A Cross-Layer Approach to Mixed-Control Topology Management for MANETs

Topology Control (TC) algorithms are generally applied to tactical network environments to create or maintain connectivity graphs with specific topological properties. In the context of this work, network topology defines the connectivity and link properties between nodes in the network. While protocols in the communications stack are traditionally designed to adapt to different traffic demands and underlying changes in network topology, TC algorithms offer an opportunity for applications to become proactive, and to drive changes in network topology. In most cases, topology control is achieved through a number of independent control strategies such as power management, node mobility or spectrum allocation, each of which operates at a different time scale, with different constraints and capabilities. In this work we introduce a mixed topology control strategy for highly dynamic tactical networks. The proposed approach combines two controllers (one for transmit power and one for node mobility) to enable a self-regulating link maintenance algorithm that compensates for short term variations in link conditions while supporting a more permanent, slower adaptation based on node position. While applied for transmit power and node mobility in this paper, the approach is generic enough to be extended to different parameters. After describing the control formulation and its stability analysis, we introduce simple leader-follower scenarios simulated in NS-3 to illustrate the capabilities and properties of the proposed approach.