Abstract How to Measure Interactivity in Telecommunications

Most recently, the notion of interactivity has gained rapidly increasing interest within the telecommunications community. Especially in the context of network quality planning (E-Model) it is suspected that interactivity might be of crucial impact on the perceived Qualityof-Service of bi- and multilateral communication over delayed transmission channels. In order to explore this in depth, an instrumental (objective) metric for conversational interactivity is an indispensable prerequisite. However, it is interesting that already the task of providing a concise definition of interactivity is a surprisingly hard job, as we demonstrate in this paper through a comprehensive survey on the various proposals made in the related work. As a preliminary conclusion, this demonstrates that current approaches do not allow for deriving a metric which is both meaningful and easy to be technically implemented. Therefore, we propose to use an axiomatic approach based on the relationship between the stateful activity of the speakers and the resulting interactivity of their conversation. We demonstrate that our resulting concept of interactivity is closely related to the notion of physical temperature as known from statistical thermodynamics. Finally, we back our approach using results from dedicated user tests.