called party; called subscriber
Technical term in telecommunications and computing for the party receiving a call or connection request.
If the called party does not answer, the call will disconnect after a set time.
In this system, the called subscriber's number must be registered in advance.
発信者 is the calling party or originator, while 着加入者 is the called party or recipient.
Compound of 着 (arrive, receive) + 加入 (join, subscribe) + 者 (person). The reading ちゃっか is a phonetic shift from ちゃく + か.