Green Security in Ultra-Dense Networks

Future digital services should follow the user anywhere and be personalized/customized on his/her specific requests. Thus, future connectivity networks should face an unprecedented demand of digital services on mobility, together with a high variability of requirements and specializations. One of the most promising methods to provide such flexible and scalable connectivity is deploying base stations of different sizes closer to users: the ultra dense networks (UDNs) paradigm. UDNs will have to be optimized taking into consideration several factors, among which energy consumption and security are two key features that cannot be left apart. This paper proposes a secure & green optimization procedure to jointly select the users' serving base station and its transmission power with the aim of improving security and reducing power consumption. Towards this goal we introduce a metric that jointly considers secrecy-rate and power consumption in a UDN scenario and does not depend neither on the eavesdropper position nor the channel state, since it is derived by averaging the considered ratio over the whole network. The formulated problem is solved by resorting to a meta-heuristic optimization algorithm. The accuracy of the solution is proven by comparing the obtained results with other algorithms and with the optimal solution. Moreover, the efficacy of the applied metric in finding a suitable trade-off between secrecy-rate and power consumption is shown in comparison with different association metrics.