Method of supporting power control on supplemental channel in base station

1. A method of transmitting power control information to a BSC (Base Station Controller) in a BTS (Base station Transceiver System) of a mobile communication system, comprising the steps of:

receiving forward power control (FPC) mode information indicating a slow power control from the BSC and transmitting the FPC mode information to an MS (Mobile Station);

extracting an EIB (Erasure Indicator Bit) that is a power control command in a frame period from a reverse pilot channel received from the MS according to the FPC mode information;

determining the status of the EIB; and

transmitting a reverse SCH (Supplemental Channel) message including the EIB status information to the BSC.

2. The method of claim 1 , further comprising the steps of determining a threshold for a forward SCH (Supplemental Channel) power control based on the EIB status included in the reverse SCH message in the BSC.

3. The method of claim 1 , wherein the EIB status is determined using eight odd-numbered PCBs (Power Control Bits) in a PCG (Power Control Group) of the reverse pilot channel.

4. A method of transmitting a signal to a BSC (Base Station Controller) in a BTS (Base Station Transceiver System) of a mobile communication system, comprising the steps of:

checking a forward power control mode (FPC_MODE);

receiving an EIB (Erasure Indicator Bit) on a reverse pilot channel from an MS (Mobile Station) when the forward power control mode indicates a slow power control; and

transmitting a reverse SCH (Supplemental Channel) message including the received EIB to the BSC.

5. The method of claim 4 , further comprising the step of performing a fast power control on a forward SCH based on a plurality of PCBs (Power Control Bits) received for one frame period on the reverse pilot channel from the MS if the forward power control mode indicates a fast power control.

6. A method of transmitting power control information to a BTS (Base Station Transceiver System) in a BSC (Base Station Controller) of a mobile communication system, comprising the steps of:

receiving a reverse SCH (Supplemental Channel) frame and a reverse SCH message including power control information from the BTS;

extracting an EIB (Erasure Indicator Bit) that is a power control command in a frame period from the reverse SCH message;

determining a forward power control threshold based on the EIB;

extracting information about the quality of a reverse SCH frame from the reverse SCH message; and

changing a reverse power control threshold in a forward SCH(Supnlemental Channel) message directed to the BTS based on the extracted quality information when reverse power control information should be adjusted; and

transmitting a forward SCH message including the threshold to the BTS.

7. A method of controlling the power of forward channels transmitted from a BTS (Base Station Transceiver System) to an MS (Mobile Station) in a mobile communication system, comprising the steps of:

determining power control rates for a forward FCH (Fundamental Channel)/DCCH (Dedicated Control Channel) and a forward SCH (Supplemental Channel);

performing a fast power control on the FCH(Fundamental Channel)/DCCH at the determined power control rate according to a plurality of power control commands received for one frame period from the MS; and

performing a slow power control on the SCH at the determined power control rate according to a power control command received for one frame period from the MS.

8. The method of claim 7 , wherein a forward power control threshold is changed according to the power control command received for one frame period in the slow power control.

9. The method of claim 7 , wherein the transmission power of the SCH is increased or decreased by a predetermined power value according to the plurality of power control commands received for one frame period in the fast power control.

10. A method of controlling the power of forward channels transmitted from a BTS (Base Station Transceiver System) to an MS (Mobile Station) in a mobile communication system, comprising the steps of:

determining power control rates for a forward FCH(Fundamental Channel)/DCCH (Dedicated Control Channel) and a forward SCH (Supplemental Channel);

performing a slow power control on the FCH/DCCH at the determined power control rate according to a power control command received for one frame period from the MS; and

performing a fast power control on the SCH at the determined power control rate according to a plurality of power control commands received for one frame period from the MS.

11. The method of claim 10 , wherein a forward power control threshold is changed according to the power control command received for one frame period in the slow power control.

12. A method of transmitting power control information to a BSC (Base Station Controller) in a BTS (Base station Transceiver System) of a mobile communication system, comprising the steps of:

detecting a discontinuous transmission (DTX) period by measuring the energy of a supplemental channel (SCH) frame received from a mobile station (MS);

checking a forward power control mode (FPC_MODE) if the DTX period is detected;

extracting a power control command from a reverse pilot channel according to the forward power control mode;

performing a fast power control on a forward SCH according to a power control bit (PCB) if the power control command is the PCB; and

transmitting a reverse SCH message including an erasure indicator bit (EIB) status value to the BSC if the power control command is an EIB.