Adriana Hava

Increasing User Perceived Quality by Selective Load Balancing of Video Traffic in Wireless Networks

Wireless mesh networks (WMNs) are becoming increasingly popular mostly due to their deployment flexibility. The main drawback of these networks is their lack of guaranteeing high Quality of Service (QoS) levels to their clients. The latest ubiquitous mobile and wireless support and significant growth in smartphone features have fueled user demand for rich media services on their devices. Unfortunately, this traffic increase puts additional pressure on WMN resources, eventually affecting user QoS levels and providing solutions to address this is highly challenging. This paper shows how by using ViLBaS, an innovative selective load balancing solution for video deliveries in WMN, increased QoS levels of remotely transmitted video are obtained. ViLBaS employs distributed monitoring of network traffic, identifies the node most affected by congestion and prevents imminent packet drops by rerouting the video flows around the congested node. A hybrid simulation-emulation-based test-bed is built and used for assessing ViLBaS performance in comparison with classic solutions employing the best-known routing metrics. Real video traffic was transmitted from a sever to a client over a WMN topology and the received video quality was assessed in different scenarios. The results demonstrate that ViLBaS outperforms all other solutions when delivering various video content with diverse characteristics and at different quality levels.

Enabling IPTV Service Assurance Using OpenFlow

One 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.

Integration of QoS Metrics, Rules and Semantic Uplift for Advanced IPTV Monitoring

Abstract Increasing 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.

Experience of developing an openflow SDN prototype for managing IPTV networks

IPTV is a method of delivering TV content to endusers that is growing in popularity. It is a paid service, hence the implications of poor video quality may ultimately be a loss of revenue for the provider. Consequently, it is vital to provide service monitoring and reconfiguration mechanisms to ensure quality requirements set out in service level agreements are upheld. 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.

ABI: A mechanism for increasing video delivery quality in multi-radio Wireless Mesh Networks

Wireless 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 their clients. Equipping wireless mesh nodes with multiple radios in order to increase the available network bandwidth has become a common practice nowadays due to the low cost of the wireless chipsets. As 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 offering high QoS level for video deliveries to the mesh networks clients. In WMN context, this paper proposes the Available Bandwidth Increase (ABI), a mesh node-based mechanism for efficient usage of the available bandwidth, which manages the wireless radio interfaces by activating them only when needed such as the energy consumption is maintained low. The proposed ABI is thoroughly evaluated and it is shown that it can provide video deliverie at good QoS level and at low energy consumption.

A new load balancing mechanism for improved video delivery over Wireless Mesh Networks

Wireless Mesh Networks (WMNs) are becoming increasingly popular and user demand for high-quality rich media services is continuously growing. Despite the fact that WMNs offer significant flexibility, they suffer in respect to Quality of Service (QoS) provisioning. This paper proposes a novel mechanism for providing enhanced QoS support to video services in multi-hop WMNs. The mechanism makes use of an innovative hybrid hierarchical architecture which combines centralized and distributed approaches. The proposed solution relies on performance monitoring at WMN nodes and performs load balancing by off-loading traffic from the highest loaded nodes to less loaded neighbours. Simulation-based results presented outline the performance of our proposed mechanism in terms of QoS metrics (delay, throughput, packet losses and PSNR) in different network load scenarios. The results clearly demonstrate how our proposed mechanism outperforms the traditional OLSR protocol in terms of QoS performance.

Prototyping telematic services in a wireless vehicular mesh network environment

Next 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.

An energy-efficient mechanism for increasing video quality of service in Wireless Mesh Networks

The 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.

Towards an emulated IoT test environment for anomaly detection using NEMU

The 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.

On monitoring overhead impact in wireless mesh networks

A wireless mesh network is characterized by dynamicity. It needs to be monitored permanently to make sure its properties remain within certain limits in order to provide Quality-of-Service to the end users or to identify possible faults. To establish in every moment what is the appropriate reporting interval of the measured information and the way it is disseminated are important tasks. It has to achieve information quickly enough to solve any issue but excessive as to affect the data traffic. The problem that arises is that the monitoring information needs to travel in the network along with the user traffic and thus, potentially causing congestion. Considering that a wireless mesh network has highly dynamic characteristics there is a need for a good understanding of the influences of disseminating monitoring information in the network along with user traffic. In this paper we provide an evaluation of the network performance while monitoring information is collected from network nodes. We study how different monitoring packet sizes and different reporting frequency of the information can impact the user traffic and compare these values to the case in which only user data travels across the network.