Survey of Service Discovery Architectures for Mobile Ad hoc Networks

Efficient and timely service discovery is a crucial feature for the usability of mobile ad-hoc networks. In recent years a number of service discovery protocols have been developed and they have different view points toward the mobile ad hoc environment. These different view points made them have different service discovery architectures. In this paper we classify the existing service discovery protocols for mobile ad-hoc networks into several discovery architectures and survey the features of the discovery architectures. Depending on whether a directory exists or not, the service discovery architecture can be divided into two categories: directory-less architecture and directory-based architecture. The directory-based architecture can be also divided into two categories: centralized directory architecture and distributed directory architecture. The centralized directory architecture relies on one or a few centralized directories but in the distributed directory architecture, directories are further distributed and deployed dynamically. We also subdivide the distributed directory architecture, depending on whether directories reside on mobile ad hoc networks or on infrastructure-based networks, into two categories: infrastructure-less distributed directory architecture and infrastructure-based distributed directory architecture. In this paper we discuss the difference of the environments on which each of the discovery architectures is based. Moreover, we show the pros and cons of them compared with one another.