GSM的CBC配置的物理信道上，PCH与AGCH所占用的块的总数为3，请问具体计算过程

非常感谢！

这问题问的一点也不严谨，如果CBCH信道和SDCCH信道使用相同的信道，如果配置CBCH(SDCCH/4)的话，CBCH占用时隙0，本来PCH和AGCH占用0,2,4,6 4个信道，那么这时候只剩下3个了

Channel                                   Sub‑                 Direction                 Allowable                Allowable                        Burst       Repeat                     Interleaved block
designation                              channel                                            timeslot                   RF channel                      type         length in                  TDMA frame
                                                number                                            assignments             assignments                                     TDMA frames         mapping

FCCH                                                                        D                    0                              C0                                    FB                    51                            B0(0),B1(10),B2(20),B3(30),B4(40)

SCH                                                                          D                    0                              C0                                    SB                    51                            B0(1),B1(11),B2(21),B3(31),B4(41)

BCCH Norm                                                              D                    0,2,4,6                     C0                                    NB                   51                   B(2..5)

BCCH Ext                                                                 D                    0,2,4,6                     C0                                    NB                   51                   B(6...9)

PCH                                                                          D                    0,2,4,6                     C0                                    NB                   51                                B0(6..9),B1(12..15),B2(16..19)
AGCH                                                                                                                                                                                                                             B3(22..25),B4(26..29),B5(32..35),
                                                                                                                                                                                                                                         B6(36..39),B7(42..45),B8(46..49)

NCH                                                                          D                    0                              C0                                    NB                   51                                B0(6..9),B1(12..15),B2(16..19)
                                                                                                                                                                                                                                        B3(22..25),B4(26..29),B5(32..35),
                                                                                                                                                                                                                                B6(36..39)

RACH                                                                       U                    0,2,4,6                     C0                                    AB                   51                                       B0(0),B1(1)..B50(50)

CBCH(SDCCH/4)                                                      D                    0                              C0                                    NB                   51                   B(32..35)

CBCH(SDCCH/8)                                                      D                    0 ... 3                       C0 ... Cn                           NB                   51                   B(8..11)

SDCCH/4                                        0                        D                    0                              C0                                   NB1                  51                   B(22..25)
                                                                                 U                                                                                                                                            B(37..40)
                                                       1                        D                                                                                                                                            B(26..29)
                                                                                 U                                                                                                                                            B(41..44)
                                                       2                        D                                                                                                                                            B(32..35)
                                                                                 U                                                                                                                                            B(47..50)
                                                       3                        D                                                                                                                                            B(36..39)
                                                                                 U                                                                                                                                            B(0..3)

SACCH/C4                                      0                        D                    0                              C0                                   NB3                 102                  B(42..45)
                                                                                 U                                                                                                                                            B(57..60)
                                                       1                        D                                                                                                                                            B(46..49)
                                                                                 U                                                                                                                                            B(61..64)
                                                       2                        D                                                                                                                                            B(93..96)
                                                                                 U                                                                                                                                            B(6..9)
                                                       3                        D                                                                                                                                            B(97..100)
                                                                                 U                                                                                                                                            B(10..13)