Patent ID: 6944138

Claim:
A base station controller having a plurality of physical links between a base station transceiver and a mobile switching center in a mobile communication system, comprising: an ATM switch for switching an input ATM cell stream according to routing information; an ATM interface having the plurality of physical links, for transmitting an ATM cell stream, and IMA processing ATM cells received over the plurality of physical links to restore the received ATM cells into one ATM cell stream; and an AAL2 cell processor for detecting the starting point of at least one AAL2 packet, directly transmitting an ATM cell stream switched by the ATM switch through a first path, receiving a restored ATM cell stream through a second path, switching at least one AAL2 packet multiplexed within each ATM cell in the received ATM cell stream according to routing information provided during call setup, multiplexing the switched AAL2 packets according to ATM connections, changing a CID (Channel Identification) of at least one AAL2 packet if it is determined that there is more than one AAL2 packet to be switched to an identical ATM connection at the same time, and creating an internal ATM cell having a format for switching by the ATM switch, wherein the CID is changed in order to be a unique number for identifying an identical ATM connection at the same time.