Now showing 1 - 8 of 8
- PublicationDAPP: A Delay-Aware Packet Prioritisation Scheme for VoIP in Wireless Multi-hop NetworksIn this paper we propose a mechanism entitled Delay-Aware Packet Prioritisation (DAPP) that works at WiFi packet queue level. DAPP enqueues packets according to their time spent in the network, such that more delayed packets are enqueued towards the head of the queue. We study the effects of such an approach in wireless multi-hop scenarios where VoIP packets with various delay impairments reach a congested node. Packets’ delay builds up as congestion increases and we show that DAPP improves a network’s VoIP capacity by distributing the negative effects of delay to those VoIP packets that so far travelled in good network conditions. This is to the advantage of those VoIP packets already negatively affected by network conditions, as they are allowed to pass a congested node with less further delay accumulation. We use extensive NS-3 simulations where a wide range of network impairments affect VoIP calls, and we demonstrate that DAPP is able to improve the VoIP capacity and fairness among VoIP calls in a wireless multi-hop network.
- PublicationAn Energy-efficient Mechanism for Increasing Video Quality of Service in Wireless Mesh NetworksThe continuous growth in user demand for high-quality rich media services puts pressure on Wireless Mesh Network (WMN) resources. Solutions such as those which increase the capacity of the mesh network by equipping mesh routers with additional wireless interfaces provide better Quality of Service (QoS) for video deliveries, but result in higher overall energy consumption for the network. This paper presents LBIS, a distributed solution which combines the benefits of both load-balancing and interface-shifting in order to enhance QoS levels for video services delivered over multi-hop WMNs, while maintaining low energy consumption levels within the network. Simulation-based results show very good performance of our proposed mechanism in terms of QoS metrics (delay, packet loss), Peak Signal-to Noise Ratio (PSNR) and energy consumption in mesh network topologies, and with varying video traffic loads and distributions. The results demonstrate how LBIS can increase the QoS for video deliveries by more than 30% at the cost of an insignificant increase of the overall network energy consumption compared to the WMN with multiple radio interfaces without the LBIS adaptation.
- PublicationExperience of developing an openflow SDN prototype for managing IPTV networksIPTV is a method of delivering TV content to endusers that is growing in popularity. The implications of poor video quality may ultimately be a loss of revenue for the provider. Hence, it is vital to provide service assurance in these networks. This paper describes our experience of building an IPTV Software Defined Network testbed that can be used to develop and validate new approaches for service assurance in IPTV networks. The testbed is modular and many of the concepts detailed in this tutorial may be applied to the management of other end-to-end services.
1223Scopus© Citations 9
- PublicationIntegration of QoS Metrics, Rules and Semantic Uplift for Advanced IPTV MonitoringIncreasing and variable traffic demands due to triple play services pose significant Internet Protocol Television (IPTV) resource management challenges for service providers. Managing subscriber expectations via consolidated IPTV quality reporting will play a crucial role in guaranteeing return-on-investment for players in the increasingly competitive IPTV delivery ecosystem. We propose a fault diagnosis and problem isolation solution that addresses the IPTV monitoring challenge and recommends problem-specific remedial action. IPTV delivery-specific metrics are collected at various points in the delivery topology, the residential gateway and the Digital Subscriber Line Access Multiplexer through to the video Head-End. They are then pre-processed using new metric rules. A semantic uplift engine takes these raw metric logs; it then transforms them into World Wide Web Consortium’s standard Resource Description Framework for knowledge representation and annotates them with expert knowledge from the IPTV domain. This system is then integrated with a monitoring visualization framework that displays monitoring events, alarms, and recommends solutions. A suite of IPTV fault scenarios is presented and used to evaluate the feasibility of the solution. We demonstrate that professional service providers can provide timely reports on the quality of IPTV service delivery using this system.
2199Scopus© Citations 6
- PublicationPrototyping telematic services in a wireless vehicular mesh network environmentNext generation telematic services are expected to play a key role in future automotive applications. In order to achieve strong integration between the services and the underlying network infrastructure there is a need for both simulation and emulation of the entire system. This paper presents a combined simulation and emulation approach for telematic services prototyping in an emulated wireless vehicular mesh networking environment. The ns-3 wireless mesh model, SUMO vehicular mobility model and different telematic services are integrated to demonstrate high scalability and flexibility of the proposed approach.
257Scopus© Citations 4
- PublicationEnabling IPTV service assurance using OpenFlowOne difficulty facing Internet Protocol Television (IPTV) service providers is the issue of monitoring and managing their service delivery network. An in-depth monitoring regime is required, which performs measurements within different networking devices. When network conditions deteriorate to the point where they could disrupt IPTV services, Network Operators (NOs) can use the measurements as a basis to reconfigure the network with minimal delay. OpenFlow (OF) presents a potential solution to this problem as it provides vendor-neutral access to the packet forwarding interface of the different hardware device types. This work investigates how OF can leverage video packet inspection measurements taken from within the IPTV service delivery network and combine these with of statistics to make decisions regarding routing in order to assure service quality.
530Scopus© Citations 14
- PublicationTowards an emulated IoT test environment for anomaly detection using NEMUThe advent of the Internet of Things (IoT) has led to a major change in the way we interact with increasingly ubiquitous connected devices such as smart objects and cyber-physical systems. It has also led to an exponential increase in the number of such Internet-connected devices over the last few years. Conducting extensive functional and performance testing is critical to assess the robustness and efficiency of IoT systems in order to validate them before their deployment in real life. However, creating an IoT test environment is a difficult and expensive task, usually requiring a significant amount of physical hardware and human effort to build it. This paper proposes a method to emulate an IoT environment using the Network Emulator for Mobile Universes (NEMU), itself built on the popular QEMU system emulator, in order to construct a testbed of inter-connected, emulated Raspberry Pi devices. Additionally, we experimentally demonstrate how our method can be successfully applied to IoT by showing how such an emulated environment can be used to detect anomalies in an IoT system.
- PublicationABI: A mechanism for increasing video delivery quality in multi-radio Wireless Mesh Networks with Energy SavingWireless Mesh Networks (WMNs) are becoming increasingly popular mostly due to their ease of deployment. One of the main drawbacks of these networks is that they suffer with respect to Quality of Service (QoS) provisioning to its clients. Equipping wireless mesh nodes with multiple radios for increasing the available bandwidth has become a common practice nowadays due to the low cost of the wireless chipsets. Even though the available bandwidth increases with each radio deployed on the mesh node, the energy consumed for transmission increases accordingly. Thus, efficient usage of the radio interfaces is a key aspect for keeping the energy consumption at low levels while keeping a high QoS level for the mesh network’s clients. In the light of the above presented aspects concerning WMNs, the contribution of this paper is two-fold: (i) ABI, a mechanism for efficient usage of the available bandwidth for the mesh nodes, and (ii) decreasing the energy consumption by activating the radios only when needed. The solution proposed is throughly evaluated and shows that the two contributions can provide good QoS and decrease the overall energy consumption.
119Scopus© Citations 3