Error control for multimedia communications in wireless sensor networks: A comparative performance analysis

The emerging multimedia applications of Wireless Sensor Network (WSNs) impose new challenges in design of algorithms and communication protocols for such networks. In the view of these challenges, error control is an important mechanism that enables us to provide robust multimedia communication and maintain Quality of Service (QoS). Despite the existence of some good research works on error control analysis in WSNs, none of them provides a thorough study of error control schemes for multimedia delivery. In this paper, a comprehensive performance evaluation of Automatic Repeat Request (ARQ), Forward Error Correction (FEC), Erasure Coding (EC), link-layer hybrid FEC/ARQ, and cross-layer hybrid error control schemes over Wireless Multimedia Sensor Network (WMSNs) is performed. Performance metrics such as energy efficiency, frame Peak Signal-to-Noise Ratio (PSNR), frame loss rate, cumulative jitter, and delay-constrained PSNR are investigated. The results of our analysis show how wireless channel errors can affect the performance of multimedia sensor networks and how different error control scenarios can be effective for those networks. The results also provide the required insights for efficient design of error control protocols in multimedia communications over WSNs.     

Multipath Security Aware Routing Protocol for MANET Based on Trust Enhanced Cluster Mechanism for Lossless Multimedia Data Transfer

The dynamic nature of mobile nodes of ad hoc network is mostly affected by security problems which reduce data forwarding rate in multimedia sources. Due to the rapid growth of wireless applications, the different multitalented routing protocols are proposed in recent years. But the recent protocols are not efficient for multimedia applications, till now, specific security aware routing protocols are not proposed for multimedia data transfers. In this paper, we proposed trust enhanced cluster based multipath routing (TECM) algorithm. We use energy efficient PSO algorithm used to create cluster formation and cluster head, super cluster head are selected from trust values, which compute form proposed TECM algorithm. The multi trust factors are used for trust computation, such as frame/packet loss ratio, frame/packet forward energy, frame/packet receiving energy, routing overhead, received signal strength, frame/packet forward rate, average forward delay and protocol deviation flag. We then combine proposed TECM algorithm with standard multipath OLSR protocol (TECM-OLSR) to analyze the performance of proposed algorithm. The simulated results show that proposed TECM-OLSR protocol is very effective in terms of loss and delivery rate, delay, routing overhead and network lifetime compare to FPNT-OLSR.     

A gradient‐based multiple‐path routing protocol for low duty‐cycled wireless sensor networks

Routing in a low duty‐cycled wireless sensor network (WSN) has attracted much attention recently because of the challenge that low duty‐cycled sleep scheduling brings to the design of efficient distributed routing protocols for such networks. In a low duty‐cycled WSN, a big problem is how to design an efficient distributed routing protocol, which uses only local network state information while achieving low end‐to‐end (E2E) packet delivery delay and also high packet delivery efficiency. In this paper, we study low duty‐cycled WSNs wherein sensor nodes adopt pseudorandom sleep scheduling for energy saving. The objective of this paper is to design an efficient distributed routing protocol with low overhead. For this purpose, we design a simple but efficient hop‐by‐hop routing protocol, which integrates the ideas of multipath routing and gradient‐based routing for improved routing performance. We conduct extensive simulations, and the results demonstrate the high performance of the proposed protocol in terms of E2E packet delivery latency and packet delivery efficiency as compared with existing protocols. Copyright © 2014 John Wiley & Sons, Ltd.     

A novel hierarchical model for vehicular traffic regulation

The aim of the research is to regulate the vehicular traffic in the most effective and efficient way in Vehicular Adhoc Networks (VANET). The challenges faced by the existing networks are ripple effect of reclustering, communication complexity, mobility, throughput and delay in an urban environment. Moreover unpredictable topology changes in VANET, obstruct expected packet delivery ratio and leads to congestion by overheads for link maintenance. The existing routing techniques suffer from excessive loss of data, delay and need for continuous monitoring where group member’s loss their link in randomwaypoint mobility scenarios. In this paper, a novel hierarchical model combining the features of hierarchical clustering, hybrid mobility model and location based 2hop Multicast Flooding (L2MF) for data forwarding has been proposed. By comparing the proposed protocol with previous protocols, the enhanced performance in packet delivery ratio, control overhead, and end-to-end delay has been proved.     

Aggregated traffic flow weight controlled hierarchical MAC protocol for wireless sensor networks

It has been discussed in the literature that the medium-access control (MAC) protocols, which schedule periodic sleep–active states of sensor nodes, can increase the longevity of sensor networks. However, these protocols suffer from very low end-to-end throughput and increased end-to-end packet delay. How to design an energy-efficient MAC protocol that greatly minimizes the packet delay while maximizing the achievable data delivery rate, however, remains unanswered. In this paper, motivated by the many-to-one multihop traffic pattern of sensor networks and the heterogeneity in required data packet rates of different events, we propose an aggregated traffic flow weight controlled hierarchical MAC protocol (ATW-HMAC). We find that ATW-HMAC significantly decreases the packet losses due to collisions and buffer drops (i.e., mitigates the congestion), which helps to improve network throughput, energy efficiency, and end-to-end packet delay. ATW-HMAC is designed to work with both single-path and multipath routing. Our analytical analysis shows that ATW-HMAC provides weighted fair rate allocation and energy efficiency. The results of our extensive simulation, done in ns-2.30, show that ATW-HMAC outperforms S-MAC; traffic-adaptive medium access; and SC-HMAC.     

一种无线传感器网络性能评估及优化方法

 文章提出了一种无线传感器网络性能评价及优化方法,以单位能耗所支持的平均数据速率为量度,分析了路由策略、接入机制及物理层传输技术对网络性能的综合影响。在讨论单跳分组成功传输概率、时延的基础上,将问题拓展至多跳网络,对网络端到端分组成功传输概率、耗时、耗能进行了统计分析,导出了单位能耗所支持的平均数据速率的表达式,并依此对网络性能进行了仿真研究。结果表明：网络性能可以通过优化分组发送概率和编码纠错能力的方法得到较大改进。     

Low-overhead video compression combining partial discrete cosine transform and compressed sensing in WMSNs

Wireless multimedia sensor network (WMSN) is a special wireless sensor network (WSN) made up of several multimedia sensor nodes, specially designed to retrieve multimedia content such as video and audio streams, still images, and scalar sensor data from the environment. Due to strict inherent limitations in terms of processing power, storage and bandwidth, data processing is a challenge in such network. Further, energy is one of the scarcest resources in WSN, especially in WMSN and therefore, saving energy is of utmost importance. Data compression is one of the solutions of such a problem. This paper proposes an energy saving video compression technique for WMSN by judicious combination of partial discrete cosine transform and compressed sensing. This amalgamation exploits the benefits of both the techniques towards fulfilling the objective of saving energy along with achieving desired peak signal to noise ratio (PSNR). When the transform technique ensures low-overhead compression, compressed sensing guarantees the reconstruction of the same video with lesser amount of measurements. Performance of the scheme is measured both qualitatively and quantitatively. In qualitative analysis, overhead of the scheme is measured in terms of storage, computation, and communication overheads and the results are compared with a number of existing schemes including the base scheme. The results show considerable reduction of all such overheads thereby justifying the appropriateness of the proposed scheme for resource-constrained networks like WMSNs. In quantitative analysis, for both ideal and packet loss environment, the scheme is simulated in Cooja, the Contiki network simulator to make it readily implementable in real life mote e.g. MICAz. When compared with the existing state-of-the-art schemes, it performs better not only in terms of 34.31% energy saving but also in getting an acceptable PSNR of 35–37 dB and SSIM of 0.85–0.88 in ideal environment. In packet loss environment, these values are 32.9–35.5 dB and 0.81–0.85 respectively implying acceptable reconstruction even in packet loss environment. Further, it requires the least storage of 51.2 KB. The observation on simulation results is also justified by statistical analysis.

     

Gigabit networking research at Bellcore

A communication architecture appropriate for gigabit networks, the multimedia end-to-end communication architecture (MECA), is described. MECA provides multimedia applications with the service they require in a single communication system. MECA encompasses the network, host-network interface, and associated protocols. The architectural characteristics of MECA are compared with those of existing communication systems and the TP++ transport protocol used by MECA is compared to existing transport protocols. Three host-network interfaces built for AURORA, a five-gigabit testbed network that includes an experimental asynchronous transfer mode (ATM) network running over a synchronous optical network (SONET), are described. The Sunshine ATM switch that supports MECA using a scalable Batcher-Banyan switching fabric and highly programmable port controllers is discussed     

Energy Efficient Reliable Multi-path Data Transmission in WSN for Healthcare Application

In healthcare applications of WSN, the data loss due to congestion may cause death alarm for a patient in critical condition. Therefore, an efficient congestion avoidance or otherwise an efficient congestion control mechanism is required. In this paper, we present an energy efficient reliable multi-path data transmission protocol for reliable data transport over WSN for the health care application. The emergency data and sensitive data packets are transmitted through an alternate path having minimum correlation with transmission interference during congestion. The proposed protocol attempts to avoid congestion by computing the probability of congestion at the intermediate nodes and transmission rate at the intermediate node is adjusted. The buffer of each node is partitioned to support fair and efficient data delivery. The reliability of the proposed protocol is achieved through hop-by-hop loss recovery and acknowledgement. The performance of the proposed protocol is evaluated through extensive simulations. The simulation results reveal that it outperforms the existing congestion control protocols for healthcare application in terms of energy efficiency, reliability and end-to-end delivery ratio.     

DC-Gear: 延时约束型无线传感网占空比调控策略研究

Many Wireless Sensor Network (WSN) systems are deployed in unattended areas using non-rechargeable batteries. To enable sustainable operations, most WSN systems employ duty-cycling mechanisms, such as Low Power Listening (LPL). For reliable delivery of each packet with LPL, the sender has to transmit a preamble that is long enough to span over a complete sleep interval of the receiver. In this way, the sensor nodes avoid idle listening, however, at the cost of remarkably increased end-to-end delay of multi-hop packet transmissions. To address this issue, in this paper we propose a new duty-cycling mechanism called DC-Gear. DC-Gear exploits a“sleep less but save more” phenomenon, which means increasing the duty cycle in a timely and appropriate manner while minimizing the overall energy cost and satisfying the end-to-end delay constraint. We have implemented DC-Gear with TelosB motes and demonstrated its performance advantages through extensive experiments.     

End-to-end optimized TCP-friendly rate control for real-time video streaming over wireless multi-hop networks

Rate control is an important issue in video streaming applications. The most popular rate control scheme over wired networks is TCP-Friendly Rate Control (TFRC), which is designed to provide optimal transport service for unicast multimedia delivery based on the TCP Reno’s throughput equation. It assumes perfect link quality, treating network congestion as the only reason for packet losses. Therefore, when used in wireless environment, it suffers significant performance degradation because of packet losses arising from time-varying link quality. Most current research focuses on enhancing the TFRC protocol itself, ignoring the tightly coupled relation between the transport layer and other network layers. In this paper, we propose a new approach to address this problem, integrating TFRC with the application layer and the physical layer to form a holistic design for real-time video streaming over wireless multi-hop networks. The proposed approach can achieve the best user-perceived video quality by jointly optimizing system parameters residing in different network layers, including real-time video coding parameters at the application layer, packet sending rate at the transport layer, and modulation and coding scheme at the physical layer. The problem is formulated and solved as to find the optimal combination of parameters to minimize the end-to-end expected video distortion constrained by a given video playback delay, or to minimize the video playback delay constrained by a given end-to-end video distortion. Experimental results have validated 2–4 dB PSNR performance gain of the proposed approach in wireless multi-hop networks by using H.264/AVC and NS-2.     

A Delay-Tolerant Virtual Tunnel Scheme for Asynchronous MAC protocols in WSN

Typically, asynchronous MAC protocols are used to monitor a significant facility for rare events or to detect an intrusion in wireless sensor networks. Moreover, asynchronous MAC protocols can achieve high energy efficiency due to the fact that there is no periodic control frame. However, asynchronous MAC protocols have the problem of long end-to-end delay time caused by the absence of precedent time synchronization per link. This paper proposes a new scheme, called virtual tunnel (VT), which can reduce the delivery delay of asynchronous MAC protocols in multi-hop environment. The VT scheme can achieve approximated duty cycle synchronization with on-demand approach. In this scheme, through the estimation of next wakeup time of peer node, without exceptional process, each node on the transmission path can improve end-to-end delay in multi-hop topologies. And it becomes low power consumption by reducing unnecessary retransmissions. Additionally, we devise the protection method of VT. In our simulation results, end-to-end delay according to hop counts and traffic amount is compared with the X-MAC that is an asynchronous protocol recently developed. Furthermore, it is shown that the VT scheme decreases energy consumption due to the lower end-to-end delay than the X-MAC in multi-hop topologies.     

Object-oriented communication structures for multimedia datatransport

The evolving multimedia applications generate requirements for complex transport capabilities, i.e., functional features, in the end-to-end communication system such as handling of heterogeneity among communicating terminals, supporting finer levels of user-specifiable quality of data transport service, and synchronization of various data streams for delivery at users in real time. Accordingly, the communication system may be viewed as extending the basic capabilities provided by the backbone network (e.g., bandwidth allocation) into a set of transport capabilities suitable for complex applications. This paper presents: (1) an object-oriented view of the user interface to the communication system with an elegant separation of data transport functionalities, and (2) an approach to the design of underlying transport protocols. The object-orientation decomposes an application-level data transport into a set of network channel objects, with each channel object handling a separate data stream. The object interactions are modeled using a “data-flow programming” style, which allows a richer set of protocols to implement the communication system and offers flexibility to accommodate complex and heterogeneous subscriber services/terminals. The “data-flow programming” method also allows a high degree of communication level parallelism among data transport through channels. The view of a multimedia communication system as a “parameterizable black-box”, as underscored in the object-oriented structuring, allows easier interworking of the communication system with existing networks and easier integration of multimedia transport into programming environments     

Congestion Aware Geographic Routing Protocol for Wireless Ad Hoc and Sensor Networks

Geographic routing protocols forward packets according to the geographical locations of nodes. Thus, the criteria used to select a forwarding node impacts on the performance of the protocols such as energy efficiency and end-to-end transmission delay. In this paper, we propose a congestion aware forwarder selection (CAFS) method for a geographic routing protocol. To design CAFS, we devise a cost function by combining not only the forward progress made to a packet but also the amount of energy required for packet forwarding, forwarding direction, and congestion levels of potential forwarders. Among the potential forwarders, CAFS selects the next forwarder having the minimum cost. In our simulation studies, we compare the performance of CAFS with those of the maximum progress (MP) method and the cost over progress (CoP) method in various network conditions. The results show that compared with MP, the length of a routing path in terms of the number of hops becomes longer when CAFS is used. However, the shorter hop distance helps to avoid unnecessary retransmissions caused by packet loss in a wireless channel. In addition, since CAFS considers congestion levels of candidate forwarders, it reduces the queuing delay in each forwarder. Therefore, CAFS is superior to the MP and the CoP in terms of the energy consumption, end-to-end packet transfer delay, and the successful packet delivery rate.     

Towards a new generation of transport services adapted to multimedia applications

A partial order and partial reliable connection (POC) is an end-to-end transport connection authorized to deliver objects in an order that can differ from the transmitted one. The service provided by such a connection is also authorized to lose some objects in a controlled manner. The POC approach establishes a conceptual link between connectionless best-effort (CL) and connection-oriented reliable (co) protocols. POC is motivated by heterogeneous CL networks such as Internet which are plagued by unordered delivery of packets and losses, which in turn tax the performances of current protocols. Moreover, it has been shown, that out of order delivery is able to economize the use of network resources such as memory and bandwidth, and reduces end-to-end transit delay. To take advantage of POC’S benefits, applications must be able to relax some transport constraints. In this paper a temporal extension of POC, called TPOC (for temporal POC), is introduced. TPOC offers a conceptual framework, which allows the Qos of distributed multimedia applications to be taken into account. The architecture for offering a TPOC transport service is introduced and evaluated for the transport of MPEG video streams. We demonstrate that POC connections fill not only the conceptual gap between CL protocols (such as UDP) and CO protocols (such as TCP) but also provides demonstrable performances improvements for the transport of multimedia streams such as MPEG video.     

A hybrid beaconless geographic routing for different packets in WSN

The localized operation and stateless features of geographic routing make it become an attractive routing scheme for wireless sensor network (WSN). In this paper, we proposed a novel routing protocol, hybrid beaconless geographic routing (HBGR), which provides different mechanisms for different packets. Based on the requirement of application on latency, we divide the packets of WSN into delay sensitive packets and normal packets. HBGR uses two kinds of Request-To-Send/Clear-To-Send handshaking mechanisms for delay sensitive packets and normal packets, and assigns them different priority to obtain the channel. The simplified analysis is given, which proves that delay sensitive packets have lower latency and higher priority to obtain the channel than normal packets. Moreover, forwarding area division scheme is proposed to optimize the forwarder selection. Simulation results show that HBGR achieves higher packet delivery ratio, lower End-to-End latency and lower energy consumption than existing protocols under different packet generation rates in stationary and mobility scenario. Besides, compared with normal packets, delay sensitive packets have at least 10 % (9 %) improvement in terms of End-to-End latency. The improvement increases with the increasing of packet generation rate, and achieves 58 % (73 %) when the packet generation rate is 24 packets per second in stationary (mobility) scenario.     

An Efficient,Scalable Key Transport Scheme (ESKTS) for Delay/Disruption Tolerant Networks

In the past, security protocols including key transport protocols are designed with the assumption that there are two parties communication with each other and an adversary tries to intercept this communication. In Delay/Disruption Tolerant Networking (DTN), packet delivery relies on intermediate parties in the communication path to store and forward the packets. DTN security architecture requires that integrity and authentication should be verified at intermediate nodes as well as at end nodes and confidentiality should be maintained for end communicating parties. This requires new security protocols and key management to be defined for DTN as traditional end-to-end security protocols will not work with DTN. To contribute towards solving this problem, we propose a novel Efficient and Scalable Key Transport Scheme (ESKTS) to transport the symmetric key generated at a DTN node to other communicating body securely using public key cryptography and proxy signatures. It is unique effort to design a key transport protocol in compliance with DTN architecture. ESKTS ensures that integrity and authentication is achieved at hop-by-hop level as well as end-to-end level. It also ensures end-to-end confidentiality and freshness for end communicating parties. This scheme provides a secure symmetric key transport mechanism based on public key cryptography to exploit the unique bundle buffering characteristics of DTN to reduce communication and computation cost .     

Energy‐aware geographic routing in wireless sensor networks with anchor nodes

Energy efficiency has become an important design consideration in geographic routing protocols for wireless sensor networks because the sensor nodes are energy constrained and battery recharging is usually not feasible. However, numerous existing energy‐aware geographic routing protocols are energy‐inefficient when the detouring mode is involved in the routing. Furthermore, most of them rarely or at most implicitly take into account the energy efficiency in the advance. In this paper, we present a novel energy‐aware geographic routing (EAGR) protocol that attempts to minimize the energy consumption for end‐to‐end data delivery. EAGR adaptively uses an existing geographic routing protocol to find an anchor list based on the projection distance of nodes for guiding packet forwarding. Each node holding the message utilizes geographic information, the characteristics of energy consumption, and the metric of advanced energy cost to make forwarding decisions, and dynamically adjusts its transmission power to just reach the selected node. Simulation results demonstrate that our scheme exhibits higher energy efficiency, smaller end‐to‐end delay, and better packet delivery ratio compared to other geographic routing protocols. Copyright © 2011 John Wiley & Sons, Ltd.     

Web Based Cross Layer Optimization Technique for Energy Efficient WSN

In recent days, wireless sensor networks (WSN) plays a major role in the real time applications like military battlefield surveillance, industrial process monitoring, machine health monitoring and so on. In WSN, selecting the cluster head (CH) is the challenging task. CH selection is done by considering parameters of single layer only. In cross layer protocol more than one layers are considered for inter related parameters such as integration of MAC/physical layer and integration routing/MAC/physical layers. The main drawback of layer-based approach is not considering the effect on improvement of particular layer parameter to other layer parameters. In this paper, new cross layer technique for energy efficient module is designed to address the energy efficiency issues, which is common to all layers and used to optimize the energy from one layer parameter by others. Nowadays everything is possible with the help of Internet, so sharing the information between WSN and TCP through the energy efficient cross layer can be done. It is done with transport layer to enhance the application filed to be reliably connected to the web. In this paper, dynamically adapted sleep scheduling mechanism is used with residual energy of each node. Virtual end-to-end packet rate selection and congestion control feedback mechanism are considered for end to end delay. This reduces the packet loss with the support of data-rate adaptation technique.

     

End-to-End Performance Improvement of the Wireless Channel for Video Transmission

Real time video transmission in wireless environment considers various parameters of wireless channel like information rate, error resiliency, security, end-to-end latency, quality of service etc. The available internet protocols are transmission control protocol and user datagram protocol (UDP). But most of the real-time applications uses UDP as their transport protocol. UDP is a fast protocol suitable for delay sensitive applications like video and audio transmission as it does not provide flow control or error recovery and does not require connection management. Due to the tremendous growth in wired and wireless real-time applications, some improvements should be made in the existing systems or protocols. Various techniques to improve end-to-end performance of system for real time video transmission over wireless channel are available in literature. Authors claim that the solution suggested in the paper provide more reliability in wireless video transmission. In the proposed solution, adaptive redundant packets are added in every block (or datagram) transmitted in order to achieve a desired recovery rate at the receiver. The suggested method dose not use any retransmission mechanism. The network simulator NS-2 is used to evaluate the method and the simulation results indicate that the proposed method can guarantee satisfied end-to-end performance by increased packet delivery ratio, reduced end-to-end delay and hence increased network throughput for video transmission in wireless network.