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Linking rural health facility to the internet using packet radio in developing countries (OAUNet a case study) by O.O. Abiona & O.A. Adewara Obafemi Awolowo University, Ile-Ife Nigeria.
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We shall consider §What is packet radio §Choice of packet over other mode §Component of a packet station §Distance limitation of packet radio §Channel Sharing §What is AX.25 §The OAUNet
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Continue….. §Problems in rural community §Services for rural connectivity §Conclusion
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What is packet radio §A particular digital mode of amateur radio communication which corresponds to computer telecommunication. §The telephone modem is replaced by a “magic” box called a Terminal Node Controller (TNC) §Telephone is replaced by an amateur radio transceiver.
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Continue…... §The phone system is replaced by the “free” amateur radio waves. §Packet radio takes any data stream sent from a computer and sends that via radio to another amateur radio station similarly equipped.
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Why packet over other modes §Transparency §Error correction §Automatic control.
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Components of a packet station
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Terminal Node Controller (TNC) §A modem §A computer processor §Associated circuitry to convert communication b/w your computer(RS-232) and the packet radio protocol in use.
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Function of a TNC §Assembles a packet from data received from the computer. §Computes an error check for the packet. §Modulates it into audio frequencies. §Transmit the packet over the connected radio. §It also reverses the process
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Computer or Terminal §A computer running terminal emulation program or a dumb terminal. §E.g hyperterminal, procomm+, X-Talk, Pacterm
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A Radio §For 1200/2400bps UHF/VHF packet. §Commonly available narrow band FM voice radio. §For HF packet 300bps data is used over single side band modulation. §For high speed packet (starting at 9600bps) special radio or modified FM radio are used.
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Distance limitation of packet radio §It is used at higher radio frequencies (VHF), the range of the transmission is some what limited. §Limited to unobstructed “line-of-sight” §For two meter packet (144-148MHZ) the range could be 10 - 100miles
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Channel Sharing §Can support multiple conversation on the same frequency at the same time. §Multiple conversation are possible in a managed time shared fashion. §It uses the AX.25 to accomplish this shared channel.
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What is AX.25 §Is the communication protocol used for packet radio. §Is based on the wired network protocol X.25.
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The OAUNet Obafemi Awolowo University Network
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Obafemi Awolowo University Academic Network Project OAUNET - Current Design Present load estimates Overview of Network
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INFRASTRUCTURAL PROBLEMS AND SOLUTIONS Problem:Analogue exchange necessitating Solution: Store and forward / VSAT Internet connectivity since January 1999. Problem: Unreliable Power Supply Solution: Back-up-- UPS & Generators
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Services Provided Basic E-mail Web access File Transfer Remote access
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OAUNET - Main Network Diagram Main HUB sctechcs usb chsagric NC First Generation Second Generation Third Generation Key sc - sciences tech - Technology cs - Computer Science usb - Secretariat chs - Health Science Agric- Agriculture NC - NACTEM TH - OAU Teaching hospital TH WaveLan 2Mbps VSAT Earth Station 64 Kbps Dial up MODEM 14.4 Kbps ***** Packet and HF radio links to rural Health establishments in the area Breezecom Lan 2-3 (FHSS)Mbps CERD Breezecom LAN 2-3 Mbps (FHSS)
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Main HUB or network Firewall Proxy Mail Server Comm. Server Backup Server Inter Subnet Router WLAN Antenna WEB Server Terminal Equipment CISCO router 10 base 2 Ethernet Backbone (Server Bus) Pentium II PCs
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Architecture of Most Subnets Using AT&T Wireless HUB One or more client computers Running Windows or Linux +GUI Provide Print services, and telnet. Clients are Auto- configured through DHCP Ethernet 915 MHz Antenna 2 Mbps link to Main network
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Sciences Subnet HUB One or more client computers Running Windows or Linux + KDE Provide Print services, and telnet clients Auto- configured through DHCP Located in Public access rooms and Private offices and Laboratories 915 MHz Antenna Server for Physics Dept. & Electronics Dept. WavePoint Radio 2 Mbps link to Main network
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Computer Science Subnet CS Server Floor 3 Floor 2 Floor 1 Ground FloorHUB Dean of Faulty & other Faculty staff Head of Dept. & other Senior Dept. staff Other Dept. Staff & Laboratories Machines in public rooms & access areas Linux Router For MIS, Computer Centre & URC 10 Mbps Link to Main network To MIS To URC To Computer Centre & IBM AS 400 Main Frame
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Library Subnet 915 MHz Antenna WavePoint Linux Router With Netware Emulation Novell Netware 4 Server with TCP/IP Mecury MAIL Server Windows 95 Netware clients and other Library catalog system Pegasus Mail Clients 2 Mbps link to Main network
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CONTENTS FOR THE INTERNET Observatories/Data banks: Science Database, Water Resources and Rural Development National Databank, Raw Materials Research Council Databank
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Monthly Growth of Users
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Percentage Level of Awareness
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1 2 3
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Other Services Provided Consultancy services to Educational Institutions. This entails: -Network site survey -Structured Cabling -Computer hardware Installations and Repairs -Web enabling services -Internet Services (system configuration) Federal University of Technology, Akure (FUTA),University of Lagos, Yaba, Lagos State University, Badagry, University of Agriculture, Abeokuta,University of Ilorin,Dept. of Physics, University of Ibadan and the College of Education, Ikere-Ekiti
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Antenna types (1) SPECIFICATIONS Antenna: Antenna Gain*8 dBi Frequency Range2.4 to 2.5 GHz Impedance50 Ohms PolarizationVertical Dimensions17" length; 43 cm Weight.45 lbs; 205 g SPECIFICATIONS Antenna: Antenna Gain*24 dBi Frequency Range2.4 to 2.5 GHz Impedance50 Ohms PolarizationVertical or horizontal Dimensions24" x 36" x 15"; 610 x 915 x 381mm Weight5.4 lbs; 2.43 kg
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915 MHz Antenna types (2)
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Problems of rural Community §They lack well developed telecommunication infrastructure. §Lack of constant electricity supply. §Lack of good road network. §Lack of portable water supply §etc...
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Services for rural Connectivity §E-mail services. §Ftp. (minimal) §Www (minimal or hardly used).
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The established link TNC Radio OAUNet Radio TNC
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Cost estimation for high speed Packet radio Link. S/N DescriptionAmount 1.2 Nos of TNC @ $200.00$400.00 2.2 Nos of Radio @ $100.00$200.00 3.2 Nos of Antenna @ $50.00$100.00 4.Accessories$ 50.00 Total$750.00 Low Cost Implimentation S/N DescriptionAmount 1.2 Nos of TNC @ $00.00$00.00 2.2 Nos of Radio @ $100.00$200.00 3.2 Nos of Antenna @ $50.00$100.00 4.Accessories$ 50.00 Total$350.00
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Conclusion §In view of the problems facing the rural community and developing nations in general, coupled with the problem of funds to acquire high speed connectivity, Packet radio could be a way out for developing countries to spread internet connectivity to rural communities. §We want to thank ICTP for making this possible for OAU, Ife and Nigerian Universities at large.
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END Thank You.
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