Wireless ad hoc podcasting

Podcasting has become popular for dissemination of streaming contents over the Internet. It is based on software clients that query servers for updates of subscribed content feeds. Podcasting may be used for any media content, but it is most commonly associated with audio streams. It provides a simple, no-frills broadcasting system for delay tolerant contents. A main limitation with this system is the inflexible separation of downloading to a docked media player and expending of the data when on the move. We herein present how podcast could be supported by our previously proposed delay-tolerant broadcasting system in order to reduce the expected times between updates and to provide a new ad hoc podcasting mode among mobile nodes. Our system substitutes the client-server paradigm inherent in present podcasting by a peer-to-peer paradigm where mobile nodes provide each other with contents. We present the protocol for this, and an evaluation of solicitation and caching strategies that greatly affect the application-level throughput. Our design is aiming at simplicity in order to enable implementation in mobile phones with media players and other devices that communicate over short ranges by means of Bluetooth or wireless LAN.