South Korea in early 2001 and is now established there. While introducing many new facilities the new system is still backwards compatible with cdmaOne (IS-95). The 3X variant requires three times the bandwidth, i.e. 3.75 MHz. For the forward link, the basic channels including the pilot, paging and sync channels are retained and provide backwards compatibility, but further channels are included to enhance the performance. These include a forward broadcast control channel that may be used for functions including paging. Although this facility was accessible via the paging channel on cdmaOne, the introduction of a new channel means that the congestion sometimes encountered on the paging channel is relieved. A forward auxiliary pilot channel is also included and this is used to assist in receiver decoding under poor conditions. A forward quick paging channel is another introduction. This is used to wake up a mobile in sleep or idle mode SO that it can receive a message. The use of this channel enables the mobile to be kept in idle mode to conserve battery life. 274 Newnes Guide to Radio and Communications Technology New dedicated channels are also included. One named the forward dedicated control channel is introduced. This is used primarily for signal- ling and it can also be used for the retransmission of other high priority traffic including data. A second named the forward supplemental channel is used purely for data traffic and is able to handle much higher data rates than the forward fundamental channel used in cdmaOne (IS-95). Modifications are also included for the reverse link. Two new common channels, namely the reverse common control channel, and the reverse enhanced access channel, are provided. These give more reliable access by allocating slots to users before they transmit bursts of data on the reverse link, and to provide a coherent form of reception for the base station probe receiver. New dedicated channels are also included. These include a reverse pilot channel, a reverse supplemental channel and