Providing QoS for Multimodal System Traffic Flows in Distributed Haptic Virtual Environments

Future internet architectures will be required to support the transmission of data that is multimodal in nature, and this will include the ability to transport reflected force, or haptic information. This paper presents for the first time, an investigation into providing specific network Quality of Service (QoS) for haptic traffic together with voice and video traffic. Because it originates from a different human sense, the QoS required to support haptic traffic is significantly different from that used to support conventional real-time traffic such as voice or video. Each type of network impairment has different (and severe) impacts on the user´s haptic experience. While some recent efforts have established the basic range of the network QoS parameters for haptic interaction, to date there has been no specific provision for this traffic over a QoS enabled IP network. The work presented here involves both simulation and practical experimentation whereby haptics, voice and video are transmitted over a best effort IP network and a QoS-enabled IP network. The results show that the network simulation model compares favourably with the physical network, and can be used to generate a scalable haptic network model where multiple connections carrying haptic traffic may be examined. Both approaches show that reducing network delay and jitter by using specific QoS classes for haptic traffic can lead to improvements in users´ haptic experiences with distributed applications such as virtual environments.