Mobile-friendly Peer-to-Peer client routing using out-of-band signaling

It is expected that Peer-to-Peer (P2P) services will co-exist with the client-server based services such as IMS. Mobile users may subscribe to the traditional wireless cellular services while participating in P2P overlay networks. In this paper, a method is proposed to reduce the signaling overhead in a mobile P2P system. With the help of the underlying infrastructure, a mobile device in the P2P overlay can be located using out-of-band non-P2P signaling. This reduces its P2P signaling for location update while a mobile device is changing the point of attachment in the P2P overlay. As the signaling cost depends on both the client´s mobility and traffic models, an analytical model has been developed to determine the optimal threshold for the registration update. Analytical results have shown that the proposed method could save up to 70% signaling cost when the Call-to-Mobility Ratio (CMR) is low. On the other hand, it would be better to fall back to the base client routing method when the CMR is high, i.e., perform the registration update whenever the client changes the point of attachment in the P2P overlay.