android 10 默认使用4G

修改：

android/frameworks/base/telephony/java/com/android/internal/telephony/RILConstants.java 
index 5205973..324248a 100644
@@ -231,7 +231,7 @@ public interface RILConstants {
     int NETWORK_MODE_NR_LTE_TDSCDMA_CDMA_EVDO_GSM_WCDMA = 33;
 
     int PREFERRED_NETWORK_MODE = Integer.parseInt(TelephonyManager.getTelephonyProperty(0,
-            "ro.telephony.default_network", Integer.toString(NETWORK_MODE_WCDMA_PREF)));
+            "ro.telephony.default_network", Integer.toString(NETWORK_MODE_LTE_ONLY)));
 
     int BAND_MODE_UNSPECIFIED = 0;      //"unspecified" (selected by baseband automatically)
     int BAND_MODE_EURO = 1;             //"EURO band" (GSM-900 / DCS-1800 / WCDMA-IMT-2000)

找到项目对应的mk里面添加：

# 4G by default
PRODUCT_PROPERTY_OVERRIDES += \
    ro.telephony.default_network=11

hardware/ril/include/telephony/ril.h 里面定义了对应的网络类型，具体以实际项目生效的ril.h为准

// Do we want to split Data from Voice and the use
// RIL_RadioTechnology for get/setPreferredVoice/Data ?
typedef enum {
    PREF_NET_TYPE_GSM_WCDMA                = 0, /* GSM/WCDMA (WCDMA preferred) */
    PREF_NET_TYPE_GSM_ONLY                 = 1, /* GSM only */
    PREF_NET_TYPE_WCDMA                    = 2, /* WCDMA  */
    PREF_NET_TYPE_GSM_WCDMA_AUTO           = 3, /* GSM/WCDMA (auto mode, according to PRL) */
    PREF_NET_TYPE_CDMA_EVDO_AUTO           = 4, /* CDMA and EvDo (auto mode, according to PRL) */
    PREF_NET_TYPE_CDMA_ONLY                = 5, /* CDMA only */
    PREF_NET_TYPE_EVDO_ONLY                = 6, /* EvDo only */
    PREF_NET_TYPE_GSM_WCDMA_CDMA_EVDO_AUTO = 7, /* GSM/WCDMA, CDMA, and EvDo (auto mode, according to PRL) */
    PREF_NET_TYPE_LTE_CDMA_EVDO            = 8, /* LTE, CDMA and EvDo */
    PREF_NET_TYPE_LTE_GSM_WCDMA            = 9, /* LTE, GSM/WCDMA */
    PREF_NET_TYPE_LTE_CMDA_EVDO_GSM_WCDMA  = 10, /* LTE, CDMA, EvDo, GSM/WCDMA */
    PREF_NET_TYPE_LTE_ONLY                 = 11, /* LTE only */
    PREF_NET_TYPE_LTE_WCDMA                = 12,  /* LTE/WCDMA */
    PREF_NET_TYPE_TD_SCDMA_ONLY            = 13, /* TD-SCDMA only */
    PREF_NET_TYPE_TD_SCDMA_WCDMA           = 14, /* TD-SCDMA and WCDMA */
    PREF_NET_TYPE_TD_SCDMA_LTE             = 15, /* TD-SCDMA and LTE */
    PREF_NET_TYPE_TD_SCDMA_GSM             = 16, /* TD-SCDMA and GSM */
    PREF_NET_TYPE_TD_SCDMA_GSM_LTE         = 17, /* TD-SCDMA,GSM and LTE */
    PREF_NET_TYPE_TD_SCDMA_GSM_WCDMA       = 18, /* TD-SCDMA, GSM/WCDMA */
    PREF_NET_TYPE_TD_SCDMA_WCDMA_LTE       = 19, /* TD-SCDMA, WCDMA and LTE */
    PREF_NET_TYPE_TD_SCDMA_GSM_WCDMA_LTE   = 20, /* TD-SCDMA, GSM/WCDMA and LTE */
    PREF_NET_TYPE_TD_SCDMA_GSM_WCDMA_CDMA_EVDO_AUTO  = 21, /* TD-SCDMA, GSM/WCDMA, CDMA and EvDo */
    PREF_NET_TYPE_TD_SCDMA_LTE_CDMA_EVDO_GSM_WCDMA   = 22  /* TD-SCDMA, LTE, CDMA, EvDo GSM/WCDMA */
} RIL_PreferredNetworkType;

用命令可以查看或者设置当前的网络类型
查看

:/ #  settings list global | grep preferred
preferred_network_mode1=0
preferred_network_mode=11

设置

  settings put global preferred_network_mode1 11

Android settings使用详解之设置优先网络

android 13
高通6125 直接设置ro.telephony.default_network为11，导致sim卡不识别。所以只能通过去代码设置

+    private void setDefaultNetworkMode(){
+        int mode = SystemProperties.getInt("dev.default.network", -1);
+        Log.d(tag,"SetDefaultNetworkMode:" + mode);
+       // mode = 11;
+       // Log.d(tag,"debug SetDefaultNetworkMode:" + mode);
+        if(mode >= 0){
+            TelephonyManager telephonyManager = (TelephonyManager) getContext().getSystemService(Context.TELEPHONY_SERVICE);       telephonyManager.setPreferredNetworkType(TelephonyManager.ALLOWED_NETWORK_TYPES_REASON_USER,mode);
+        }
+    }