These procedures may be used for the invocation and operation of supplementary services in association with existing calls or outside any existing calls .

这些程序可以用于申请和运行与现存 呼叫相关的或在任何现存呼叫以外的 补充业务。

The ECT supplementary service enables an ISDN user who has two calls into one call .

ECT 补充业务能使具有两个 呼叫的用户转移到一个呼叫中去。

The ECT supplementary service enables a user who has two calls each of which can be an incoming or an outgoing call to connect the other users in the two calls .

本建议规定明确 呼叫转移（ECT） 补充业务的第二级。ECT 补充业务使来话或去话 呼叫两个呼叫的一用户连接至该两个呼叫的其他用户。