While SMS is relatively affordable in many developing countries, voice calls remain quite expensive. One solution to this is to use voice mail to gain many of the advantages of voice calls, but in a way that can be supported over a highly partitioned Mesh network, where end-to-end network paths may never exist.
It is proposed to explore the implementation of voice mail in an efficient and mesh-optimised manner in the Serval Mesh (app for Android). It is anticipated that it would be layered over the Rhizome store-and-forward protocol, and use Rhizome journal and low-bandwidth codecs such as CODEC2 to reduce bandwidth requirements.
This technology was first developed in the first half of 2013 as a student project.