在代码中modem_proc/build/ms/cust8953.genq.prodq.h中，可以看到默认支持接入层版本
#define LTE_3GPP_DEFAULT_RELEASE_VERSION LTE_3GPP_REL10_SEP12
You can use the below EFS to control the lte release version.
Please note that You can only downgrade the LTE release version.
If you modem supports Release 10 then you can only downgrade it to below 10.
/nv/item_files/modem/lte/lte_3gpp_release_ver
lte.h
typedef enum
{
/Rel8 versions/
LTE_3GPP_REL8 = 0x10,
LTE_3GPP_REL8_DEC08 = 0x11,
LTE_3GPP_REL8_MAR09 = 0x12,
LTE_3GPP_REL8_JUN09 = 0x13,
LTE_3GPP_REL8_SEP09 = 0x14,
LTE_3GPP_REL8_DEC09 = 0x15,
LTE_3GPP_REL8_MAR10 = 0x16,
LTE_3GPP_REL8_JUN10 = 0x17,
LTE_3GPP_REL8_SEP10 = 0x18,
LTE_3GPP_REL8_DEC10 = 0x19,
LTE_3GPP_REL8_MAX,
/Rel 9 versions/
LTE_3GPP_REL9 = 0x20,
LTE_3GPP_REL9_MAR10 = 0x21,<