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Service discovery plays an important role in mobile ad hoc networks (MANETs). The lack of central infrastructure, limited resources and high mobility make service discovery a challenging issue for this kind of network. This article proposes a new service discovery mechanism for discovering and advertising services integrated into the Optimized Link State Routing Protocol Version 2 (OLSRv2). In previous studies, we demonstrated the validity of a similar service discovery mechanism integrated into the previous version of OLSR (OLSRv1). In order to advertise services, we have added a new type-length-value structure (TLV) to the OLSRv2 protocol, called service discovery message (SDM), according to the Generalized MANET Packet/Message Format defined in Request For Comments (RFC) 5444. Each node in the ad hoc network only advertises its own services. The advertisement frequency is a user-configurable parameter, so that it can be modified depending on the user requirements. Each node maintains two service tables, one to store information about its own services and another one to store information about the services it discovers in the network. We present simulation results, that compare our service discovery integrated into OLSRv2 with the one defined for OLSRv1 and with the integration of service discovery in Ad hoc On-demand Distance Vector (AODV) protocol, in terms of service discovery ratio, service latency and network overhead.

This paper proposes a service discovery protocol for discovering and advertising services in a proactive ad hoc network. The protocol we have defined is piggybacked into the OLSR protocol. We define a new message type into OLSR called Service Discovery Message (SDM) for both advertisement and discovery of services. The advertisement frequency and advertisement lifetime are user-controlled parameters, so that they can be modified depending on the user requirements. Each node maintains a service cache to store information about its own services, and the services each device discovers in the network. We also present simulation results of our protocol and show that the service discovery protocol defined here achieves much efficiency in discovering services, while it introduces practically no packet overhead compared to the basic OLSR protocol.