Enabling Mobile Peer-to-Peer Networking
Mobile and Wireless Systems, LNCS 3427, Dagstuhl, Germany, (January 2005)Abstract
P2P file sharing systems account for a high percentage of the traffic volume
in the fixed Internet, having exceeded http (WWW) or email traffic 1 2. The
increasing availability of mobile data networks such as GPRS and UMTS in conjunction
with attractive pricing schemes makes P2P file sharing an interesting
application also in the mobile context. But the operation of P2P systems in mobile
environments encounters several problems, such as a relatively narrow and
expensive air interface, highly varying online states (presence) of the subscribers,
a hierarchical network structure (GPRS), and limited device capabilities.
P2P is a distributed application architecture where equal entities, denoted as
peers, voluntarily share resources, e.g. files or CPU cycles, via direct, end-to-end
exchanges. In order to share resources, P2P applications need to support two fundamental
coordination and control functions: Resource mediation mechanisms,
i.e. functions to locate resources or entities, and resource control mechanisms,
i.e. functions to permit, prioritize, and schedule the access to resources. Pure
P2P architectures are implementing both mechanisms in a fully decentralized
manner 3, while Hybrid P2P systems utilize central entities that collect mediation
data. An example for a Hybrid P2P system is the eDonkey filesharing
protocol, where the index servers collect and distribute file location information
about all peers.
The desire of mobile network operators is to add value to the P2P data
flows and to turn P2P into a service they can charge for. When creating such
services operators retain control on traffic and content. However the basic P2P
user experience and connectivity should be preserved. In this paper, we describe such a service and analyze its impact on the
network usage by means of a simulation.