, different distance to the sink, nodes in a network are not treated equally, especially in a network with high traffic. In this paper, we propose a fairness adaptive time division multiple access scheduling algorithm (FATS) considering the fairness of network resource allocation. This algorithm, combining several heuristic algorithms, can assign network resources to the nodes to lead to maximizing the minimum end‐to‐end packet delivery success ratio. Because the wireless link is usually time‐varying, this algorithm can also assign the time slots to the nodes adaptively and energy‐efficiently according to the variation of link quality. We define several criteria for the slot assignment and adjustment. The change in slot assignment can be finished quickly during normal packet transmission, which causes little affect to the network. Meanwhile, considering the required data rate, FATS can achieve the maximum transmission capacity of the network with specified static or dynamic reliability. The simulation results show that the FATS can significantly reduce the difference of the end‐to‐end packet delivery ratio, track the variation of link quality quickly, and achieve the fairness of resource allocation.Copyright © 2012 John Wiley & Sons, Ltd.     

Experimental proof of concept of an SDN‐based traffic engineering solution for hybrid satellite‐terrestrial mobile backhauling

Satellite networks are expected to be an integral part of 5G service deployment. One compelling use case is mobile backhauling, where the exploitation of a satellite component can improve the reach, robustness, and economics of 5G rollout. The envisaged availability of new satellite capacity, together with the development of better integration approaches for the provisioning and operation of the satellite component in a more flexible, agile, and cost‐effective manner than done today, are expected to revamp such use case within the 5G ecosystem. In this context, sustained in the architectural designs proposed within H2020 VITAL research project, this paper presents an experimental proof of concept (PoC) of a satellite‐terrestrial integration solution that builds upon software‐defined networking (SDN) technologies for the realization of end‐to‐end traffic engineering (E2E TE) in mobile backhauling networks with a satellite component. A laboratory test bed has been developed and validated, consisting of a small‐scale private mobile network with a backhaul setting that combines Ethernet‐wired links, a satellite link emulator (OpenSAND), OpenFlow switches, and an OpenFlow controller running the network application for E2E TE. Provided results show the operation of a E2E TE application able to enforce different traffic routing and path failure restoration policies as well as the performance impact that it has on the mobile network connectivity services.     

An adaptive end‐to‐end RTO calculation framework for DTNs with scheduled connectivity

In this work, we propose an end‐to‐end retransmission framework for dynamically calculating efficient retransmission time‐out intervals in delay‐tolerant networks (DTNs) with scheduled connectivity. The proposed framework combines deterministic and statistical information about the network state to calculate worst‐case estimates about the expected round trip times. Such information includes connectivity schedules, convergence layer protocols specifics, communication link characteristics, and network statistics about the maximum expected packet error rates and storage congestion. We detail the implementation of the proposed framework within the end‐to‐end application data conditioning layer proposed for the DTN architecture, realized by the Delay‐Tolerant Payload Conditioning protocol, as part of the Interplanetary Overlay Network–DTN reference implementation, and evaluate its performance in a complex deep‐space emulation scenario in our DTN testbed. Our results show that our approach achieves great accuracy in round‐trip time estimations and, therefore, faster retransmissions of lost data, in comparison to the statically configured retransmission mechanism of the original Delay‐Tolerant Payload Conditioning protocol. As a result, in‐order data reception rate and storage requirements on the receiver side are significantly improved, at minimum or even zero extra cost in transmission overhead due to duplicate transmissions.     

Low‐jitter slot assignment algorithm for deadline‐aware packet transmission in wireless video surveillance sensor networks

This work presents a distributed time‐slot assignment algorithm which adopts TDMA as Medium Access Control, specially suited to support applications with strict delay, jitter, and throughput requirements characterized by convergecast traffic pattern in sensor networks. (e.g. wireless video surveillance sensor networks). The proposed algorithm has three characteristics: (1) every node is guaranteed a path to the base station for its data delivery. In the path, sufficient resource is reserved and weighted fairness can be achieved. (2) It uses cascading time‐slot assignment and jitter minimization algorithm in each node to minimize jitter and end‐to‐end delay. (3) Nodes are only active during their scheduled slots and sleep otherwise. This offers energy saving by reducing idle listening and avoiding overhearing. The performance of the proposed algorithm is evaluated over simulations and analyzed theoretically in comparison with existing slot assignment algorithm. The results show that our algorithm provides lower end‐to‐end delay, jitter, and higher throughput. Copyright © 2010 John Wiley & Sons, Ltd.     

Enhancing quality of experience using peer‐to‐peer overlay on device‐to‐device communications

With the recent development of LTE‐A/5G technologies, data sharing among mobile devices offer an attractive opportunity to reduce Internet access. However, it requires smart strategies to share the data with low trade‐offs in time, cost, and energy. Several existing schemes offer a super‐peer‐based two‐tier model using a distributed hash table (DHT) organization for smart devices having device‐to‐device (D2D)/Bluetooth/WiFi capabilities. The primary focus of these schemes has been to reduce Internet usage by increased D2D content sharing. However, the real challenge is not in creating a two‐tier model, but evolving an efficient overlay that offers enhanced opportunities for D2D content sharing over the existing model. In this paper, we formulated a P‐median‐based selection of tier‐1 devices in a distribution network and solved it using the Lagrangian relaxation method. The tier‐2 devices become clients seeking content sharing services from tier‐1 devices. A strong motivation in this work is to raise a user's perception of the grade of service known as quality of experience (QoE). We analyzed the challenge for QoE assessment in resource‐constrained smartphones under the proposed model of enhanced D2D communication. Our focus is to establish a framework to evaluate QoE for applications and services over LTE‐A/5G networks with an improved D2D communication level. The simulation and the experimental results validate the claim that substantial improvements in QoE are possible with the proposed mathematical model for selecting and placing tier‐1 mobile devices and maintaining a DHT for D2D communication.     

Real‐time performance evaluation of asynchronous time division traffic‐aware and delay‐tolerant scheme in ad hoc sensor networks

Wireless infrastructureless networks demand high resource availability with respect to the progressively decreasing energy consumption. A variety of new applications with different service requirements demand fairness to the service provision and classification, and reliability in an end‐to‐end manner. High‐priority packets are delivered within a hard time delay bound whereas improper power management in wireless networks can substantially degrade the throughput and increase the overall energy consumed. In this work a new scheme is being proposed and evaluated in real time using a state‐based layered oriented architecture for energy conservation (EC). The proposed scheme uses the node's self‐tuning scheme, where each node is assigned with a dissimilar sleep and wake time, based on traffic that is destined for each node. This approach is based on stream's characteristics with respect to different caching behavioral and storage‐capacity characteristics, and considers a model concerning the layered connectivity characteristics for enabling the EC mechanism. EC characteristics are modeled and through the designed tiered architecture the estimated metrics of the scheme can be bounded and tuned into certain regulated values. The real‐time evaluation results were extracted by using dynamically moving and statically located sensor nodes. A performance comparison is done with respect to different data traffic priority classifications following a real‐time asymmetrical transmission channel. Results have shown the scheme's efficiency in conserving energy while the topology configuration changes with time. Copyright © 2009 John Wiley & Sons, Ltd.     

Web browsing optimization over 2.5G and 3G: end‐to‐end mechanisms vs. usage of performance enhancing proxies

2.5 Generation (2.5G) and Third Generation (3G) cellular wireless networks allow mobile Internet access with bearers specifically designed for data communications. However, Internet protocols under‐utilize wireless wide area network (WWAN) link resources, mainly due to large round trip times (RTTs) and request‐‐reply protocol patterns. Web browsing is a popular service that suffers significant performance degradation over 2.5G and 3G. In this paper, we review and compare the two main approaches for improving web browsing performance over wireless links: (i) using adequate end‐to‐end parameters and mechanisms and (ii) interposing a performance enhancing proxy (PEP) between the wireless and wired parts. We conclude that PEPs are currently the only feasible way for significantly optimizing web browsing behavior over 2.5G and 3G. In addition, we evaluate the two main current commercial PEPs over live general packet radio service (GPRS) and universal mobile telecommunications system (UMTS) networks. The results show that PEPs can lead to near‐ideal web browsing performance in certain scenarios. Copyright © 2006 John Wiley & Sons, Ltd.     

An immunological approach for file recovery over JXTA peer‐to‐peer framework

Peer‐to‐peer (P2P) file‐sharing systems are characterized by highly replicated content that is distributed among nodes with enormous aggregate resources for storage and communication. File consistency is often compromised by undesirable changes, which should be detected and corrected in a timely fashion. The artificial immune system (AIS) is a novel evolutionary paradigm inspired by aspects of the biological immune system (BIS), such as protection, decentralization, autonomy, and anomaly detection. The AIS paradigm suggests a wide variety of mechanisms for solving complex computer problems. In this paper, we propose the ImmunoJXTA framework for file consistency management and file recovery using the main aspects of AIS in P2P systems. We implemented ImmunoJXTA on the JXTA P2P framework to recover distributed inconsistent files between peers efficiently. Promising results are achieved from experimental runs of the proposed framework. Copyright © 2010 John Wiley & Sons, Ltd.     

Slack time–based scheduling scheme for live video streaming in P2P network

Nowadays, peer‐to‐peer network plays a significant role in data transfer and communication. The past few years have witnessed considerable growth in this area because of its inherent advantages. Peer‐to‐peer live streaming has a significant impact on video transmission over the Internet. Major factors that influence the performance of P2P live streaming are overlay construction and scheduling strategies. Although, a large number of scheduling schemes are developed but none of them is comprehensive enough to provide solutions to live streaming issues. These suffer from substantial delay and low video quality at the receiver side. In this paper, a new start‐up–based selection procedure and slack time–based scheduling scheme is proposed. The start‐up selection procedure defines the start‐up buffer location for new peer, and the scheduling scheme selects both the chunk and peers. The proposed scheduling scheme uses both push and pull priority–based strategies. The simulation results of the proposed approach demonstrates significant improvement in both the network performance and video quality at the receiver side. It is observed that playback delay, startup delay, and end‐to‐end delay in the network are reduced and quality of the video at receiver side is improved as the distortion and frame loss ratio is decreased.     

A self‐adaptive algorithm for super‐peer selection considering the mobility of peers in cognitive mobile peer‐to‐peer networks

Cognitive peer‐to‐peer networks are obtained from a combination of cognitive networking concepts and peer‐to‐peer networks. These networks are able to improve their performance while operating under dynamic and unknown environments. A cognitive peer‐to‐peer network tries to learn an appropriate configuration for itself considering the unknown physical properties of peers. Cognitive mobile peer‐to‐peer networks refer to cognitive peer‐to‐peer networks which are built over mobile ad hoc networks. In these networks, heterogeneity of the mobility of peers and resource limitation in wireless networks create challenges for network management algorithms. Because of the dynamicity of these networks, the management algorithms should be designated in self‐adaptive manner. In one type of these networks, some peers, called super‐peers, undertake to perform network managerial tasks. The mobility of peers leads to connection failure among peers and reselection of new super‐peers. Therefore, the selection of super‐peers, due to their influential role, requires an algorithm that considers the peers' mobility. Up to now, no self‐adaptive algorithm has been designated for super‐peer selection considering the mobility of peers in a self‐adaptive manner. This paper proposes M‐SSBLA, a self‐adaptive algorithm for super‐peer selection considering the mobility of peers based on learning automata. The proposed algorithm is obtained from cooperation between a learning automata‐based cognitive engine and MIS. MIS is a well‐known super‐peer selection algorithm in mobile peer‐to‐peer networks. We compared the proposed algorithm with recently reported algorithms, especially for a network with high mobility. Simulation results show that the proposed algorithm can cover maximum ordinary‐peer with a few super‐peer and improve robustness against super‐peer failures while decreasing maintenance overhead.