三大运营商北斗短信什么时候开通的？北斗短信怎么收费？支持北斗的手机有哪些？北斗短信有什么用？
1、三大运营商北斗短信什么时候开通的？— When were Beidou SMS services launched by the three major Chinese telecom operators?
2、北斗短信怎么收费？— What are the charging standards for Beidou SMS?
3、支持北斗的手机有哪些？— Which mobile phones support Beidou?
4、北斗短信有什么用？— What is Beidou SMS used for?
5、北斗短信怎么收发？— How to send and receive Beidou SMS?