Andrej Mihailovic

Evaluation of mobility and quality of service interaction

With the fast adoption of IP-based communications for mobile computing, users are expecting a similar service in wireless and wired networks. This raises the need for setting guarantees to the quality of the offered service (QoS), despite the technology of the access network (AN) or the mobility of the terminal. As mobile computing is getting more popular on a daily basis, new broadband cellular wireless ANs will appear with overlapping coverage in hot spots. This generates a new challenge for QoS provision, as it will have to deal with fast mobility of terminals. Various QoS architectures have been defined, but none provides full support for guaranteed service levels for mobile hosts (MHs). This paper discusses the problems related to providing QoS to MHs and identifies the existing solutions and future work needed.

Multicast for mobility protocol (MMP) for emerging Internet networks

This paper contains a design description for an IP-mobility protocol called multicast for mobility protocol (MMP). The protocol is intended to provide fast and efficient location management and routing for mobile hosts in internet networks. The general configuration of the protocol which is divided into two parts: global and local, or macro and micro mobility, makes it an optimal and attractive solution for the emerging internet-based mobility-enabled stub networks, referred to as IP access networks. This version of MMP contains various enhancements to the initial version such as the introduction of a new control message MMP instruct and protocol mechanisms for handling new protocol issues such as: paging, support for mobile sources, advance registrations, implementation adaptations. However, the initial main concepts of mobile IP-controlled macro mobility and micro mobility enabled by a sparse mode multicast protocol called core based trees (CBT) are still the main characteristics of the protocol.

A framework for the evaluation of IP mobility protocols

In this paper we suggest a classification scheme for IP mobility protocols and propose a framework for comparing them. We then use the framework to provide an initial comparison of previous proposals for supporting micro-mobility. The authors are part of project BRAIN (Broadband Radio Access for IP based Networks)-a European collaborative project under the IST (Information Societies Technology) programme. One aim of the project is to propose an open architecture for wireless broadband Internet access, concentrating on issues in the access network.

Future internet elements: cognition and self-management design issues

The scope of this paper is to introduce an innovative paradigm for cognitive self-managed elements of the Future Internet. The present Internet model is based on clear separation of concerns between protocol layers, with intelligence moved to the edges, and with the existent protocol pool targeting user and control plane operations with less emphasis on management tasks. Future Internet shall be engineered based on cognitive behavior with a high degree of autonomy, by proposing the operation of self-managed Future Internet elements around a novel hierarchical feedback-control cycle. The concepts are based on a hierarchical Distributed Cognitive cycle for System & Network Management (DC-SNM) which aims at facilitating the promotion of distributed management. The management approach encompasses a hierarchical distribution of cognitive cycles, breaking down the execution and decision making levels to (autonomic) network elements, network domain types and up to the service provider realm in order to address management, dynamic organization and (re)configuration of future internet elements.

Proactive autonomic load uniformisation with mobility management for wireless Internet Protocol (IP) access networks

The agent micro-mobility protocols, such as Hierarchical Mobile IPv6 and Proxy Mobile IPv6, have become leading contenders for providing micro-mobility support to mobile nodes (MNs). The presence of mobility agents (MAs) in these networks can lead to constrained routing and create areas of bottleneck around the MAs. When an MA is integrated in the access network all traffic is forced to flow through that MA potentially over-utilising paths along the MA, whereas other paths of the network remain under-utilised. For the efficient deployment of such networks, optimal and robust MA selection and load balancing mechanisms are required. This study introduces proactive autonomic load uniformisation, a self-managed load balancing scheme in which the congestion caused by MAs is reduced leading to better utilisation of the network resources. Assuming that the network supports multiple MAs, the proposed solution selects the optimal MAs by distributing optimally the incoming load within the network while at the same time maintaining the quality of service requirements for the MNs. The results show that the congestion is lowered by 25% within the network and the load is distributed uniformly across the MAs.

A Study on QoS Provision for IP-Based Radio Access Networks

The fast adoption of IP-based communications for hand-held devices equipped with wireless interfaces is creating new challenges for the Internet evolution. Users expect flexible access to Internet based services, including not only traditional data services but also multimedia applications. This generates a new challenge for QoS provision, as it will have to deal with fast mobility of terminals being independent of the technology of the access network. Various QoS architectures have been defined, but none provides full support for guaranteed service levels for mobile hosts. This paper discusses the problems related to providing QoS to mobile hosts and identifies the existing solutions and future work needed.

Introducing Multi-Plane Routing for next-generation all-IP wireless access networks

It becomes more and more recognized that using IP as the underlying foundation for the next-generation of wireless networks makes strong economic sense. This is evident in installation and operation, and technical aspects as it takes advantage of the ubiquitous installed IP infrastructure. Because of that, a resilient, efficient and easy implementable routing paradigm is needed. Multi-Plane Routing (MPR) is a routing technique, using the recent multi-topology approach, that leverages multiple alternative paths (from each source-destination pair) through a network. In this paper, we introduce MPR for wireless access networks and show that, with an optimal link weight assignment, it can reduce the maximum link utilization by up to 40% and end-to-end delay by up to 90%. MPR also increases the overall network performance by maximizing path diversity across the routing planes and splitting traffic using a branching factor. Finally, our experiments show that our nascent approach can achieve high performance in next-generation all-IP wireless access networks with a moderate number of routing planes.

Building Knowledge Lifecycle and Situation Awareness in Self-Managed Cognitive Future Internet Networks

This paper describes aspects for developing cognitive functionalities in self-managed networks according to the vision of the Future Internet networks being developed in the Self-NET project. The project develops and prototypes architecture and solutions for realising a vision on Internet evolution based on integration of cognition and autonomics in self-managed networks demonstrated in numerous and diverse use-cases developed. Two specific topics are investigated in the paper as they present the building blocks of this development. The first topic is definition and formulation of the knowledge lifecycle in self-managed networks and the second one is on building situation awareness in such networks as a ubiquitous concept in dynamic control. Both of the topics are interrelated and are crucial elements of building cognitive networks primarily as their resolving and definition demonstrate the practical side of applying diverse available work on the topics and provide a focus for their understanding and development.

A Cost-Optimal QoS Aggregation Policy for Network Mobility: Analysis and Performance Comparisons

The potentially large population density and high handover rates of mobile users aboard a public transport vehicle underpin the need for robust and scalable quality-of-service (QoS) provisioning mechanisms designed for such environments. Traditional QoS approaches fall short of such criteria and have led to the proposal of a number of aggregation-based QoS mechanisms that maintain a single QoS state in the access network for the entire moving network subnet. Although such proposals can increase handover scalability, the dynamic connectivity and population of users within public transport vehicles can lead to bursts of requests being made due to passengers embarking on a vehicle in groups, intermittently increasing the control signaling density in the network and consequently increasing the cost to the operator. QoS aggregation policies alleviate this problem by buffering QoS requests at the mobile router installed on the vehicle for a period of time and then aggregating these into a single request to alter the resources reserved in the access network for the moving network. A number of such policies have previously been proposed in the literature to control and manage the buffering duration at the mobile router. However, since the aggregation decision of these policies is based on a static request-rate-dependent parameter, cost inefficiency can occur when the request rate is variable, as is typical of public transport vehicles due to passengers embarking and disembarking. This paper therefore provides a full mathematical and simulation-based analysis of a novel cost-driven aggregation policy and compares its performance with that of other policies previously proposed in the literature. Our results show that our cost-driven policy can reduce operator costs due to signaling by up to 21% compared with other policies while, at the same time, not putting the user at a disadvantage with long and unpredictable waiting times to establish a session.

Providing multi-homing support in IP access networks

Amongst the activities of the European Commission IST research project-MIND is extensive consideration of the multi-homing issues in IP access networks. Analysis of the various multi-homing scenarios reveals diverse aspects of multi-homing relevant to both the operations of the access network as well as the hosts connected to it. The originality of the work presented in this paper arises from the uniqueness of the multi-homing setup in IP access networks that support terminal mobility such as the one developed in the BRAIN project and the ad hoc and self-organising network extensions developed in MIND. This paper presents a part of our work on multi-homing by showing the required architectural support from the involved network elements and utilisation of the existing general mechanisms for the support of IP connectivity.