An Overview and Comparison of Demand Assignment Multiple Access (DAMA) Concepts for Satellite Communications Networks
Provides a broad survey of Demand Assignment Multiple Access (DAMA), a loosely-defined class of multiple-access techniques for allocation of satellite resources. DAMA schemes can be divided into two main classes: "Pure" DAMA, which involves circuit-switched resource allocation, is efficient for voice and for large file transfers, but inefficient for text messages and most short data transmissions. "Hybrid" DAMA schemes, which allocate resources using circuit switching in combination with packet switching or other techniques, address the limitations of pure DAMA in several different ways. The report explains the workings of these protocols and discusses implementation issues, including alternative control locales (fully centralized, fully distributed, and hierarchical). It examines vulnerabilites of these protocols (including unintentional interference, jamming of links, and destruction of critical nodes) and presents alternative mitigation strategies for these vulnerabilities, including some new design approaches. Performance results are included for many of the protocols, drawing on the published literature wherever possible and including some new performance results as well.