Abstract:
An aspect of the present invention is a method of monitoring a package. The method includes mounting a transponder on the package, the transponder having at least two signal transmission devices and emitting a first output signal configuration on the signal transmission devices when the integrity of the package is intact and emitting a second output signal configuration on the signal transmission devices if the integrity of the package has been compromised.

Description:
FIELD 
   This invention relates generally to the monitoring of packages and, more particularly, to a system for, and a method of, monitoring packages. 
   BACKGROUND 
   Package identifying transponders are used in supply chain logistics to track packages in the supply chain. A form of transponder increasingly being used is a radio frequency identification (RFID) tag which may be an active device or a passive device. The tag is attached to the package to be monitored and, generally, when interrogated by an interrogator, emits a response signal representative of the identity of the package to which the tag is attached. 
   It has been proposed to use RFID tags to monitor whether or not a package has been tampered with. With such an arrangement, the connection between the RFID chip and its antenna is broken when an attempt is made to gain unauthorized access to contents of the package so that, when the RFID tag is interrogated, there is no response to the interrogation signal. The lack of a response is meant to serve as an indication that tampering with the package has occurred. 
   There are two problems associated with such an arrangement. Firstly, it is a relatively simple procedure to re-establish the connection between the RFID chip and its antenna. Someone with nefarious intentions and who is aware of the arrangement could re-establish the connection so that, when the RFID tag is subsequently interrogated, it responds as it is supposed to. 
   Secondly, the connection between the RFID chip and its antenna may be broken for reasons other than tampering. An otherwise safe package may then be disposed of needlessly due to the failure to receive a response when interrogated. 
   SUMMARY 
   An aspect of the present invention is a method of monitoring a package. The method includes mounting a transponder on the package, the transponder having at least two signal transmission devices and emitting a first output signal configuration on the signal transmission devices when the integrity of the package is intact and emitting a second output signal configuration on the signal transmission devices if the integrity of the package has been compromised. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a schematic, block diagram of a system, in accordance with an embodiment of the invention, for monitoring a package; 
       FIG. 2   a  shows a schematic block diagram of a first embodiment of a transponder for use with the system; 
       FIG. 2   b  shows a schematic block diagram of a part of the transponder of  FIG. 2   a;    
       FIG. 3  shows a flow chart of a first embodiment of a method for monitoring a package using the transponder of  FIG. 2   a;    
       FIG. 4  shows a schematic block diagram of a second embodiment of a transponder for use with the system; 
       FIG. 5  shows a flow chart of a second embodiment of a method for monitoring a package using the transponder of  FIG. 4 ; 
       FIG. 6  shows a schematic block diagram of a third embodiment of a transponder for use with the system; 
       FIG. 7  shows a flow chart of a third embodiment for monitoring a package using the transponder of  FIG. 6 ; and 
       FIG. 8  shows a flow chart of a fourth embodiment of a method for monitoring a package. 
   

   DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
   In  FIG. 1  of the drawings, reference numeral  100  generally designates a system, in accordance with an embodiment, for monitoring a package. The system  100  incorporates a transponder in the form of an RFID tag  102  mounted on a package  104  such as, for example, a bottle of prescription medication. The package  104  includes a receptacle  106  and a closure member such as a screw cap  108 . 
   The system  100  further includes a transceiver in the form of a tag reader  110 . The tag reader  110  can either be a portable device or may be fixedly arranged on a structure such as a building, a vehicle, or the like. As the package  104  carrying the RFID tag  102  passes within a field of the reader  110 , an identity code within the tag  102  is read. The tag reader emits an electric field via its antenna and uses its antenna as a signal reception device to monitor for a signal emitted by the tag  102 . 
   In the case of a portable tag reader  110 , it may be swept over packages to read the tags  102 . Where the tag reader  110  is fixedly mounted, when the package passes within the field of the tag reader  110 , the tag  102  of the package  104  is read. 
   The tag reader  110  communicates with a central control unit in the form of a computer  112  to which a database  114  is connected. Thus, when the tag reader  110  reads the code of the tag  102 , this is communicated to the computer  112  which can determine, from accessing the database  114 , the identity of the package  104 . 
   The system  100  is intended to detect tampering with packages  104 . In  FIG. 2   a  a first embodiment of an RFID tag  200  used in the system  100  is illustrated. The tag  200  includes an RFID tag integrated circuit (IC) or chip  202  in which an identity code is stored when the tag  200  is affixed to a package. The identity code stored in the IC  202  is able to be read by a transceiver (not shown in  FIG. 2   a ) to determine the identity of the package. The IC  202  is connected to a signal transmission device in the form of an antenna  204 . 
   As shown in  FIG. 2   b  of the drawings, the tag IC  202  includes a data storage module in the form of a tag memory  206  in which at least the identity code of the package is written. The tag  200  could be a passive device in which case the tag  200  does not have any power source and the only information contained in the tag memory is limited to the identity code and, possibly, a little information regarding the contents of the package. 
   The IC  202  further includes a power regulation module  208  for regulating power received from the antenna  204  in the case of a passive device. Further, the IC  202  includes a tag modem and antenna interface  210  and a microcontroller  212  controls the operation of the tag  200 . 
   As will be described in greater detail below, the tag  200  could be used for sensing parameters or physical properties associated with the package. Thus, optionally, as illustrated by the dotted block  214 , the tag IC  202  may include sensor circuitry  216  which receives signals from sensors monitoring the physical parameters or properties of the package. An output from the sensor circuitry  216  is fed via an analog to digital converter  218  to the microcontroller  212  of the IC  202 . 
   In this embodiment, the tag  200  is an active device and includes a power source in the form of a battery  220 . Further, the tag includes a switch  222  having a normally open contact  224  and a normally closed contact  226 . 
   The power source  220  is a low cost power source and could, instead of the battery, be a piezoelectric effect supply or similar technology. 
   With the tag  200 , under normal operating conditions, a switchable member  228  of the switch  222  engages the normally closed contact  226 . When tampering with the package is detected, the switchable member  228  momentarily switches to the normally open contact  224  powering the IC  202  and allowing the IC  202  to record in its memory  206  that a connection to the tag antenna  204  has been momentarily broken. The tag memory  206  is then write protected. 
   Thus, if no tampering of the package has been detected during the passage of the package through the supply chain, when the tag  200  is interrogated it would emit a first response via the antenna  204 . Conversely, if tampering with the package has been detected, a second, different response would be output from the antenna  204  when the tag  200  is interrogated. This second response contains information from the memory  206  that a tampering incident was detected. A user of the system is then able to take suitable action in respect of the package in respect of which there has been tampering. 
   Thus, the tag  200  is used as described below with reference to  FIG. 3  of the drawings, where a method of monitoring a package, in accordance with this embodiment, is designated generally by the reference numeral  300 . As an initial step, at  302 , the manufacturer packages the product and sends it to a distributor. The distributor scans unopened packages using a tag reader which updates the distribution “pedigree” on the manufacturer website at step  304 . 
   At step  306 , a determination is made as to whether or not the package scans appropriately as unopened and authentic. If a negative answer is obtained, the package is voided and the manufacturer is informed. The package is removed from distribution as shown at step  308 . 
   If an affirmative answer is received, then, as shown at step  310 , larger lots of pallets, cases, boxes, etc of the packages are broken up into smaller collections of items. The smaller collections are shipped to retailers or consumers as shown at step  312 . 
   At step  314  a further determination is made as to whether or not the integrity of the package is still intact. If the answer is no or shows that the package has been opened, step  308  applies as does step  316  which is to check the distribution pedigree to determine where interdiction occurred, if possible, in order to fix the process. 
   If an affirmative answer is received, then, at step  318  the package is put to its intended use, such as, for example, consuming its contents or on-selling the package. 
   In  FIG. 4  of the drawings, a tag  400  which monitors physical properties associated with the package or with the contents of the package includes a tag integrated circuit (IC) or chip  402  which communicates with a signal transmission device in the form of an antenna  404 . The tag  400  is an active device and includes a power source such as a battery  406 . 
   In this embodiment, the tag  400  includes a sensor  408  for monitoring the physical properties of the package or the contents of the package. Examples of the types of properties or parameters which could be sensed by the sensor  408  include temperature, pressure, light, radiation, impact, humidity, tilt, or the like. This is not an exhaustive list and other physical properties of the package or its contents could be monitored by an appropriate sensor  408 . As an example, goods are often packaged in an evacuated container. Should a lid or closure cap of the container be removed, there would be an increase in pressure within the container. The sensor  408  could monitor such change in pressure. 
   While only a single sensor  408  has been illustrated, there could be a plurality of sensors connected to the tag IC  402 , each sensor monitoring a different property or parameter of the package or its contents. Additionally, because the tag  400  is an active device, when the sensor  408  detects a change in the property or parameter being monitored, the event is written to the memory (not shown in this embodiment) of the IC  402 . 
   In respect of the tag  400 , if there has been no change in the physical property or parameter of the package during the passage of the package through the supply chain then, when the tag  400  is interrogated, a first response will be emitted via its antenna  404 . Conversely, if there has been change in physical property associated with the package, for example, by the package having been tampered with, this change will be written from the sensor  408  to the memory of the integrated circuit  402 . 
   In such circumstances, when the tag  400  is interrogated a second, different signal will be emitted from the antenna  404  of the tag  400 . In so doing, an operator will be able to determine that the package has been tampered with and the appropriate action can then be taken. 
   Thus, a method of using the tag  400  is shown in  FIG. 5  of the drawings and is designated generally by the reference numeral  500 . As an initial step, at  502 , the manufacturer seals the package with the tag. As shown at step  504 , the powered tag monitors the physical property of the package which is not expected to change during shipping but which will change if the tag is tampered with, for example, by being opened in unauthorised circumstances. 
   When the package is received, a determination is made, as shown at step  506 , whether the physical property is in its “original” state or not. If a negative answer is received, i.e. that the package has been tampered with and this is evident from the response received by the interrogator, the package is voided as shown at step  508 . If an affirmative response is received, the package is deemed to be authentic and its integrity intact and the supply chain distribution, sale or consumption can proceed as shown at step  510 . 
   In  FIG. 6  of the drawings, yet a further embodiment of a tag is illustrated and is designated generally by the reference numeral  600 . The tag  600  includes a tag integrated circuit (IC) or chip  602 . The tag further includes a first signal transmission device, or antenna,  604  and a second signal transmission device, or antenna,  606 . The antenna  604  is connected to a first input  608  of the IC  602  via a normally closed switch  610 . The second antenna  606  is connected to a second input  612  of the chip  602 . The antenna  606  is connected to the input  612  directly or, optionally, via a normally open switch  614 . 
   This tag  600  may be a passive device, excluding any form of power supply or, optionally, may also include a power supply (not shown) such as a battery. In this embodiment, when the package to which the tag  600  is attached remains unopened then, when the tag  600  is interrogated, a signal is emitted from the first antenna  604 . If tampering with the package occurs, the antenna  604  is disabled. The second antenna  606  is then connected to the tag integrated circuit  602  and only operates after the first antenna  604  has been disabled. The second antenna  606 , because it is connected to a different input  612 , enables the tag IC  602  to distinguish when it is receiving a signal from the first antenna  604  and when it is receiving a signal from the second antenna  606 . The tag IC  602 , when it is interrogated, thus responds differently depending on which antenna  604  or  606  is connected to it. 
   This also allows the tag  600  to detect the state change before versus after the first time the package has been tampered with because the input which caused the tag IC  602  to be activated is known. Some tag ICs  602 , even if passive, have a small amount of writable and protectable memory. The first time the second antenna  606  is powered without the first antenna sending a signal to the tag IC  602  can indicate that the package has been tampered with and this information can be stored on the tag IC  602 . If the switch  614  is provided, this switch only closes when the package has been tampered with. 
   In  FIG. 7  of the drawings a variation of the use of the tag  600  is shown and its method of operation is designated generally by the reference numeral  700 . 
   In an initial step  702 , the manufacturer attaches the tag to a package and sends it into the supply chain or distribution chain. Further down the distribution chain, as shown at step  704 , a distributor, retailer or consumer scans the package to test its integrity and authenticity. 
   At step  706  a query is made as to whether or not both antennas respond to the query. If both antennas respond, a first output signal configuration is output from the package. This output signal configuration includes output signals from both antennas. 
   If the answer is in the affirmative, the package integrity is taken to be intact. The package continues in the distribution chain or is used as shown at step  708 . A “distribution pedigree” is updated on the manufacturer&#39;s website, if desired, as shown at step  710 . Unconsumed or unopened packages continue in the distribution chain as shown at step  712 . 
   If both antennas do not respond to the query, a further query is made as to whether or not the breakable antenna (antenna  604 ) responded. This is shown at step  714 . If the answer is in the affirmative, it is suspected that there is a defect in the tag as the second antenna (antenna  606 ) should always respond. This may also be an indication of tampering. At step  718 , the package is returned to the manufacturer or distributor and is not used or consumed. Optionally, the “distribution pedigree” on the manufacturer&#39;s website is updated. 
   If the answer to the question at step  714  is in the negative, a further question is asked as to whether or not the second antenna responded. This is shown at step  722 . If the answer is in the affirmative, it is suspected that there has been tampering with the package, as shown at step  724  as the first antenna did not respond. A “tampered” message is written to the memory of the tag IC and is write protected. 
   If the answer is in the negative then, as shown at step  726 , it is assumed that there has been a complete hardware failure for the tag system. This may be evidence of tampering or environmental stress. Because the tag serial number (identity code) is not available to automatically update the manufacturer&#39;s website a fallback to other exception processing procedures occurs as shown at step  728 . 
   A further variation of the method using the tag  600  is shown in  FIG. 8  and is designated generally by the reference numeral  800 . At step  802 , at the time of manufacture, assembly or fill, an encryption key is assigned to the tag and is recorded in a database  804  (corresponding to the database  114  of  FIG. 1 ). A set of secret commands and public commands are also recorded on the tag as shown at  808 . Thus, as shown at step  810 , the tag is now “secured”. 
   When a secured tag  812  is interrogated by an interrogator  814  it is interrogated with an encoded message  816 . The encoded message  816  contains a message string  818  which is encrypted with a key  820 . When the tag  812  is interrogated, a determination is made, at step  822 , as to whether or not the key  806  stored on the tag  812  decodes the message  818 . If the answer is negative, a determination is made, at step  824 , whether or not it is a request or command that needs to be signed or encrypted. 
   If the answer is yes, the request is ignored as shown at step  826 . If the answer to the question asked at  822  is yes or the answer to the question  824  is no then, as shown at step  828 , the message from the interrogator  814  is operated. 
   Thus the tag may conceal evidence of tampering from people who do not have the correct encryption codes. This is done by the tag ignoring any request that is not correctly encrypted. Instead, the tag may respond to most commands but ignore certain sensitive requests unless the request is properly encrypted with the correct code. If desired, the tag could also respond with a “not tampered” response to an incorrectly encrypted interrogation. 
   It is therefore an advantage of embodiments of the invention that systems and methods are provided which readily indicate when a package has been tampered with in a positive manner. In other words, rather than there being no response from the tag associated with the package, a second, different response is received indicating that there has been tampering. Hence, false indications of tampering are greatly reduced and the ability of unauthorized personnel to reconnect broken antennas will be ineffective due to prior storage of tamper evidence in the memory of an integrated circuit of the tag. 
   It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.