Low Power Operating System for Heterogeneous Wireless Communication Systems

Suet-Fei Li, Roy Sutton, Jan Rabaey

"PACT 01 Conference, Barcelona, Spain September 8-12, 2001

Operating systems in embedded wireless communication increasingly must satisfy a tight set of constraints, such as power and real time performance, on heterogeneous software and hardware architectures. In this domain, it is well understood that traditional general-purpose operating systems are not efficient or in many cases not sufficient. More efficient solutions are obtained with OS’s that are developed to exploit the reactive event-driven nature of the domain and have built-in aggressive power management.  As proof, we present a comparison between two OS’s that target this embedded domain: one that is general-purpose multi-tasking and another that is event-driven.  Preliminary results indicate that the event-driven OS achieves an 8x improvement in performance, 2x and 30x improvement in instruction and data memory requirement, and a 12x reduction in power over its general-purpose counterpart. To achieve further efficiency, we propose extensions to the event-driven OS paradigm to support power management at the system behavior, system architecture, and architecture module level. The proposed novel hybrid approach to system power management combines distributed power control with global monitoring.