MOBILITY MANAGEMENT IN AMBIENT NETWORKS Ramón Agüero Calvo Abigail Surtees Jochen Eisl Michael Georgiades University of Cantabria Roke Manor Research Ltd Siemens AG University of Surrey Avda. Castros s/n, 39005 Santander Old Salisbury Lane, Romsey, SO51 0ZN St.-Martin-Str.76 81541 Munich Guildford, GU2 7XH Spain United Kingdom Germany United Kingdom ramon@tlmat.unican.es abigail.surtees@roke.co.uk jochen.eisl@siemens.com m.georgiades@surrey.ac.uk Abstract – Allowing a user to remain connected to the network whilst on the move is becoming a common requirement for any new communication system. The EU project Ambient Networks, therefore, considers mobility requirements and techniques in some depth. Two key ideas have been developed: the handover toolbox which contains and manages a variety of mo- bility protocols, handover techniques and, in particu- lar, mobility optimisations; and the concept of routing groups, the establishment of which enables the mobil- ity optimisations such as delegation of mobility man- agement and aggregation of mobility signalling. In this paper we present these ideas and show how they are aligned with the Ambient Networks principles of being easily deployable, adaptable, and able to support heterogeneous network configurations. Keywords – Ambient Networks; mobility; handover; mobility optimisations; I. INTRODUCTION Ambient Networks (AN) is a multi-national collabora- tive project within the European Sixth Framework Pro- gramme, investigating networking aspects of mobile sys- tems beyond today’s 3rd generation standards. Ambient Networks is investigating how heterogeneous network configurations, diverse mobile user systems, and applica- tions with specific mobility requirements can be integrated into an internetworking architecture. In addition, the ar- chitecture should be flexible and support plug & play techniques in order to be easily deployable. ANs can “compose” and provide these network services based on the common Ambient Control Space (ACS), which can be distributed physically among different networks. Mobility is a fundamental part of the Ambient Network paradigm, particularly when considered alongside the novel challenges coming from the concept of network composition. There are several different mobility proto- cols available today; however, each is specific to the envi- ronment for which it was developed. Network heteroge- neity brings with it the need for integrated mobility and thus the need for new approaches to mobility solutions. This paper presents the mobility solution proposed for Ambient Networks. The functions discussed here are de- signed to fulfil the Ambient Network requirements, be flexible and adaptable, and work in co-operation with the rest of the Ambient Network architecture. The paper is structured as follows: section II gives a brief overview of the AN architectural philosophy. Sec- tion III describes the mobility framework within Ambient Networks, with particular emphasis on the functional enti- ties defined to support mobility. Section IV provides two use cases to show how these functions work together within the Ambient Network architecture to provide opti- mal mobility solution for the different scenarios. Section V proposes some aspects for future work, and, finally, Section VI concludes the paper. II. AMBIENT NETWORK PHILOSOPHY The Ambient Networks architecture is designed to be scalable and flexible. The key requirements of ANs are the ability for networks to compose – that is, support on- the-fly negotiations and agreements across different ad- ministrative domains; and provide the ability to reconfig- ure in a self-managed way. The Ambient Network archi- tecture is discussed in detail in [1] and a high level view with the three main features is shown in Figure 1. 1. The Ambient Control Space (ACS) consists of co- operating control functions, e.g. to support security and mobility. It is designed such that, although only a small number of control functions are required, additional functions can easily be added or re- moved. The control functions can be broken down into functional entities (FEs). 2. The Ambient Connectivity abstraction layer pro- vides the ACS with a generic, technology independ- ent view of the underlying connectivity. 3. The Ambient network interfaces: • The Ambient Network Interface (ANI) connects the components of the ACS belonging to different Ambient Service Interface Ambient Service Interface Ambient Connectivity Domain Management Mobility Multiaccess Media Delivery Context Provisioning Security Connectivity Controller Domain Management Mobility Multiaccess Media Delivery Context Provisioning Security Connectivity Controller Ambient Network Interface Ambient Network Interface Ambient Network Interface Ambient Network Interface Ambient Network Interface Ambient Network Interface Ambient Network Interface Ambient Resource Interface Ambient Resource Interface Figure 1. Ambient Network High Level Architecture