Emergent Sorting in Networks of Router Agents

Abstract

In this paper we study basic properties of so called Emergent Sorting Networks. These are directed networks which consist of router agents and buffer sites that are located between every two neighbouring agents. The agents can move objects from their input buffer sites to their output buffers. It is assumed that the objects may differ in type and are inserted randomly at an input agent. Brueckner (2000) presented a set of simple local policies for the agents which lead to a sorted outflow (batches of objects of the same type) of the objects out of an output agent. In this paper we introduce a pheromone based variant of the routing policies. The different policies are studied on quadratic and linear network topologies in terms of sorting performance and fairness.

This work was supported by German Research Foundation (DFG) through the project “Organisation and Control of Self-Organising Systems in Technical Compound” within SPP 1183, by the Integrated Action grant MEC HA2006-0127 (Germany/Spain), by grant TIN2007-66523 (FORMALISM) of the Spanish government, and by the EU project FRONTS (FP7-ICT-2007-1) funded by the European Comission under the FET Proactive Initiative Pervasive Adaptation. In addition, Christian Blum acknowledges support from the Ramón y Cajal program of the Spanish Ministry of Science and Technology of which he is a research fellow.