Energy Efficient Nano-Node Association and Resource Allocation for Hierarchical Nano-Communication Networks

Nano-communication networks operating in the Terahertz (THz) band are being developed quickly owing to the high bandwidth range. In this paper, we investigate energy efficient data transmission in hierarchical nano-communication networks with multiple inbody nano-nodes and micro-nodes. Considering the channel characteristic of the THz band, we formulate a weighted energy efficiency optimization problem for the joint design of nano-node association and resource allocation in such networks. By regarding nano-node association results as the network cluster configurations, the non-convex optimization problem is decomposed into a network clustering problem and a resource allocation problem. The network clustering problem is a combine optimization problem, whose optimal cluster configuration is derived using Markov approximation theory. Besides, the resource allocation problem, which is a mixed integer nonlinear programming problem, is solved by comprehensively using continuity relaxation theory and an improved dynamic programming method. An adaptive frequency selection and power control algorithm is given for nano-nodes to determine the optimal frequency and transmit power under a specific cluster configuration. To gain more insights into the obtained solutions, a joint network clustering and resource allocation algorithm is presented to accommodate hierarchical nano-communication networks to achieve the energy efficient data transmission. Simulation results validate the theoretical analysis of the proposed algorithms.