Download the this issue (complete journal, excluding cover) (~2.4 MB).

Jump to:

1. Reliable File Transfer Using Forward Error Correction
2. On the Generating Function and its Application to Ternary Line Codes
3. Clear-Air Signal Level Measurement for Microwave Line-of-Sight Link Application in South Africa

Reliable File Transfer Using Forward Error Correction by D. Churms, B.A.A. Olsen and D.J.J. Versfeld
Abstract: An adaptive reliable file transfer protocol was designed and implemented. The protocol is based on forward error correction techniques, which improves the packet loss correcting potential of the protocol. The protocol outperforms TCP at loss rates above 10 %, making it suitable for use over wireless links with a poor signal to noise ratio. Future testing and optimisation using large files or alternative techniques for estimating network characteristics could improve the applicability of the protocol.
Download Paper (~711 kB)
 

On the Generating Function and its Application to Ternary Line Codes by K. Ouahada and H.C. Ferreira
Abstract: One of the major problems researchers face is how to verify experimental or simulation results of any class of codes. Usually this can be done by deriving bounds to test the performance of codes. As they are used in binary codes and especially in linear convolutional codes, where the sum of any two codewords is another codeword and the all-zeros sequence is a codeword, the major step to derive these bounds is to calculate the generating function. Since ternary line codes are non-linear line codes, we will investigate in this paper the possibility of deriving the generating function for at least some of these codes.
Download Paper (~1259 kB)
 

Clear-Air Signal Level Measurement for Microwave Line-of-Sight Link Application in South Africa by P.K. Odedina and T.J. Afullo
Abstract: This paper presents an analysis of the 19.5 GHz clear-air signal level measurement variations over a line of sight link set up between two campuses of University of KwaZulu-Natal in Durban, South Africa. The measurement over the link spans a period of eleven months. An analytical expression for fade depth exceedance is proposed for KwaZulu-Natal, in South Africa. The link outage probability is compared with the results obtained from two ITU-R models as per recommendations P.530-8 and P.530-12, Morita’s model for Japan, and the model of Vigants used in the United States. The Morita model over sea and coastal regions gives an outage probability of 0.060 %, compared to 0.037 % obtained from the measurements, with the two ITU-R models also giving close values of 0.027 % and 0.024 %, respectively. However, Vigants’ model is found to be the least appropriate for outage estimation in South Africa.
Download Paper (~1195 kB)