On file-based content distribution over wireless networks via multiple paths: Coding and delay trade-off

This paper presents a digital fountain code as a design criterion in order to mitigate packet erasure in wireless wearable body area networks (WBANs). First, we measure its radio propagation around the human body between two antennas attached to participants, and then analyze the measurement results from the standpoint of occurrence ratio of packet erasure. Then, we evaluate the application of digital fountain code into such WBANs where a rateless code is introduced as such code in order to provide a design criterion for the code.

Mobile ad hoc networks (MANETs) are self-configured networks without any infrastructure-based network. The mobile nodes (MNs) are continuously deployed in an infrastructure-based network, whereas infrastructure-less network MNs are placed at random positions with mobility, i.e., movements of MNs. The major problem of ad hoc networks is routing and mobility of a node between the source and destination of a node. Due to the high movement in a wireless network, the MNs are not able to establish the connection between source and destination nodes. The network performances measures such as bandwidth and delay which are often changed due to MNs mobility, i.e., these network metrics include inconsistencies in a wireless ad hoc network. The uncertainties create a problem in the choice of the best route from the origin node to the recipient node unit. In this work, fuzzy mobility (FM) is used to resolve the issue of routing and mobility for better route selection in a wireless network. The performance results compared with the well-known existing wireless ad hoc routing protocols based on the packet delivery ratio (PDR), delay and throughput metrics. A fuzzy mobility-based selection gives better results when compared to other mobility models such as Random Way Point (RWP) and Random Direction (RD).KeywordsAd hoc networkFuzzyMobilityRouting first section

<p>This paper studies whether a packet will ultimately succeed in reaching a given destination, how longthis will take and how much energy may be expended, in the context of a network with imperfectrouting tables and non-homogeneous network characteristics. It also investigates the effect of non-cooperativeroutersthatmayactuallychoosetodropcertainpacketsiftheyviewthemtobedangerousfordestinationnodes,aswhenpacketsmaybecarryingworms,virusesormalware,andwhencertainpackets have been identified as being part of a Denial of Service attack. The approach we take is toconstruct a probability model for packet travel from a source to destination node in a large non-homogeneous multiple hop network.The randomness models the lack of precise routing informationat each of the network hops, and randomness in routing can also be used to model networks whereone wishes to explore alternate paths in a network to discover the more reliable paths, or those thatmay have other desirable characteristics such as lower delay or lower packet loss. We assume thateach packet has the same time out: when the time-out elapses, the packet is dropped if it has notyet reached the destination, and some time later the source will retransmit a duplicate packet. A numerical–analytical solution is developed to compute the average travel time of the packet fromsource to destination and to estimate its total energy consumption. Two applications of these resultsare then presented. In the first one, the packet is an ‘attack’packet (e.g. a Denial of Service packet, orsome malware) and as it approaches the destination node it is being frequently inspected by routersthat may decide to drop it if they correctly detect that it is a threat. The second example considers awireless network where areas which are remote from the source and destination nodes have poorer wireless coverage so that packet losses become more frequent as packets ‘unknowingly’ (due to routing table errors) meander away from the main coverage area. Other applications in wireless networks are also provided and a simulation study is performed to validate the analytical model.</p>

A fundamental challenge in wireless networks is how to handle packet loss due to noise, interference, and dynamic channel effects, especially when there is no per-packet acknowledgement due to additional delay and potential loss of feedback packets. We design and implement a packet coding optimization scheme, applied at the source node, to enhance end-to-end transmission reliability in a lossy multi-hop network. Specifically, each source node transmits a file of packets to its destination node in the network where the end-to-end packet acknowledgement is not readily available because of the possible error or delay effects over multiple hops. By simply retransmitting packets, a source node cannot guarantee innovative packet arrivals at the destination node. Thus, we design an optimization scheme for adaptive packet coding applied at the source node to avoid transmitting redundant packets, thereby significantly improving the throughput, even for the case of a single unicast session. This scheme does not require any knowledge of network topology and can seamlessly operate with any routing or network coding protocol used at the intermediate relay nodes. We analyze the throughput properties of coded transmissions and verify the feasibility of performance gains via simulations. Then, we provide high fidelity emulation testbed results with real radio transmissions over emulated channels to evaluate the throughput gains. Without relying on end-to-end acknowledgment for each packet, we show that the adaptive packet coding optimization scheme can achieve significantly higher throughput than the retransmission scheme in lossy networks with unicast traffic.

Channel bonding (CB) is a proven technique to increase bandwidth and reduce delays in wireless networks. It has been applied in traditional wireless networks such as cellular networks and wireless local area networks along with the emerging cognitive radio networks. This paper first focuses on providing a survey of CB schemes for traditional wireless networks such as cellular networks, wireless local area networks, and wireless sensor networks, and then provides a detailed discussion on the CB schemes proposed for cognitive radio networks. Finally, we highlight a number of issues and challenges regarding CB in cognitive radio sensor networks and also provide some guidelines on using CB schemes in these futuristic networks.

Mesh routers in wireless mesh networks (WMNs) utilize multiple radio interfaces in order to improve the performance of wireless network, resulting in transmitting multiple packets simultaneously on different orthogonal channels without interference. For the purpose of achieving the goal, routing protocols should be designed to improve the utilization of the network resources when selecting routes between source and destination nodes. However, single path routing protocols cannot explore the path providing sufficient bandwidth if the source traffic requires more bandwidth than the available bandwidth of the route. In this paper, we therefore propose a novel multipath routing algorithm which can explore multiple paths with sufficient bandwidth and transmit packets along disjointed paths simultaneously. we also introduce the path metrics which can estimate the available bandwidth of the path, considering the interface utilization information of each node, the channel diversity of route, and the intra-flow of the traffic. Using NS-2 simulations, we observe that our proposed multi-path routing protocol contributes to the performance improvements in terms of the end-to-end delay and the throughput in WMNs.

The increasing popularity of video streaming applications that distribute data to a large number of clients motivates the design of reliable multimedia delivery systems capable of adapting to diverse transmission conditions. Receiver-driven layered multicast (RLM) efficiently addresses the issue of heterogeneity in clients' available bandwidths and packet loss rates by shifting rate control to the receiver side. We propose a system for RLM over the Internet and 3G wireless networks based on layered Wyner-Ziv video coding and digital fountain codes. Layered Wyner-Ziv video coding improves robustness to packet loss compared to current scalable video coders, such as MPEG-4 FGS coder, while generating a scalable output bit stream. Digital fountain codes are near-capacity erasure protection codes that are ideally suited for multicast applications due to their rateless property. By combining an error-resilient Wyner-Ziv video coder and rateless fountain codes, our system allows reliable video multicast to an arbitrary number of heterogeneous receivers without the requirement of feedback channels. Simulation results show performance improvements over a previous scheme that exploits multiple description and layered coding.

Video transmission over wireless multi-hop networks is challenging due to the varying nature of the wireless channel as well as the inherent difference between the video data traffic and the general data traffic. A single bit error in a packet may lead to the packet loss, which results in poor quality of the entire video frame. In this paper, we first analyze the effect of payload length on the overhead of bit error, video frame reassembly and network efficiency. Then, to improve the quality of video transmission, we propose an adaptive payload length algorithm based on the digital fountain codes while take transmission efficiency into account. The simulation environment is also designed to evaluate the performance of multi-hop video transmission, which is based on the ARM embedded system. Numerical simulations show that adaptive payload length algorithm can improve the quality of video transmission over wireless multi-hop networks.KeywordsVideo transmissionMulti-hopFountain codesPayload length

In order to reduce computational complexity and transmission delay in the cooperative transmission system based on digital fountain codes, the paper proposes the cooperative communication scheme based on a distributed Raptor codes .The throughput is treated as the parametric analysis of the system complexity and the link packet loss rate is looked as parametric analysis of the transmission delay of the system.Moreover, the distributed Raptor codes compares with LT codes and other digital fountain codes transmission scheme.Theoretical analysis and simulation results indicate that the Raptor codes in throughput and decoding success rate is more greatly improved than LT codes.When the link packet loss rate is big, this distributed Raptor codes cooperative transmission scheme can greatly improve the performance of the system on the transmission delay and the larger link deletion probability is, obviously the greater advantages is.

This paper proposes a scheme to provide in a CSMA/CA based multi-hop wireless ad hoc network, a consistent and accurate proportional differentiation in average end-to-end packet delay. The proposed scheme, called PDMED uses a cross-layer approach that requires a distributed scheduler to adapt to the information from a QoS monitor, a route monitor and a channel monitor. Conceptually, the distributed scheduler dynamically adjusts the backoff duration of a flow based on its instantaneous deviation from the maximum average end-to-end packet delay. This is done such that a flow with a larger deviation from the maximum is given a longer backoff duration to give way to transmissions from other flows with smaller deviations. PDMED has been extensively evaluated through random event simulations using OPNET. The results confirm that it is capable of providing a consistent and accurate proportional differentiation, which is otherwise not achievable under various traffic conditions.

Abstract—On demand routing protocols for ad hoc networks such as Ad Hoc On Demand Distance Vector (AODV) initiate a route discovery process when a route is needed by flooding the network with a route request packet. The route discovery process in such protocols depends on a simple flooding as a broadcast technique due to its simplicity. Simple flooding results in packet congestion, route request overhead and excessive collisions, namely broadcast storm problem. A number of routing techniques have been proposed to control the simple flooding technique. Ideally, the broadcast of route request or the route discovery process must be stopped as soon as the destination node is found. This will free the network from many redundant packets that may cause network collision and contention. In this paper, chasing packet technique is used with standard AODV routing protocol to end the fulfilled route requests. The chase packet is initiated by the source node and is broadcasted in parallel with route request packet. As soon as the destination is found the chase packet starts its work by trying to catch and discard the route request in early stages before it broadcasts further in the network. Performance evaluation is conducted using simulation to investigate the performance of the proposed scheme against the existing approach that uses chase packet technique such as Traffic Locality Route Discovery Algorithm with Chase (TLRDA-C). Results reveal that the proposed scheme minimizes end-to-end packet delays and achieves low routing request overhead.

Wireless ad-hoc mesh network is a special kind of network, where all of the nodes move in time. Node is intended to help relaying packets of neighboring nodes using multi-hop routing mechanism in order to solve problem of dead communication. Wireless mesh network which engages broadcasting and contains multiple hops become increasingly vulnerable to problems such as routing problem and rapid increasing of overhead packets. During this progress, the delay on account of multi hop characteristics and redundant packets caused by communication nature potentially existed during communication. Typically, delay will increase in linearity with number of hops. There is a certain minimum level of delay that will be experienced due to the time it takes to transmit a packet through a link. Topology development holds a significant point prior to the data transmission. Without improved topology development protocol, this problem can decrease network’s performance in overall data transmission. We analyze the delay performance of a multi-hop wireless network with a dynamic route between each source and final destination pair. There are fluctuate interference constraints on the set of links that impose a fundamental delay performance of any instant network topology. At first, we present a similar Link State Routing network simulation to derive such referential lower bounds. We conduct extensive simulation studies to suggest that the average delay of multi-hop transmission policy can be made lower compared to the referential bound by using appropriate functions of network metrics. This paper provides a broadcast framework that engages various network metrics and at the same time maintaining connectivity of nodes (mobile terminals). The framework captures the essential features of the wireless network metrics, i.e. bandwidth, throughput, network buffer, direction, and round trip time. This research is useful since, in many cases, it find that the throughput is the most important parameter in reduction of delay transmission. This result is confirmed with another composite simulation result. Most of network hop delay is impacted with this composite metric, particularly in delay minimization on the longer hops. The reduction achievement on average delay by this algorithm is 0.577% and the total average delay reduction for this simulated network is 0.683%. This research will be further designed primarily for achieving maximum throughput in the multiple wireless network area.

The growth of the internet and smart device users in Indonesia is quite rapidly and is expectedto continue to increase each year . Internet users in Indonesia come from various backgrounds andages . It is often done internet users are watching streaming video via their smart devices . Moreand more users are accessing internet streaming video it will affect the condition of the bandwidthprovided by the ISP ( Internet Service Provider ) which would affect the user experience due tobuffer the video stream when the video is being watched . Looking at these problems , a companyengaged in the field of streaming TV ( PT Distribution Media Technology ) setting up a streaming TVservice using a technology that is relatively new in Indonesia , namely Adaptive Bitrate Streamingtechnology that can solve the problems of the video stream buffer . Knowing that the AdaptiveBitrate Streaming technology is relatively new in Indonesia , the researchers tried to analyze theAdaptive Bitrate Streaming technology as well as the influence of bandwidth conditions for thesetechnologies . In this study , researchers used a quantitative method to analyze the Adaptive BitrateStreaming technology , implement the technology on several devices and analyze the effect ofbandwidth on facility conditions VOD ( Video on Demand ) which is implemented using AdaptiveBitrate Streaming technology that existed at Valu TV service ( PT Distribution Media Technology ) .The results of this analysis is to find out how to work the Adaptive Bitrate Streaming technology andits implementation on bandwidth conditions while riding , stable , and down . With the AdaptiveBitrate Streaming technology , users can watch a video streaming video comfortably without bufferdespite their internet bandwidth conditions are unstable.

Recently, HTTP-based video streaming traffic has continued to increase. Therefore, video service providers have been using HTTP-based adaptive streaming (HAS) technology to reduce the traffic load of the HTTP server. Accordingly, many adaptive bit rate (ABR) schemes have been proposed to provide a high quality of experience (QoE) to video service clients. In this paper, we propose a new ABR scheme using an adaptive network-based fuzzy inference system (ANFIS), which is one of the neuro-fuzzy structures. The proposed scheme learns optimal fuzzy parameters by using (1) the learning ability of ANFIS and (2) the video streaming data providing high QoE to clients. Then, the bit rate of the next segment is determined according to these trained parameters. In the simulation using NS-3, we show that the proposed scheme selects the appropriate bit rate under various wireless network conditions and provides better QoE to clients than the existing schemes.

We consider a multihop wireless line network with a single unidirectional data flow and show that by limiting the buffer sizes at the relay nodes to unity, the flow of traffic in the system can be efficiently regulated in a completely distributed fashion. Upon exerting this simple transmission policy, we find that the transport of packets in the wireless network is analogous to the flow of particles in the totally asymmetric simple exclusion process (TASEP). Using existing results from statistical mechanics, we characterize the end-to-end delay and throughput performance of multihop wireless line networks for two different channel access schemes. Additionally, we apply our findings towards the design of long networks. This paper also aims at promoting the TASEP as a powerful tool for analyzing the performance of ad hoc networks.