http://www.csun.edu/~andrzej/COMP529-S05/papers/Mesh%20Networks%20Survey.pdf

Wireless mesh networks: a survey

Due to the explosive growth of the Internet and increasing demand for multimedia information on the Web, streaming video over the Internet has received tremendous attention from academia and industry. Transmission of real-time video typically has bandwidth, delay, and loss requirements. However, the current best-effort Internet does not offer any quality of service (QoS) guarantees to streaming video. Furthermore, for video multicast, it is difficult to achieve both efficiency and flexibility. Thus, Internet streaming video poses many challenges. In this article we cover six key areas of streaming video. Specifically, we cover video compression, application-layer QoS control, continuous media distribution services, streaming servers, media synchronization mechanisms, and protocols for streaming media. For each area, we address the particular issues and review major approaches and mechanisms. We also discuss the tradeoffs of the approaches and point out future research directions.

/pdf/streaming-video-over-the-internet-approaches-and-directions-9hlbajlshe.pdf

Streaming video over the Internet: approaches and directions

In this paper, we describe AntHocNet, an algorithm for routing in mobile ad hoc networks. It is a hybrid algorithm, which combines reactive path setup with proactive path probing, maintenance and improvement. The algorithm is based on the nature-inspired ant colony optimisation framework. Paths are learned by guided Monte Carlo sampling using ant-like agents communicating in a stigmergic way. In an extensive set of simulation experiments, we compare AntHocNet with AODV, a reference algorithm in the field. We show that our algorithm can outperform AODV on different evaluation criteria. AntHocNet's performance advantage is visible over a broad range of possible network scenarios, and increases for larger, sparser and more mobile networks. Copyright © 2005 AEIT.

/pdf/anthocnet-an-adaptive-nature-inspired-algorithm-for-routing-3avashheqe.pdf

AntHocNet: an adaptive nature-inspired algorithm for routing in mobile ad hoc networks

Delivering real-time video over the Internet is an important component of many Internet multimedia applications. Transmission of real-time video has bandwidth, delay, and loss requirements. However the current Internet does not offer any quality of service (QoS) guarantees to video transmission over the Internet. In addition, the heterogeneity of the networks and end systems makes it difficult to multicast Internet video in an efficient and flexible way. Thus, designing protocols and mechanisms for Internet video transmission poses many challenges. In this paper, we take a holistic approach to these challenges and present solutions from both transport and compression perspectives. With the holistic approach, we design a framework for transporting real-time Internet video, which includes two components, namely, congestion control and error control. Specifically congestion control consists of rate control, rate-adaptive encoding, and rate shaping; error control consists of forward error correction (FEC), retransmission error resilience, and error concealment. For the design of each component in the framework, we classify approaches and summarize representative research work. We point out there exists a design space which can be explored by video application designers and suggest that the synergy of both transport and compression could provide good solutions.

/pdf/transporting-real-time-video-over-the-internet-challenges-3zu1pb0nx9.pdf

Transporting real-time video over the Internet: challenges and approaches

Wireless Sensor Networks (WSNs) are applicable in numerous domains, including industrial automation where WSNs may be used for monitoring and control of industrial plants and equipment. However, the requirements in the industrial systems differ from the general WSN requirements. In recent years, standards have been defined by several industrial alliances. These standards are specified as frameworks with modifiable parts that can be defined based on the particular application of WSN. However, limited work has been done on defining industry-specific protocols that could be used as a part of these standards. In this survey, we discuss representative protocols that meet some of the requirements of the industrial applications. Since the industrial applications domain in itself is a vast area, we divide them into classes with similar requirements. We discuss these industrial classes, set of common requirements and various state-of-the-art WSN standards proposed to satisfy these requirements. We then present a broader view towards the WSN solution by discussing important functions like medium access control, routing, and transport in detail to give some insight into specific requirements and the classification of protocols based on certain factors. We list and discuss representative protocols for each of these functions that address requirements defined in the industrial classes. Security function is discussed in brief, mainly in relation to industrial standards. Finally, we identify unsolved challenges that are encountered during design of protocols and standards. In addition some new challenges are introduced and discussed.

An Industrial Perspective on Wireless Sensor Networks — A Survey of Requirements, Protocols, and Challenges

Mobile ad hoc networks (MANETs) consist of a collection of wireless mobile nodes which dynamically exchange data among themselves without the reliance on a fixed base station or a wired backbone network MANET nodes are typically distinguished by their limited power, processing, and memory resources as well as high degree of mobility In such networks, the wireless mobile nodes may dynamically enter the network as well as leave the network Due to the limited transmission range of wireless network nodes, multiple hops are usually needed for a node to exchange information with any other node in the network Thus routing is a crucial issue to the design of a MANET In this paper, we specifically examine the issues of multipath routing in MANETs Multipath routing allows the establishment of multiple paths between a single source and single destination node It is typically proposed in order to increase the reliability of data transmission (ie, fault tolerance) or to provide load balancing Load balancing is of especial importance in MANETs because of the limited bandwidth between the nodes We also discuss the application of multipath routing to support application constraints such as reliability, load-balancing, energy-conservation, and Quality-of-Service (QoS)

/pdf/multipath-routing-in-mobile-ad-hoc-networks-issues-and-4nimg1w1i9.pdf

Multipath Routing in Mobile Ad Hoc Networks: Issues and Challenges

Most of the QoS routing schemes proposed so far require periodic exchange of QoS state information among routers, imposing both communication overhead on the network and processing overhead on core routers. Furthermore, stale QoS state information causes the performance of these QoS routing schemes to degrade drastically. In order to circumvent these problems, we focus on localized QoS routing schemes where the edge routers make routing decisions using only "local" information and thus reducing the overhead at core routers. We first describe virtual capacity-based routing (VCR), a theoretical scheme based on the notion of virtual capacity of a route. We then propose proportional sticky routing (PSR), an easily realizable approximation of VCR and analyze its performance. We demonstrate through extensive simulations that adaptive proportional routing is indeed a viable alternative to the global QoS routing approach.

/pdf/adaptive-proportional-routing-a-localized-qos-routing-4pwizweqbt.pdf

Adaptive proportional routing: a localized QoS routing approach

Most of the QoS routing schemes proposed so far require periodic exchange of QoS state information among routers, imposing both communication overhead on the network and processing overhead on core routers. Furthermore, stale QoS state information causes the performance of these QoS routing schemes to degrade drastically. In order to circumvent these problems, we focus on localized QoS routing schemes where the edge routers make routing decisions using only local information and thus reducing the overhead at core routers. We first describe virtual capacity based routing (vcr), a theoretical scheme based on the notion of virtual capacity of a route. We then propose proportional sticky routing, an easily realizable approximation of vcr and analyze its performance. We demonstrate through extensive simulations that adaptive proportional routing is indeed a viable alternative to the global QoS routing approach.

/pdf/adaptive-proportional-routing-a-localized-qos-routing-2pnfnjk8fv.pdf

Video delivery from a server to a client across a network is an important component of many multimedia applications. While delivering a video stream across a resource constrained network, loss of frames may be unavoidable. Under such circumstances, it is desirable to find a server transmission schedule that can efficiently utilize the network resources while maximizing the perceived quality-of-service (QoS) at the client. To address this issue, we introduce the notion of selective frame discard at the server and formulate the optimal selective frame discard problem using a QoS based cost function. Given network bandwidth and client buffer constraints, we develop an O(N log N) algorithm to find the minimum number of frames that must be discarded in order to meet these constraints. The correctness of the algorithm is also formally established. Since the computational complexity of the optimal algorithm for solving the optimal selective frame discard problem is prohibitively high in general, we also develop several efficient heuristic algorithms for selective frame discard. These algorithms are evaluated using JPEG video traces.

/pdf/efficient-selective-frame-discard-algorithms-for-stored-5gdius7zsw.pdf

Efficient selective frame discard algorithms for stored video delivery across resource constrained networks

Video delivery from a server to a client across a network is an important component of many multimedia applications. While delivering a video stream across a resource constrained network, loss of frames may be unavoidable. Under such circumstances, it is desirable to find a server transmission schedule that can efficiently utilize the network resources while maximizing the perceived quality-of-service (QoS) at the client. To address this issue, in this paper we introduce the notion ofselective frame discard at the server and formulate the optimal selective frame discard problem using a QoS-based cost function. Given network bandwidth and client buffer constraints, we develop an O (N log N) algorithm to find the minimum number of frames that must be discarded in order to meet these constraints. The correctness of the algorithm is also formally established. We present a dynamic programming based algorithm for solving the problem of optimal selective frame discard. Since the computational complexity of the optimal algorithm is prohibitively high in general, we also develop several efficient heuristic algorithms for selective frame discard. These algorithms are evaluated using JPEG and MPEG video traces.

/pdf/efficient-selective-frame-discard-algorithms-for-stored-eogtxaxrb2.pdf

Rose P. Tsang

Papers

Multipath Routing in Mobile Ad Hoc Networks: Issues and Challenges

Adaptive proportional routing: a localized QoS routing approach

Adaptive proportional routing: a localized QoS routing approach

Efficient selective frame discard algorithms for stored video delivery across resource constrained networks

Efficient Selective Frame Discard Algorithms for Stored Video Delivery Across Resource Constrained Networks