CONTENTS

Annex 1 - Characteristics of a fixed-satellite service hypothetical reference digital path forming part of an integrated services digital network    
 1     Introduction      
 2     64 kbit/s satellite channels forming part of the ISDN HRX
        2.1     Performance requirements of the FSS HRDP         
        2.2     Other error-causing mechanisms    
                     2.1.1 Satellite system error performance objectives
                     2.1.2 ITU-T Recommendation G.821 requirements
                     2.1.3 BEP models required to meet ITU-T Recommendation G.821
                     2.2.4 Signal path switching in the satellite
                     2.2.5 Effects of equipment switch-overs on ITU-T Recommendation G.821 parameters
 3     Error-performance calculations and models          
        3.1     Introduction           
        3.2     Method of calculation        
        3.3     Performance of models      
        3.4     Practical measurement procedures 
                    3.4.1 Introduction
                    3.4.2 Measurement algorithms
 4     Examples of typical satellite link performance        
        4.1     Attenuation model  
        4.2     Propagation considerations relating to short-term objectives
        4.3     Results of measurements on the TELECOM-1 satellite       
 5     Error distributions on a satellite link and the effects of uncoded operation and operation utilizing forward error correction    
        5.1     Introduction           
        5.2     Characteristics of typical FEC coding schemes       
                    5.2.1 Rate 7/8 BCH coding
                    5.2.2 Convolutional encoding-Viterbi decoding
                    5.2.3 Convolutional coding-sequential decoding
        5.3     Effects on degraded minutes, severely errored seconds and errored seconds           
                    5.3.1 Qualitative discussion
                    5.3.2 Measurements
                    5.3.3 Quantitative analysis
        5.4     Mathematical modelling      
                    5.4.1 The Neyman-A contagious distribution
                    5.4.2 Analytical representation for a BCH code
       5.5     Impact on system design in the 14/11 GHz band     
        5.6     Conclusions