* *Let denote the selected sector number of sensor in the current -*covset * |

* *, denote the total sector set of sensor and denote the maximal sector |

* *number from each sensor in the current |

* *Set , . |

* ***while** (each target is covered by at least available sectors) **do** |

* ** *, , , , |

* ** *Initialize the sector weight of each sector. |

* ** ***while** **do** |

Sort sectors in in descending order based on the number of available |

lifetime. If some sectors have the same value, give the priority to the sector |

with the maximal value of the sector weight. |

* ** ** *Choose the first sector from the sort set. |

* ** * * *, , |

* * * ***if** **then** |

* * * ***for all** target **do** |

**if** is covered by **then** |

**if** **then** |

* *Update the sector wight of each sector. |

* ***end while** |

* *Minimize , check each whether it is redundant. |

* *Compute *MAX_Lifetime*(). |

* * |

* *, (*MAX_Lifetime*()/*ε*), , |

* *** for all** sectors **do** |

* * |

* ***if** **then** |

**end while** |

**return ** *SDQ*-*covsets*: and the network lifetime |