Assessing QoS trade-offs for real-time video

Demand for real-time video in law enforcement, emergency and first responder situations has been in rapid growth. Further, different users will have different requirements which, depending on their needs, may change over time. At some times, a user may require high frame rate to detect motion, while at other times the user may be more concerned with resolution for object recognition. In this paper we describe our model for quantifying Quality of Experience (QoE) and managing Quality of Service (QoS) that incorporates end user or mission needs. We describe our distributed utility-based QoS optimization technique, D-Q-RAM and show how it can be used to make QoS trade-offs in response to mission needs to maximize QoE. We experimentally demonstrate QoS optimized trade-offs as user preferences shift between resolution and frame rate in a live 802.11 ad hoc wireless network. The results show the ability to meet all individual user needs, changing or not, while minimizing the impact on other users.