Abstract:
Systems and methods are provided for prioritizing traffic information and broadcasting the traffic information in a prioritized order. The method generally comprises receiving data regarding traffic conditions on various roads, wherein each road can be characterized as being a major, medium, or minor road. In one approach, traffic data regarding major roads are broadcast to vehicles first, followed by traffic data regarding medium roads, while traffic data regarding minor roads are either broadcast last or not at all, depending on the traffic information handling capacities of the vehicles and the traffic information system in general.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method and system for communicating information to vehicles from a remote location, and more particularly, to a method and system for prioritizing traffic information and broadcasting the prioritized traffic information to the vehicles. 
     2. Description of Related Art 
     Navigation systems for determining a route from a start point to a destination point are well known in the art. In addition, navigation systems having capabilities for determining the geographic position of a reference point are also well known in the art, such as a Global Positioning System (GPS) or a self-contained system having distance and bearing sensors. As an example, a commonly used navigation system allows a user (or driver) of a vehicle to enter a destination into the navigation system. The navigation system then looks up an appropriate route from an original point (using its geographic positioning capabilities) to the destination point in a road map database (e.g., the route may be a route having the shortest distance from the start point to the destination point, one which would take the vehicle the least time, or some other route), and guides the user to the destination along the searched route through a visual display or vocal guide. 
     In searching the appropriate route, some types of mobile navigation system use traffic information (e.g., position data on traffic jams; information on roads closed by accidents, construction, or maintenance; lane-regulated locations) delivered from a traffic information supplier in addition to using the road map database. Conventionally, however, known methods for providing and utilizing the above-described traffic information for navigation remain very inflexible, cumbersome, and inefficient. For example, in certain methods, the same traffic information is transmitted to many or all vehicles in a given geographic region. A drawback with these methods is that many vehicles are inundated with a large amount of traffic information. Users and/or navigation systems are required to sift through the redundant, superfluous, or otherwise unwanted information to pick out pertinent traffic information. 
     As a result, there remains a need for systems and methods that allow for the transmittal of vehicle-relevant traffic information from a remote location to one or more vehicles. Moreover, it is desired that the navigation system be provided with enough information to properly determine efficient routes without being inundated with low priority, redundant, or superfluous traffic information. There is a need that the traffic information be provided to a user in a useful, prioritized, and efficient manner. 
     Accordingly, it would be very desirable to provide a traffic information management system and method that overcomes the above-described shortcomings of the prior art while retaining their advantages. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system and method for prioritizing traffic information and broadcasting the traffic information to one or more vehicles in a prioritized order. 
     In accordance with one aspect of the embodiments described herein, there is provided a system for communicating traffic information to at least one vehicle from a remote location in a prioritized order. The system generally comprises an information center for generating and prioritizing broadcast data messages regarding road traffic conditions, and for sending the broadcast data messages in the prioritized order. The system further comprises a relay section that receives the prioritized broadcast data messages sent from the information center and relays the broadcast data messages to the at least one vehicle according to the prioritized order. In one embodiment, the information center assigns a priority rating to each broadcast data message based on the type of road (e.g., a major, medium or minor road type) for which the traffic information is broadcast. 
     In accordance with another aspect of the embodiments described herein, there is provided a method for creating and broadcasting broadcast data messages to at least one vehicle in a prioritized order. The method generally comprises receiving first and second data packets regarding traffic conditions on first and second roads, respectively, the first and second roads having first and second characteristics (e.g., road type, whether road is on vehicle&#39;s route to destination, etc.), respectively. First and second priority ratings are generated based on the first and second characteristics, respectively. The method further comprises concatenating the data packets and the priority ratings to generate broadcast data messages that are broadcast to the at least one vehicle. In one approach, the first broadcast data message is broadcast before the second broadcast data message if the first priority rating is higher than the second priority rating, while the second broadcast data message is broadcast before the first broadcast data message if the second priority rating is higher than the first priority rating. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1   a  is a schematic diagram of a first embodiment of a system pursuant to aspects of the invention; 
         FIG. 1   b  is a schematic diagram of a broadcast communication network; 
         FIG. 1   c  is a schematic diagram of a navigation device in communication with a mobile unit; 
         FIG. 2  is a schematic diagram of an alternate embodiment of a system; 
         FIG. 3  is a schematic diagram of a system for communicating broadcast messages to a vehicle; 
         FIG. 4  is a schematic diagram of an exemplary vehicle information receiver of the system; 
         FIG. 5   a  is a block diagram of an embodiment of a single-packet broadcast data message; 
         FIG. 5   b  is a block diagram of another embodiment of a single-packet broadcast data message; 
         FIG. 5   c  is a block diagram of a packet type field for the priority rating encoded into a broadcast data message; 
         FIG. 6  is a block diagram of an embodiment of a multi-packet broadcast data message; 
         FIG. 7  is a block diagram of an embodiment of a broadcast data message; 
         FIG. 8  is a block diagram of a header for a single-packet message; and 
         FIG. 9  is a block diagram of a header for a multi-packet message. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention satisfies the need for a system and method for prioritizing information and broadcasting the prioritized information. In particular, the present invention is directed to a system and method for prioritizing and broadcasting traffic information. In the detailed description that follows, like element numerals are used to describe like elements illustrated in one or more of the figures. 
     With reference to  FIG. 1   a , there is provided a first embodiment of a system for facilitating the exchange of information between a remote location  10  and a vehicle  12  pursuant to aspects of the invention. The vehicle  12  includes a navigation device  14 . Referring now also to  FIG. 1   c , the navigation device  14  may include an output unit  21 , a receiver unit  22 , an input unit  23 , a position detection unit  24 , a navigation memory unit  30 , a navigation processor unit  26 , and an RF transceiver unit  52  that are all in electrical communication with one another. The navigation memory unit  30  includes at least a portion of a user profile and in some embodiments may include the entire user profile. In addition, the navigation memory unit  30  includes a road map database portion and, in some embodiments, includes a disk reading unit for reading road map information not built into the navigation device  14 . As is provided in greater detail below, the user profile and/or the road map database stored in the memory  30  may be updated in the vehicle by way of the input unit  23 , which can include at least one of a keyboard, a touch sensitive display, and a microphone. The user profile and/or the road map database may also be updated by way of information received through the receiver unit  22  and/or the RF transceiver unit  52 . 
     The receiver unit  22  receives information from the remote location  10  and, in one embodiment, is in communication with the remote location by way of a one-to-many communication system. One-to-many communication systems include systems that can send information from one source to a plurality of receivers, such as a broadcast network  31 . Broadcast networks include television, radio, and satellite networks. Referring now to  FIG. 1   b , in one embodiment, the broadcast network  31  is the XM Radio satellite network  40 , which comprises broadcast towers  42 , satellite servers (not shown), and satellites  43 . The broadcast towers  42  transmit information to the satellites  43 , which bounce the information back down to the receiver unit  22  of the navigation device  14 . 
     Referring now back to  FIG. 1   c , the information received by the receiver  22  may be processed by the navigation processor unit  26 . The processed information may then be displayed by way of the output unit  21 , which includes at least one of a display and a speaker. In one embodiment, the receiver unit  22 , the navigation processor unit  26  and the output unit  21  are provided access to only subsets of the received broadcast information based on user preferences and/or traffic information demands. The user preferences, as well as user identity information and traffic-related information, can be part of the user profile. 
     The position detection unit  24  may include a GPS receiver that communicates with a plurality of GPS satellites (separate from the XM satellites) to determine the position of the vehicle  12 . For example, the GPS receiver searches for and collects GPS information (or signals) broadcast from four or more GPS satellites that are in view of the GPS receiver. Next, using the time interval between the broadcast time and reception time of each broadcast signal, the GPS receiver calculates the distance between the GPS receiver and each of the four or more GPS satellites. These distance measurements, along with the position and time information received in the broadcast signals, allow the GPS receiver to calculate the geographic position of the vehicle  12 . 
     In the embodiment shown in  FIG. 1   a , the mobile unit  18  is used to receive and transmit information from and to the remote location  10 ; and, in an alternate embodiment shown in  FIG. 2 , an RF transceiver  152  is used to receive and transmit information from and to the remote location  110 . The mobile unit  18  may be a wireless phone or any other device that communicates with other devices by way of the wireless communication network  46 . As shown in  FIG. 1   c , in one embodiment, the mobile unit  18  includes a wireless receiver  32 , a wireless transmitter  34 , a mobile unit processor  40 , and an RF transceiver unit  54  that are in communication with one another. The mobile unit  18  is in two-way communication with the remote location  10  by way of the receiver  32 , the transmitter  34 , and the wireless communication network  46 , which comprises numerous base stations. In one embodiment, information is transmitted from or to the vehicle or remote location over a high bandwidth GPRS/1XRTT channel of the wireless communication network  46 . If the high bandwidth channel is unavailable, a low bandwidth DTMF channel can be used. The receiver  32  receives information from the remote location  10 , and the transmitter  34  transmits information to the remote location  10 . In other embodiments, the transmitter  34  also transmits information to suppliers of traffic or other information  48 ,  50 . 
     In one embodiment, the information received from and transmitted to the remote location  10  by way of the mobile unit  18  is accessed by the user through the navigation device  14 , which is in communication with the mobile unit  18 . The mobile unit  18  may be embedded in the vehicle  12  and be in communication with the navigation device  14  by, for example, a cable (not shown). 
     In another embodiment, the navigation device  14  and mobile unit  18  are in communication with one another by way of RF transceiver units  54  and  52 . Both the navigation device  14  and the mobile unit  18  include RF transceiver units  52 ,  54 , which, in one embodiment, comply with the Bluetooth® wireless data communication format or the like. The RF transceiver units  52 ,  54  allow the navigation device  14  and the mobile unit  18  to communicate with one another. In other embodiments not shown, the receiver  32  and transmitter  14  of the mobile unit  18  and the receiver unit  20  of the navigation device  14  allow the navigation device  14  and mobile unit  18  to communicate with one another. In yet other embodiments, there may be an RF transceiver that is separate from the navigation device  14  and the mobile unit  18  and that allows the navigation device  14  and mobile unit  18  to communicate with one another. 
     In the alternate embodiment shown in  FIG. 2 , the navigation device  114  transmits and receives information to and from the remote location  110  by way of the RF transceiver  152 , access points  170 ,  172 , and gateways  174 ,  176  that are in communication with the network  162 . In one embodiment, the RF transceiver  152  and the access points  170 ,  172  are compliant with the IEEE 802.11 specification, and such transceivers and access points include Wi-Fi® —certified equipment. The access points  170 ,  172  are typically in communication with the gateways  174 ,  176  by way of a cable, and the gateways are in communication with the remote location  110  by way of the network  162 . The access points  170 ,  172  are in communication with the RF transceiver  152  and have a limited range over which they can communicate with the RF transceiver  152 . Thus, it is preferable that there be numerous access points  170 ,  172  positioned so that the distance between the access points and the areas through which a vehicle  12  might pass is less than or equal to the limited range of the access points. When the access points  170 ,  172  are so positioned, the RF transceiver  152  effectively exchanges information with the access points  170 ,  172  and, thus, the remote location  110 . 
     Note that in the alternate embodiment of  FIG. 2 , the navigation device  114  also includes input and output units, a receiver unit, a memory unit, and a processor unit, none of which are shown. The components of the alternate navigation device embodiment  114  have the same functionality as do the corresponding components of the navigation device  14  of the first embodiment. 
     The remote location  10 ,  110  includes a remote server  44 ,  144 , a remote transmitter  56 ,  156  and receiver  58 ,  158 , and a remote memory  60 ,  160  that are in communication with one another. As provided above, in the first embodiment, the remote transmitter and receiver  56 ,  58  communicate with the navigation device  14  and mobile unit  100  by way of the broadcast  31  and wireless  46  communication networks, respectively. In the alternate embodiment, the remote transmitter and receiver  156 ,  158  communicate with the navigation device  114 , including the RF transceiver  152 , by way of the broadcast communication network  131  and a network  162 . The remote location  10 ,  110  is also in communication with suppliers of traffic and/or other information  48 ,  50 ,  148 ,  150  such as government traffic information suppliers, private traffic information suppliers, and users of other vehicles, by way of the network  62 ,  162 . 
     In both the first and alternate embodiments shown in  FIGS. 1 and 2 , the network  62 ,  162  is typically a wide area network (WAN) such as the Internet. In other embodiments, some of the information suppliers  48 ,  50 ,  148 ,  150 , such as the government and private traffic information suppliers, may be in communication with the remote location  10 ,  110  by way of a local area network (LAN), while other information providers  48 ,  50 ,  148 ,  150  such as the vehicle users, are in communication with the remote location by way of the Internet. In yet other embodiments, the RF transceiver  152  is in communication with the remote location  110  and/or the information providers  148 ,  150  by way of a network  162  that is a LAN. In these other embodiments, the LAN  162  is compliant with the IEEE 802.3 specification or is an Ethernet network. 
     As provided in greater detail below, the information suppliers  48 ,  50 ,  148 ,  150  may transmit updated user profiles and traffic-related information to the remote location  10 ,  110 . A plurality of user profiles are in a user profile database, which, along with traffic-related information, is stored in the remote memory  60 ,  160 . The updated user profiles and new traffic-related information are transmitted from the remote location  10 ,  110  to the navigation device  14 ,  114  by way of the broadcast network  31 ,  131 . In other embodiments, the new traffic-related information and updated user profiles may be transmitted to the vehicles  12 ,  112  by way of the wireless network  46  or the network  162 . At the vehicle, the user profile stored in the memory  30  of the navigation device  14  is updated, and the vehicle-related information is made accessible to the user by way of the output unit  26  of the navigation device  14 . In other embodiments, the information providers may communicate directly with the mobile unit  18  or RF transceiver  152  by way of the wireless communication network  46  or the network  162 . 
     Referring now to  FIG. 3 , a schematic diagram of another embodiment of an information provision system for a vehicle is provided. Broadcast messages originate at a remote location referred to herein as a center. The center communicates the broadcast message via a relay section  205  to each vehicle. The medium for communicating the broadcast messages may include a one-to-many communication system (e.g., television, radio and satellite networks) that can send information from one source to a plurality of receivers, such as the XM Radio satellite network. As explained above, the broadcast messages can also be transmitted to the vehicle over a wireless communication network, such as a high bandwidth GPRS/1XRTT channel. In one embodiment, the high bandwidth channel supports data rates of about 45 Kbps to about 125 Kbps. In another embodiment, the high bandwidth channel supports data rates of about 56 Kbps to about 114 Kbps. If the high bandwidth channel is unavailable, a low bandwidth channel (e.g., a DTMF channel) can be used. In one embodiment, the low bandwidth channel supports data rates of about 1 Kbps to about 120 Kbps. In another embodiment, the low bandwidth channel supports data rates of about 30 Kbps to about 90 Kbps. 
     The center includes a message generator  201  for generating message data for the provision of information to the vehicle operator, a broadcast data converter  202  for converting the generated message into a broadcast data format, a broadcast timing processing section  203  that determines the timing for sending message data converted into broadcast data by the broadcast data converter  202 , and a transmitter  204  for transmitting from the center the broadcast data sent from the broadcast timing processing section  203 . The relay section  205  receives the broadcast data and relays it to the vehicle. It should be appreciated that the message generator  201 , broadcast data converter  202 , and/or broadcast timing processing section  203  may be provided by computer servers having associated memory. These servers may further include capacity to maintain data records corresponding to the vehicles and vehicle operators to which the center communicates. The broadcast data may include, for example, information related to the vehicle user such as sales campaign periods for dealers and the like, specific regional information, seasonal information, inspection periods, recall information, and lease periods, and information dispatched in accordance with need from the center, and the like. The center may also be in communication with information providers such as vehicle dealers, repair/maintenance facilities, and other service providers by way of conventional communications networks. A plurality of user profiles may be included in a user profile database, which, along with other vehicle-related information, is stored in memory at the center. 
     The vehicle includes a receiver  206  that is capable of receiving broadcast data relayed from the relay section  205  via a suitable antenna. The receiver  206  includes processing capability to recover or extract the broadcast data and communicate that information to a display  207  (i.e., text display device) and to a voice/audio output section or device  208  (i.e., voice message output device or speaker). The display  207  may comprise the visual display of a navigation device, or the like. The voice output section  208  may comprise the speaker of an audio device. 
       FIG. 4  illustrates the components of the receiver  206  in greater detail, which includes a decoder  209 , a filter processing section  210 , and a memory  211 . The broadcast data received by the receiver  206  is decoded by decoder  209  to separate the data according to the broadcast band into broadcast data from the center and general broadcast data from the relay section  205 . The memory  211  stores the broadcast data processed by the filter processing section  210 . This memory  211  may comprise a storage medium, such as a hard disk, solid state memory, or other suitable memory. The filter processing section  210  permits management of the stored message packets, as will be further described below. For example, in one embodiment, un-needed information is deleted before storage in memory  211 . 
     The center generates messages for broadcast to the vehicles having a number of alternative formats. In a first such format, a single broadcast message includes a plurality of individual message components that are each intended for specific vehicles. Each vehicle receives the entire broadcast message, and filters out the message components that are directed to other vehicles, thereby storing only the message components that are applicable to that vehicle. In another such format, the broadcast message is not intended for a specific vehicle, but rather for a class of vehicles that are a subset of the entire universe of vehicles. The broadcast message includes filter data that specifies characteristics of the intended message recipients, such as identifying the vehicle make, model, year, geographic location, and other characteristics of the particular vehicle operator (e.g., having specific lease termination dates). Each vehicle receives the broadcast message, and uses the filter data to determine whether the message components are applicable to that vehicle. 
     As explained above, in accordance with one aspect of the embodiments described herein, there is provided a system and method for prioritizing and broadcasting traffic information/data in a prioritized order, such that higher priority traffic information/data is broadcast more frequently than lower priority traffic information. This is beneficial because if all the traffic data were broadcast at once, it would take a long time to update the traffic data due to the large volume of data. To limit such volume problems, the present method broadcasts traffic data by order of priority. For example, in one approach, data relating to accidents on major roads are transmitted most frequently, followed by data relating to accidents on medium class roads and slow traffic on major roads, followed by data relating to construction and accidents on minor class roads. 
     In one approach, traffic data relating to major roads are updated more frequently than traffic data for relatively minor roads. In another approach, traffic data for roads on the vehicle&#39;s route to a destination point are updated more frequently than for roads that are not on the vehicle&#39;s route. In yet another approach, traffic data for roads that are on or the closest to the vehicle&#39;s route to a destination are updated more frequently than for roads that farther removed from the vehicle&#39;s route. The criteria (e.g., major/medium/minor road class, distance from vehicle&#39;s route to destination point, etc.) for assigning priority ratings to the traffic data/information can be varied or adjusted for each particular application, user preferences, etc. 
     The priority ratings for traffic information/data can be encoded into the broadcast data messages according to any known suitable approach. For example,  FIG. 5   a  illustrates a block diagram of an embodiment of a single-packet broadcast data message. The exemplary data message comprises a header, a CRC code, and a payload section that comprises a filter code section (FCX) and a broadcast data portion. The priority rating can be encoded into the header and/or the broadcast data portion.  FIG. 5   b  illustrates another embodiment of a broadcast data message that comprises a header, a CRC code, and a payload section that comprises an FCX, a priority criteria field/portion, and a broadcast data portion. The priority rating is preferably encoded into the priority criteria field of the payload section. In one exemplary embodiment, shown in  FIG. 5   c , the priority rating comprises the type or class of road, which is encoded with two bits of data. Major roads are denoted with a 11, while medium roads are denoted with a 10, while minor roads are denoted with a 01. A priority rating of 00 can be used if the road type is unknown. 
     The FCX may define certain characteristics of vehicles to which the message applies, such as vehicle type, model year, mileage, sales zone, etc., as explained in further detail in U.S. patent application Ser. No. 11/232,311, titled “Method and System for Broadcasting Data Messages to a Vehicle,” filed on Sep. 20, 2005, the content of which is incorporated in its entirety into this disclosure by reference. The filter processing section  210  in the vehicle would use the criteria defined in the filter code section to determine whether to present the data message to the vehicle operator or to discard the data message. The CRC code may be generated using any suitable algorithm, such as, but not limited to, the following polynomial:
 
 G ( X )= X   16   +X   15   +X   2 +1
 
     It should be appreciated that when the same message data is broadcast to plural vehicles of a common group, and when there are large numbers of target vehicles in the target group, the overall data amount is small (i.e., the broadcast efficiency is high). The payload section may include one set of broadcast data or multiple sets of broadcast data. It will also be understood that the CRC code is merely exemplary, and that any other suitable method of checking for errors in the data message can be implemented with the present invention. 
       FIG. 6  is a block diagram of an embodiment of a multi-packet broadcast data message containing 1-to-1 linked type source data. The data message contains a plurality of message portions. Each message portion can be targeted to a single vehicle using the VIN code as the filter code section. The data message includes a header, a payload section, and a CRC code. The payload section includes the 1-to-1 linked source data. Since different data is being broadcast to each vehicle, the overall quantity (i.e., the average data quantity times the number of vehicles) tends to be large (i.e., the broadcast efficiency is degraded). Analogous to the single-packet broadcast data message shown in  FIGS. 5   a  and  5   b , the multi-packet broadcast data message can comprise priority ratings encoded into one or more of its message portions. For example, in one embodiment, one or more of the 1 to 1 portions of a multi-packet broadcast data message can comprise encoded priority ratings (e.g., encoded into priority criteria fields—not shown). In another embodiment, the priority rating(s) can be encoded into the header. 
     With reference to  FIG. 7 , in one embodiment, the contents of the message data include message title data, message display-text data, and message readout-text data, which are converted into the broadcast data by the broadcast data converter  202 . The converter  202  sets the parameters of the broadcast data message, such as the length, the activation date (i.e., when the message will be first shown to the operator), the expiration date (i.e., when the message will be deleted from a message storage device on the vehicle), and a symbol code indicating the message category or type. In one embodiment, the symbol code comprises the priority rating, which determines how frequently the message data is broadcast to the vehicles. 
     The aforementioned message parameters are typically encoded or stored in the broadcast data header. The converter  202  receives the FCX of the message data and creates a FCX section for the broadcast message data. The FCX section and the broadcast data portion are then fed into a common process for composing a combined message, referred to as Source Data. 
     Depending on the length of the message body, the broadcast message may be a single packet or multiple packets in length. For a single packet message, a header and CRC code is created and added to the Source Data to produce the Broadcast Packet. Alternatively, for a multiple packet message, the message body is partitioned into sections and each section has a header and CRC code added thereto. Separate Broadcast Packets are produced from each section. Whether a single packet message is created or a multiple packet message is created, the message is then passed from the center to the relay section  205 , which may be provided by a satellite network (e.g., XM Satellite Radio) or the like, as discussed above. The relay section  205  formulates the message into a data format suitable for broadcast to the vehicles. For example, different channels of the broadcast spectrum may be adapted to carry different formats of the broadcast message. 
       FIG. 8  is a block diagram of an exemplary header for a single-packet message, showing the fields within the single-packet message, as well as exemplary associated data sizes. In one embodiment, the data sizes of the fields are on order of about one to four bytes; however, it will be understood that the data sizes of the fields can be varied according to the particular application. The packet type field can comprise the priority rating for determining the relative frequency with which the message is broadcast to the vehicles. This exemplary header may be utilized for the standard broadcast data message and the 1-to-1 linked type broadcast data message (discussed above). Likewise,  FIG. 9  is a block diagram of an exemplary header for a multi-packet message, showing the fields of the message, as well as exemplary associated data sizes. The data sizes of the fields can be on order of about one to four bytes; however, the data sizes of the fields can be varied according to the particular application. In one embodiment, the packet type field comprises the priority rating for one or more of the data packets of the multi-packet message. 
     Having thus described a preferred embodiment of a method and system for prioritizing traffic information and broadcasting the traffic information in a prioritized order, it should be apparent to those skilled in the art that certain advantages of the within system have been achieved. It should also be appreciated that various modifications, adaptations, and alternative embodiments thereof may be made within the scope and spirit of the present invention. For example, the use of broadcast communication networks has been illustrated, but it should be apparent that many of the inventive concepts described above would be equally applicable to the use of other non-broadcast communication networks.