Using Triggers for Emulation of Opportunistic Networking

Opportunistic networks do not require the availability of an end-to-end path, but may instead take advantage of tem- porary connectivity opportunities. Opportunistic networks pose a challenge for network emulation as the traditional em- ulation setup where application/transport endpoints send/ receive packets from the network following a black box approach is no longer applicable. Instead opportunistic networking protocols and applications need to react to the dynamics of the underlying network beyond what is conveyed through the exchange of packets. In order to support emulation evaluations for such challenging applications we in this paper introduce the concept of emulation triggers that can emulate arbitrary cross-layer feedback and that are synchronized with the emulated scenario. The design and implementation of triggers in the KauNet emulator are described. The use of triggers in the context of opportunistic networking is brie y sketched