CONTENTS

 1     Scope of this Recommendation
 2     References
 3     Terms and definitions
 4     Introduction
 5     Modelling for dimensioning of circuit groups
        5.1     Modelling of offered traffic
        5.2     Categories of circuit groups
        5.3     GOS objectives
 6     Characterization of overflow traffic from a first-choice group
        6.1     Calculating traffic intensity of individual overflow
        6.2     Calculating peakedness of individual overflows
 7     Dimensioning methods for an overflow group
        7.1     Principles
        7.2     Calculating individual call blocking probabilities
 8     History
 9     Bibliography
Annex A - Example methods for calculating overflow variances from a first-choice group
        A.1     Assumptions and notations
        A.2     Variance calculation methods
                  A.2.1     Exact solution method
                  A.2.2     Approximation method
Annex B - Example method for calculating individual call blocking  probabilities of an overflow group
        B.1     Reduced network method
        B.2     Notations
        B.3     Determination of equivalent capacity n_i
        B.4     Time congestion Π
        B.5     Blocking probability B_i
        B.6     The second overflow
        B.7     Field of application
        B.8     Processing time and programming effort