In some applications, such as slotted indoor CDMA communications, where the network performance depends mainly on periodic crosscorrelation functions of spreading codes, minimisation of the peak crosscorrelation level (CCL) is not a sufficient measure to ensure an optimal performance. The occurrence frequency of CCLs is introduced as another important parameter to judge CDMA code families. The 4-CCL and 5-CCL code families which possess more ideal OFs of CCLs than the Gold (1967) code are presented. A new technique using a multivariable Bernoulli process to model the outputs of a CDMA receiver is developed to evaluate the network level BER performance in a slotted system. The results obtained show that the 4-CCL and 5-CCL codes obviously outperform the Gold code in the BER performance.<<ETX>>