it DIGITAL RADIO TECHNOLOGY AND APPLICATIONS Proceedings of an International Workshop organized by the International Development Research Centre, Volunteers in Technical Assistance, and United Nations University, held in Nairobi, Kenya, 24-26 August 1992 Edited by Harun Baiya (VITA, Kenya) David Balson (IDRC, Canada) Gary Garriott (VITA, USA) 1 1 X 1594 F SN % , IleCl- -.01 INTERNATIONAL DEVELOPMENT RESEARCH CENTRE Ottawa Cairo Dakar Johannesburg Montevideo Nairobi New Delhi 0 Singapore 141 V /IL s 0 /'A- 0 . Preface The International Workshop on Digital Radio Technology and Applications was a milestone event. For the first time, it brought together many of those using low-cost radio systems for development and humanitarian-based computer communications in Africa and Asia, in both terrestrial and satellite environments. Ten years ago the prospect of seeing all these people in one place to share their experiences was only a far-off dream. At that time no one really had a clue whether there would be interest, funding and expertise available to exploit these technologies for relief and development applications. VITA and IDRC are pleased to have been involved in various capacities in these efforts right from the beginning. As mentioned in VITA's welcome at the Workshop, we can all be proud to have participated in a pioneering effort to bring the benefits of modern information and communications technology to those that most need and deserve it. But now the Workshop is history. We hope that the next ten years will take these technologies beyond the realm of experimentation and demonstration into the mainstream of development strategies and programs. To the extent that integration occurs, we believe we will see these technologies used to reliably network those traditionally left out of conventional telecommunications services (the "last mile" problem) into the burgeoning and incredible array of information services now becoming available. Through their efforts and vision, the readers of this volume will make real their response to the "last mile" (including perhaps even a future Workshop)! Acknowledgments This workshop and its proceedings are a result of a significant grant from the International Development Research Centre in Canada, long-term planning collaboration and logistical support by Volunteers in Technical Assisstance, from both their headquarters in the United States and their Kenyan national office, an additional grant from the United Nations University and the intellectual contribution of all the participants. Organization of this workshop was carried out in consultation with the organizers of the Workshop on Science and Technology Communication Networks in Africa - the African Academy of Sciences and the American Association for the Advancement of Science. In so doing, through holding the two workshops back-to-back in Nairobi, the degree of participation in both was enhanced. Contents .................................................. Workshop Background 1 - David Balson Whither Digital Radio* ................................................. 3 - Gary Garriott Development Applications of Packet Radio Technology: The New Challenge ........... 14 - S. Ramani Digital Radio Applications in Terrestrial and Satellite Environments .................. 25 HealthNet in Zambia: The Technical Implementation of a Communications System for Health Workers* ....................................... 27 - Mark Bennett Eastern and Southern Africa Network (ESANET), Communications Research for Development - The Experience of the Nairobi Node* .................... 41 - Anthony J. Rodrigues and Geoffrey M. Macharia Digital Radio Technology and it's Application in Tanzania ................... 50 - William Sangiwa Experiences in Setting Up a PACSAT Station in Tanzania ................... 54 - H.R. Mgombelo and S.J. Braithwaite Sdminaire Radio par paquets, Note de Prdsentation, VITA/PEP ................ 62 - Yondailaou gue Tolloum Mindanao Packet-Radio Network for Cooperative and Agribusiness Development ..................................................71 - Josefito A. Guillermo Packet and Satellite Radio in Sierra Leone .............................. 90 - Joseph Sandi How a Packet Radio Communications Systems has served ISERST* ............ 96 - Djama Dirieh Packet Radio in Mozambique: One Failure One Success ................... 107 - Phil Gray Satellite-Based Developments .......................................... 119 University of Surrey/SST Presentation Notes ........................... 121 - Martin Sweeting VITA Operations using UOSAT-3 ................................... 135 - Eric Rosenberg and Gary Garriott SatelLife and HealthNet: The System and Its Operation ................... 145 - Dieter Klein Regulatory Issues ................................................... 157 Kenyan PACSAT Licensing Experience ............................... 159 - A.J. Rodrigues and G.M. Macharia Summary of Discussion ......................................... 175 Training Issues ..................................................... 177 Summary of Discussion ......................................... 179 Conclusions ....................................................181 APPENDICES ....................................................185 Agenda ....................................................187 Participant List ............................................... 190 Additional Papers .............................................. 201 The United Nations University ............................... 203 - Ines Wesley-Tanaskovic The Big Opportunity: The Case of Healthnet in Zambia .............. 213 - Regina Cammy Shakakata CEntral AMerican NETwork ................................. 227 - William C. Hast Experience With Low Cost Digital Communications (or Networking in and around the University of Yaoundd) ......................... 231 - William S. Shu Technical Background Papers ..................................... 241 Error Correcting Radio Systems: A Discussion of SITOR and Packet Radio ...........................................245 - Norman J. Sternberg PACTOR - Radioteletype with Memory ARQ and Data Compression ...... 290 - Hans-Peter Helfert and Ulrich Strate CLOVER Fast Data on HF Radio .............................. 300 - Bill Henry and Ray Petit HF Radio Data Communication ............................... 304 - Bill Henry and Ray Petit 'Also published in: African Academy of Sciences, American Association for the Advancement of Science. Electronic Networking in Africa : Advancing Science and Tchnology for Development ; Workshop on Science and Technology Communication Networks in Africa, Aug. 27-29, 1992, Nairobi, Kenya. Washington, DC : AAAS, 1992. A workshop organized in consultation with the organizers of the International Workshop on Digital Radio Technology and Applications Workshop Background Through support for research, Canada's International Development Research Centre (IDRC) assists scientists in developing countries to identify long-term, practical solutions to pressing development problems. Support is given directly to scientists working in universities, private enterprise, government and non-profit organizations. IDRC's Information Sciences and Systems Division (ISSD), in the process of looking at telecommunications issues, became interested in packet radio technology over a decade ago. Dr. Ramani (Tata Institute of Fundamental Research, India), who is a participant in this workshop, proposed the concept of a low-earth-orbit communications satellite to be built by developing countries for development communications at an ISSD-sponsored Workshop on Computer-based Conferencing in 1981. This workshop gave birth to ISSD's Telematics Program. This Program has promoted and supported the development, testing and evaluation of networking techniques and technologies in developing countries in support of development and research objectives. Since this 1981 workshop the Program has promoted this technology as a response to "last mile" communications problems. The concept was explored further by Dr. Ramani and others: Richard Miller and Dr. Ramani co- authored a paper on the concept for ICCC '82. Ramani with the Indian Space Research Organization and Space Applications Centre; and with Yash Pal, Secretary-General of UNISPACE '82, at that Conference where one of its recommendations urged further developments in this field. In late 1982, Volunteers in Technical Assistance and the Radio Amateur Satellite Corporation (AMSAT) picked up the concept and developed the Data Communications Experiment (DCE) payload as a prototype of their proposed low-earth-orbit electronic messaging satellite, PACSAT. The DCE was launched in 1984 on UOSAT-2 (a satellite built by the University of Surrey). An upgraded PACSAT Communications Experiment (PCE) was launched in 1990 on UOSAT-3. IDRC funded a demonstration of the DCE at the Pacific Telecommunications Conference in Honolulu in 1985. In 1987, the Telematics Program funded the Lesotho Telecommunications Corporation (Lesotho's PTT) to carry out research on the viability of using ground-based packet radio technology for the provision of communication services in support of development applications in rural areas. VITA played an important role in assisting in the technology transfer process within this project. Unfortunately, due to a variety of problems, this project did not achieve all of its objectives, although it did prove the technical viability of the approach. In 1988, a representative of the International Physicians