QoS‐aware routing and power control algorithm for multimedia service over multi‐hop mobile ad hoc network

This paper presents a QoS (quality of service) aware routing and power control algorithm consuming low transmission power for multimedia service over mobile ad hoc network. Generally, multimedia services need stringent QoS over the network. However, it is not easy to guarantee the QoS over mobile ad hoc network since its network resources are very limited and time‐varying. Furthermore, only a limited amount of power is available at mobile nodes, which makes the problem more challenging. We propose an effective routing and power control algorithm for multimedia services that satisfies end‐to‐end delay constraint with low transmission power consumption. The proposed algorithm supports the required bandwidth by controlling each link channel quality over route in a tolerable range. In addition, a simple but effective route maintenance mechanism is implemented to avoid link failures that may significantly degrade streaming video quality. Finally, performance comparison with existing algorithms is presented in respect to traditional routing performance metrics, and an achievable video quality comparison is provided to demonstrate the superiority of the proposed algorithm for multimedia services over mobile ad hoc network. Copyright © 2010 John Wiley & Sons, Ltd.     

Delay constraint multipath routing for wireless multimedia ad hoc networks

According to the disadvantages of real time and continuity for multimedia services in ad hoc networks, a delay constraint multipath routing protocol for wireless multimedia ad hoc networks, which can satisfy quality of service (QoS) requirement (QoS multipath optimized link state routing [MOLSR]), is proposed. The protocol firstly detects and analyzes the link delay among the nodes and collects the delay information as the routing metric by HELLO message and topology control message. Then, through using the improved multipath Dijkstra algorithm for path selection, the protocol can gain the minimum delay path from the source node to the other nodes. Finally, when the route is launched, several node‐disjoint or link‐disjoint multipaths will be built through the route computation. The simulation and test results show that QoS‐MOLSR is suitable for large and dense networks with heavy traffic. It can improve the real time and reliability for multimedia transmission in wireless multimedia ad hoc networks. The average end‐to‐end delay of QoS‐MOLSR is four times less than the optimized link state routing. Copyright © 2014 John Wiley & Sons, Ltd.     

Cache Optimization on Hot‐Point Proxy Caching Using Weighted‐Rank Cache Replacement Policy

The development of proxy caching is essential in the area of video‐on‐demand (VoD) to meet users' expectations. VoD requires high bandwidth and creates high traffic due to the nature of media. Many researchers have developed proxy caching models to reduce bandwidth consumption and traffic. Proxy caching keeps part of a media object to meet the viewing expectations of users without delay and provides interactive playback. If the caching is done continuously, the entire cache space will be exhausted at one stage. Hence, the proxy server must apply cache replacement policies to replace existing objects and allocate the cache space for the incoming objects. Researchers have developed many cache replacement policies by considering several parameters, such as recency, access frequency, cost of retrieval, and size of the object. In this paper, the Weighted‐Rank Cache replacement Policy (WRCP) is proposed. This policy uses such parameters as access frequency, aging, and mean access gap ratio and such functions as size and cost of retrieval. The WRCP applies our previously developed proxy caching model, Hot‐Point Proxy, at four levels of replacement, depending on the cache requirement. Simulation results show that the WRCP outperforms our earlier model, the Dual Cache Replacement Policy.     

Managing QoS requirements for video streaming: from intra‐node to inter‐node

Streaming video over IP networks has become increasingly popular; however, compared to traditional data traffic, video streaming places different demands on quality of service (QoS) in a network, particularly in terms of delay, delay variation, and data loss. In response to the QoS demands of video applications, network techniques have been proposed to provide QoS within a network. Unfortunately, while efficient from a network perspective, most existing solutions have not provided end‐to‐end QoS that is satisfactory to users. In this paper, packet scheduling and end‐to‐end QoS distribution schemes are proposed to address this issue. The design and implementation of the two schemes are based on the active networking paradigm. In active networks, routers can perform user‐driven computation when forwarding packets, rather than just simple storing and forwarding packets, as in traditional networks. Both schemes thus take advantage of the capability of active networks enabling routers to adapt to the content of transmitted data and the QoS requirements of video users. In other words, packet scheduling at routers considers the correlation between video characteristics, available local resources and the resulting visual quality. The proposed QoS distribution scheme performs inter‐node adaptation, dynamically adjusting local loss constraints in response to network conditions in order to satisfy the end‐to‐end loss requirements. An active network‐based simulation shows that using QoS distribution and packet scheduling together increases the probability of meeting end‐to‐end QoS requirements of networked video. Copyright © 2005 John Wiley & Sons, Ltd.     

Interactive Broadcasting System for VBR Encoded Videos

Video broadcasting has been proved to be an efficient technique to increase the scalability of a video-on-demand (VoD) system. In this paper, we address the problems in providing interactive functions for VBR encoded videos in a broadcast VoD system. A traffic smoothing scheme is proposed to support the VCR functions in delivering VBR videos over CBR channels by the staggered broadcasting protocol. By introducing a small buffering delay, the customers are able to join back to the broadcasting groups after the interactive functions. A system model is then developed to determine the optimal parameters such that the system can meet the delay requirement as well as provide the expected quality of service to the customers. The results show that the proposed system framework is very efficient in terms of bandwidth requirement and buttering delay to provide interactive VoD services.     

Energy‐delay‐aware caching strategy in green CCN using markov approximation

One of the basic challenges in content‐centric networking (CCN) is how to optimize the overall energy consumption of content transmission and caching. Furthermore, designing an appropriate caching policy that considers both energy consumption and quality of service (QoS) is a major goal in green CCN. In this paper, the problem of minimizing the total CCN energy consumption while being aware of the end‐to‐end delay is formulated as an integer linear programming model. Since it is an Non‐deterministic Polynomial‐time (NP)‐hard problem, the Markov approximation method for an energy‐delay aware caching strategy (MAEDC) is proposed through a log‐sum‐exp function to find a near‐optimal solution in a distributed manner. The numerical results show that the MAEDC achieves near‐optimal energy consumption with better delay profile compared with the optimal solution. Moreover, due to the possibility of distributed and parallel processing, the proposed method is proper for the online situation where the delay is a crucial issue.     

FPN‐SAODV: using fuzzy petri nets for securing AODV routing protocol in mobile Ad hoc network

In this paper, we use fuzzy Petri nets (FPNs) to propose a secure routing protocol in mobile ad hoc network. The proposed method is based on secure ad hoc on‐demand distance vector (SAODV), which is named FPN‐SAODV. In FPN‐SAODV routing protocol, for each packet delivery or firing each transition, a type of bidirectional node‐to‐node fuzzy security verification is conducted that can be carried out with five security threshold levels. This inference uses four fuzzy variables that have been selected to well represent the malicious behaviors of some public attacks in mobile ad hoc network. Furthermore, a through route security verification has been used for selecting the most secure route among each candidate path through source node to destination. Both of these verifications utilize FPN inherent features for their operation. For evaluation purpose, we used the metrics such as packet delivery ratio, end‐to‐end delay, average security level of the nodes, and percentage of true/false detector nodes. These metrics have been used for investigating the inner operation of FPN‐SAODV as determining the proper level of security threshold level in node‐to‐node security verification module. Also, these are used for comparison of FPN‐SAODV performance versus the original AODV. Copyright © 2015 John Wiley & Sons, Ltd.     

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 heterogeneous‐network aided public‐key management scheme for mobile ad hoc networks

A mobile ad hoc network does not require fixed infrastructure to construct connections among nodes. Due to the particular characteristics of mobile ad hoc networks, most existing secure protocols in wired networks do not meet the security requirements for mobile ad hoc networks. Most secure protocols in mobile ad hoc networks, such as secure routing, key agreement and secure group communication protocols, assume that all nodes must have pre‐shared a secret, or pre‐obtained public‐key certificates before joining the network. However, this assumption has a practical weakness for some emergency applications, because some nodes without pre‐obtained certificates will be unable to join the network. In this paper, a heterogeneous‐network aided public‐key management scheme for mobile ad hoc networks is proposed to remedy this weakness. Several heterogeneous networks (such as satellite, unmanned aerial vehicle, or cellular networks) provide wider service areas and ubiquitous connectivity. We adopt these wide‐covered heterogeneous networks to design a secure certificate distribution scheme that allows a mobile node without a pre‐obtained certificate to instantly get a certificate using the communication channel constructed by these wide‐covered heterogeneous networks. Therefore, this scheme enhances the security infrastructure of public key management for mobile ad hoc networks. Copyright © 2006 John Wiley & Sons, Ltd.     

Improved video streaming using MSVC and nonoverlapping zone routing multipath propagation over MANETs

Providing real‐time video streaming in mobile ad hoc networks is difficult because of the time‐dependent channel status and stringent service requirements. The currently existing route request‐reply–based multihop overlay networks cause considerable control overheads in video transmission resulting in loss of data and communication breakdown. Such networks are more suitable to nonstreaming video applications rather than to time‐sensitive video streaming applications. Therefore, a powerful mechanism needs to be adopted to handle the channel failures amicably and reduce latency effectively in time critical video streaming applications over mobile ad hoc networks. In order to be resilient to the channel failures and reduce latency in such applications, 2 strategies, namely, multistate video coding and 2‐tier–based nonoverlapping zone routing multipath propagation through directional antennas have respectively been incorporated. The performance of the proposed nonoverlapping zone routing multipath propagation system is compared with those of the existing multicast zone routing and zone‐based hierarchical link state routing protocols with parameters average end‐to‐end delay, routing overhead and packet delivery ratio using NS 2.34. The simulation results show that latency and resilience get considerably improved. Finally, the video quality of the proposed work has been verified by subjective and objective video testing methods.     

Dynamic bandwidth allocation and buffer dimensioning under equal segment scheme to support video‐on‐demand services

This paper focuses on the optimization of network bandwidth allocation and buffer dimensioning to transport pre‐stored MPEG video data from source to playback destination across ATM networks. This is one of the most important issues in the support of video‐on‐demand (VoD) service. This paper provides a novel scheme in the dynamic allocation of bandwidth to segments of video using ABR mode. The dynamic bandwidth allocation is based on a new concept, called playback tunnel which is obtained from the traffic characteristics of the pre‐stored MPEG video trace to determine the optimum of transmission bandwidth as well as the buffer capacity to ensure that the playback buffer neither underflows nor overflows. The proposed scheme is tested with real‐life MPEG video traces. The obtained results have shown its significant performance improvement in terms of the capacity of playback buffer, the start‐up playback delay, the size of video segment and the network multiplexing gain. Copyright © 2001 John Wiley & Sons, Ltd.     

A secure and trust based on-demand multipath routing scheme for self-organized mobile ad-hoc networks

A mobile ad hoc network (MANET) is a self-configurable network connected by wireless links. This type of network is only suitable for provisional communication links as it is infrastructure-less and there is no centralized control. Providing QoS and security aware routing is a challenging task in this type of network due to dynamic topology and limited resources. The main purpose of secure and trust based on-demand multipath routing is to find trust based secure route from source to destination which will satisfy two or more end to end QoS constraints. In this paper, the standard ad hoc on-demand multi-path distance vector protocol is extended as the base routing protocol to evaluate this model. The proposed mesh based multipath routing scheme to discover all possible secure paths using secure adjacent position trust verification protocol and better link optimal path find by the Dolphin Echolocation Algorithm for efficient communication in MANET. The performance analysis and numerical results show that our proposed routing protocol produces better packet delivery ratio, reduced packet delay, reduced overheads and provide security against vulnerabilities and attacks.     

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.     

QoS‐driven jointly optimal subcarrier pairing and power allocation for OFDM amplify‐and‐forward relay systems

In this paper, we investigate the quality‐of‐service (QoS) driven subcarrier pairing and power allocation for two‐hop amplify‐and‐forward OFDM relay systems. By integrating the concept of effective capacity, our goal is to maximize the system throughput subject to a given delay QoS constraint. We propose a jointly optimal subcarrier pairing and power allocation scheme, which can be implemented with two separate steps. First, pair the subcarriers over the source‐relay channel and relay‐destination channel by the descending order of the subcarriers’ channel gains. Second, by making use of the derived equivalent end‐to‐end channel gains of the subcarrier pairs, optimally allocate power over the subcarrier pairs, and then optimally partition the power of the subcarrier pairs between the source and the relay. The simulation results show that our proposed scheme can efficiently provide different levels of delay QoS guarantees, even if under stringent delay QoS constraints. The simulation results also verify that our proposed scheme shows significant superiorities over the other existing schemes. Copyright © 2013 John Wiley & Sons, Ltd.     

QoS‐aware broadcasting in VANETs based on fuzzy logic and enhanced kinetic multipoint relay

Vehicular ad hoc networks (VANETs) are emergent concepts in terms of infrastructure‐less communication. The data dissemination is usually done using broadcast schemes. Data broadcast in VANETs is a challenging issue due to the high mobility vehicles and the varying density. On one hand, these vehicles have to share and disseminate the safety‐critical information, in real time, to other intended vehicles. On the other hand, the existing broadcast solutions do not succeed, till now, to fulfill VANETs requirements especially in terms of performance and QoS. In this paper, we propose a new QoS‐aware broadcast method in order to face VANETs communications challenges. We choose to adapt a concept originally devoted to mobile ad hoc networks (MANETs) and join it to other specific VANET techniques to introduce a new broadcasting protocol in the aim of optimizing QoS fulfilment. The proposed solution is fundamentally based on enhanced kinetic strategy assisted with fuzzy logic for QoS‐aware multipoint relay (MPR). The protocol efficiency is eventually tested through an experimental study and compared with existing methods. The results prove the over‐performance of the proposed solution.     

Provision of continuous VCR functions in interactive broadcast VoD systems

Video broadcasting is one of the feasible solutions to implement a large-scale video-on-demand (VoD) system. Nevertheless, it is still an open issue for the provision of continuous VCR functions in a delay insensitive broadcast VoD system. In this paper, we propose to jointly optimize an active buffer management scheme with contingency channels to support the VCR functions in an efficient protocol called partitioned broadcasting. We develop a greedy channel management scheme by exploiting the property of the broadcasting protocol such that the system bandwidth capacity can be fully utilized. Incorporating the channel management scheme with the partitioned video broadcast, the VoD system not only provides delay insensitive services but also handles all the interactive requests. Extensive simulation results demonstrate that the partitioned broadcasting system outperforms the traditional system based on the staggered broadcasting protocols. It is found that 20 broadcasting channels and 10 contingency channels are sufficient to support on average 720 customers for a single video with less that one second start-up delay and all types of VCR functions.     

Fuzzy Logic QoS Dynamic Source Routing for Mobile Ad Hoc Networks

Considering the characters of dynamic topology and the imprecise state information in mobile ad hoc network,we propose a Fuzzy Logic QoS Dynamic Source Routing(FLQDSR)algorithm based on Dynamic Source Routing(DSR)protocol while adopting fuzzy logic to select the appropriate QoS routing in multiple paths which are searched in parallel.This scheme considers not only the bandwidth and end-to-end delay of routing,but also the cost of the path.On the otherhand the merit of using fuzzy logic is that it can be implemented by hardware.This makes the realization of the schemeeasier and faster.However our algorithm is based on DSR,the maximal hop count should be less than 10,i.e.,the scaleof mobile ad hoc network should not be very large.Simulation results show that FLQDSR can tolerate a high degree of in-formation imprecision by adding the fuzzy logic module which integrates the QoS requirements of application and the rout-ing QoS parameters to determine the most qualified one in every node.     

Cross-Layer Design for Data Accessibility in Mobile Ad Hoc Networks

Mobile ad hoc networks (MANET) are becoming an integral part of the ubiquitouscomputing and communication environment, providing new infrastructure formultimedia applications such as video phone, multimedia-on-demand, and others.In order to access multimedia information in MANET, Quality of Service (QoS)needs to be considered, such as high success rate to access multimedia data,bounded end-to-end delay, and others. In this paper, we present a dataaccessibility service for a group of mobile users to access desired data withhigh success rate. This accessibility service is only possible if we utilizeadvanced data advertising, lookup and replication services, as well as a novelpredictive location-based QoS routing protocol in an integrated fashion. Usingcross-layer design, we illustrate how the QoS routing protocol assists dataadvertising, lookup and replication services to achieve high data accesssuccess rate. Simulation results have shown that our design is successful ina dynamic MANET.     

移动自组网QoS路由协议研究

移动自组网是由一组带有无线收发装置的移动节点组成的一个多跳的临时性的自治系统。随着无线通信中多媒体业务的增加,在移动自组网中提供QoS(Quality of Sevice服务质量)保障具有越来越重要的意义,而QoS路由技术则是其中的核心技术和热点问题。文章指出移动自组网QoS路由的困难,对移动自组网典型QoS路由协议进行了详细的分析与比较,并对几种较新的移动自组网QoS路由协议进行了介绍,末了对移动自组网QoS路由协议的发展进行了展望。     

Performance study of a wireless mobile ad hoc network with orientation‐dependent internode communication scheme

A Petri‐net‐based simulation model of a wireless mobile ad hoc network is developed and studied. The model covers all the fundamental aspects of behaviour of such a network and uses a novel scheme of orientation‐dependent (or sector‐dependent) internode communication, with random states of links. The proposed scheme enables representation of reliability aspects of wireless communication, such as fading effects, interferences, presence of obstacles and weather conditions in a general and rather easy way. The simulation model was implemented in terms of a class of extended Petri nets to explicitly represent parallelism of events and processes in the WLAN as a distributed system. In the simulation, the behaviour of four fundamental performance metrics — packet delivery ratio, average number of hops, relative network traffic and end‐to‐end delay — were investigated with varying distance of transmission and different combinations of model parameters. Copyright © 2012 John Wiley & Sons, Ltd.