基于时隙ALOHA的标签识别机制-2 Tag inventory and access The MAC protocol for the C1G2 system is based on Slotted ALOHA, where each frame has a number of slots and each active tag will reply in a randomly selected slot per frame. When a reader(interrogator)wishes to read a set of tags,it first powers up and transmits a continuous wave(CW)to energize the tags.It then initiates a series of frames,varying the number of slots in each frame to best accommodate the number of tags.After all tags are read,the reader powers down.We refer to an individual frame as a Query Round,and the series of Query Rounds between power down periods as a Query Cycle. Query Cycle Query Round Query Round cee0。 Query Round基于时隙ALOHA的标签识别机制-2 • Tag inventory and access – The MAC protocol for the C1G2 system is based on Slotted ALOHA, where each frame has a number of slots and each active tag will reply in a randomly selected slot per frame. – When a reader (interrogator) wishes to read a set of tags, it first powers up and transmits a continuous wave (CW) to energize the tags. It then initiates a series of frames, varying the number of slots in each frame to best accommodate the number of tags. After all tags are read, the reader powers down. We refer to an individual frame as a Query Round, and the series of Query Rounds between power down periods as a Query Cycle. Query Round Query Round …… Query Round Query Cycle