GREEN: A Configurable and Re-configurable Publish-Subscribe Middleware for Pervasive Computing [chapter]

Thirunavukkarasu Sivaharan, Gordon Blair, Geoff Coulson
2005 Lecture Notes in Computer Science  
In this paper we present GREEN a highly configurable and reconfigurable publish-subscribe middleware to support pervasive computing applications. Such applications must embrace both heterogeneous networks and heterogeneous devices: from embedded devices in wireless ad-hoc networks to high-power computers in the Internet. Publish-subscribe is a paradigm well suited to applications in this domain. However, present-day publish-subscribe middleware does not adequately address the configurability
more » ... reconfigurability requirements of such heterogeneous and changing environments. As one prime example, current platforms can-not be configured to operate in diverse network types (e.g. infrastructure based fixed networks and mobile ad-hoc networks). Hence, we present the design and implementation of GREEN (Generic & Re-configurable EvEnt Notification service), a next generation publish-subscribe middleware that addresses this particular deficiency. We demonstrate the configurability and re-configurability of GREEN through a worked example: consisting of a vehicular ad-hoc network for safe driving coupled with a fixed wide area network for vehicular traffic monitoring. Finally, we evaluate the performance of this highly dynamic middleware under different environmental conditions. Introduction Recent advance in wireless network technologies (e.g IEEE 802.11) and computational devices (e.g. PDA, PC) have created opportunities for the vision of pervasive computing applications [1], which embrace both fixed infrastructure based (wired and wireless) networks and wireless ad-hoc networks. Event based communication based upon the publish-subscribe model is well-suited to pervasive computing applications, as it presents an asynchronous and decoupled communication model [44] . Notably, pervasive computing applications operate across highly heterogeneous environments in terms of network types (e.g. WAN, MANET) and device types. However, many publish-subscribe middleware have specifically targeted fixed infrastructure based networks e.g SIENA [5], Gryphon [6], Hermes [7] and JEDI [8] . At the other extreme STEAM [9] is specifically designed for wireless ad-hoc networks. We argue that publish-subscribe middleware that operates over a single homogenous network environment (i.e. WAN or MANET) and offers a single (or fixed) interaction type (i.e topic based or content based) cannot cope with the diversity of environmental constraints and requirements presented by pervasive computing applications. Dealing with such extreme heterogeneity is a fundamental 3 The GREEN Architecture Overview This section describes the GREEN architecture, a generic, configurable, reconfigurable and reflective publish-subscribe middleware to support pervasive computing application development. GREEN uses OpenCOM as its component Component Component Binding Interface Receptacle
doi:10.1007/11575771_46 fatcat:ow2groxn7jgxxlogd4r6vc62la