协议规定
根据3GPP协议,emergency APN配置需要注意。
3GPPspec TS24.301 6.5.1.2 UE requested PDN connectivity procedure initiation In order to request a PDN connection for emergency bearer services, the UE shall not include an APN in the PDN CONNECTIVITY REQUEST message or when applicable, in the ESM INFORMATION RESPONSE message.
平台差异
| | QOCM | MTK |
| emergency | 不用拆分WiFi与否的场景 | 需要配置两条emergency APN。 在cellular下都要有一条apn=""(空)的emergency apn存在。 |
| xcap | 上层不会主动往下请求,都是MD用。 | 若与default APN共用一条,则需要拆分 |
mms | 若与default APN共用一条,则需要拆分 |
---|
高通平台
1、在高通平台上,某些运营商可以不拆分数据网和WLAN下的emergency APN,拆分了反而会存在问题,根据modem反馈的情况,上层Telephony 适配APN。
2、xcap 类型的APN上层AP不会主动请求下发,都是modem使用的,当前不配置bearer也没有影响,因为modem有一套自己维护的?
MTK平台
1、根据MTK要求,在cellular下都要有一条apn=""(空)的emergency apn存在,否则PDN建立会存在问题。
3GPPspec TS24.301 6.5.1.2 UE requested PDN connectivity procedure initiation In order to request a PDN connection for emergency bearer services, the UE shall not include an APN in the PDN CONNECTIVITY REQUEST message or when applicable, in the ESM INFORMATION RESPONSE message.
MTK依据上述协议,将apn=""(APN空)的emergency 类型APN设为最高优先级使用,即上层向MD下发了sos APN。
2、对于mms和xcap APN,如果配置在与default 类型的APN在同一条的情况,则需要另外拆分。
一条bearer为18的用于wlan transport,另一条不包含18的给cellular。
APN配置代码
KaiOS系统配置案例
1、没有拆分的时候,QCOM的EMC/SUPL会PDN fail。
javascript
{"carrier":"LTE-V EMERGENCY","apn":"","type":["Emergency"],"protocol":"IPV4V6","roaming_protocol":"IPV6","bearer":917503,"user_visible":"false"},
{"carrier":"v EMERGENCY","apn":"VZWEMERGENCY","type":["Emergency"],"protocol":"IPV4V6","roaming_protocol":"IPV6","bearer":131072,"user_visible":"false"},
2、正确配置,功能正常
javascript
{"carrier":"VZWEMERGENCY","apn":"VZWEMERGENCY","type":["Emergency"],"protocol":"IPV4V6","roaming_protocol":"IPV6","bearer":1048575,"mvno_match_data":"BAE0000000000000","mvno_type":"gid","user_visible":"false"}
Note:For VZW TC3.1,E911 SUPL CASE。
对于bearer是十进制转换,适配二进制,对应关系如下:
- 00011111111111111111=131,071(1-17)
- 131072=00100000000000000000(仅18WIFI)
- 01100000000000000000=393216(18+19)
- 00100010000000000000=139264(14+18)
- 262143=00111111111111111111(1-18)
- 917503=11011111111111111111(除18)
- 26375=0110011100000111(1-3,9-11,19+18)
- 11111111111111111111(1-20)=1048575
- 11111111111111111110(1-19)=1048574