Abstract

MANETs (Mobile Ad-hoc Networks) offer exciting new research opportunities now that devices with wireless capabilities become more widespread. Many wireless technologies, such as 802.11, support these ad-hoc style networks. Opportunities lie in many areas, such as routing protocols, services and applications. The network topology of MANETs is constantly changing and the devices on these networks, like laptops and PDAs, have limited processing and battery power.

Research on low-level protocols that do semantic service discovery on ad-hoc networks is emerging. Pervasive and mobile computing applications require these protocols, but using them requires a lot of engineering and knowledge of network protocols and service matching.

This dissertation describes the design, implementation and evaluation of middleware that makes the task of defining, advertising and discovering semantic services on MANETs more straight-forward by offering APIs to complete these tasks. As part of the semantic service matching, context such as location and workload can be defined and matched to further improve the discovery results. Services and context are described using ontologies. Queries for services can be expressed in a newly developed query language called RaSSQL (RDF and Semantic Service Query Language). The middleware, implemented in Python, is based on ideas from the OntoMobil protocol, but can use any protocol that discovers services based on concept dissemination.

To evaluate the middleware, an application was developed that demonstrates the use of the middleware’s APIs to define a set of semantic services and location context. These services are queried using a RaSSQL query defining a desired service profile and service location. A peer flood protocol is implemented as the low-level protocol. Additionally, it is explained how the OntoMobil protocol could be implemented in the middleware.