Practical Voice Communications in Challenged Networks

Today's Push-To-Talk (PTT) services are infrastructure based and require stable end-to-end paths for successful communication. However, users with PTT enabled mobile devices may roam in challenged environments where infrastructure is not available. In such cases the traditional PTT services may exhibit poor performance or even fail completely. Delay-Tolerant Networking (DTN) is a research area which addresses the communication requirements specific to challenged networks. In this paper, the authors apply the DTN concept of asynchronous message forwarding to transmit voice messages. They present an implementation of the DT-Talkie for heterogeneous clients such as Maemo, Symbian and Android based personal handheld devices. They also demonstrate the use of a DTN throw-box with large storage capacity to improve message forwarding.