Schwerpunktthema it 6/2008 Next Generation Mobile Internet – Network and Service Platform Die nächste Generation des mobilen Internet – Netz- und Serviceplattform Wolfgang Kellerer, Jörg Widmer, Hendrik Berndt, DOCOMO Communications Laboratories Europe GmbH, München Summary The Internet has become the main network tech- unserer Gesellschaft und hat sich damit zu der Schlüsseltech- nology supporting communications and Web services in all nologie der vernetzten Welt entwickelt. Damit das Internet areas of our society. In order to perform this role effi- dieser Rolle bei gesteigerten Anforderungen weiterhin gerecht ciently, a fundamental redesign of the Internet architecture werden kann, wird derzeit seine grundlegende Überarbeitung is being discussed. In particular, mobile devices and wire- diskutiert. In Zukunft werden insbesondere mobile Endgeräte less access networks will constitute an important part of the und drahtlose Zugangsnetze einen erheblichen Anteil an der Internet infrastructure. Based on a general discussion of re- Internet Infrastruktur haben. Daher geht dieser Artikel aus- quirements, this article focuses on the challenges of a next gehend von einer generellen Betrachtung der Anforderungen generation mobile Internet and discusses research approaches speziell auf die Herausforderungen eines Next Generation Mo- for mobility, addressing, heterogeneous access, and service bile Internet ein und diskutiert Forschungsansätze für Mobilität, platforms. Zusammenfassung Das Internet un- Adressierung, heterogene Zugangsnetze und Diensteplattfor- terstützt Kommunikation und Web Dienste in allen Bereichen men. KEYWORDS C.2.1 [Computer Systems Organization: Computer Communication Networks: Network Architecture and Design Future]; future Internet, mobile Internet, virtualization, overlay networks 1 Introduction ation Network (NGN) in fixed in- originating from its basic design The Internet has become the com- frastructures and the All IP Network principles. Targeted as a network for munications backbone of our soci- in mobile systems, the Internet Pro- robust data transport over a fixed ety in all respects. When using the tocol (IP) suite is expected to play infrastructure, its suitability for to- term Internet, we usually do not the dominant role in networking. day’s variety of services including limit ourselves to its core set of pro- With our theme on mobile Internet real-time traffic and mission crit- tocols such as TCP/IP but refer to in this article we cover the aspects of ical applications is limited. To fix itswholeofferofservicesandap- a next generation Internet encom- some of the problems, plenty ad- plications provided by a plethora passing the particular requirements ditional protocols have been pro- of protocols on all protocol layers. of mobile and wireless systems. posed, complementing IP in such Moreover, the Internet has stretched The importance of the Internet areas as security, mobility, and out from the fixed line infrastruc- can also be observed in the area quality of service (QoS). However, ture to cellular networks. There, of service delivery platforms, where none of these proposals have seen access to the Internet was offered the IP Multimedia System (IMS) widespread deployment in the In- as an add-on for second generation becomes more and more import- ternet. For a number of reasons, mobile networks. Today, the Inter- ant as a service platform for packet adding functionality to the current net protocols are an integral part of switched services for fixed and mo- Internet has become almost im- third generation mobile communi- bile networks. possible, leading to an ossification cation systems such as UMTS. With Despite its popularity, the Inter- of the Internet architecture. Thus, the emergence of the Next Gener- net suffers from several deficiencies recently initiatives have started to it – Information Technology 50 (2008) 6 / DOI 10.1524/itit.2008.0505 © Oldenbourg Wissenschaftsverlag 345 Schwerpunktthema reconsider the Internet design as ture. Yet, this is not reflected in Among the research undertaken such. the Internet design where both iden- to reconsider the Internet design, The most pressing problems to tity and location are designated by two directions can be observed. The be solved for the future Internet are IP addresses. This creates prob- clean slate approach tries to come summarized in the following para- lems when a host moves between up with a new Internet architecture graphs [1]. They can be grouped networks, is attached to multiple from scratch, whereas the evolu- by short term, mid term and long networks for multi-homing, or in tionary approach builds on step by term problems according to their case it has multiple service-specific step improvements, starting from urgency [2]. addresses. the existing design. Both should not The most obvious annoyance of Another problem of the Inter- be regarded as exclusive but rather the Internet that has to be solved on net to be solved in the medium complement each other. With over- a short term basis is probably Spam, term is the layered protocol refer- lays and virtualization, we describe followed by security as the biggest ence model itself, which is one of the tools for the implementation of so- imminent problem facing the Inter- main reasons why the other prob- lutions for both approaches. net. Today’s security infringements lems remain unsolved. Due to many The remainder of this article such as viruses, phishing, denial-of- short sighted fixes but also due to its is structured as follows. First, we service attacks, etc. largely diminish huge success as the platform for net- highlight selected mobile operator the users’ trust in the network and working, the architecture has ossi- related solution concepts to deal prevent critical applications from fied and lost all necessary flexibility. with the above requirements. In being deployed. A further problem Finally, while the problem of ad- Section 3 and Section 4, we describe is the presence of middleboxes such dress space depletion is addressed by mechanisms such as overlays, virtu- as firewalls or NATs, some of them IPv6, its widespread deployment is alization and cross-layer design as deployed to improve network secu- lagging behind. Enhancing the ad- tools to implement solutions in the rity. They do not fit well with the dress space through IPv6 or any core network and in the wireless original concept of end-to-end con- other suitable solution thus remains access network, respectively. Service nectivity and cause enormous prob- a problem to be solved in the long platform related aspects of a next lems for application developers. term. generation Internet are discussed in Medium term problems relate As a very general tendency, one Section 5. to QoS, management, routing, mo- can observe that the solutions to bility and the overall layered archi- those problems will move some 2 Selected Future Internet tecture itself. Despite many research intelligence back to the network, Concepts and standardization efforts the best- which is in favor of the operators to Of the general architectural prob- effort characteristic of the Internet be able to handle traffic flexibly with lems of the Internet discussed prevails. QoS is addressed by simple respect to the varying application above, some are more relevant to overprovisioning today. However, to requirements. In general, the oper- mobile operators than others. To cope with the rise in traffic volume ator expectations for a future Inter- use IP as a basis for future opera- and the requirements of emerging net target an innovation-friendly In- tor networks, specifically the aspects applications (e. g., real-time, inter- ternet that is service oriented rather of device mobility and multi-hom- active) as well as the use of net- than designed for host-to-host ing (or the use of multiple radio works with different physical layer packet forwarding, to prepare for interfaces for different wireless net- characteristics (e. g., wireless), com- unknown upcoming applications. works on the same device) need to prehensive solutions have to be de- For a mobile operator,thesame be solved. Also, addressing is an im- veloped and deployed in order to problems apply for its IP core net- portant issue, in particular if the transform the Internet from a com- work. In particular, when changing increase in the number of devices modity best-effort network to a com- the viewpoint from mainly fixed connected to an operator network mercialtelco-gradeone.Inthesame hosts to mobile hosts several chal- continues to increase. However, as way, Internet network management lenges have to receive additional long as device mobility or the use is lacking some of the functionality attention: Address management has of multiple radio interfaces are con- known from traditional telecommu- to be able to cope with a rapidly fined to the network(s) of a single nications. Further, the slow conver- increasing number of mobile ter- mobile operator, it is possible to de- gence and other deficiencies of the minals, each possibly equipped with ploy solutions without coordinating BGP protocol limit the scalability of several air interfaces of different with other operators, thus signifi- inter domain routing and thus limit QoS characteristics. Furthermore, cantly simplifying deployment hur- the business relationships between the heterogeneity of device capabil- dles compared to Internet ISPs. Internet service providers (ISPs). ities and wireless access links needs On the other hand, mobile op- Many of the Internet hosts are