Abstract:
An electronic security seal (e-Seal) is disclosed. The e-Seal monitors security of shipments including intermodal containers, reports tampers in real-time, monitors environmental status of goods and reports exceptions in real-time, and reports the location of the shipment with high frequency. The security monitoring complies with the ISO 17712 standard, adding electronic real-time reporting of tamper time and location and LED tamper indication. The e-Seal can be manufactured and operated at low cost due to diagnostic and logistic features. The e-Seal supports low cost upgrades due to a modular architecture allowing a plug-in update of separate functions. The e-Seal allows flexible usage across supply chain tradelanes, due to highly programmable operation including over-the-air remote programming via wireless communications. The e-Seal provides low power operation to save battery usage and lower costs.

Description:
RELATED APPLICATION 
       [0001]    This application claims the benefit of priority from U.S. patent application Ser. No. 12/510,990, for “Wireless Tracking and Monitoring Electronic Seal,” filed Jul. 28, 2009, and U.S. Provisional Patent Application No. 61/225,525, for “Wireless Tracking and Monitoring Electronic Seal,” filed Jul. 14, 2009, both of which are incorporated by reference herein in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    This subject matter is related generally to providing in-transit visibility of shipments in real-time. 
       BACKGROUND 
       [0003]    Goods which are transported via intermodal shipping containers need to be monitored for the security of the container, the location of the container, and the environmental status of the goods. Mechanical security seals on container doors can be tampered and restored or replaced to approximate condition so as to pass a casual inspection, so that pilfered or tampered goods are not discovered until the container is opened at the destination. Conventional electronic security seals (e-Seals) improve upon mechanical seals, as they can provide a wireless report of a security tamper. e-Seals are limited by a need for external power such as from the cab of a truck, which is not available for other intermodal transport such as trains, barges or ships. Power consumption limits battery powered e-Seals to infrequent location and reporting updates. Environmental monitoring of the container goods can be performed using chart recorders inside the container, which do not provide real-time knowledge of temperature, humidity or shock damage to the goods until the container is opened at the destination. The practical use of conventional e-Seals is limited by the high cost of such devices. 
       SUMMARY 
       [0004]    An improved electronic security seal (e-Seal) is disclosed. The e-Seal can monitor the security of shipments including intermodal containers, report tampers in real-time, monitor environmental status of the goods and report exceptions in real-time, and report the location of the shipment with sufficient frequency to allow management of supply chain exception events. The security monitoring complies with the ISO 17712 international standard for container security seals, adding electronic real-time reporting of tamper time and location as well as tamper indication to thwart undetected tampering. These security features greatly enhance the ability to decide the need to inspect a shipment mid-journey. 
         [0005]    The e-Seal can be manufactured and operated at low cost due to a number of diagnostic and logistic features designed into the e-Seal. In addition the e-Seal supports low cost upgrades to multiple form factors and usages due to a modular architecture allowing a plug-in update of one function without requiring redesign of other e-Seal functions. The e-Seal allows flexible usage across a myriad of supply chain tradelanes, long and short, domestic and international, due to highly programmable operation including over-the-air remote programming via wireless communications. The e-Seal provides low power operation to save battery usage and lower costs. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a block diagram of an example e-Seal system. 
           [0007]      FIG. 2  is a diagram of the modular architecture of the e-Seal of  FIG. 1 . 
           [0008]      FIG. 3  is a physical diagram of an example e-Seal of  FIG. 1 . 
           [0009]      FIG. 4  is a block diagram of the e-Seal of  FIG. 1 . 
           [0010]      FIG. 5  is a state diagram of the low power operation of the e-Seal of  FIG. 1 . 
           [0011]      FIG. 6  is a diagram of the programmable operation of the e-Seal of  FIG. 1 . 
           [0012]      FIGS. 7A and 7B  are flow diagrams of the operation across various supply chain conditions of the e-Seal of  FIG. 1 . 
           [0013]      FIG. 8  is an event diagram of the features allowing low cost manufacturing of the e-Seal of  FIG. 1 . 
           [0014]      FIG. 9  is an event diagram of the features supporting low cost logistics and operation of the e-Seal of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
     Overall e-Seal System 
       [0015]      FIG. 1  is a block diagram of an example electronic security seal (e-Seal) system  100 . The e-Seal system  100  can include an e-Seal  101 , an asset  102  (e.g., a container  102 ), a navigation system  103  (e.g., GPS), a wireless communications system  104  and a tracking service  105  (e.g., a server). The description that follows is for an intermodal container (e.g., a shipping container). However, the e-Seal  101  can be used with any physical asset (e.g., tracking heavy machinery). 
         [0016]    In some implementations, the e-Seal  101  mounts to the hasp of the door of the intermodal container  102 . An interior set of environmental sensors  106  can be connected to the e-Seal  101  through a wireless interface. The e-Seal  101  can receive navigation signals from a location means, such as, for example, Global Navigation Satellite Systems (GNSS)  103 . The e-Seal  101  can communicate through wireless cellular infrastructure  104  to a central server  105  which can be operated by a tracking service provider. The server  105  can monitor multiple e-Seals  101  on intermodal container shipments, to provide real-time in-transit visibility to customers of those shipments. 
       e-Seal Architecture 
       [0017]      FIG. 2  is a diagram of the modular architecture of the e-Seal  101 . In some implementations, this architecture can be comprised of at least six modular functions. The architecture enables any one function to be changed or upgraded without changing the other five modular functions. This allows the e-Seal  101  to incorporate new technologies, while minimizing the costs and schedules of e-Seal upgrades. 
         [0018]    One example implementation of the interface to the security function  201  is a two-wire circuit, where closed is secured and open is not secured. This can be implemented via a connector on the e-Seal  101  circuit board with a two-wire cable to the security function  201 . The physical security mechanism, whether a bolt seal, cable seal, or indicative seal, can use the same e-Seal  101  circuit board, reducing costs and speeding schedule for providing these alternate security functions  201 . 
         [0019]    One example implementation of the interface to the power function  204  is a circuit with battery positive, battery negative and battery temperature. This can be implemented via a connector on the e-Seal  101  circuit board with a cable to the power function  204 . The physical power mechanism, whether a 2-cell battery, 4-cell, or 6-cell, can use the same e-Seal  101  circuit board, reducing costs and speeding schedule for providing these alternate power functions  204 . This allows the e-Seal  101  to be rapidly deployed across shorter domestic shipping tradelanes requiring lower cost smaller batteries, or longer international shipping tradelanes requiring larger batteries. 
         [0020]    Similarly, the location function  200 , environmental function  202 , communications function  203  and logistics function  205 , can all be upgraded to alternative implementations with minimal or no changes to other of the e-Seal functional modules. This allows the e-Seal to be provided as a low cost device, advancing the state of the art to a practical and affordable solution, improving on the high cost devices mentioned in the Background paragraph. 
         [0021]    The location function  200  may be initially implemented using Global Positioning System (GPS) navigation satellites. This location function  200  may be updated to other location means including but not limited to: other Global Navigation Satellite Systems (GNSS); GNSS augmentations such as Satellite Based Augmentation Systems (SEAS), differential systems, or aiding systems; or beacon location systems such as Radio Frequency Identification (RFID), cellular identification (ID), WiFi, or Real Time Locating System (RTLS). 
         [0022]    The security function  201  may be initially implemented using monitoring of locking the container doors. This security function  201  may be updated to other security monitors including door opening, light sensors, vibration sensors, as well as capability beyond standard intermodal containers such as refrigerated containers, other container form factors, or permanently designed into smart containers. 
         [0023]    The environmental function  202  may be initially implemented using temperature, humidity or shock sensors. This environmental function  202  may be updated to other environmental monitors sensors including CO2, other gases, smoke, light, sound, chemical, biological, radiation, or additional sensors. 
         [0024]    The wireless communication function  203  may be initially implemented using cellular communications such as GSM/GPRS. This wireless communication function  203  may be updated to other wireless communications including HSDPA cellular, CDMA cellular, SMS cellular; satellite communication including IRIDIUM, ORBCOMM, Globalstar, Inmarsat GVS; RFID; ZigBee, Bluetooth, WiFi; or WiMax. 
         [0025]    The power function  204  may be initially implemented using rechargeable batteries. This power function  204  may be updated to other methods of powering the e-Seal  101  including permanent non-rechargeable batteries, an external power source such as from refrigerated containers, thin film batteries, solar power recharging, or piezoelectric ambient vibration recharging. 
         [0026]    The logistics function  205  may be initially implemented using a method of operating the wireless e-Seal with bar code labels and use of an external port for serial communications, battery recharging, and signaling turning the e-Seal to sleep mode. This logistics function  205  may be updated to other logistical labels, controls and interfaces including RFID labels, non-tamperable security enhanced labels; other means to turn to sleep mode; alternative serial communications; or logistical support with no physical port using wireless communications including GSM/GPRS, HSDPA, CDMA, SMS; satellite communication including IRIDIUM, ORBCOMM, Globalstar, Inmarsat GVS; RFID; ZigBee, Bluetooth, WiFi; or WiMax. 
       e-Seal Configuration 
       [0027]      FIG. 3  is a diagram of one example form of the e-Seal  101 . The e-Seal components are contained within a housing  300  which is of robust construction to operate within the intermodal container shipping environment. The housing  300  includes a security compartment  301  and an electronics compartment  302 . Various security mechanisms  303  can connect to the housing  300  and security compartment  301 . Example security mechanisms  303  include bolt seals, indicative seals, or cable seals to monitor the security of locking of a container, or mechanical or light sensor mechanisms to monitor the closed door status of the container. In some implementations, the electronics compartment  302  can include a transparent window  304  to allow a Light Emitting Diode (LED) display of the e-Seal status. 
       e-Seal Design 
       [0028]      FIG. 4  is a block diagram of the e-Seal  101 . In some implementations, the e-Seal  101  can include a microprocessor  400 , a power interface  401 , a security interface  402 , a logistics interface  403 , an environmental interface  404 , wireless communications  405 , a wireless antenna  406 , a navigation system  407  (e.g., GNSS), a navigation antenna  408 , a battery fuel gauge  409 , a status indicator  410  and memory  411  (e.g., non-volatile memory). Other implementations can include more or fewer components. 
         [0029]    The microprocessor  400  controls the operation of the e-Seal  101 . The microprocessor  400  can run off of a high speed clock when operating, or run off of a low speed clock when in sleep mode to conserve power. The microprocessor  400  is coupled to power interface  401 , security interface  402 , logistics interface  403  and environmental interface  404 . The microprocessor  400  controls the wireless communications module  405  which is coupled to the wireless communications transmit/receive antenna  406 . The microprocessor  400  controls the navigation module  407  (e.g., GNSS) which is coupled to the navigation antenna  408 . The microprocessor  400  receives battery status information from the battery fuel gauge  409 . The microprocessor  400  displays e-Seal status via a status indicator  410  (e.g., an LED display). The microprocessor  400  stores state information between wakeups, stored location and sensor data, and other system data in a memory  411  (e.g., non-volatile memory). The microprocessor  400  can be awakened by a vibration sensor  412  (or other sensor), and can read  2  or  3  axis acceleration measurements from an accelerometer  413 . In some implementations, the microprocessor  400  can read measurements from a magnetometer or gyros for use in determining headings and orientations. 
       e-Seal Low Power Operation 
       [0030]      FIG. 5  is a state diagram of the low power operation of the e-Seal  101 . The e-Seal  101  can remain in a low power sleep mode when not in use on a container. When the e-Seal  101  is turned on via detecting a security bolt circuit closing or other commissioning event, a location fix can be measured and the start of the journey reported over wireless communications  500 . The e-Seal  101  can then enter a low duty cycle operating mode  501 , in which the e-Seal  101  briefly wakes up at intervals to measure location or environmental parameters  502 , then returns to a low power sleep mode  501 . The e-Seal  101  may also briefly wake up at intervals to measure location or environmental parameters and make a wireless communications report  503 , then return to a low power sleep mode  501 . 
         [0031]    In some implementations, a battery fuel gauge monitors the battery capacity, for use in determining if the battery is low as compared to a programmable threshold. In the event of a low battery condition  506 , the wakeup intervals for location fixes or wireless communications  500  can be slowed to programmable values, to extend the operation of the e-Seal  101  to the completion of the journey. 
         [0032]    In some implementations, the e-Seal  101  can be programmed for each shipment usage, to reduce wireless communications power needs by customizing the frequency bands searched to those which will be available along the shipment tradelane, while remembering from one wakeup to the next which frequency band was last successful  504  to further reduce the need to search for a usable frequency band. 
         [0033]    The e-Seal  101  can monitor for entry into a geofenced area, persisting in a geofenced area, or exiting a geofenced area. The occurrence of these geofence events  505  can reduce (or temporarily increase) the frequency of wakeup intervals based upon the need for location reporting in the geofenced portion of the shipment tradelane. For example, entry into a geofenced ocean region can suspend wakeups for wireless cellular reporting. 
         [0034]    Upon detection of a tamper event, the e-Seal  101  wakes up from low power sleep mode, takes a location fix  507 , and makes a wireless communications report  508 . Should wireless communications not be available, the e-Seal  101  can return to low power sleep mode with a programmable interval for waking up to retry the wireless communications report  509 . 
         [0035]    Upon completion of a shipment, as indicated by a server (e.g., server  105 ) sending an over an air command, or by a user operating a turnoff plug in a connector located on the e-Seal  101  protected during secure operation by the security mechanism  303 , the e-Seal  101  can return to the low power sleep mode  510 . 
         [0036]    The low power operation described above is one example of low power operation of the e-Seal  101 . Other low power operations can be performed as well. 
       e-Seal Programmable Operation 
       [0037]      FIG. 6  is a diagram of the programmable operation of the e-Seal  101 . In some implementations, one set of parameters  600  can be programmed to vary the intervals for location measurements, environmental sensor measurements, or wireless reports. Another set of parameters  601  can be programmed to vary the size of buffers used to store measurements when out of range of wireless communications. Another set of parameters  602  can be programmed to vary the duration of status indications. Another set of parameters  603  can be programmed to vary the wireless networks access names and frequencies. Another set of parameters  604  can be programmed to vary the environmental sensors operating characteristics and thresholds. Another set of parameters  605  can be programmed to vary the geofence location definitions and actions to be taken upon entering, persisting or exiting a geofence. Additional parameters  606  can be defined and programmed for other characteristics of the e-Seal  101 . 
         [0038]    These various programmable parameters may be updated over a serial interface  607  prior to shipping the e-Seal  101  to the origin of an intermodal container shipment. 
         [0039]    These various programmable parameters may be updated over wireless communications  608  when the e-Seal  101  has already been shipped to a remote customer location. 
       e-Seal Supply Chain Operation 
       [0040]      FIGS. 7A and 7B  are flow diagrams of the operation across various supply chain conditions of the e-Seal  101 . The e-Seal  101  provides a method to reset a security tamper detection over the air through the wireless communications from the server, to enable multi-stop container loading or customs inspections where the party opening the container is a trusted party able to authenticate themselves to the server to generate the over the air tamper reset command to the e-Seal  101 . 
         [0041]    Referring to  FIG. 7A , in some implementations the container is initially sealed and the e-Seal  101  secured ( 700 ). Upon a subsequent need to open the container prior to the destination, the authorized party authenticates themselves to the server ( 701 ). The e-Seal  101  can then be removed and the container opened ( 702 ). The e-Seal  101  will report a tamper to the server ( 703 ), and due to the authentication of the authorized party the server sends a tamper reset command over the air ( 704 ). The container can then be closed and the e-Seal  101  secured to continue monitoring of the remainder of the shipment ( 705 ). 
         [0042]    Referring to  FIG. 7B , in some implementations the e-Seal  101  provides a method to obtain the current date and time from the wireless communications networks, as an alternative to time from GNSS, for indoor or blockage cases in which the container and e-Seal  101  may be out of coverage of GNSS satellites. The e-Seal  101  provides a method when detecting a security tamper out of coverage of GNSS or wireless communications, to count time intervals using the e-Seal internal clock, then when later arriving in GNSS or wireless coverage to obtain the current date and time, and count backwards to arrive at an accurate time stamp of the security tamper for reporting to the server. When an event requiring a timestamp occurs, such as the container is sealed or a tamper is detected ( 706 ), the availability of GNSS coverage is tested ( 707 ). If GNSS is available then accurate time can be recorded from GNSS ( 708 ). If GNSS is not available, then cellular coverage is tested ( 709 ). If cellular coverage is available then accurate time can be recorded from the cellular infrastructure ( 710 ). If neither GNSS nor cellular coverage are available, then a temporary timestamp is recorded based upon the e-Seal internal clock, and a counter is started ( 711 ). When the e-Seal  101  reaches either GNSS or cellular coverage, then the time can be measured, and counted backwards using the counter to arrive at an accurate timestamp replacing the temporary timestamp ( 712 ). 
       e-Seal Low Cost Manufacture 
       [0043]      FIG. 8  is an event diagram of the features allowing low cost manufacturing of the e-Seal  101 . In some implementations, this can be accomplished by automating an End Of Line Test (EOLT). Automation speeds the execution time of this test, reduces labor costs for this test, and reduces manual entry errors for this test. The EOLT operator  800  issues a command to the automated EOLT tester  801  to test a newly manufactured e-Seal  101 . The EOLT operator  800  operates the e-Seal to cause a security tamper, in a realistic manner the same way as customers would operate the e-Seal  101 , for purposes of testing the security mechanism  303 . The EOLT  801  requests status from the e-Seal  101  which responds with the tamper status to the EOLT  801 . This supports a pass/fail determination  805  of the correct assembly and functioning of the security mechanism. The EOLT then issues a tamper override reset command to the e-Seal  101  to continue the test. 
         [0044]    The EOLT  801  issues an accelerometer self test command to the e-Seal  101 , which responds to support a pass/fail determination  806  of the correct assembly and functioning of the accelerometer. The EOLT  801  turns on a vibration source  804 , issues a vibration sensor self test command to the e-Seal  101 , which responds to support a pass/fail determination  807  of the correct assembly and functioning of the vibration sensor. The EOLT  801  commands the e-Seal  101  into GNSS test mode, in which the e-Seal  101  can receive just one satellite signal without requiring the full number of satellites to make a navigation fix. The EOLT  801  turns on the GNSS simulator  802  which is a low cost single channel unit, transmitting a single GNSS channel. The EOLT  801  requests GNSS status from the e-Seal  101 , which responds to support a pass/fail determination  808  of the correct assembly and functioning of the GNSS module. The EOLT  801  then issues a GNSS maintenance command to the e-Seal  101 , which responds with the GNSS module version information  809 , so that the EOLT  801  can record this version information in the manufacturing record for this serial number e-Seal  101 . 
         [0045]    The EOLT  801  issues a wireless maintenance command to the e-Seal  101 , which responds with the wireless module version information  810 , so that the EOLT  801  can record this version information in the manufacturing record for this serial number e-Seal  101 . The EOLT turns on the wireless simulator  803 , which places a call to the e-Seal  101 , and when the e-Seal  101  responds then the wireless simulator  803  can measure the wireless signal strength from the e-Seal  101 . The wireless simulator  803  responds with the measured signal strength to support a pass/fail determination  811  of the correct assembly and functioning of the wireless module. The EOLT  801  requests battery status from the battery fuel gauge, which responds with the measured battery parameters to support a pass/fail determination  812  of the correct assembly and functioning of the battery fuel gauge, as well as the battery pack in the e-Seal  101 . 
       e-Seal Low Cost Operation 
       [0046]      FIG. 9  is a diagram of the features supporting low cost logistics and operation of the e-Seal  101 . In some implementations, this can be accomplished by automating logistics tests, both for newly received e-Seals from manufacturers, as well as e-Seals returned from customer shipments. Automation speeds the execution time of this test, reduces labor costs for this test, and reduces manual entry errors for this test. Low cost logistics is also supported by the automated test features used during manufacturing, as discussed regarding  FIG. 8 . Low cost is further supported by maintaining data and statistics history during operation of the e-Seal  101  on a container shipment, so that this history data can be read and stored when the e-Seal  101  is returned from that shipment. This e-Seal history data supports trend tracking and lowered lifecycle costs of e-Seal product improvements. 
         [0047]    The logistics technician  900  can test the e-Seal  101  by starting it, in a realistic manner the same way as a customer would start the e-Seal  101 . The e-Seal  101  is allowed to run for a test period. The e-Seal  101  receives satellite navigation signals from the GNSS constellations  902 , records fixes, and measures statistics of successful fixes  904 . The e-Seal  101  makes wireless reports to the wireless infrastructure  903 , and measures statistics of successful calls  905 . At the conclusion of the test period, the logistics test program  901  requests the GNSS statistics  904  and wireless statistics  905  from the e-Seal  101 , which responds to support a pass/fail determination  906  of the correct functioning of the main e-Seal functions. 
         [0048]    During customer usage of an e-Seal  101  to track and monitor a container shipment, the e-Seal  101  maintains performance statistics in a history file. These statistics include GNSS  902  fixes  907 , wireless infrastructure  903  calls  908 , and battery level and voltage  909 . When an e-Seal is returned from a customer shipment destination, the logistics program can request this history file in a history report, and store this data  910  for the purpose of trend tracking for that e-Seal  101  serial number and product improvement for that model of e-Seal  101 . 
         [0049]    Shipping of e-Seals to customers may require temporary warehouse storage following peak shipping periods. The logistics program can issue a command to the e-Seal  101  to reduce the battery charge to a programmable capacity percentage, to extend the lifetime of rechargeable batteries by storing them in a warehouse  911  at an optimum charge capacity. 
         [0050]    The e-Seal  101  supports a firmware update over local serial port from the logistics program. For e-Seals which may be in remote customer locations and require a firmware update, the e-Seal  101  supports over the air update of firmware over wireless communications. The server  105  may send a command and protocol to perform over the air wireless update of firmware for e-Seals  100  at remote customer locations, confirming successful update  912 , so that firmware updates can be made without having to ship the e-Seal  101  back to logistics refurbishment facilities. 
         [0051]    A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. For example, elements of one or more implementations may be combined, deleted, modified, or supplemented to form further implementations. As yet another example, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. In addition, other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Accordingly, other implementations are within the scope of the following claims.