Patent ID: 8130104
Filing Date: 2012-03-06
Classification: G07C

Abstract:
1. An apparatus for detecting the crossing of a border line section between a first zone and a second zone, comprising: i. an antenna assembly located near said border line section, comprising: (a) a first antenna section connected to a first transmitter, having a directional antenna with a radiating element oriented in a first direction and a radiation pattern aligned to radiate greater power in the first direction, and (b) a second antenna section connected to a second transmitter, having a directional antenna with a radiating element oriented in a second direction opposite the first direction and a radiation pattern aligned to radiate greater power in the second direction; wherein said first antenna section is directed from said border line section toward said first zone and said second antenna section is directed from said border line toward said second zone, and ii. a smart tag that can be affixed to an object; wherein said smart tag detects an event of said smart tag crossing said border line section, by receiving transmission of identification data of said first antenna section but not of said second antenna section when said smart tag is in said first zone, and then receiving transmission of identification data of said first antenna section and said second antenna section simultaneously, and then receiving transmission of identification data of said second antenna section but not of said first antenna section when said smart tag is in said second zone and then detecting that receipt of said transmission of identification data of said second antenna section has stopped while transmission of identification data of said first antenna section is not being received.