Basic considerations in calculating storage for an electronic telegraph switching center

The primary factors on which the amount of message delay depends are the number of message minutes awaiting transmission at the end of a busy-hour period (MMAXE) and the number of message minutes awaiting retransmission at the initiation of this period (MMAXI). The irregularity of the incidence of messages can have an unfavourable influence and also a high value of maximum message length. Tables are given relating MMAXE with values of MMAXI for various average message lengths. While the employment of paper tape, which cannot be reused, eliminates the problem of storage capacity, electronic stores, consisting of ferrite matrices or magnetic drums, have the advantage of being capable of repeated use. The major problem is to determine the size of the optimum store section, arranging for each message to use as many sections as are necessary. This optimum size is dependent upon the holding time of a store section and the control equipment associated with each section. Some data on optimum storage size are given for ferrite matrices.