Query Privacy Preserving for Data Aggregation in Wireless Sensor Networks

Algorithm 1

The grid division.

	Input: The side length of cell, ; The communication radius, ; The position of BS, ; The position of a node, .
	Output: the nodes belong to the cells, .
(1)	Begin
(2)	BS broadcasts
(3)	For ()
(4)	If node receives then
(5)	Calculate according to equation (2)
(6)
(7)	Obtain the position ;
(8)	End If
(9)	End For
(10)	Return Cell information of all nodes, .
(11)	End