Filip De Greve

FAMOUS: A Network Architecture for Delivering Multimedia Services to FAst MOving USers

When today’s commuters in the train or in a car want to access the Internet, they see themselves restricted to simple web surfing or e-mail. Interactive multimedia services, like online gaming or video conferencing are still unavailable to them, even with promising new technologies like UMTS or WiMAX. The impact of high bit rate multimedia traffic on the access network and aggregation network is an important topic, that has not been addressed in enough detail before. We designed a network architecture for offering these multimedia services to fast moving users. We refer to the overall network architecture as the FAMOUS network architecture, which consists of two parts: (i) an access network part which has to deal with large number of users, asking for a high bandwidth, while experiencing a high handoff frequency and (ii) an aggregation network part which has to deal with dynamic tunnels of very high bandwidth, while experiencing a low handoff frequency. In this paper, we detail the FAMOUS architecture, together with optimized handoff strategies, an optical switching architecture, a design methodology for dimensioning aggregations networks and automatic tunnel pre-configuration and activation. Moreover, performance results of these mentioned aspects will be presented.

Optimization models for designing aggregation networks to support fast moving users

In this paper, the focus is on the design of an aggregation network for offering high bandwidth services to fast moving users (e.g., users in trains or cars). The overall considered network architecture consists of two parts: an access network part and an aggregation network part. The users in the fast moving vehicles are connected to the access network via a wireless connection. In the aggregation part, traffic of different users is bundled together in tunnels, and as the users move from one access network to another access network, tunnels have to move with them. Two problems concerning this issue are tackled in this paper. The first one can be described as follows: how to determine the tunnel paths in the aggregation network to meet the fast moving traffic demand of requests while achieving low congestion and minimizing the network dimensioning cost. Secondly we need protocols to manage the tunnels by means of configuration and activation at their due time. GVRP (GARP (Generic Attribute Registration Protocol) VLAN Registration Protocol) and a new GARP protocol, called G2RP, were designed and implemented as protocols for the automatic tunnel configuration and activation, respectively. Finally, the performance of the different algorithms used for the network capacity planning and the tunnel path determination is compared on basic train scenarios.

Design of wireless mesh networks for aggregating traffic of fast moving users

In this paper, we examine wireless mesh networks and present a theoretical model for evaluating the expected throughput for fast moving users. We propose intelligent techniques for improving the throughput: distribution of neighbour nodes over the available wireless interfaces and distributed channel assignment for minimising the interference. Evaluations show that the neighbour nodes should be equally distributed over the wireless interfaces based on the relative difference in hop count to the closest gateway. We also present load-aware techniques which dynamically adapt the nodes according to the current traffic conditions. Load-aware techniques are able to achieve larger throughput but in many cases gain margins are smaller than expected. It is also shown that a poor choice in neighbour interface binding or channel assignment technique leads to a decreased performance in such away that adding interfaces or channels would not further improve the throughput.

A tunnel-based qos management framework for delivering broadband internet on trains

Current satellite, GPRS and GSM systems show different shortcomings to provide Broadband Internet access to trains In this paper, we motivate that an Ethernet based aggregation network in combination with WiFi and WiMAX antennas is the best approach for realizing Broadband Internet access in trains The focus is on the management system for the Ethernet aggregation network and more specifically on the implementation of the module for tunnel switching trigger management The components of the management system are presented and different tunnel switching strategies supported by the framework are compared in terms of minimal, average and maximal packet loss.

Aggregation network design for offering multimedia services to fast moving users

Nowadays, passengers in fast moving vehicles can consume narrow-bandwidth services such as voice telephony or email but there is no widely deployed platform to support broadband multimedia services. In this paper, an aggregation network architecture for the delivery of multimedia services to train passengers is presented. For the topology design and capacity assignment of this network, a novel method is presented that calculates the required dynamic tunnels to meet the traffic demands of the fast moving users while achieving low congestion and optimizing the utilization of the network resources. The method enables that under conditions of train delay the Quality of Service (QoS) requirements of the traffic flows are guaranteed. The capacity assignment efficiency is demonstrated for different network scenarios and due to the time-dependent complexity of the problem, heuristic approaches are designed to solve problems of realistic size.

Management of aggregation networks for broadband internet access in fast moving trains

Current satellite, GPRS and GSM systems lack from different shortcomings to provide broadband Internet access to fast moving trains. In this paper, we motivate that an Ethernet based aggregation network architecture is the best approach for realizing broadband Internet access in trains. The focus is on the management system for the Ethernet aggregation network and more specifically on the implementation of the management module for tunnel switching trigger management. The components of the management system are presented and three mechanisms for the implementation of the tunnel switching trigger management are detailed: a prediction based, a signaling based and a location aware approach. The different mechanisms are compared with respect to availability, complexity and network usage.

Optimizing routing schemes for fast moving users in MST-Based networks

With the currently emerging trials for best-effort internet solutions on trains, solutions are required for delivering multimedia services to fast moving users. Research has already been devoted to dimensioning Ethernet aggregation networks, taking user movement into account while neglecting the experienced network performance. This paper extends this design for resilient networks and aims at minimizing packet loss and packet reordering in the dimensioning and routing process. For deployment in an Ethernet network which supports Multiple Spanning Trees (MSTs), effective path aggregation methods are proposed for finding a minimal set of spanning trees and these are thoroughly evaluated for different scenarios. Moreover the spanning tree assignment problem with predefined backup conditions is studied.