發送短信 : Power preservation friendly congestion control

  _  _      ___     ______    __   __    _  _   
 | \| ||   / _ \\  |      \\  \ \\/ //  | \| || 
 |  ' ||  | / \ || |  --  //   \ ` //   |  ' || 
 | .  ||  | \_/ || |  --  \\    | ||    | .  || 
 |_|\_||   \___//  |______//    |_||    |_|\_|| 
 `-` -`    `---`   `------`     `-`'    `-` -`