gs capacity capacity Erlangs Erlangs Limiting for one sector per MHz sector sector direction carrier 20 MHz per cell cdma2000 voice Reverse 530.9 cdma2000 data Forward sector interference at 30 percent of that same power, g = 0.3, the same as cdmaOne and cdma2000. The forward overhead for global channels is about the same as cdmaOne and cdma2000, but there is a substantial overhead within each channel for pilot and power control. W-CDMA maintains global forward channels that are not orthogonal to the sub- scriber channels, and it maintains both a global pilot and a pilot within each channel. There is also high-speed power control in both directions, so we set the voice overhead to h = 0.3 in the forward direction and to h = 0.2 in the reverse direction. We consider the overhead insignificant compared with the high-speed data channel, so h = 0 for data. W-CDMA has very fast power control in both directions, so we set p = -0.5 dB in both directions. The AMR speech coder uses a lower bit rate than cdmaOne or cdma2000 when the radio channel is reaching saturation, but it does not have four-rate speech coding for voice activity detection, so we set V to 0.6 for voice, 1.5 times higher than the cdma2000 value. Our data service example has U = 0.2. If half the system is in a state of soft or softer handoff and half those calls involve three or four sectors, then the soft- handoff factor used in the forward direction should be about S = 0.8. Orthogonal codes give us j = 0 in the forward direction and j = 1 in the reverse direction because W-CDMA has no JD in the base station receiver. Finally, the multipath factor depends heavily on the radio environment, and we are figuring that the densest and busiest areas are fairly hostile, so m = 0.4 is our estimate for this higher chip rate. In computing the values in Table 30.5 (the same as those in Tables 30.1 and 30.2), we put these parameters into Eqs. (30.1) and (30.2). We used three-sector cells and four carriers in 20 MHz for these calculations. 30.7.4 TD-SCDMA The chip rat