In an embodiment, a mapping relationship of discovery resource elements between adjacent discovery resource periods is established. Through the mapping relationship, a discovery resource element of which position is identified by a coordinate (n1, k1) in the preceding discovery resource period of the current resource period uniquely may correspond to a discovery resource element of which position is identified by a coordinate (n2, k2) in the current discovery resource period.

Thus, positions of the discovery resource elements for sending device discovery signals in the current discovery resource period can be determined according to positions of the discovery resource elements which send the device discovery signals in the preceding discovery resource period of the current discovery resource period and the mapping relationship.

In accordance with an aspect of the embodiment, the mapping relationship may be k2=mod(floor((n1*K+k1+A)/N),K) and n2=mod(n1*K+k1+A,N), herein floor(a) represents rounding down a, for example, floor(2,8)=2; mod(a,b) represents the value of a modulo b, for example, mod(8,3)=2. The value of A may be an integer, for example, a constant, or A is a cell-specific parameter, including any one or more of the following forms of parameters:

physical cell identity (PCID);

a number calculated based on the physical cell identity, for example, A=mod(PCID,K) or A=mod(PCID,N);

a parameter configured by a network side device; and