Abstract:
A cargo, containerized cargo, high value asset monitoring and tracking communication system including a local area network (LAN) transmitter that transmits a first message having a first frequency spectrum, and a wide area network (WAN) uplink device that receives the first message from the local area network radio transmitter, whereby both WAN and LAN share the same spectrum. Further, the WAN uplink device transmits a second message having a second frequency spectrum overlapping the first frequency spectrum to a WAN receiver using an orbital satellite. At least one of the LAN transmitter and the WAN uplink device transmits with a transmission characteristic different from a transmission characteristic of the other. A communication device and method include similar features.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to U.S. Provisional Application No. 60/540,409, filed Jan. 30, 2004, the entire contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention is related to the field of wide area network (WAN) and local area network (LAN) communication methods, devices and systems. In particular, the present invention relates to WAN/LAN communication methods, devices and systems for cargo, containerized cargo, and high value asset tracking and management.  
         [0004]     2. Discussion of the Background  
         [0005]     Cargo items are transported through different regions of the world using various modes of transportation. It is common for a particular cargo item to be transported through one or more different geographic regions or political regions as it is transported from a source location to a destination location. Further, a party with an interest in the cargo items is frequently interested in managing cargo item data before, during and after this transportation. Cargo management tasks typically include at least tracking the location of the cargo item from a tracking location. Cargo management systems have been proposed that use WAN/LAN technology for cargo item tracking.  
         [0006]     An example of a background cargo item tracking system, shown in  FIG. 7 , includes WAN transmitters  702 / 708  that communicate with an orbital satellite  700  via WAN links  714 / 716 . Each WAN transmitter  702 / 708  receives information about the first and second cargo items  706 / 712  via first and second cargo sensors  704 / 710 , and each WAN transmitter  702 / 708  sends the received cargo item information to a remote tracking location  714  via an orbital satellite  700 . However, this background cargo tracking system only includes a remote management feature and does not include a local management feature that would provide a tracking or a management function for a user located near the cargo, without receiving information through the orbital satellite. Further, to effectively send information from WAN transmitters  702 / 708  to satellite  700 , each of the WAN transmitter&#39;s  702 / 708 , and therefore each of the cargo items, are physically situated with adequate clearance from obstacles such that a satellite radio signal may be transmitted without signal degradation. In situations where cargo items are stacked on top of each other, or are located in an obstructed area such as a ship cargo hold or truck container, there is a problem of physically situating each cargo item with adequate clearance from obstacles.  
         [0007]      FIG. 8  shows a second background cargo item tracking system that includes wireless LAN (WLAN) transmitters  806 / 808  that receive information about first and second cargo items  814 / 816  from first and second cargo sensors  810 / 812 . The first and second WLAN transmitters  806 / 808  transmit this information to local management station  818  using WLAN signals  826 / 824  and to WLAN receiver  804  using WLAN signals  820  and  822 . WLAN signals  820 / 822  are signals according to a background wireless LAN communication standard, such as IEEE 802.11, which uses a first frequency spectrum. A WAN transmitter  802  receives the cargo item information from the WLAN receiver  804  and transmits the cargo information to an orbital satellite  800  using WAN signal  828  and to remote management location  822  via communication link  830 . WAN signal  828  is according to a background WAN signal communication standard, such as HDLC, which uses a second frequency spectrum.  
         [0008]     However, the background cargo tracking systems also do not adequately address several additional problems. Each of the geographic regions (e.g., mountain region, ocean region, etc. . . . ) or political regions (e.g., separately administered locality, state, nation, etc. . . . ) through which the cargo items are transported may differently require or regulate the communication spectrum allocated for the purposes of LAN communication. For example, communication according to the wireless LAN communication standard IEEE 802.11 is not allowed in all political regions of the world. Further, each mode of transportation (e.g., truck, rail, car, air, ship, etc . . . ) and packaging arrangement (e.g., container, palette, case, etc. . . . ) employed to transport the cargo may further limit the available spectra. For example, when transporting cargo items by truck through a mountain region of a first nation, a first LAN communication spectrum may be preferred or required; however, when transporting cargo items within stacked rail containers through an ocean region on a ship, a second LAN communication spectrum may be preferred or required. Thus, background systems also do not adequately address the problem of operating within different modes of transportation, packaging arrangements and regions.  
         [0009]     In addition, cost and complexity of background LAN communication devices used to communicate cargo item information are high due to the need for supporting various different LAN communication spectra to communicate in different regions and packing arrangements.  
       SUMMARY OF THE INVENTION  
       [0010]     Accordingly, one object of this invention is to provide a novel communication system including a local area network (LAN) transmitter configured to transmit a first message having a first frequency spectrum, a wide area network (WAN) uplink device configured to receive the first message from the LAN radio transmitter and transmit a second message having a second frequency spectrum overlapping the first frequency spectrum to a WAN receiver using an orbital satellite, and at least one of the LAN transmitter and the WAN uplink device configured to transmit with a transmission characteristic different from a transmission characteristic of the other.  
         [0011]     Another object of this invention is to provide a novel network communication device including a local area network (LAN) receiver configured to receive a first message having a first frequency spectrum, a wide area network (WAN) transmitter configured to transmit a second message having a second frequency spectrum overlapping the first frequency spectrum to a WAN receiver using an orbital satellite, and the WAN transmitter further configured to transmit the second message with a transmission characteristic different than that of the first message received by the LAN receiver.  
         [0012]     Another object of this invention is to provide a novel network communication device including a local area network/wide area network (LAN/WAN) transmitter configured to transmit a first LAN message having a first frequency spectrum and to transmit a WAN message having a second frequency spectrum overlapping the first frequency spectrum to a WAN receiver using an orbital satellite, a LAN receiver configured to receive a second LAN message having the first frequency spectrum, a sensor interface configured to receive a sensed cargo information from an operatively connected cargo sensor and add the sensed cargo information to the first LAN message, and the LAN/WAN transmitter further configured to transmit the second message with a transmission characteristic different than that of at least one of the first LAN message transmitted by the LAN/WAN transmitter and the second LAN message received by the LAN receiver.  
         [0013]     Another object of this invention is to provide a novel network communication device including a local area network (LAN) transmitter configured to transmit a first message having a first frequency spectrum overlapping a second frequency spectrum of a second message received by an orbital satellite, a sensor interface configured to receive a sensed cargo information from an operatively connected cargo sensor and add the sensed cargo information to the spread spectrum local area network radio message, and the LAN transmitter is further configured to transmit the second message with a transmission characteristic different than that of the second message received by the satellite receiver.  
         [0014]     Another object of this invention is to provide a novel communication method, including transmitting a first message having a first frequency spectrum from a local area network (LAN) transmitter, receiving the first message from the LAN transmitter at a wide area network (WAN) uplink device, transmitting a second message having a second frequency spectrum overlapping the first frequency spectrum to a WAN receiver using an orbital satellite, and at least one of the transmitting a first message and transmitting a second message further comprising transmitting with a transmission characteristic different from a transmission characteristic of the other.  
         [0015]     Another object of this invention is to provide a novel communication system including a local area network/wide area network (LAN/WAN) transmitter configured to transmit a first message having a first frequency spectrum and transmit a second message having a second frequency spectrum overlapping a first frequency spectrum to a WAN receiver using an orbital satellite, and the LAN/WAN transmitter is further configured to transmit the first message with a transmission characteristic different than that of the second message received by the WAN receiver or the orbital satellite. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]     A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:  
         [0017]      FIG. 1  is a block diagram of a cargo management communication system according to an embodiment of the present invention;  
         [0018]      FIG. 2  is a block diagram of a cargo management communication system according to another embodiment of the present invention;  
         [0019]      FIG. 3  is a block diagram of a cargo management communication system according to another embodiment of the present invention;  
         [0020]      FIG. 4  is a block diagram of a cargo management communication system according to another embodiment of the present invention;  
         [0021]      FIG. 5  is a block diagram of a communication device according to an embodiment of the present invention;  
         [0022]      FIG. 6  is a block diagram of a communication device according to another embodiment of the present invention;  
         [0023]      FIG. 7  is a block diagram of a cargo management communication system in the background art; and  
         [0024]      FIG. 8  is a block diagram of another cargo management communication system in the background art. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to  FIG. 1  thereof, which shows a WAN/LAN communication system according to an embodiment of the present invention. This embodiment includes at least first and second shared spectrum WLAN transmitters  110 / 112  configured to receive information about first and second cargo items  126 / 128  via first and second cargo sensors  118 / 120 .  
         [0026]     Each cargo sensor collects information regarding at least one associated cargo item via sensing interface  122 / 124 . The cargo sensors include at least one of a location sensor, for example a GPS receiver; one or more container sensors, for example, temperature (including the temperature of perishable goods in a “reefer” container), door open, container volume, vibration/shock, accelerometer, acoustic pressure, sound, light in container, passive infrared (PIR) (such as those used to detect changes in heat for security motion sensors), microwave, dust, humidity, security/tampering, or orientation sensors, or other sensors for collecting information about the status of a cargo item or container, the environment of the cargo item or container, or other information of interest. The cargo sensors  118 / 120  are connected to shared spectrum WLAN transmitters  110 / 112  via sensor links  114 / 116  and may be provided near or far from the WLAN transmitters  110 / 112 , or near or far from the cargo item as appropriate for the type of sensor and cargo.  
         [0027]     A shared spectrum WLAN receiver  104  is configured to receive the first and second cargo information from first and second shared spectrum WLAN transmitters  110 / 112  via shared spectrum WLAN signals  106 / 108 . Further, local management location  134  is also configured to receive the first and second cargo information from the first and second shared spectrum WLAN transmitters  110 / 112  via shared spectrum WLAN signals  130 / 132  or via shared spectrum WLAN signals  106 / 108  (not shown). The shared spectrum WLAN signals  130 / 132  include spread spectrum modulated data. For example, the WLAN signals  130 / 132  include a header, an ID, status bits, data payload and error detection/correction bits.  
         [0028]     A WAN transceiver  100  is configured to receive the first and second cargo information from the shared spectrum WLAN receiver  104  and to transmit WAN signal  142  including the cargo information to orbital satellite  140 . The WAN signal  142  includes spread spectrum modulated data. An orbital satellite  140  transmits the cargo information to remote management location  138  via communication link  136 . Each of remote management location  138  and local management location  134  are configured to provide monitoring and management features using the received cargo information.  
         [0029]     In the present embodiment, a communication frequency spectrum of the spread spectrum encoded data of each of the shared spectrum WLAN signals  106 / 108 / 130 / 132  is the same as a communication frequency spectrum of the spread spectrum encoded data of the WAN signal  142 . Alternative embodiments are also possible in which a portion of the communication frequency spectrum of each of the shared spectrum WLAN signals  106 / 108 / 130 / 132  overlaps at least a portion of the communication frequency spectrum of the WAN signal  142 . A further alternative is the use of narrow band satellite data communication whereby the near/far effect and FM capture are used to allow both WAN and LAN to co-exist on the same spectrum.  
         [0030]     Each of the WAN signal and the WLAN signals include spread spectrum modulated data according to a standard message format and protocol, for example, according to a direct sequence satellite communication message format protocol as used in the GlobalStar satellite. For example, the WLAN signals may include Direct Sequence Spread Spectrum (DSSS) with Binary Phase Shift Keying (BPSK) modulated data, though other modulation and encoding schemes are also possible. Further, the WLAN signals include, for example, a header, status bits, data payload and error detection bits.  
         [0031]     The WLAN signals  106 / 108 / 130 / 132  and WAN signal  142  are configured to minimize the effects of possible interference with each other by arranging the power of the WAN signal  142  sufficient to send data to the orbiting satellite and arranging the power of the shared spectrum WLAN signals  106 / 108 / 130 / 132  at a lower power than the WAN signal  142 . The power of the WLAN signals  106 / 108 / 130 / 132  is sufficient to send data to local management location  134  and shared spectrum WLAN receiver  104 . However, the power of the WLAN signals  106 / 108 / 130 / 132  is insufficient to be demodulated by the orbital satellite. Further, the power of the WLAN signals  106 / 108 / 130 / 132  is also configured such that the orbital satellite does not demodulate sufficient energy from a temporal LAN message collision to materially reduce reception of messages intended for the satellite.  
         [0032]     In another alternative embodiment, the WLAN signals  106 / 108 / 130 / 132  and WAN signal  142  are configured to minimize the effects of possible interference with each other based on a difference of code division multiple access (CDMA) codes. In particular, the WAN signal  142  is configured to use a first CDMA code and WLAN signals  106 / 108 / 130 / 132  are configured to use a second CDMA code different from the first, such that the orbital satellite does not demodulate sufficient energy from a temporal LAN message collision to materially reduce reception of messages intended for the satellite. The first and second CDMA codes are configured to use at least one of a different Direct Sequence Spread Spectrum (DSSS) hop pattern code and a different Frequency Hopping Spread Spectrum (FHSS) hop pattern code.  
         [0033]     In another alternative embodiment, the WLAN signals  106 / 108 / 130 / 132  and WAN signal  142  are configured to minimize the effects of possible interference with each other based on a difference of message duration. In particular, the WAN signal  142  is configured to transmit messages having a first message duration and WLAN signals  106 / 108 / 130 / 132  are configured to transmit messages having a second message duration that is shorter than the first message duration such that an error correcting feature of the remote management location  138  or of a receiver (not shown) in the orbital satellite  140  can eliminate or otherwise ignore a portion of a WLAN signal  106 / 108 / 130 / 132  that collides in time (e.g., that is received at the same time as WAN signal  142 ).  
         [0034]     In another alternative embodiment, the WLAN signals  106 / 108 / 130 / 132  and WAN signal  142  are configured to minimize the effects of possible interference with each other based on the use of a difference in data rate and redundant transmissions. In particular, the WAN signal  142  is configured to communicate data at a first message rate and the WLAN signals  106 / 108 / 130 / 132  are configured to communicate data at a second data rate that is higher than the first data rate. Further, at least one of the remote management location or a receiver in the satellite is configured to recover from temporal message collisions that occur when a WAN signal  142  is received at the same time as a WLAN signal  106 / 108 / 130 / 132  by using an error correction code, and the WLAN receiver  204  is configured to recover from a temporal message collisions that occur when a WAN signal  142  is received at the same time as a WLAN signal  106 / 108 / 130 / 132  by using a redundant transmission occurring over a period of time at least longer than a duration of a WAN transmission.  
         [0035]     Thus, by sharing all or at least a portion of the communication spectrum between WLAN signals and WAN signals, the present embodiment advantageously allows the WLAN signals to operate using a satellite radio frequency spectrum that is already allocated for communication purposes throughout most regions. Thus, the WLAN signals comply with local requirements throughout most political regions and further are compatible with most geographical regions. Hence, the local management feature is able to operate in a greater number of regions.  
         [0036]     In addition, because each cargo item is associated with a shared spectrum WLAN transmitter that communicates with a ground based WLAN receiver, it is not necessary for each cargo item to be physically situated with adequate clearance from obstacles such that a satellite radio signal may be transmitted without signal degradation. Thus, the present system allows greater flexibility with regard to cargo item placement and results in more reliable communication of cargo item information.  
         [0037]      FIG. 2  shows an example of a cargo management system according to another embodiment of the present invention. Parts of the cargo management system in this example are the same as in embodiments described above. However, this example includes first, second and third hybrid cargo terminals  202 / 204 / 200 , each configured to perform a WLAN function and a WAN function. First and second hybrid cargo terminals  202 / 204  are configured to perform a WLAN function and are configured to receive cargo item information from first and second cargo items  126 / 128  via first and second cargo sensors  118 / 120  as described above. Further, the first and second hybrid cargo terminals  202 / 204  are configured to transmit WLAN signals  106 / 108  to the third hybrid cargo terminal  200  and to transmit WLAN signals  130 / 132  to the local management location  134 . The third hybrid cargo terminal  200  is configured to receive cargo information in the WLAN signals  106 / 108  from the cargo terminals and to transmit the cargo in WAN signal  142  to the orbital satellite  140 .  
         [0038]      FIG. 3  shows an example of a cargo management system according to another embodiment of the present invention. Parts of the cargo management system in this example are the same as in the example of  FIG. 2 . However, this example includes WLAN/WAN repeater  300  configured to receive WLAN signals  106 / 108  from the hybrid cargo terminals (or in an alternative embodiment, from shared spectrum WLAN transmitters) and retransmit each received signal at an increased power level to form WAN signal  142 .  
         [0039]      FIG. 4  shows an example of a cargo management system according to another embodiment of the present invention. Parts of the cargo management system in this example are the same as in the example of  FIG. 2 . However, in this example, the first and second hybrid cargo terminals are configured to transmit WLAN signals  402 / 404  to the local management location  134  and to transmit WAN signals  406 / 408  to the orbital satellite  140 .  
         [0040]     Further, the features of the invention are not limited to the arrangement of functions shown in cargo management system examples  FIGS. 1-4 , but include at least each permutation of the features represented therein.  
         [0041]      FIG. 5  shows an example of a hybrid cargo terminal  500  according to an embodiment of the present invention. The hybrid cargo terminal  500  includes a shared WAN/WLAN transmitter  502  operatively connected to WLAN receiver  504  and sensor interface  506 . The WLAN receiver  504  is configured to receive WLAN signals from a wireless local area network and perform a LAN receiving function on those signals. The LAN receiving function includes functions such as monitoring, filtering, segmenting, parsing, interpreting or packaging the received WLAN signals to produce LAN messages for the WAN/WLAN transmitter. The sensor interface  506  is configured to receive cargo item information from cargo sensors.  
         [0042]     The shared WAN/WLAN transmitter  502  is configured to receive cargo item information from the sensor interface and to produce and transmit a WLAN signal including that information. The WAN/WLAN transmitter  502  is also configured to receive the LAN messages from the WLAN receiver  504  and to produce a WAN signal based on the received LAN messages.  
         [0043]     Because the WAN and WLAN signals produced by the WAN/WLAN transmitter share a common radio frequency spectrum or overlapping radio frequency spectrums, the WAN/WLAN transmitter is less complex than other combinations of WAN and WLAN transmitters that transmit WAN and WLAN signals having different radio frequency spectra. For example, the WAN/WLAN transmitter may be implemented using common elements to perform WAN and WLAN signals such as a common antenna, common power amplifier, common power supply, or common transmitter control logic. Thus, the WAN/WLAN transmitter exhibits benefits in size, weight, cost, and reliability, for example, and therefore exhibits resulting benefits in flexibility of deployment and use, reduced power dissipation, increased battery life, reduced shipping costs, and reduced fuel costs, for example.  
         [0044]      FIG. 6  shows an example of a WLAN/WAN repeater  600  according to an embodiment of the present invention. The WLAN/WAN repeater  600  includes WLAN receiver  604  operatively connected to WAN transmitter  602 . The WLAN receiver  604  is configured to receive WLAN signals and the WAN transmitter is configured to rebroadcast the received WLAN signals at a higher power level to produce WAN signals.  
         [0045]     Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.