6501389
A Hierarchical Queueing Model for Streaming Video over Multi-Hop Wireless Networks
In our previous work, we proposed a distributed buffer (DB) scheme to tackle the problem of transporting layered video over erroneous multi-hop wireless networks. In DB scheme, some intermediate nodes are selected as DB nodes, which are used to pre-buffer video packets before the video streaming starts. In this paper, a novel hierarchical queueing model for DB nodes is proposed. The video playback quality including buffer overflow probability and video quality throughput can be computed based on the proposed queueing model. The simulation result matches the queueing performance of video streaming application.
17038094
On-line Algorithm for Server Selection of Video Streaming over P2P Networks
Abstract We consider a video streaming application over P2Pnetworks and introduce the P2P on-line server selection problem. This task is related to the classic K-server problem, known from the theory of online algorithms. The difference is that our problem has a dynamic cost matrix, due to network congestion which may trigger the rerouting of streaming paths. With the assumption that the number of hops of any alternative path from the server node p to the requesting node q is at most δ times the number of hops of the shortest path from p to q, our dynamic work function algorithm works for the P2P on-line server selection problem with competitive ratio δ×(2k-1). 1. Introduction In this paper we consider a video streaming application over P2Pnetworks. As we know, it isdifficult to provide large scale streaming service using traditional, centralized client-serverarchitecture, since a bottleneck occurs at the server. The network service model known as Peer-to-Peer (P2P) solves this problem, due to its distributed nature. We address the issue of optimizing the server selection for video streaming in P2P networks.Optimization tasks are classified into online and offline problems. Optimization problems in which the input is received piece by piece and the corresponding piece of output must be produced before knowing the entire input are called online problems. In some optimization tasks, such as job scheduling, both the online and offline versions of the problem are meaningful. Many other situations, such as telephone circuit switching, investment planning etc. are intrinsically online. For these problems, offline algorithms are not acceptable. Competitive algorithms were introduced by Sleator and Tarjan [1] in the context of optimization problems. They sought a worst case complexity measure for on-line algorithms that have to make decisions based on current and previous parts of the input. In the on-line problem the input is given as a sequence σ = σ
6971305
Video streaming over multi-hop wireless networks
In this paper, we considered the problem of transporting layered video over erroneous multi-hop wireless networks and proposed a distributed system. Our proposed distributed scheme is comprised of distributed control (DC), distributed buffer (DB) and distributed error control schemes. The DC scheme improves the efficiency of the network bandwidth usage and reduces the end-to-end delay of the streaming application. End-to-end delay jitter can be reduced by proper use of the DB nodes' buffer. Replacing the traditional EEC and ARQ with our distributed FEC and ARQ scheme reduces the error-protection overhead and ARQ delay and improves the wireless channel throughput. A layered video module is developed in GlomoSim 2.03 for video streaming application. We simulated our distributed scheme employing the layered video module in GlomoSim 2.03. Our simulation results confirm that QoS of streaming video over erroneous multi-hop wireless network can be improved using our proposed distributed scheme.
59897458
Algorithms and qos of video streaming over wireless networks
Video streaming over wireless networks has attracted much attention recently. It is well known that video streaming is QoS Stringent applications and wireless link suffers from erroneous and time-variant conditions. Significant research work has been conducted on QoS guarantee of video streaming application in Physical, MAC and Network layers. In this dissertation, the author designed a combination of packet ordering algorithm and transmission scheme for streaming video over a single wireless link and a distributed system for streaming video over multi-hop wireless networks, respectively. 
QoS routing has been widely researched and a number of routing protocols have been proposed to support routing of QoS stringent real-time applications. Recently, scalable video coding has been used for adaptation of video streaming to heterogeneous networks, especially wireless networks. The author proposed the routing criteria and routing algorithms for the routing of base layer (BL) and enhancement layer (EL) of MPEG-4 FGS. 
Research on Mobile Ad Hoc networks (MANETS) has been driven by either large scale military applications or specialized civilian applications which are tailored to very specialized missions and cost is typically not a main issue. Wireless mesh networks (WMN) meet the demand of a limited number of people wanting to form an ad hoc network for sharing information. In wireless mesh networks, Peer-to-Peer (P2P) video streaming service request generally can be satisfied by more than one video server. WMN P2P video streaming service can be modeled by K-server problem. Competitive work function algorithm is running in the distributed manner and is robust to the update message loss. Modified work function algorithm is proposed for P2P video streaming service over congested WMN. And the author conjectured that the modified work function algorithm is still competitive.
2177063
A New Lightweight and Scalable Encryption Algorithm for Streaming Video over Wireless Networks
A process for improving the stability of a cadmium chalcogenide/copper chalcogenide photovoltaic cell is disclosed. The improvement comprises positioning a layer of a polymer composition containing electrically conductive particles between the copper chalcogenide layer and the metal electrode such that the metal electrode does not make physical contact with the copper chalcogenide layer.
10659233
Wiener indices of balanced binary trees
We study a new family of trees for computation of the Wiener indices. We introduce general tree transformations and derive formulas for computing the Wiener indices when a tree is modified. We present several algorithms to explore the Wiener indices of our family of trees. The experiments support new conjectures about the Wiener indices.
189947
Evaluating Service Identification with Design Metrics on Business Process Decomposition
One of the key activities to construct a successful Service-Oriented Architecture (SOA) is the identification of services with the right level of abstraction. Most of existing SOA design methodologies advocate identifying services from the top-down decomposition of business processes. However, the identification quality in these methodologies heavily depends on the expertise and experience of individual designers. The ability to quantitatively evaluate service identification is absolutely needed. In this paper, we propose an approach that supports such evaluation by applying the measurement technology to the service-based business process decomposition. A model to capture related architectural elements with their relationships is presented. A set of design metrics are proposed for measuring various features of identified services in the service portfolio, including service granularity, coupling, cohesion, and business entity convergence. To apply the approach, a prototypical measurement tool for service identification is developed. An automotive work order scenario is used as an illustration example to explain our approach and demonstrate its effectiveness.
16457860
A New Secure Authentication Scheme Based Threshold ECDSA For Wireless Sensor Network
Security is an important issue for Wireless Sensor Network (WSN), especially for security-sensitive application. In this paper, we address secure authentication problems in WSN. First, we propose distributed authentication model for WSN, and secondly, advance the threshold ECDSA authentication scheme in this model, finally construct a new way to choose distributed CA severs of threshold authentication scheme. Our simulation results and analysis show that our scheme can reduce effectively bandwidth and computation resources while providing a robust, highly secure and highly available authentication service.
15663663
Kernel based articulated object tracking with scale adaptation and model update
Kernel based object tracking (KBOT) is one of the most popular and effective techniques for tracking task. However the constancy of the target model and unsound scale adaptation method are two main limitations. In this paper, we present a kernel based approach incorporated with scale estimation and target model update for articulated object tracking task. After predicating the object center with scale fixed KBOT, we extend scale selection theory to estimate the local optimal object scale. Once the object scale has been estimated, a kernel density estimation based strategy is developed to update the target model. Experimental results show that our approach is superior to traditional KBOT in the following two aspects: 1) it is less affected by the object scale change; 2) it is less prone to appearance variation.
6929789
WSN02-2: Adaptive Network Resource Management in IEEE 802.11 Wireless Random Access MAC
Effective and efficient management of wireless network resources is attracting more and more research attention, due to the rapid growing deployment of wireless mesh and ad hoc networks and to the increasing demand for Quality of Service (QoS) support in these networks. This paper proposes an adaptive network resource management scheme in the popular IEEE 802.11 random access MAC by adaptively adjusting the minimum contention window sizes of traffic flows. First, a novel generalized processor sharing (GPS) model is presented for the IEEE 802.11 random access MAC revealing the relationship between the minimum contention window size of a traffic flow and the amount of network resource this flow can receive. Using this GPS MAC model, a feedback control system model for the proposed adaptive network resource management system is developed, by directly extending our previous work in wireline GPS networks. Based on the feedback control system model, adaptive P and adaptive PI controllers are designed, and their performances are studied in simulations. Simulation results show that by using the designed controllers, the proposed adaptive network resource management approach is able to provide guaranteed distinct QoS support to traffic flows.
14929484
An Auxiliary Ground Station Based Traffic Load Balancing Scheme for LEO Satellite Systems
In the Low Earth Orbit (LEO) satellite mobile communication system, traffic load in a spot beam fluctuates dramatically with a wide dynamic range due to the non-uniform geographical distribution of the traffic sources and the periodic satellite motion. The compromise between the utilization rate of valuable satellite channels and the blocking probability of a call causes higher proportion of channel idle time and cost of per connection. A new scheme based on auxiliary ground station (AGS) is proposed to solve this problem. The AGS is set to manage short distance calls. Simulation results illustrate that the proposed scheme balances the whole traffic load in LEO, improves the utilization rate of channels, and reduces the blocking probabilities of new calls and the dropping probabilities of handover calls. The cost of per connection is reduced at the same time.