The fundamental paradigm of context-aware computing has lead to a diversity of conceivable context-based applications. In order to support these applications, efficient and scalable context management platforms have become utterly important. In this paper we propose a layered reference model that encapsulates suitable abstractions to tackle the complexity of context management in mobile ad-hoc networks. For each layer, we outline strategies and mechanisms we have developed to manage context information efficiently so that it can readily be used by context-based services and applications in these networks. In addition, we discuss refinements of the current model that we currently investigate, which are related to data semantics such as context quality and expressive location models, performance enhancement by adaptation, and aspects regarding the integration of ad-hoc context management with infrastructure-based systems leading to a hybrid system structure.