An empirical model for multi-contact point haptic network traffic

The emergence of force feedback haptic devices that can remotely interact with virtual environments presents a number of challenges to the underlying networks that have to support their interactions. One important issue concerns the characterisation of haptic traffic, particularly whenever multiple users remotely interact over a network such as the Internet. Previous research has characterised the traffic produced by single contact-point haptic devices when remotely interacting with a distributed haptic virtual environments (DHVEs). The research presented in this paper extends this work to consider the more complex traffic produced by haptic devices with multiple contact points, whenever interacting remotely with virtual environments. Such devices produce a rich mixture of different traffic streams that are interdependent but also characterised by the interactions of the individual users. The aim of the work presented here is to characterise the traffic generated by multi-point DHVE network connections. The approach taken develops an analytical model of DHVE traffic based on empirical measurements. Suitable probability distributions models are subsequently derived for each type of traffic. The results show that each traffic type exhibits either a Normal or a Weibull distribution. The results permit the development of a multi-contact point haptic traffic generator model which can then be used by simulation and analytical studies in order to examine how such interactive applications can be transmitted over different network situations and topologies.