Ingo Viering

A Distributed Power Saving Algorithm for Cellular Networks

We consider power saving in a cellular network. Subject to constraints generated by network planning and dynamic Radio Resource Management algorithms, there is room for reducing Base Station (BS) transmit powers. We suggest that power is reduced in a way that does not move cell boundaries significantly. For this, there is a power difference constraint d max that upper limits the difference in power reductions in neighboring BSs. The BSs exchange information about their current level of power. Each BS has a target maximum power reduction. We propose a distributed algorithm, where the BSs take turns to reduce their power, respecting their neighbors current power settings and the power difference constraint. We show that this algorithm converges to a global optimum.

Real-time Network Simulation of 3GPP Long Term Evolution

In 2004 the 3GPP has started to standardize the new system Long Term Evolution. The key advantages are higher data rates, smaller latency, simpler network architecture and higher spectral efficiency. The worldwide first live demonstration of LTE using our real-time simulation platform was given in September 2006. From that time the network simulator has been continuously enhanced with new functionality also considering latest progress in 3GPP standardization. The simulator shows the behavior of a future LTE network for various scenarios, under different load conditions. Real-time IP traffic is passed through the simulator demonstrating the user perception of future applications with different QoS configurations (e.g. video streaming and gaming). In particular, the aspect of radio resource management including scheduling functionality is highlighted and comprehensively illustrated via an elaborate graphical user interface.