Wireless Sensor Networks of Infrastructure Health Monitoring for High-Speed Railway

Table 3

CtrlInfo bit values.

Bit	Name	Description
15	AckReq	1: acknowledgment request, 0: no acknowledgment request
14	AckRep	1: acknowledgement reply, 0: no acknowledgement reply
13	Sleeping	0: no sleeping, 1: sleeping enabled
12-11	Node Type	00: ED, 01: RP, 10: RP-R, and 11: AP
10	Direction Flag	0: from child to parent, 1: from parent to child
9–7	Depth	The depth value of the node that retransmits the frame recently, the maximum value is 8
6	Security	0: no encryption, 1: encryption enabled
5–0	Reserved Bits	Reserved