Speaker: Abdullah Alqasir, ECpE Graduate Student
Advisor: Ahmed Kamal
Title: Cooperative Small Cell HetNets with Sleeping and Energy Harvesting
Abstract: This work considers a heterogenous wireless cellular network (HetNet) where many small base stations (SBSs) coexist with each other. SBSs can be deactivated and put to sleep to save energy and are equipped with two power sources, harvested energy (HE) source and a grid power source, where first an SBS will use its available HE to serve the associated users. Then, the SBS will request any shortage of its energy from other active or deactivated SBSs which have surplus of HE. Finally, if there is still shortage in energy, the SBS will use the power drawn from the grid. This transfer of energy is facilitated through the use of the promising technology of the smart grid (SG). We investigate the grid energy minimization problem by optimizing both the transmission power and activation/deactivation (Dynamic Sleeping) of the SBSs. However, since the formulated problem is a Mixed Integer NonLinear Problem (MINLP), Generalized Bender Decomposition (GBD) is used to decompose the problem into two subproblems: user association and energy harvesting which are solved iteratively. Moreover, a new heuristic approach is proposed to provide a computationally efficient algorithm to solve and optimize the user association and energy harvesting problems of the system model. This approach uses network centrality to develop a measuring parameter, Base Station Centrality (BSC), of the SBS centrality in the network. BSC is presented to mark the SBSs that have the most potential to be deactivated without affecting the QoS of users. Finally, extensive simulations are performed to verify the superiority of the proposed BSC-based strategy over the GBD in terms of operational cost.