Jürgen Jähnert

The 'pure-IP' Moby Dick 4G architecture

Network operators, service providers and customers are players who have different interests and raise different requirements on the functionality of future mobile communication networks. However, some new capabilities, such as mobility, security, ubiquity and quality are spelled out by all, which means that there exist some fundamental mechanisms which are in fact needed in every network. This paper concentrates on critical elements of the network infrastructure which need to be deployed in 4G networks before services can be offered. In the paper we discuss these elements, and show how they can be combined to satisfy versatile service requirements. Furthermore, the paper shows how to combine these mechanisms of three traditionally quite separate architectures-for Authentication, Authorisation, Accounting and Charging (AAAC), for Mobility (Mobile IP with Fast Handover), and Quality-of-Service (QoS). A technology-independent paging concept is also integrated in this system. The resulting integrated system architecture is general and can be deployed in heterogeneous environments. Our implementation has recently been completed, validated and verified with applications such as data transfer, voice-over-IP, video streaming and real time concurrent gaming. This prototypical implementation incorporates TD-CDMA, 802.11 WLANs and Ethernet, and treats all transmission technologies as physical and data-link layers, while higher-level functions are supported in a uniform way with an all-IPv6-based signalling.

Usability and evaluation of a deployed 4G network prototype

This article presents a field evaluation of an IP-based architecture for heterogeneous environments that has been developed under the aegis of the Moby Dick project, covering UMTS-like (universal mobile telecommunications system) TD-CDMA (time division-code division multiple access) wireless access technology, wireless and wired LANs. The architecture treats all transmission capabilities as basic physical and data-link layers, and replaces all higher-level tasks by IP-based strategies. The Moby Dick architecture incorporates mobile IPv6, fast handovers, AAA-control (authentication, authorisation, accounting), charging and quality of service (QoS) in an integrated framework. The architecture further allows for optimised control on the radio link layer resources. It has been implemented and tested by expert users, and evaluated by real users on field trials with multiple services available.

Extensions of AAA for future IP networks

The design of an extended and generic authentication, authorization, accounting, and charging architecture (AAAC Arch.) has been performed within the IST project MobyDick. In addition, this architecture has been implemented to address MobyDicks main objective: to facilitate the deployment of a ubiquitous mobile IPv6-based, quality-of-service (QoS)-aware infrastructure through a flexible and evolutionary AAAC Architecture. While the AAAC Arch. is based on the DIAMETER protocol, basic concepts developed cover session and services models, user profiles to allow for user mobility and QoS-aware authorization. Based on those basic building blocks for the extended AAAC Arch., the implementation of user registration, service authorization, metering, accounting, charging, and auditing is discussed. The paper closes with the presentation of the two trial sites used and their testbeds.

Grids in a Mobile World: Akogrimo's Network and Business Views

ABSTRACT The use of wireless networking technologies has emerged over recent years in many application domains. The area of grids determines a potentially huge application domain, since the typical centralized computing centers require access from anywhere, e.g., from field engineers who are situated in a wireless network domain. Thus, the integration of suitable business views on mobile grids, of grid views on available technologies, and network views in a fully IP-based network domain determines the key challenge. The Akogrimo projects architecture developed, is outlined and discussed in this paper and provides the major details required to offer a fully integrated and interoperable solution for those three views of concern.

Cost-efficient metering and accounting in 4G networks

The commercialisation of the Internet has been smoothly progressing. However, there is a lack of suitable mechanisms to provide scalable and efficient support for charging and billing. Such support is crucial for the overall success of a commercialised network. Though the demand for standardized and efficient solutions in support of reliable, open and flexible mobile services has increased, existing authentication, authorization and accounting mechanisms are not yet sufficiently ready to support these requirements. Moreover, the current transition from traditional circuit switched networks towards a packet based wireless IP network infrastructure, also in the wireless area, increases significantly the pressure to provide the missing mechanisms on IP layer. Although the basic mechanisms are available and widely understood, their efficient and scalable integration is still a mute point.

Problem Statement: Metering and Accounting in the Full-IP 4G Environment

The current migration from traditional circuit-switched networks towards a packet-based wireless-IP network infrastructure is adding significant pressure for the provision of commercialized IP-based services. However, due of the lack of suitable mechanisms to provide scalable and efficient support for IP-based charging and billing, the commercialization of the Internet has only been progressing slowly. Such IP-based charging and billing support is crucial to the overall success of a commercialized wireless IP-based network as aspired in 4G. Within the IETF, both an IP-based metering framework and an AAA architecture dealing with authentication, authorization and accounting have been developed which targets the missing functions and mechanisms. Although the basic mechanisms are available and widely understood, their efficient and scalable integration into a mobile environment is still an open point.

Provision of QoS for Legacy IP Applications in an ATM-over-HFC Access Network

With the increasing needs for delivering higher bandwidths to residential areas, new technologies (e.g. xDSL) are emerging that are enabling broadband access. Network technologies, which are based upon upgrades of existing network infrastructures, are, economically, one of the most promising approaches. One of these, competing with several other approaches, is hybrid fibre coax networks (HFC) currently being used for CATV broadcasting. The various access network technologies will be interconnected via broadband core networks resulting in heterogeneous networks which, have to provide end-to-end applications based on the Internet Protocol. Since the CATV network is of a shared nature, the provisioning of IP-based Quality of Service (QoS) requires suitable inter-layer signalling in order to provide QoS-related information as soon as possible to the relevant instances. This paper presents a system architecture using ATM-over-HFC for high-speed Internet access providing IP-based QoS. The architectures seamless interoperability with other network technologies supports both IP-based and native ATM applications.