Moby Dick Consolidated System Integration Plan

D0103v1.doc Version 1 6.7.2003
3 Moby Dick Architecture
3.1 Conceptual view
In the wired-network infrastructure circuit-switched voice communications have dominated the
telecommunications market since it’s beginning. Packet-switched voice and data communications are
currently the key drivers for the development of new communication systems and technologies. This
trend can be also observed in the wireless network segment. Also here, technologies like GPRS and of
course UMTS are lower layer designs based on circuit switched principles, but a tendency towards packet
based network design principles is evident.
The emphasis on packet-data communications brings an outstanding opportunity for heterogeneous
environments. Recent developments in the TCP/IP protocol are intended to support the development of a
multi-technology network mainly independent of the underlying physical layers, where all relevant
functions are performed at the IP level.
The importance of IP communications has already been recognized in UMTS (as well as in EDGE/IMT-
2000), which provides an IP packet service using a tunnelling mechanism but still employing all the
mechanisms of 2 nd Generation Networks. Even with these facilities, several operators question the
approach of bringing the concept of packet switching into the existing connection-oriented network
environments, since it is considered an intermediate step towards a pure IP-based solution, which will be
most probably be available in the fourth Generation mobile communication (4G) networks.
The Moby Dick approach can be regarded as a more radical alternative. The Moby Dick architecture is
being developed using three key design principles:
• The network should implement as many functions as possible using standard IP-based protocols and
technologies, by reusing as many commonalities in different access technologies as possible.
• The network should be able to provide real-time services with quality comparable to traditional
cellular networks.
• The services should be generally accessible regardless of the access network and uninterrupted
during handoff.
The overall network architecture includes the following elements (Figure 1):
Figure 1: General Network Architecture
• Mobile end-systems running user applications. Each end-system can be equipped with interfaces of
different technologies simultaneously. In particular, within the Moby Dick project, the interfaces to
TD-CDMA (UMTS-TDD), wireless LANs (802.11), and fixed networks (Ethernet) are supported;
• Access Routers, providing an interface between a wireless and a wired-network domain. It is
assumed that these domains are different IP-subnets. These gateways are associated with the tra-
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