MS_TXPWR_MAX_CCH

Value range: 0~31

Unit:  level

Content: This parameter determines the max. allowed output power of the MS when it begins to access a cell and has not yet received power command.

Recommendation: 5(900MHz), 0(1800MHz)

During MS’s communication with BTS, its transmitting power is controlled by the network via power command. This command is transmit in SACCH (There are two head bytes. One is power control byte, the other is time advance). MS must get the power control head from the downlink SACCH, and use its stipulated transmitting power as the output power. If power level of the MS cannot output that power, the transmitting power will use the nearest value.

Since SACCH is associated with signaling, it must be used after combining with other channels, such as SDCCH, TCH. Therefore, the network’s control of MS power begins after MS receives SACCH.While the power used by MS before it receives SACCH (power used when RACH is sent) is determined by the maximum power level of control channel.

List is the corresponding dBm values related to the 32 maximum transmitting power control levels for GSM900:

{39, 39, 39, 37, 35, 33, 31, 29, 27, 25, 23, 21, 19, 17, 15, 13, 11, 9, 7, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5}

For GSM1800:

{30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 36, 34, 32}.

This parameter will affect cell selection and cell reselection.

C1 = RLA_C - RXLEV_ACCESS_MIN- MAX((MS_TXPWR_MAX_CCH- P),  0)

   RLA_C: mean receiving level of MS

   RXLEV_ACCESS_MIN: minimum receiving level of MS permitted to access

   P: maximum physical transmitting power level of MS.