Future broadband access network challenges

Copyright @ 2010 IEEEThe optical and wireless communication systems convergence will activate the potential capacity of photonic technology for providing the expected growth in interactive video, voice communication and data traffic services that are cost effective and a green communication service. The last decade growth of the broadband internet projects the number of active users will grow to over 2 billion globally by the end of 2014. Enabling the abandoned capacity of photonic signal processing is the promising solution for seamless transportation of the future consumer traffic demand. In this paper, the future traffic growth of the internet, wireless worldwide subscribers, and the end-users during the last and next decades is investigated. The challenges of the traditional access networks and Radio over Fiber solution are presented

Continuum Equilibria and Global Optimization for Routing in Dense Static Ad Hoc Networks

We consider massively dense ad hoc networks and study their continuum limits as the node density increases and as the graph providing the available routes becomes a continuous area with location and congestion dependent costs. We study both the global optimal solution as well as the non-cooperative routing problem among a large population of users where each user seeks a path from its origin to its destination so as to minimize its individual cost. Finally, we seek for a (continuum version of the) Wardrop equilibrium. We first show how to derive meaningful cost models as a function of the scaling properties of the capacity of the network and of the density of nodes. We present various solution methodologies for the problem: (1) the viscosity solution of the Hamilton-Jacobi-Bellman equation, for the global optimization problem, (2) a method based on Green's Theorem for the least cost problem of an individual, and (3) a solution of the Wardrop equilibrium problem using a transformation into an equivalent global optimization problem

Single user TCP downstream throughput probability models in IEEE802.11b WLAN system

Single User, Transmission Control Protocol Downstream Throughput (TCPDST) probability models in an IEEE802.11b WLAN have been developed, validated and evaluated for performance. Measurement of single user TCPDST were taken using Tamosoft throughput test while that of signal to noise ratio (SNR) were taken using inSSIDer 2.1. The Tamosoft throughput tests were conducted using different quality of service (QoS) traffic. These QoS traffic (which were sent through an infrastructure based network) correspond to different wireless multimedia tags. Measurements were taken in free space, small offices and open corridor environments. By assuming a normal distribution, single user TCPDST Cumulative distribution function (CDF) probability models were developed for different signal categories namely: (i) all the SNR considered, (ii) strong signals only, (iii) grey signals only and (iv) weak signals only. The models were validated and their performances evaluated using root mean square (RMS) errors. RMS errors were computed by comparing model predicted values with validation data. The RMS errors for single user CDF all signals model was 0.1466%. RMS errors for strong signals models, grey signals model and weak signals model respectively were 0.1466%, 0.6756% and 0.1233% indicating acceptable performances. All signals, strong signals, grey signals and weak signals CDF probability models predicted probabilities of obtaining TCPDST values greater than 5Mbps as 74.79%, 90.55%, 13.00% and 4.77% respectively while probabilities of obtaining TCPDST values less than 2Mbps were predicted as 4.91%, 0.00%, 18.98% and 52.41% respectively. These probability models will provide additional useful information needed to design efficient distributed data networks. Keywords: Throughput, TCP, WLAN, probability model

Efficient Cluster Formation Protocol in WSN

WSN which is called as Wireless Sensor Networks plays vital role in many applications. Most WSNs exploit clustering method for data communication from sensor destination nodes to the sink. So, Clustering should be made as efficient as possible. In most of the existing clustering protocols, residual nodes (non-cluster nodes) may be formed during clustering. Though these nodes can send their data directly to the base station, it needs large amount of energy. In the proposed method, PSO algorithm which is termed as Particle Swarm Optimization is used for cluster configuration which evades the formation of residual nodes. The base station performs cluster formation. Network Simulator-2 (NS-2) tool is used to achieve simulation. Simulation outcomes reveal enhanced operation of the proposed protocol than existing LEACH and OEERP protocols

Route selection impacts on achieving enhanced IMS QoS

ArticleThe different planes in the IMS interact via specific reference points to deliver multimedia services to the user. QoS provisioning for IMS communications has been standardized for access networks only, with the assumption of an over provisioned IP core. Effective provisioning of multimedia services requires performance guarantee along the complete path of the sessions. End-to-end QoS in IP networks is affected by the route traversed by the user traffic. Moreover QoS guarantees in one ISP domain are not effective for transit traffic exiting the domain. QoS extensions to exterior gateway routing protocols have been proposed to transfer route QoS information beyond one autonomous system (domain). This paper explores options for mapping inter-domain QoS information learnt on the media plane into control plane session information for IMS QoS control. Through testbed evaluations we show the effect of routing on delays experienced in IMS communications.The different planes in the IMS interact via specific reference points to deliver multimedia services to the user. QoS provisioning for IMS communications has been standardized for access networks only, with the assumption of an over provisioned IP core. Effective provisioning of multimedia services requires performance guarantee along the complete path of the sessions. End-to-end QoS in IP networks is affected by the route traversed by the user traffic. Moreover QoS guarantees in one ISP domain are not effective for transit traffic exiting the domain. QoS extensions to exterior gateway routing protocols have been proposed to transfer route QoS information beyond one autonomous system (domain). This paper explores options for mapping inter-domain QoS information learnt on the media plane into control plane session information for IMS QoS control. Through testbed evaluations we show the effect of routing on delays experienced in IMS communications

REED: Flexible rule based programming of wireless sensor networks at runtime

Wireless Sensor Networks (WSN) have emerged as an enabling technology for a variety of distributed applications. WSN middleware eases the development of these applications by providing a uniform programming environment. In this paper we present a rule based approach called REED (Rule Execution and Event Distribution) and describe how it supports flexible programming of WSNs at runtime. Indeed REED is required by the nature of its project setting to allow runtime programming. We demonstrate that by combining this runtime programmability with rules in an event, condition, action format we can support a range of paradigms, including Publish-subscribe and data aggregation algorithms. Current WSN middleware solutions have limited on-line programmability support so the applications cannot re-configure their WSNs while operational. Yet the runtime nature of the prototype requires both the distribution of rules and the events that trigger them so we also describe the rule management approach used to support the rule distribution; in particular a novel rule merging and filtering algorithm is described. The paper reports on the results gained from a REED prototype system constructed in our laboratory using Gumstix

Context-Aware Voip congestion control service

Published in The African Journal of Information and Communication, Issue no 11 2010/2011IP networks can have difficulty coping with delay-sensitive VoIP traffics during emergency situations caused by fires and related disasters. During emergencies there is a huge increase in voice and video traffic, causing a huge strain on the network. The strain on the network is as a result of both essential and non-essential traffic. In such crisis situations, calls originating from or destined for rescue personnel, such as doctors and police, are considered essential. Any other calls from eyewitnesses and the public are considered non-essential, since they degrade the quality of service for the emergency response teams by consuming the scarce network resources. Providing the rescue team with the quality of service that they require necessitates network access restriction for non-essential traffic. In this paper, the authors present a voice and video service that uses Context-Awareness and Semantic Web technologies to restrict network access to privileged users during crisis situations. The service monitors the network for crisis conditions, enables the network to respond appropriately when a crisis occurs, detects the end of the crisis and reverts to its default state.IP networks can have difficulty coping with delay-sensitive VoIP traffics during emergency situations caused by fires and related disasters. During emergencies there is a huge increase in voice and video traffic, causing a huge strain on the network. The strain on the network is as a result of both essential and non-essential traffic. In such crisis situations, calls originating from or destined for rescue personnel, such as doctors and police, are considered essential. Any other calls from eyewitnesses and the public are considered non-essential, since they degrade the quality of service for the emergency response teams by consuming the scarce network resources. Providing the rescue team with the quality of service that they require necessitates network access restriction for non-essential traffic. In this paper, the authors present a voice and video service that uses Context-Awareness and Semantic Web technologies to restrict network access to privileged users during crisis situations. The service monitors the network for crisis conditions, enables the network to respond appropriately when a crisis occurs, detects the end of the crisis and reverts to its default state

Context-aware VoIP congestion control service

IP networks can have difficulty coping with delay-sensitive VoIP traffics during emergency situations caused by fires and related disasters. During emergencies there is a huge increase in voice and video traffic, causing a huge strain on the network. The strain on the network is as a result of both essential and non-essential traffic. In such crisis situations, calls originating from or destined for rescue personnel, such as doctors and police, are considered essential. Any other calls from eyewitnesses and the public are considered non-essential, since they degrade the quality of service for the emergency response teams by consuming the scarce network resources. Providing the rescue team with the quality of service that they require necessitates network access restriction for non-essential traffic. In this paper, the authors present a voice and video service that uses Context-Awareness and Semantic Web technologies to restrict network access to privileged users during crisis situations. The service monitors the network for crisis conditions, enables the network to respond appropriately when a crisis occurs, detects the end of the crisis and reverts to its default state

EFFICIENT CAMERA SELECTION FOR MAXIMIZED TARGET COVERAGE IN UNDERWATER ACOUSTIC SENSOR NETWORKS

In Underwater Acoustic Sensor Networks (UWASNs), cameras have recently been deployed for enhanced monitoring. However, their use has faced several obstacles. Since video capturing and processing consume significant amounts of camera battery power, they are kept in sleep mode and activated only when ultrasonic sensors detect a target. The present study proposes a camera relocation structure in UWASNs to maximize the coverage of detected targets with the least possible vertical camera movement. This approach determines the coverage of each acoustic sensor in advance by getting the most applicable cameras in terms of orientation and frustum of camera in 3-D that are covered by such sensors. Whenever a target is exposed, this information is then used and shared with other sensors that detected the same target. Compared to a flooding-based approach, experiment results indicate that this proposed solution can quickly capture the detected targets with the least camera movement