APPARATUS AND METHOD FOR CONNECTION CONTROL VIA SUB-CHANNEL IN DIGITAL TELECOMMUNICATION SYSTEM

The present invention discloses an apparatus for controlling a channel connection and a sub-channel connection installed in a terminal connected to sub-terminals and more than one channel. The apparatus comprises a channel multiplexing unit for multiplexing each channel into subchannels, a switching unit for selectively connecting a subchannel to the sub-terminal and another sub-channel, a channel setup unit for controlling a channel connection setup of each channel, sub-channel setup units for controlling a sub-channel connection setup of a sub-channel connected thereto, the subchannel setup unit being provided to each sub-channel, a connection request receiving unit for receiving a relay connection request to relay a call to an end-called terminal via an available sub-channel in a channel from the channel's connected terminal, the terminal being connected to the channel's connected terminal via a sub-channel connection set up in the channel, a connection managing unit for issuing an order to the sub channel setup unit connected to the available sub-channel to set up a sub-channel connection as per the relay connection request, and for issuing an order to the channel setup unit and the sub-channel setup unit to set up a channel connection and a sub-channel connection to the end-called terminal, respectively, and a changeover control unit for controlling the switching unit to connect two sub-channels when the sub-channel connection is set up. 57