Overseas certifications require that GSM quad-frequency and HSPA be disabled and only WCDMA BAND1 be retained. 1. Disable HSPA:
<1> use the AT command to close HSPA. The method is as follows:
At + ehsm = Disable HSDPA/HSUPA
At + ehsm = Enable HSDPA/HSUPA
<2> valid after power failure
2. Disable four GSM frequencies
<1> how to disable a single card: Modify the RAC mode settings in the nvram_user_custpack.c file, and set the RAT mode to UMTS_RAT mode. This means that only UMTS is retained to disable GSM.
<2> dual-card shutdown method:
Card 1: Modify the RAC mode settings in the nvram_user_custpack.c file, and set RAT mode to UMTS_RAT mode, which means only UMTS is retained. This setting is only valid for Card 1. Disable Card 1 GSM
Card 2: At this time, Card 2 still supports GSM. You must enable Card 2 into flight mode to disable Card 2 GSM quad-frequency. Method: If the AT command is AT + EFUN = 1, sim1 enters normal mode and sim2 enters flight mode. After the test is complete, cancel the setting by running the AT + EFUN = 3 command. sim1 and sim2 are both in normal mode by default.
Note:
1. You cannot comment out the four-frequency comment directly, which will cause the modem assert.
2. For the method of disabling GSM for multiple cards, changing the RAC mode can only be changed to Card 1. Other cards can still be normally changed to GSM, and other cards must be switched to flight mode.
In the multi-card design, the following method is used to separate some cards into the flight mode:
At + efun = Here Yes bitmap
0x01 is sim1
0x02 is sim2
0x04 is sim3
0x08 is sim4
And so on
If the bit value of this sim is 0, it means flightmode, and 1 means normal mode.
