Airtel is an outdated data communication process used internally within the FBI in addition to Teletype and facsimile. It indicates a letter that must be typed and mailed on the same day.

1. Airtel has launched a new plan that offers unlimited data for a low monthly fee.
   Airtel推出了一項新計劃，以低月費提供無限流量。
2. Many customers prefer Airtel because of its reliable network coverage.
   許多客戶更喜歡Airtel，因為它的網絡覆蓋可靠。