Andrei Bogdan Rus

Cross-layer QoS and its application in congestion control

The paper proposes a preliminary design of cross-layer quality of service applied to congestion control in future Internet. This is an alternative solution to QoS-aware routing, whenever the infrastructure operator cannot add new resources, and/or when re-routing is not possible. Dedicated software, running in each node, collects a list of local parameters such as available transfer rate and one-way delay between all neighbors. Then this real-time status information is distributed to all the in-network management enabled nodes that are allowed to be reached. Due to the statistics regarding individual link traffic, a minimal network coding scheme, triggered by cross-layer quality of service, is temporarily activated. This system presents an enhanced distributed routing that preserves the performances of the running services, despite the congestion which cannot be eliminated.

Evaluation of network traffic prediction based on neural networks with multi-task learning and multiresolution decomposition

Network traffic exhibits strong correlations which make it suitable for prediction. Real-time forecasting of network traffic load accurately and in a computationally efficient manner is the key element of proactive network management and congestion control. This paper compares predictions produced by different types of neural networks (NN) with forecasts from statistical time series models (ARMA, ARAR, HW). The novelty of our approach is to predict aggregated Ethernet traffic with NNs employing multiresolution learning (MRL) which is based on wavelet decomposition. In addition, we introduce a new NN training paradigm, namely the combination of multi-task learning with MRL. The experimental results show that nonlinear prediction based on NNs is better suited for traffic prediction purposes than linear forecasting models. Moreover, MRL helps to exploit the correlation structures at lower resolutions of the traffic trace and improves the generalization capability of NNs.

An OpenNetInf-based cloud computing solution for cross-layer QoS: Monitoring part using iOS terminals

This paper presents a monitoring application for quality of service parameters, called iQoSStats, dealing with Available Transfer Rate and One-Way Delay. The tool is running on iOS5-based iPad terminal. Due to the lack of Java support, a proxy server is needed to allow the connection to the cloud computing solution based on OpenNetInf. It relies on an information-centric communication paradigm and provides large-scale information dissemination. The intention was to use this infrastructure to support cross-layer QoS for the Future Internet.

Active measurement of the available transfer rate used in an algorithm for generalized assignment problem

This paper proposes a solution for active measurement of the Available Transfer Rate needed in a multi-tunnel architecture with a smart mobile router offering uninterrupted services for its wireless customers. It simultaneously uses several wireless/mobile access networks to the Internet in order to reach the service continuity gateway located somewhere in a broadband network. This customer-oriented approach uses the measurements to select the tunnels between the router and the gateway. Furthermore an algorithm for solving the Generalized Assignment Problem minimizes the costs. The allocation decision must be taken once every second in order to obtain the minimum possible cost.

Enhancement of information object management tool about Audio-video/ network status/ QoS content in OpenNetInf

This paper presents new facilities added to the existing Information Object (IO) Management Tool used in the open-source implementation of NetInf (Network of Information). The project was realized within a virtual machine running Ubuntu 10.10 and the contributions to the source code developed in Eclipse environment refer to the following: a) a more friendly way to introduce the search criteria, by suggesting the sub-attributes and by providing the results organized as tables; b) a new mechanism to create dedicated IOs about audio-video, network status and QoS content; c) automatic publishing of objects concerning the network configurations; d) graphical representation of statistics about QoS parameters. The enhancements proposed herein are useful for business decisions in networking, following the architecture proposed in FP7-4WARD project. However we tried to demonstrate the deployment of cross-layer QoS techniques in the Future Internet with the help of information-centric approaches (NetInf being one possible solution).

Case study of a gearbox-like routing algorithm selection in runtime

Routing protocols for the Future Internet need to adapt for any given status of the network. However the legacy routing algorithms (e.g. Dijkstra) could not seize the congestion determined by any other event except link failure and/or Layer 2 technology changes. Instead of a sophisticated mechanism we select the most competitive path determination solution to be used by a generic link-state based routing protocol, operating similar to a gearbox system. We suppose the Service Providers work with the Modified Dijkstras algorithm for a single path routing. Whenever a multi-path delivery is needed, the Ford-Fulkerson scheme might be considered. For Infrastructure Providers the mechanism is similar, except the single path approach, involving this time the Floyd-Warshall algorithm. This paper does not cover the routing protocol implementation, being rather a case study. The major achievement of this proposal refers to a more efficient use of resources (i.e. Available Transfer Rate). The feasibility of this idea was demonstrated with per algorithm OMNET++ simulations on eight-node topology. The scalability is limited to an autonomous system and inter-domain routing solution is for further work.

Implementation of QoS-Aware Virtual Routers

The main contribution of this paper consists of presenting the advantages of using QoS parameters (measured above the MAC Sub-Layer), when taking routing decisions. The proposed entity called “QoS-Aware Virtual Router” uses cross-layering techniques to extract lower layers performance indicators (i.e. available transfer rate and one way delay) and offering them to higher layer protocols. The QoS information measured in real-time is used to calculate a composite metric that is characterizing globally a path from a source to a destination. In this paper we are making a detailed presentation of the proposed mechanism and compare its performances with a best effort solution.

Seamless connectivity platform architecture for public transportation

Providing ubiquitous connectivity to the passengers of public transportation vehicles is an important goal of the communication system designers in the context of fast development of the intelligent transportation systems and of Future Internet communication technologies. Efficient usage of transmission resources available in the heterogeneous networking environment, characteristic to todays wireless networks, and effective routing over these networks with minimal involvement of the operators core networks are some of the requirements for a fast and cost effective deployment. This paper proposes the architecture of an ubiquitous connectivity system for public transportation, the architecture design being considered on three distinct levels: system, functional and platform level. The proposed system architecture specifies a minimal set of entities required to implement envisaged connectivity solution and based on a functional analysis the subsystems and modules are derived. By mapping the functional architecture on the hardware components intended to be used the platform architecture is developed.