PCO Based Event Propagation Scheme for Globally Synchronized Sensor Networks

Impulse Radios within communication networks using Pulse Coupled Oscillator (PCO) global synchronization can be efficiently duty cycled for significant power savings. In this paper we utilize the emergent dynamical behavior in the PCO network to enable a simple event communication scheme particular to this type of network. In this scheme, each coupled radio node accesses the channel by simply changing its pulse repetition frequency in response to an event sensed by its sensor. This forces the network to a new, higher operating frequency, which can be locally measured at every node in the network to communicate occurrence of an event in the network. In this paper we show how this synchronization occurs and how it is ideally suited for low power operation. The proposed event propagation scheme enables a node to broadcast information about an event to an entire network in a simple fashion without the need of any data-packet formation or complex MAC/Routing protocols. We show that resynchronization and recovery of the network happens almost immediately. The latency involved corresponds to the distance-delay (due to finite speed of light) plus a very small circuit delay of (4-5ns) per hop related to detection of impulses.