International Symposium on Signal Processing and its Applications (ISSPA)).Kuala Lumpur. Malaysia, 13 - I6 August, 2001. Organized by the Dept. of Microelectronics and Computer Engineering, UTM,Malaysia and Signal Processing Research Centre, Q W ,Australia
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IMPLEMENTATION OF CRYPTOGRAPHIC ALGORITHMS FOR RADIO TELEMETRY USING LABVIEW Shuhaimi bin Shamsuddin, Dr. Mohd Dani bin Baba, Dr. Deepak K.Ghodgaonkar Faculty o f Electrical EngineeringUniversity Technology M A W , 40450 Shah Alam, Selansor, MALAYSIA (Tel: 603-55 164979), Email: sbs sbs l964O,yahoo.com, dani@,elect.itm.edu.my,
[email protected].
ABSTRACT maximum level. Otherwise the signals received will be corrupted.
The objective of this paper is to discuss on the implementation of cryptographic security algorithms for radio telemetry using graphical programming software from National Instruments known as LabVIEW [ 11. The telemetry system consists of a remote telemetry station (RTS) and base telemetry station (BTS) for acquiring and monitoring environmental conditions respectively. RTS setup includes a desktop computer integrated with data acquisition system, 1200 bps modem and GP300 Motorola walkie talkie [2]. Meanwhile, BTS is having the same setup as RTS except that it does not have a data acquisition system. The walkie-talkie operating frequency is 477.1 MHz with FM transmission. A combination of One Time Pad (OTP) and Caesar Cipher cryptographic algorithms will be implemented in order to safeguard the information from the eavesdroppers [4,5,6]. OTP was chosen because it is suitable for low bit rate data.
4 RESULT PC to PC wireless data transmission has been successhlly tested within laboratory condition. The data received is shown in fig 5. The transmission power is 500mW at 477.1 MHz with 25 kHz channel spacing. BER for 1200bps is in the range of I O 3 to 10’. ’ The next stage of the experiment will be conducted in the field condition. The communication distance between BTS and RTS will be increased gradually during the trial.
5 CONCLUSION From the laboratory test, it shows that LabVIEW is a very useful and practical tool for developing software based cryptography. For higher data rate, high speed modem and wider channel bandwidth should be employed in the system.
1 INTRODUCTION The task of radio telemetj system is to acquire and transmit data from RTS to BTS, which will retrieve the data for analysis and observation. Practical applications include remote weather station, testing of moving vehicles such as cars, rockets and missiles, and monitoring of animals’ movements [3].
6 ACKNOWLEDGEMENTS This work is supported by Bureau for Research and Consultancy (BRC) of University Technology MARA under the supervision of Electrical Engineering Faculty members. They are Assoc. Prof. Dr. Mohd Dani bin Baba and Assoc. Prof. Dr. Deepak K. Ghodgaonkar.
3 IMPLEMENTATION All the inputs are analog signals. The 12 bits 200 ksampledsec data acquisition card digitizes these signals. The signals ~ l bel read by the data acquisition virtual instrument (VI) and encrypted by the encryption VI before feeding them to the modem and walkie talkie to be transmitted to BTS (figure 1 and 3). The walkie talkie at the BTS will receive, demodulate the signals and then relayed them to the modem which will digitizes the signatcbefore relaying them to the PC via RS232 port for decryption and presentation process by its respective VI(figure 2 and 4). The radio volume must be set to its
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International Symposium on Signal Processing and its Applications (ISSPA), Kuala Lumpur, Malaysia, 13 - I6 August, 2001. Organized by the Dept. of Microelectronics and ComputerEngineering, UTM, Malaysia and Signal Processing Research Centre, QUT, Australia
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7 References: [ 11 -GaryW. Johnson, “LabVIEW Graphical Programming: Practical Applications in Instrumentation and Control,” 2nded. McGraw Hill, New York, 1997.
[4] Bruce Schneier, “Applied Cryptography: protocols, algorithms, and source code in C,” 2nd ed., John Wiley and Sons, Inc., 1996.
[2] Deepak K. Ghodgaonkar, Hadzli Haji Hashim, Norasimah Khadri, Mohd Shukri Haji Ahmad and Awang MokhtarrMohamad, “A Study of Bit Error Rate, Modulation Type and Signal Speed For a Wireless Data Communication System Using Portable Two Way Radio,” IEEE Proceedings Malaysia Section 2”dNational Conference on TelecommuniGations Technology, 1-2 Dec 1998, pp. 88-93.
[5] Gary W. Johnson, ed. “LabVIEW Power Programming,” McGraw-Hill, New York, 1998. [6] Ahmet M. Eskicioglu, Louis Litwin, “Cryptography,”. IEEE Potentials FebMar 2001,pp36-38.
[3] Frank Carden, “Telemetry System Designs,” Artech House, Inc., Norwood, 1995. Fig. 4 VI diagram for Decryption
Fig. 1 VI diagram for RTS Panel ~6pldBptov& I_--
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Fig. 5 Data received from RTS T e k m SOkSIs
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Fig. 2 VI diagram for BTS Panel
Fig. 6 Waveform at pin 2 of RTS serial port. Fig.3 VI diagram for Encryption
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