On congestion control for interactive real-time applications in dynamic heterogeneous 4G networks

Real-time multimedia applications, such as VoIP, video conferencing or on-line gaming are key applications to the success of 4G. In today´s Internet these applications are not subject to congestion control, therefore the growth of popularity of these applications may endanger the stability of the Internet. On the other hand, 4G networks will be much more dynamic due to mobility and multi-homing, and the network conditions may vary abruptly requiring a fast response from the control mechanism. In this article we compare the feedback-based to the reservation-based congestion control approach and focus on the first one, by evaluating some mechanisms with respect to media friendliness, scalability and dynamic behaviour. We also present a set of requirements for the ideal congestion control mechanism of real-time flows in 4G networks