TELECOMMUNICATIONS NETWORKS

摘要

In a telecommunications network comprising digital main switching units (1) and local exchanges (3), the local exchange (3) is arranged to permit alternative alert signals to consumer premises (4) by way of the local loop (5). The alternative signals may be cadenced to provide information to apparatus connected in a consumer's premises (4) without causing activation of traditional telephone, facsimile or answering machines. Such information may be supplemented by the presence or absence of a line polarity reversal before the activation signal is sent and by modulated signals, such as FSK signalling.