Masters student: Elroy Julius, 2006

Supervisor: Bill Tucker

Project link

Research question

This research aims to find an empirical solution for the guaranteed delivery of synchronous and asynchronous messages within a multi-modal semi-synchronous IP-based communications platform. The platform is based on an asynchronous transport mechanism that makes use of various web services to perform communication modality conversions, e.g. voice to text. We believe that a publish-subscribe approach may yield an effective solution to the problem of guaranteeing the delivery of both synchronous and asynchronous messaging. We have chosen the problem of Deaf Telephony in order to investigate the envisaged solution as many current Deaf Telephony solutions, such as SMS or Internet relay, provide no guarantee that delivery has been made. This is especially critical in 911 or emergency-type scenarios. The research therefore also addresses the user interface component of ensuring that the end-users know that messages have indeed reached their destination.

Related work

As much of Deaf Telephony is text-based, we are particularly interested in developments in Text over Internet Protocol (ToIP). Recent work by Omnitor pioneer Gunnar Hellstrom and Cisco architect Paul Jones describes a mechanism for integrating text and audio into one Real Time Protocol (RTP) packet for transmission over a SIP synchronous session. We are also interested in extending this approach to session and page mode delivery of asynchronous messages. In order to guarantee delivery of both types of messages, we are looking to publish-subscribe systems, an emerging paradigm for building a range of distributed applications. The publish-subscribe architecture makes use of Message Oriented Middleware (MOM) to guarantee reliable delivery of messages within a communication domain. We are particularly interested in JORAM [2] and are currently attempting to integrate ToIP communications into JORAM. We have also examined other publish-subscribe systems such as Nerada and Proteus.

Research methodology

Our approach is divided into two efforts: a classical prototyping approach to the design and development of the underlying publish-subscribe mechanisms to guarantee delivery of semi-synchronous multi-modal messaging and an Action Research/Participatory Design approach to the development of the Deaf Telephony service that makes use of the underlying platform. In many ways, the two approaches are complementary, as both require an iterative approach to the design and development of software artefacts. The measurement methodology is different, as we require a quantitative positivistic approach to prove that the system does indeed guarantee delivery of messages under adverse conditions. We can manifest such conditions in the laboratory. We intend to take the service to the Deaf community mainly in order to develop an appropriate user interface to show end-users that messages have been delivered.

Expected outputs

There will be several research outputs: knowledge gained, software artefacts and academic publications. We expect to find that the publish-subscribe approach to guaranteeing delivery will prove useful for both synchronous and asynchronous message delivery. This project also intends to produce the next prototype approach in a series of Deaf Telephony applications initiated earlier [3]. This project’s Work in Progress paper was recently accepted at SATNAC 2004 [4] and will be submitted as a full paper for SATNAC 2005 in addition to at least one international conference and/or journal.

References

[1] Gunnar Hellstrom and Paul Jones. “RTP Payload for Text Conversation”, Network Working Group Internet Draft, June 2004. www.ietf.org/internetdrafts/draft-ietf-avt-rfc2793bis-08.txt.

[2] L. Bellisard, D. Felliot, A. Freyssinel, S. Lacourte, and N. Tachkler. “Java Open Reliable Asynchronous Messaging”, Objectweb, joram.objectweb.org, 2000.

[3] Penton, W Tucker and M Glaser. "Telgo323: An H.323 Bridge for Deaf Telephony". Proceedings of the 5th South African Telecommunications Networks & Applications Conference, SATNAC 2002, Drakensberg, South Africa.

[4] Elroy P. Julius and William D. Tucker. "Guaranteed delivery of semi-synchronous IP-based communication", Proceedings of the 7th South African Telecommunications Networks & Applications Conference, SATNAC 2004, Stellenbosch, South Africa.

[5] Meryl Glaser and William D. Tucker. "Telecommunications bridging between Deaf and hearing users in South Africa", Conference and Workshop on Assistive Technologies for Vision and Hearing Impairment, CVHI 2004, Granada, Spain.