Overview

Podcasting is a form of narrowcasting. The audio production of podcasts is very similar to radio broadcasting, though generally done using much cheaper facilities. The distribution method is both much cheaper than radio broadcasting and much more powerful since it permits an unlimited selection of "programs on demand". Wikipedia has an extensive discussion of common uses of podcasting which should be reviewed carefully. Specific uses for distance education, including literacy support, for universal communications by voicemail and in support of broadcasting will be discussed in detail on other pages here. This page focuses on the generic technology involved.

In particular there is a vast literature on podcasting in education and many educational institutions have network administrators with extensive experience who can assist by mentoring a local implementation project. A major advantage of the internet is that such mentoring can be carried out online without travel and accommodation expenses. This literature includes advice on the actual production (and publication) of podcast audio files.

Both audio and video podcasting and related "internet radio" are already quite developed among people with access to the internet in developing countries and among people from those countries working or studying abroad and wanting to keep in touch with their own culture.

Here is an example of a Nepal oriented web site site including internet radio from Nepalese broadcast stations and audio and video podcasts.

http://www.nepal1st.com/

An important project directly relevant to the proposals here is One Media Player Per Teacher (OMPT). The proposal here is for a mass rollout with supporting systems scaled to provide a robust and efficient service instead of individual projects with proportionately higher costs for distributing program material and charging batteries. Experience from OMPT strongly confirms that battery charging will be a major problem in remote areas and there is no real benefit from using more expensive media players with video capabilities or even easier to read LCD control displays. Consequently the cheapest possible MP3 players are proposed, but with provision of a large scale podcasting service made possible through exchange of flash cards.

Podcasts are already widely delivered directly to cell phones as mobilecasts. For cheaper delivery, including areas without cellphones, the use of a CardPodCaster is proposed on a separate page here. This is simply a cheap MP3 player combined with a flash card reader and a system for exchanging flash cards with synchronized updates provided by computers that are directly subscribed to conventional podcasts. Thus a conventional podcasting service is a necessary part of the proposed CardPodCaster service, but only requires a much smaller number of computers located in areas with internet or at least email connectivity. This page discusses only the conventional podcasting service that enables publishers with internet or email connectivity to distribute their material easily without worrying about how it eventually reaches people in remote areas that have only CardPodCaster MP3 players with flash cards, but have no internet or email connectivity at present.

Podcatching

Podcasting took off with Apple's iTunes, which is still the most popular "podcatching" software available for both Windows and Macintosh platforms. The iTunes tutorial provides a good background. There are many alternatives available for all platforms including Linux.

Playlists, including smart playlists are an important aspect of podcatching. They are also the essence of internet radio which can be produced automatically using such methods as Shoutcast and the free software Icecast. This is also the basis for radio software - including free software, used for broadcast automation in networks of broadcast stations to directly combine podcasting with broadcasting.

Songbird

An important free software example is mozilla Songbird. It can be easily installed on all platforms (including Linux, Windows and Macintosh) and is designed for easy cross platform extensions with adequate developer tools. The SQLite manager should greatly simplify development.

The major Songbird internationalization effort provides online facilities for contributing localization to additional languages with minimum effort.

Most of the features of such software are not required for simple distribution of podcast channels to mp3 players and flash cards but the framework is more than adequate to support whatever we do need. Review is strongly recommended for understanding of what is possible.

Aggregator

Wikipedia has a more generic discussion of aggregator software also used for other feeds of syndicated web content including news headlines and blogs.

As well as individual computers subscribing to one or more feeds from separate web sites such as blogs that each provide a single "channel", central subscription services should be provided to combine and filter multiple channels into combined channels so that the end user can subscribe more easily

A widely used free software feed aggregator is planet.

Essentially a proof of concept podcasting service can be established by simply encouraging organizations to publish their podcasts as "channels" with standardized tags via blogging software and configuring planet on a central web service that end users subscribe to with their podcatcher software. They can of course also publish and subscribe to other central services.

News

Howerever additional development (by an experienced unix system administrator rather than software engineers) will be desirable to simplify both administration and operations by systematic tagging and to minimize bandwidth by distributing actual large podcast files through email lists and (moderated) internet news feeds using the standard free software INN. An INN hub server in each city ensures that files only need to travel through a "backbone" inter-city internet connection once for each city instead of once for each subscriber in that city. The hubs then pass on whatever is received in each "channel" or "newsgroup" to the local end users that have subscribed to those particular feeds (sometimes via many levels). News feed transmissions can also be prioritized and scheduled to occur only during off peak hours so that peak hours are reserved for interactive traffic and the bandwidth used for such bulk low priority traffic is essentially free.

Directory

Further development may be desirable to automate the "tuning" of archiving and deleting obsolete items and filtering to facilitate automated synchronization of updates to current material with the preferences of end users and the amount of space they have allocated on their mp3 players and flash cards. An LDAP directory service may be the best way to configure such preferences as well as being useful for many other purposes including naming publishing, subscribing, tagging and combining channels with appropriate access controls for administration. A wide range of news utilities have been developed by news administrators.