(19)
(11)EP 3 202 060 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
27.07.2022 Bulletin 2022/30

(21)Application number: 15778748.2

(22)Date of filing:  23.09.2015
(51)International Patent Classification (IPC): 
G01C 21/00(2006.01)
G01C 21/36(2006.01)
G08G 1/09(2006.01)
H04N 19/70(2014.01)
H04H 20/55(2008.01)
G01C 21/32(2006.01)
H04H 60/70(2008.01)
G08G 1/0967(2006.01)
G06T 9/00(2006.01)
(52)Cooperative Patent Classification (CPC):
G01C 21/3694; H04H 60/70; G08G 1/092; G08G 1/096716; G08G 1/096741; G08G 1/096775; G06T 9/00; H04N 19/70; H04H 20/55; G01C 21/3885
(86)International application number:
PCT/IB2015/057343
(87)International publication number:
WO 2016/051316 (07.04.2016 Gazette  2016/14)

(54)

TRANSMITTING MAP DATA IMAGES IN A LIMITED BANDWIDTH ENVIRONMENT

ÜBERTRAGUNG VON KARTENDATENBILDERN IN EINER UMGEBUNG MIT BEGRENZTER BANDBREITE

TRANSMISSION D'IMAGES DE DONNÉES CARTOGRAPHIQUES DANS UN ENVIRONNEMENT À LARGEUR DE BANDE LIMITÉE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 30.09.2014 US 201414502400

(43)Date of publication of application:
09.08.2017 Bulletin 2017/32

(73)Proprietor: HERE Global B.V.
5611 ZT Eindhoven (NL)

(72)Inventors:
  • CHINTAKINDI, Sunil Kumar
    Naperville, Illinois 60540 (US)
  • BELKIN, Anatoly
    Glenview, Illinois 60026 (US)

(74)Representative: Potter Clarkson 
The Belgrave Centre Talbot Street
Nottingham NG1 5GG
Nottingham NG1 5GG (GB)


(56)References cited: : 
EP-A1- 1 198 792
US-A1- 2008 095 096
US-B1- 6 532 413
US-A- 5 898 680
US-B1- 6 336 074
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    FIELD



    [0001] The following disclosure relates to transmitting map data images depicting a traffic condition in a limited bandwidth environment.

    BACKGROUND



    [0002] Representation and distribution of real time traffic information may be data intensive. Mobile navigation devices (e.g., car or personal navigation devices) may not be connected to or in communication with a high speed network for real time traffic updates. In certain cases, the mobile navigation device may be bandwidth constrained. For example, the mobile navigation device may only be able to receive and/or transmit up to a few kilobytes per second.

    [0003] Current techniques designed to transmit traffic information to a mobile navigation device having bandwidth constraints include radio data system-traffic message channel (RDS-TMC) based location referencing, Agora-C map based location referencing, or transport protocol experts group (TPEG) methods. For example, a RDS-TMC system may use an AM or FM radio signal to send highly compressed bit streams of traffic data to a car or personal navigation system. Unfortunately, these current standards and techniques involve "coding up" as many of the road segments as possible in terms of pre-defined identifications or using latitude/longitude based representations. Therefore, there is a continuing effort to provide improved systems and methods for providing traffic data for a navigation system in a limited bandwidth environment.

    [0004] US 2008/095096 A1 relates to a geographic information transceiving system and method using a digital broadcasting network. The system and method segments new geographic and map data of a region, on which a geographic information service is provided, makes data segment files of different sizes, and multiplexes and transmits the files.

    [0005] US 6532413 B1 relates a method for providing and processing an image based time-variant geographical information such as traffic information. The method involves transmitting traffic state information, comprising a map identifier and a plurality of traffic state data, to a user device, to be incorporated with a corresponding traffic section map stored at a user's device.

    [0006] US 5898680A relates to a FDMA/TDM satellite-based digital broadcast system which provides digital maps and other data to users in remote locations. User selection of the desired data is achieved by monitoring the TDM downlink channels of the broadcast system in accordance with a predetermined schedule or until a specific identification code is detected. Based on the user positions, the user terminals convert general data to location-specific data tailored to the needs of the user.

    [0007] US 6336074 B1 relates to a GPS navigation receiver, an output and a database of maps, wherein the output is connected to provide the determined position of the navigation receiver on a display using the database of maps stored in PDF files.

    [0008] EP 1198792 A1 relates to a method at a wireless communications system whereby map information is transmitted from a service server to a mobile client as separate map segments in a data stream. The map is gradually built up on a display unit at the mobile client depending on the client's geographical position and movement.

    SUMMARY



    [0009] Systems, methods, and apparatuses are provided ccording to the appended claims.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0010] Exemplary embodiments are described herein with reference to the following drawings.

    Figures 1a and 1b illustrate examples of a traffic map image for a metropolitan area in daytime and nighttime settings, respectively.

    Figure 2 illustrates an example of formatted or encoded map data for transmission to a navigation device.

    Figure 3 illustrates an example flowchart for transmitting map data images in a limited bandwidth environment.

    Figure 4 illustrates an example flowchart for receiving and processing encoded map data images in a limited bandwidth environment.

    Figure 5 illustrates an example system for a map data image management system.

    Figure 6 illustrates an exemplary navigation device of the system of Figure 5.

    Figure 7 illustrates an exemplary server of the system of Figure 5.


    DETAILED DESCRIPTION



    [0011] The following embodiments include systems, methods, and apparatuses for transmitting digital map images depicting a traffic condition in a limited bandwidth environment. As used herein, a "limited bandwidth environment" refers to a mobile navigation device at least temporarily unable to receive or transmit data at a rate of at least 200 kilobits/sec (i.e., third-generation (3G) standards). In certain embodiments, the limited bandwidth environment refers to a device at least temporarily unable to receive and/or transmit data at a rate of at least 100 kilobits/sec, 50 kilobits/sec, 25 kilobits/sec, or 10 kilobits/sec. In certain embodiments, a limited bandwidth environment refers to a navigation device only able to receive and/or transmit data at a rate of 1-100 kilobits/sec, 1-50 kilobits/sec, 1-25 kilobits/sec, 1-10 kilobits/sec, or 5-10 kilobits/sec.

    [0012] In certain embodiments, within the limited bandwidth environment, the navigation device may be able to receive and transmit (i.e., two-way communication) "over-the-air." Non-limiting examples of over-the-air transmissions include AM or FM radio transmission signals or Bluetooth UHF radio wave signals. The navigation device is able to receive the over-the-air signal (e.g., AM or FM radio transmission signal), but is not able to transmit a signal (i.e., one-way communication).

    [0013] In limited bandwidth situations, it may be difficult to transmit a large data file or map data images (e.g., traffic or weather data) to a navigation device efficiently. Therefore, alternative systems, apparatuses, and methods are needed to provide map information in these limited bandwidth settings. In certain embodiments, real-time map traffic images are developed and encoded. The encoded map images may be transmitted to the navigation device over-the-air (e.g., using an AM or FM transmission). The encoded map images are received by the navigation device and decoded. The decoded images may then be displayed on the navigation device.

    [0014] Such methods may allow for providing traffic information without having to wirelessly transmit a large data file or image to the mobile navigation device. Even low cost devices (e.g., devices without digital maps and little or no internet protocol connectivity) may be able to use digitized AM/FM signals to gain access to real time traffic data in and around the device's location.

    Development of Map Images



    [0015] Map images may be developed for any predefined map or road network, such as a metropolitan area or city (e.g., a selected area of a city or a selected number of road segments within a city). In some embodiments, the map images may be developed for multiple areas or road segments in multiple metropolitan areas or cities. The map images may be developed for one or more of the following: traffic data, weather data, accident data, or "special event" data.

    [0016] Traffic map images may be developed from a collection and analysis of real-time traffic data. Real-time traffic data may be collected at defined intervals and the traffic map image updated based upon the most recent data collected. For example, real-time traffic map image may be developed/updated every hour, 30 minutes, 15 minutes, 10 minutes, 5 minutes, 2.5 minutes, 1 minute, etc.

    [0017] In some embodiments, traffic map images may be developed from collection and analysis of real-time, historical, and/or predictive traffic data. Historical traffic data for a specific road segment may be collected for specified time segments or "epochs" to build a historical database. In some embodiments, traffic data may be collected at various epochs of a weekday, weekend, holiday, etc. In some examples, the traffic data is collected for every 5 minute epoch during rush hour and every 10 minute epoch for "off-hour" times.

    [0018] Traffic data may be collected for the average speed of the observed vehicles within the road segment, the frequency of vehicles, and/or the average heading of the vehicles. In certain embodiments, traffic data may be collected from probe data extracted from devices (e.g., mobile phones) within the traveling vehicles, or from fixed monitoring locations.

    [0019] Based on the collection of traffic data, traffic map images may be formed from the calculated average speed, frequency, and/or heading for each road or lane segment in real-time or at a determined historical time period. The traffic map images may be color-coded to depict the state of traffic for each road segment in the predefined road network. In other embodiments, the images may be marked in varying forms of dashed lines, etc. to depict the state of traffic. A machine-learning algorithm may be used to define what color or dashed line to code the road segment. In some embodiments, the color or dashed line may be determined based on a comparison between the average speed for the epoch and the speed limit for the road segment in real-time.

    [0020] In certain embodiments, the road segment in the traffic map image may be color-coded green to represent traffic moving at a minimum percentage of the defined speed limit for the road segment. For example, the road segment may be color-coded green when the average speed is at 80% or greater of the speed limit (i.e., 80+ km/hr where the speed limit is 100 km/hr). Yellow color-codes may represent slower traffic conditions, representing traffic moving at a certain percentage of the defined speed limit (e.g., average speeds of between 40% and 80% of the speed limit). Red color-codes may represent even slower moving traffic in comparison to the defined speed limit for the road segment (e.g., average speeds less than 40% of the speed limit). Additional color-coding is also possible, such as a black color code designation for stand-still traffic (e.g., average speeds < 5% of the speed limit), and orange for construction areas.

    [0021] In certain embodiments, the road segment may include an individual color-code or dashed line for each lane of traffic (in each direction of travel). In other embodiments, the road segment may include multiple color-codes or different forms of dashed lines representing faster moving and slower moving zones within the road segment.

    [0022] The number of overall traffic map images developed for the metropolitan location or city may be based on a number of different factors including, but not limited to the overall area of the location/city, the area of each traffic map image within the location/city, the number of node levels for the location/city (i.e., the number of sub-levels or zones within each level), the varying level of detail or types of roads depicted in the traffic map image (including whether or not the underlying road network is depicted at all), and/or the number of unique traffic images for each level or sub-level.

    [0023] In certain embodiments, multiple views of a single traffic map image may be developed. For example, daytime and nighttime views of a traffic map image may be developed. A daytime view may include color-coded traffic segments overlaying a substantially light (e.g., white) background, while a nighttime view may include color-coded traffic segments overlaying a substantially dark (e.g., black) background for better viewing in low ambient light conditions.

    [0024] In a non-limiting embodiment, Figures 1a and 1b depict two different image configurations of the same traffic pattern. In Figure 1a, a daytime view is depicted of a metropolitan area, wherein the traffic patterns are overlaid on a road network. Figure 1b represents the same traffic pattern for the metropolitan area overlaid on the road network for a selected nighttime view.

    [0025] To the extent an end-user may be interested in an expanded perspective of traffic in the city, this may be accomplished in two or three node levels to represent the entire city, and one or two zoomed in, sub-levels or nodes within the city. To the extent more narrowed or zoomed in views of a location are desired, additional sub-levels or nodes may be developed.

    [0026] In addition to the development of traffic map images for a metropolitan area, weather map images may additionally be developed from a collection and analysis of real-time weather data. Weather map images may be developed based on rain, snow, ice, etc. within the map area. Similar to the traffic map images, the weather map images may be color-coded to depict the state of weather for the map area. For example, the weather map image may be color coded based on the real-time radar intensity of the rain/snow precipitation (e.g., very light rain or snow is depicted in light blue, moderate rain is depicted in green, severe rain is depicted in red).

    Encoding the Map Image Data



    [0027] In limited bandwidth connectivity situations, current traffic image data is be encoded and transmitted to the navigation device without sending large amounts of data over-the-air. Instead, map images may be encoded for transmission in low bandwidth situations (e.g., situations wherein low sized images are readily transmittable). The map image data (e.g., traffic and/or weather data) may be encoded in ASCII, UTF-8, ISO-8859-1, or XML, for example. In one particular embodiment, the map image data is encoded in ASCII format.

    [0028] Larger developed map image files (e.g., a single 64 kilobyte (KB) image file) are broken up into smaller data files to be transmitted in multiple payloads. In certain embodiments, each payload of the multiple payloads is less than or approximately 1, 2, 4, 8, or 16 kilobytes. In one particular embodiment, each payload is approximately 4 kilobytes. The over-the-air transmission is formatted or encoded to include data in a specific order (including image data transmitted in multiple payloads).

    [0029] Figure 2 provides a non-limiting embodiment of the format of the encoded map data. For example, in Figure 2, the transmission may include a content header with the content data. The content header may comprise information such as network caller identification (NCID) and version information, protocol version information, beginning sequence number and end sequence number, and message length. Each segment of the content header may comprise a limited amount of data space (e.g., 1 or 2 bytes each). In the transmission, the content header may be followed or preceded by the content data. The content data may include the low storage sized encoded map image, along with additional data information (discussed in greater detail below).

    [0030] In certain embodiments, the content header and content data may be bookended on the front end and back end by a buffer header and a buffer trailer, respectively. In some embodiments, the buffer header may comprise service sync (start) information and/or a buffer length. The buffer trailer may comprise a cyclic redundancy check (CRC) and/or service sync (end) information. Like the content header information, each component of the buffer header and trailer may comprise a limited amount of data space (e.g., 1 or 2 bytes each).

    [0031] In certain embodiments, a plurality of content headers and content data (e.g., more than one map image) may be included between the buffer header and buffer trailer. Such a flexible payload approach (i.e., one or more content buffers) instead of a fixed length payload allows for the distribution channel to optimize and control the type of images that can be streamed to the device.

    [0032] As mentioned above, the content data includes a fraction of the overall map image to the extent the image is broken up into multiple payloads. The map image may be encoded and stored as an image byte stream. The image may be stored in .jpeg or .png format. Other image format options are also available.

    [0033] In addition to the encoded image, the content data may include various fields of information included in the overall transmission message. For example, in one field, the content data may include date and time information associated with the image data. The time stamp may be expressed in coordinated universal time (UTC) format in 33 bits of data (e.g., expressed as YYYYYYYMMMMDDDDDhhhhhmmmmmmssssss).

    [0034] The content data may also comprise information regarding the number of images included with the transmission (expressed as an integer value). The content data may also include latitude and longitude information to form a bounding box for each image. For example, the content data may include information regarding one corner of the bounding box (e.g., the Southwest latitude and longitude values), as well as the opposite corner of the bounding box (e.g., the Northeast latitude and longitude values). The latitude information may be expressed as an integer (e.g., 0=N, 1=S), followed by the value associated with the geographic coordinate from the equator (e.g., three digits for the degrees, and five digits for the decimal degrees). The longitude information may also be expressed as an integer (e.g., 0=E, 1=W), followed by the value associated with the geographic coordinate from the prime meridian (e.g., three digits for the degrees, and five digits for the decimal degrees).

    [0035] The content data may also include information regarding the length of an image description (e.g., an integer value indicating the length of the description where the value '0' indicates no description). The image description may also be provided, to the extent one exists. The description may be encoded in UTF-8 characters and comprise between 1 and 255 bytes.

    [0036] The content data may also include information regarding the type of encoded image. For example, an image type value of '0' may refer to a compressed .jpeg image. A value of '1' may refer to a .png image. Values of '2', '3', etc. may be saved for future use for different types of encoded images.

    [0037] The content data may include information regarding the view type of the encoded image (such as whether the encoded image represents a downtown view, a view of an entire metropolitan area, or a view of a segment of a city).

    [0038] The content data may also include a preferred pixel per inch (PPI) value upon decoding the image. The preferred PPI value may be stored as an integer representing the preferred value for displaying the image clearly on the navigation device.

    [0039] The content data may include the size of the image (in bytes).

    [0040] To the extent more than one image is being encoded for transmission, the image data is repeated for each additional image (e.g., latitude/longitude data, image description, image type, image byte stream, etc.).

    [0041] One embodiment of the overall formatted content data is provided in the table below. As shown in the table, certain segments are reserved for future use to potentially encode and include additional information in the transmission.
    TABLE. Map Image Transmission Message Format
    OrderSizeField NameDescription
    1 7 bits Reserved for future use ("RFU")  
    2 33 bits Date/Time Time stamp expressed in UTC. 33 bits used as: YYYYYYYMMMMDDDDDhhhhhmmmmmmssssss
    3 1 byte Number of images Integer value for number of images embedded.
    4 26 bits Southwest Latitude Southwest Latitude of the bounding box for the next image. Expressed as Integer for sign (0=N, 1=S), then degrees and decimal degrees to five decimal digits. Degrees value are three digits, decimal part is five digits.
    5 26 bits Southwest Longitude Southwest Longitude of the bounding box for the next image. Expressed as Integer for sign (0=E, 1=W), then degrees and decimal degrees to five decimal digits. Degrees value are three digits, decimal part is five digits.
    6 26 bits Northeast Latitude Northeast Latitude of the bounding box for the next image. (As Order 4).
    7 26 bits Northeast Longitude Northeast Longitude of the bounding box for the next image. (as Order 5).
    8 1 byte Length of Image Description Integer value indicating Length of Image Description. Value=0 means there is no description.
    9 1 ... 255 bytes Image Description (UTF-8) Description of the next image. UTF-8 characters.
    10 4 bits Reserved for future use ("RFU")  
    11 2 bits Image Type 0=jpg, 1=png, 2=RFU, 3=RFU
    12 2 bits View Type 0=Downtown View, 1=Suburban View 2=RFU 3=RFU
    13 2 bytes Preferred Display PPI (Pixels) Integer value for Preferred Pixel per inch value to display the picture clearly
    14 2 bytes Size of Image (in Bytes) Integer value indicating Number of Bytes in the next image byte stream
    15 1 ... n bytes Image byte Stream Byte stream of the image. Variable length
    16 Repeating fields from 4 to 13 for each additional image

    Transmitting the Encoded Map Image Data



    [0042] Following the formatting and encoding of the map image data, a server processor may instruct the transmitter to relay the encoded image(s) in an over-the-air signal (e.g., an AM or FM radio signal) to a receiver connected to the navigation device. In certain embodiments, multiple payloads of encoded image data are transmitted. In such cases, the multiple payloads may be transmitted in a specific order for decoding.

    [0043] In situations with limited connectivity and one-way communication between a transmitter and the navigation device, the navigation device may be able to receive transmissions from a transmitter. In an example not forming part of the invention, with two-way communication between a transmitter and server-side receiver and the navigation device, the navigation device may be able to receive transmissions from a transmitter and also send transmissions back to a receiver. For example, the navigation device may be able to send signals to the receiver. The navigation device transmission signals may include information regarding its current geographic position or user input information such as the level of detail or zoom level requested. In turn, the transmitter/ receiver may relay the navigation device information for processing. Such communication from the navigation device may assist in determining the specific transmission signal to return to the navigation device.

    [0044] In certain embodiments, the transmitter/receiver may be in communication with a network having access to real-time or current traffic conditions. The transmitter/receiver and network may also be in communication with a processor capable of running predictive algorithms to determine traffic conditions for inclement weather, traffic accidents, or construction scenarios. For example, the predictive algorithm may be able to calculate what the road traffic may look like in the future based on the weather or a recent traffic accident, and be able to determine what traffic map image to generate.

    Receiving and Decoding the Map Image Data



    [0045] After the navigation device has received a signal from an external transmitter with the encoded map image(s), the navigation device may then decode the map image(s).

    [0046] In certain embodiments, based on the encoded map image data described above, a receiver connected to a navigation device may be able to ensure that complete frames of image data are received. Additionally, the navigation device receiver may be able to confirm that complete buffers of content are received. Further, the formatted or encoded data may allow the navigation device receiver to decode and reassemble the data.

    [0047] In certain embodiments, the navigation device may validate and decode the received transmission by finding the start of the service sync in the buffer header. Additionally, the navigation device may validate the buffer length and the cyclic redundancy check value.

    [0048] Further, for each content data transmitted, the decoding process may include: (1) storing the sequence number and end sequence number, (2) storing the message length, (3) copying the message length bytes to a data buffer, and (4) using the sequence number to place the image data in the correct position in the received data stream.

    [0049] In certain embodiments, if the data is out of order, or if the CRC validation fails, the content data should be dropped or rejected by the navigation device receiver.

    Displaying the Decoded Map Image



    [0050] After the navigation device has decoded the transmitted map image data from the external transmitter, the navigation device may display a decoded image on the navigation device or a display in communication with the navigation device.

    [0051] In certain embodiments, more than one image may be decoded. In these situations, the end-user or the navigation device processor may determine or select which image to display. For example, the end-user or the navigation device processor may select between a view of the entire metropolitan area versus a view of the downtown area. In other embodiments, the selection may include how the image is displayed (e.g., a daytime view or a nighttime view of traffic conditions, a daytime or a nighttime view of weather conditions in the area). In some embodiments, the selected view may be determined by a navigation device processor without user input. The processor may determine which image or portion of an image to display based upon the geographic location of the navigation device (e.g., GPS location). The processor may also determine which image or portion of an image to display (e.g., a daytime image or a nighttime image) based on the time of day and time of year. For example, if the navigation device processor is aware that the time is 9:00 p.m. in Chicago in December, the processor may select a nighttime image to be displayed (if available) on the navigation device screen as a default without end-user input.

    [0052] In yet other embodiments, the end-user or navigation device processor may adjust the view of a particular map image or combination of map images to center the displayed image at the location of the end-user/navigation device. For example, the navigation device may be able to use a global positioning system locally on the device to determine whether the navigation device is located on a highway or local road, and which map image(s) to display. In other embodiments, the end-user may be able to provide input to the navigation device regarding the location of the navigation device, the level of detail requested, or the zoom level requested.

    Repeating/Refreshing the Map Reporting



    [0053] The process of (1) determining the map condition (e.g., real-time traffic or weather), (2) encoding the map image data, (3) transmitting the encoded map image data to a navigation device, (4) decoding the image data, and (5) displaying the decoded map image data may be repeated at set or variable intervals of time. In situations of one-way or two-way limited bandwidth communication, encoded map image data may be relayed to the navigation device continuously, at set times, or at random times only where the traffic condition has changed from the last reporting.

    [0054] As discussed above, advantages of these systems, apparatuses, and methods include that even low cost devices (e.g., devices without digital maps and little or no internet protocol connectivity) may be able to use digitized AM/FM signals to gain access to real time traffic data in and around the device's location. Additionally, the transmission of a flexible payload approach (i.e., one or more content buffers) instead of a fixed length payload allows for the distribution channel to optimize and control the type of images that can be streamed to the device. Further, the CRC check allows for retention of quality of images that are transmitted over-the-air. Also, the process allows for flexibility in terms of how the map level of images may be combined or separated with traffic data related colors that are rendered on the road segments. The encoding and decoding process is also agnostic to the size, format and type of images. For example, one implementation could send ten different lower quality, compressed .jpeg images to represent more complex traffic in cities such as New York, compared with just two images for Kansas City (where traffic density may not be as high). Additionally, as mentioned above, the encoding and decoding process may be performed for additional information such as weather data, accidents, or other "special events" that may be highlighted on the map image and transmitted in a similar fashion.

    [0055] Figure 3 illustrates an example flowchart for transmitting map data images in a limited bandwidth environment. The process of the flowchart may be performed by a map database server and its processor and/or navigation device and its processor. Alternatively, another device may be configured to perform one or more of the following acts. Additional, fewer, or different acts may be included.

    [0056] At act S101, a traffic condition or a weather condition is determined or predicted using a map database processor. The traffic or weather condition for a location may be determined based a collection and analysis of real-time traffic or weather data. Alternatively or additionally, the traffic or weather condition may be determined from a collection and analysis of real-time, historical, and/or predictive traffic or weather data.

    [0057] At act S103, at least one map image may be developed from the traffic or weather data. A traffic map image may include road segments that are color-coded or marked with dashed lines to represent the type of traffic pattern present on the road segment in each of the images.

    [0058] At act S105, the at least one map image is encoded in multiple payloads. Larger developed map image files are broken up into smaller data files to be transmitted in multiple payloads. The map image may be encoded with content header information such as a beginning sequence number and an end sequence number for each image segment or payload. The map image may also be encoded with other information such as a timestamp, a total number of images in the transmission, a bounding box (latitude/longitude coordinates) for the image(s), an image description, an image type identifier or value, an image view identifier, a preferred pixel per inch value for the decoded image, and/or a size of the image.

    [0059] At act S107, following the encoding of the at least one map image, each encoded image may be transmitted in at least one payload over-the-air to a navigation device for further processing. The transmission may occur via an AM or FM signal. Further, each transmission may be monitored to be below a threshold size for processing in a limited bandwidth environment.

    [0060] Figure 4 illustrates an example flowchart for receiving and processing encoded map data images in a limited bandwidth environment. The process of the flowchart may be performed by a navigation device and its processor and/or a server and its processor. Alternatively, another device may be configured to perform one or more of the following acts. Additional, fewer, or different acts may be included.

    [0061] At act S201, an AM or FM transmission signal is received by a navigation device receiver. The signal comprises at least one encoded map image with traffic information. The at least encoded one map image is received in a plurality of payloads, wherein each payload of the plurality of payloads comprises a beginning sequence number and an end sequence number.

    [0062] At act S203, each transmitted map image may be decoded by a server or processor in communication with the navigation device. The decoding may comprise combining a plurality of payloads in order of sequencing numbers of each payload to provide the decoded map image.

    [0063] At act S205, at least a portion of the decoded map image may be displayed on a navigation device display. In certain embodiments, the end-user or the navigation device processor may determine or select which image to display or which portion of an image to display.

    [0064] As discussed above, transmitting and receiving map data in a limited bandwidth environment may be performed by a navigation device and its processor and/or a server and its processor. Figure 5 illustrates one embodiment of a map data image management system 120. The system 120 may include a map developer system 121, a navigation device 122, a workstation 128, and a network 127. Additional, different, or fewer components may be provided.

    [0065] The navigation device 122 may be a personal navigation device ("PND"), a portable navigation device smart phone, a mobile phone, a personal digital assistant ("PDA"), a tablet computer, a notebook computer, and/or any other known or later developed mobile device or personal computer. Non-limiting embodiments of navigation devices may also include RDS devices, mobile phone devices, or car navigation devices such as Garmin or TomTom.

    [0066] The map developer system 121 includes a server 125 and a server database 123. The developer system 121 may include computer systems and networks of a system operator such as HERE, NAVTEQ, or Nokia Corporation. The server database 123 is configured to store traffic map images developed from historical traffic data or predictive traffic data. The database 123 is also configured to store identification keys associated with the traffic map images.

    [0067] The developer system 121, the workstation 128, and the navigation device 122 are coupled with the network 127. The phrase "coupled with" is defined to mean directly connected to or indirectly connected through one or more intermediate components. Such intermediate components may include hardware and/or software-based components. In certain embodiments, the navigation device 122 may be coupled with the network through a radio transmitter/receiver 130, which may transmit "over-the-air" radio transmission signals (e.g., an AM or FM signal) to the navigation device 122. In some embodiments, the radio transmitter/receiver 130 may receive transmission signals from the navigation device 122.

    [0068] The workstation 128 may be a general purpose computer including programming specialized for providing input to the server 125. For example, the workstation 128 may provide settings for the server 125. The settings may include a value for the predetermined interval that the server 125 requests the navigation device 122 to relay current geographic locations. The workstation 128 may be used to enter data indicative of GPS accuracy to the database 123. The workstation 128 may include at least a memory, a processor, and a communication interface.

    [0069] Figure 6 illustrates an exemplary navigation device 122 of the system of Figure 5. The navigation device 122 includes a processor 200, a memory 204, an input device 203, a communication interface 205, position circuitry 207, and a display 211. Additional, different, or fewer components are possible for the mobile device/personal computer 122. In certain embodiments, the communication interface 205 of the navigation device 122 comprises an AM and/or FM radio receiver. The receiver may be a high-definition radio receiver.

    [0070] The processor 200 may be configured to receive data indicative of the location of the navigation device 122 from the position circuitry 207. The positioning circuitry 207, which is an example of a positioning system, is configured to determine a geographic position of the navigation device 122. The positioning system may also include a receiver and correlation chip to obtain a GPS signal. The positioning circuitry may include an identifier of a model of the positioning circuitry 207. The processor 200 may access the identifier and query a database or a website to retrieve the accuracy of the positioning circuitry 207 based on the identifier. The positioning circuitry 207 may include a memory or setting indicative of the accuracy of the positioning circuitry.

    [0071] Figure 7 illustrates an exemplary server 125 of the system of Figure 5. The server 125 includes a processor 300, a communication interface 305, and a memory 301. The server 125 may be coupled to a database 123 and a workstation 128. The workstation 128 may be used as an input device for the server 125. In addition, the communication interface 305 is an input device for the server 125. In certain embodiments, the communication interface 305 may receive data indicative of use inputs made via the workstation 128 or the navigation device 122.

    [0072] The navigation device processor 200 and/or the server processor 300 may include a general processor, digital signal processor, an application specific integrated circuit (ASIC), field programmable gate array (FPGA), analog circuit, digital circuit, combinations thereof, or other now known or later developed processor. The navigation device processor 200 and/or the server processor 300 may be a single device or combinations of devices, such as associated with a network, distributed processing, or cloud computing.

    [0073] The navigation device processor 200 and/or the server processor 300 may also be configured to cause an apparatus to at least perform at least one of traffic map image retrieval methods described above. For example, the navigation device processor 200 may be configured to perform the process: (1) receive, via an over-the-air AM or FM radio transmission signal, at least one encoded map image, the at least one encoded map image comprising a traffic condition for a location; (2) decode a map image from the at least one encoded map image; and (3) display at least a portion of the decoded map image on a navigation device screen.

    [0074] In another embodiment, the server processor 300 may be configured to perform the process: (1) determine or predict a traffic condition or a weather condition for a location; (2) develop at least one map image depicting the traffic condition or the weather condition; (3) encode the map image in at least one payload; and (4) transmit the at least one payload over-the-air to a navigation device.

    [0075] The memory 204 and/or memory 301 may be a volatile memory or a non-volatile memory. The memory 204 and/or memory 301 may include one or more of a read only memory (ROM), random access memory (RAM), a flash memory, an electronic erasable program read only memory (EEPROM), or other type of memory. The memory 204 and/or memory 301 may be removable from the navigation device 122, such as a secure digital (SD) memory card.

    [0076] The communication interface 205 and/or communication interface 305 may include any operable connection. An operable connection may be one in which signals, physical communications, and/or logical communications may be sent and/or received. An operable connection may include a physical interface, an electrical interface, and/or a data interface. The communication interface 205 and/or communication interface 305 provides for wireless and/or wired communications in any now known or later developed format.

    [0077] In certain embodiments, receiving and decoding of the encoded map image on the navigation device may be used to provide functions for an autonomous vehicle. An autonomous vehicle is self-driving and may be referred to as a robot vehicle or an automated vehicle. The autonomous vehicle may include passengers but no driver is necessary. The navigation device 122 or another computer system in communication with the navigation device 122 may include instructions for routing the vehicle or operating the vehicle. An estimated travel time may be calculated based on the traffic map data and a route may be chosen based on the estimate travel time. The computing system may generate driving commands for steering the vehicle, shifting gears, increasing and decreasing the throttle, and braking. The computing system may generate auxiliary commands for controlling the headlights, turn signals, windshield wipers, defrost, or other auxiliary functions not directly related to the movement of the vehicle.

    [0078] The autonomous vehicle may include sensors for identifying the surrounding and location of the car. The sensors may include GPS, light detection and ranging (LIDAR), radar, and cameras for computer vision. Proximity sensors may aid in parking the vehicle. The proximity sensors may detect the curb or adjacent vehicles. The autonomous vehicle may optically track and follow lane markings or guide markings on the road.

    [0079] In the above described embodiments, the network 127 may include wired networks, wireless networks, or combinations thereof. The wireless network may be a cellular telephone network, an 802.11, 802.16, 802.20, or WiMax network. Further, the network 127 may be a public network, such as the Internet, a private network, such as an intranet, or combinations thereof, and may utilize a variety of networking protocols now available or later developed including, but not limited to TCP/IP based networking protocols. In certain embodiments, the network may be in communication with a radio transmitter/receiver 130 that produces and/or receives AM or FM signal to communicate with the navigation device 122.

    [0080] While the non-transitory computer-readable medium is described to be a single medium, the term "computer-readable medium" includes a single medium or multiple media, such as a centralized or distributed database, and/or associated caches and servers that store one or more sets of instructions. The term "computer-readable medium" shall also include any medium that is capable of storing, encoding or carrying a set of instructions for execution by a processor or that cause a computer system to perform any one or more of the methods or operations disclosed herein.

    [0081] In a particular non-limiting, exemplary embodiment, the computer-readable medium can include a solid-state memory such as a memory card or other package that houses one or more non-volatile read-only memories. Further, the computer-readable medium can be a random access memory or other volatile re-writable memory. Additionally, the computer-readable medium can include a magneto-optical or optical medium, such as a disk or tapes or other storage device to capture carrier wave signals such as a signal communicated over a transmission medium. A digital file attachment to an e-mail or other self-contained information archive or set of archives may be considered a distribution medium that is a tangible storage medium. Accordingly, the disclosure is considered to include any one or more of a computer-readable medium or a distribution medium and other equivalents and successor media, in which data or instructions may be stored.

    [0082] In an alternative embodiment, dedicated hardware implementations, such as application specific integrated circuits, programmable logic arrays and other hardware devices, can be constructed to implement one or more of the methods described herein. Applications that may include the apparatus and systems of various embodiments can broadly include a variety of electronic and computer systems. One or more embodiments described herein may implement functions using two or more specific interconnected hardware modules or devices with related control and data signals that can be communicated between and through the modules, or as portions of an application-specific integrated circuit. Accordingly, the present system encompasses software, firmware, and hardware implementations.

    [0083] In accordance with various embodiments of the present disclosure, the methods described herein may be implemented by software programs executable by a computer system. Further, in an exemplary, non-limited embodiment, implementations can include distributed processing, component/object distributed processing, and parallel processing. Alternatively, virtual computer system processing can be constructed to implement one or more of the methods or functionality as described herein.

    [0084] Although the present specification describes components and functions that may be implemented in particular embodiments with reference to particular standards and protocols, the invention is not limited to such standards and protocols. For example, standards for Internet and other packet switched network transmission (e.g., TCP/IP, UDP/IP, HTML, HTTP, HTTPS) represent examples of the state of the art. Such standards are periodically superseded by faster or more efficient equivalents having essentially the same functions. Accordingly, replacement standards and protocols having the same or similar functions as those disclosed herein are considered equivalents thereof.

    [0085] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

    [0086] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

    [0087] As used in this application, the term "circuitry" or "circuit" refers to all of the following: (a)hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

    [0088] This definition of "circuitry" applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in server, a cellular network device, or other network device.

    [0089] Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and anyone or more processors of any kind of digital computer. Generally, a processor receives instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for performing instructions and one or more memory devices for storing instructions and data. Generally, a computer also includes, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio player, a Global Positioning System (GPS) receiver, to name just a few. Computer readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., E PROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

    [0090] To provide for interaction with a user, embodiments of the subject matter described in this specification can be implemented on a device having a display, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.

    [0091] Embodiments of the subject matter described in this specification can be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network ("LAN") and a wide area network ("WAN"), e.g., the Internet.

    [0092] The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

    [0093] The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and may not be drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and the figures are to be regarded as illustrative rather than restrictive.

    [0094] While this specification contains many specifics, these should not be construed as limitations on the scope of the invention or of what may be claimed, but rather as descriptions of features specific to particular embodiments of the invention. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

    [0095] Similarly, while operations are depicted in the drawings and described herein in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

    [0096] Moreover, although specific embodiments have been illustrated and described herein, it should be appreciated that any subsequent arrangement designed to achieve the same or similar purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all subsequent adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, are apparent to those of skill in the art upon reviewing the description.

    [0097] In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.


    Claims

    1. A computer-implemented method for transmitting map images to a navigation device in a limited bandwidth environment in which the navigation device is at least temporarily unable to receive or transmit data at a rate of at least 200 kilobits/sec, the method comprising:

    determining or predicting (S101) a traffic condition for a location based on an analysis of real-time, historical or predictive traffic data;

    developing (S103) a map image depicting the traffic condition;

    breaking up the map image into a plurality of image segments, wherein a map image for a location with a higher traffic density is broken up into more image segments than a map image for a location with a lower traffic density;

    encoding (S105) the plurality of image segments of the map image into a plurality of payloads, each payload including an image segment of the plurality of image segments; and

    transmitting (S107) the plurality of payloads over-the-air to the navigation device (122), wherein each transmission of a payload is below a threshold size for processing in the limited bandwidth environment and wherein the plurality of payloads are transmitted with a defined order such that the plurality of image segments can be decoded and reassembled by the navigation device for display as a single map image.


     
    2. The method of claim 1, wherein the map image comprises at least one of the following:

    (1) a daytime map image of a metropolitan area,

    (2) a nighttime map image of the metropolitan area,

    (3) a daytime map image of a downtown area of a city, or

    (4) a nighttime map image of the downtown area.


     
    3. The method of claim 1, wherein the map image is encoded with buffer header and buffer trailer data, wherein the buffer trailer data includes a cyclic redundancy check.
     
    4. The method of claim 1, wherein each payload of the plurality of payloads comprises a beginning sequence number and an end sequence number, such that the plurality of image segments can be decoded and reassembled by the navigation device using the beginning and end sequence numbers.
     
    5. The method of claim 1, wherein the plurality of payloads is transmitted over an AM or FM radio signal.
     
    6. A computer-implemented method for receiving and processing encoded map image data at a navigation device in a limited bandwidth environment in which the navigation device is at least temporarily unable to receive or transmit data at a rate of at least 200 kilobits/sec, the method comprising:

    receiving (S201), by the navigation device (122) via an over-the-air transmission signal, an encoded map image, the map image depicting a traffic condition for a location determined or predicted based on an analysis of real-time, historical or predictive traffic data, wherein the encoded map image is received as a plurality of payloads with a defined order, each payload including an image segment of a plurality of image segments of the map image, wherein a map image for a location with a higher traffic density is broken up into more image segments than a map image for a location with a lower traffic density, and wherein the transmission of each payload is below a threshold size for processing in the limited bandwidth environment ;

    decoding (S203), using a processor of the navigation device, a single map image from the encoded map image; and

    displaying (S205) at least a portion of the single decoded map image on a navigation device display.


     
    7. The method of claim 6, wherein each payload of the plurality of payloads comprises a beginning sequence number and an end sequence number.
     
    8. The method of claim 7, wherein the decoding comprises combining the plurality of payloads in order of sequencing numbers of each payload to provide the decoded map image.
     
    9. The method of claim 6, wherein the encoded map image is encoded with buffer header and buffer trailer data, wherein the buffer trailer data includes cyclic redundancy check data, further comprising validating the quality of the encoded map image using the cyclic redundancy check data.
     
    10. The method of claim 9, further comprising rejecting the encoded map image by the navigation device if the cyclic validating fails.
     
    11. The method of claim 6, wherein the plurality of payloads are received via an AM or FM radio signal.
     
    12. An apparatus (125) comprising:

    at least one processor (300);

    at least one memory (301) including computer program code for one or more programs; and

    an over-the-air transmitter (305);

    the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least perform a method as claimed in any of claims 1-5.


     
    13. A system (120) comprising:

    at least one processor (300);

    at least one memory (301) including computer program code for one or more programs; and

    an over-the-air transmitter (130, 305);

    the at least one memory and the computer program code configured to, with the at least one processor, cause the system to at least perform a method as claimed in any of Claims 1-5.


     
    14. A navigation device (122) comprising:

    a display (211);

    at least one processor (200);

    at least one memory (204) including computer program code for one or more programs; and

    an over-the-air receiver (205);

    the at least one memory and the computer program code configured to, with the at least one processor, cause the navigation device to at least perform a method as claimed in any of claims 6-11.


     


    Ansprüche

    1. Computerimplementiertes Verfahren zum Senden von Kartenbildern an eine Navigationsvorrichtung in einer Umgebung mit begrenzter Bandbreite, in der die Navigationsvorrichtung wenigstens vorübergehend nicht in der Lage ist, Daten mit einer Rate von wenigstens 200 Kilobit/s zu empfangen oder zu senden, wobei das Verfahren Folgendes umfasst:

    Bestimmen oder Vorhersagen (S101) einer Verkehrsbedingung für einen Standort basierend auf einer Analyse von Echtzeit-, historischen oder prädiktiven Verkehrsdaten;

    Entwickeln (S103) eines Kartenbilds, das die Verkehrsbedingung darstellt;

    Aufbrechen des Kartenbilds in mehrere Bildsegmente, wobei ein Kartenbild für einen Standort mit einer höheren Verkehrsdichte in mehr Bildsegmente als ein Kartenbild für einen Standort mit einer geringeren Verkehrsdichte aufgeteilt wird;

    Codieren (S105) der mehreren Bildsegmente des Kartenbilds in mehrere Nutzlasten, wobei jede Nutzlast ein Bildsegment der mehreren Bildsegmente beinhaltet; und

    Senden (S107) der mehreren Nutzlasten über drahtloses Übertragen an die Navigationsvorrichtung (122), wobei jede Sendung einer Nutzlast unter einer Schwellengröße zum Verarbeiten in der Umgebung mit begrenzter Bandbreite liegt und wobei die mehreren Nutzlasten mit einer definierten Reihenfolge derart gesendet werden, dass die mehreren Bildsegmente durch die Navigationsvorrichtung für eine Anzeige als ein einzelnes Kartenbild decodiert und wieder zusammengesetzt werden können.


     
    2. Verfahren nach Anspruch 1, wobei das Kartenbild Folgendes umfasst:

    (1) ein Tageskartenbild eines Großraumgebiets,

    (2) ein Nachtkartenbild des Großraumgebiets,

    (3) ein Tageskartenbild eines Innenstadtgebiets einer Stadt, und/oder

    (4) ein Nachtkartenbild des Innenstadtgebiets.


     
    3. Verfahren nach Anspruch 1, wobei das Kartenbild mit Pufferkopf- und Pufferschlussdaten codiert wird, wobei die Pufferschlussdaten eine zyklische Redundanzprüfung beinhalten.
     
    4. Verfahren nach Anspruch 1, wobei jede Nutzlast der mehreren Nutzlasten eine Anfangssequenznummer und eine Endsequenznummer derart umfasst, dass die mehreren Bildsegmente durch die Navigationsvorrichtung unter Verwendung der Anfangs- und Endsequenznummern decodiert und wieder zusammengesetzt werden können.
     
    5. Verfahren nach Anspruch 1, wobei die mehreren Nutzlasten über ein AM- oder FM - Funksignal gesendet werden.
     
    6. Computerimplementiertes Verfahren zum Empfangen und Verarbeiten von codierten Kartenbilddaten in einer Navigationsvorrichtung in einer Umgebung mit begrenzter Bandbreite, in der die Navigationsvorrichtung wenigstens vorübergehend nicht in der Lage ist, Daten mit einer Rate von wenigstens 200 Kilobit/s zu empfangen oder zu senden, wobei das Verfahren Folgendes umfasst:

    Empfangen (S201), durch die Navigationsvorrichtung (122), über drahtloses Übertragen des Sendesignals, eines codierten Kartenbilds, wobei das Kartenbild eine Verkehrsbedingung für einen Standort darstellt, die basierend auf einer Analyse von Echtzeit-, historischen oder prädiktiven Verkehrsdaten bestimmt oder vorhergesagt wird, wobei das codierte Kartenbild als mehrere Nutzlasten mit einer definierten Reihenfolge empfangen wird, wobei jede Nutzlast ein Bildsegment aus mehreren Bildsegmenten des Kartenbilds beinhaltet, wobei ein Kartenbild für einen Standort mit einer höheren Verkehrsdichte in mehr Bildsegmente als ein Kartenbild für einen Standort mit einer geringeren Verkehrsdichte aufgeteilt wird; und wobei die Sendung jeder Nutzlast unter einer Schwellengröße zum Verarbeiten in der Umgebung mit begrenzter Bandbreite liegt;

    Decodieren (S203), unter Verwendung eines Prozessors der Navigationsvorrichtung, eines einzelnen Kartenbilds aus dem codierten Kartenbild; und

    Anzeigen (S205) wenigstens eines Abschnitts des einzelnen decodierten Kartenbilds auf einer Navigationsvorrichtungsanzeige.


     
    7. Verfahren nach Anspruch 6, wobei jede Nutzlast der mehreren Nutzlasten eine Anfangssequenznummer und eine Endsequenznummer umfasst.
     
    8. Verfahren nach Anspruch 7, wobei das Decodieren ein Kombinieren der mehreren Nutzlasten in der Reihenfolge der Sequenznummern jeder Nutzlast umfasst, um das decodierte Kartenbild bereitzustellen.
     
    9. Verfahren nach Anspruch 6, wobei das codierte Kartenbild mit Pufferkopf- und Pufferschlussdaten codiert wird, wobei die Pufferschlussdaten zyklische Redundanzprüfdaten beinhalten, die ferner ein Validieren der Qualität des codierten Kartenbildes unter Verwendung der zyklischen Redundanzprüfdaten umfassen.
     
    10. Verfahren nach Anspruch 9, das ferner ein Ablehnen des codierten Kartenbilds durch die Navigationsvorrichtung umfasst, falls die zyklische Validierung fehlschlägt.
     
    11. Verfahren nach Anspruch 6, wobei die mehreren Nutzlasten über ein AM- oder FM - Funksignal empfangen werden.
     
    12. Einrichtung (125), die Folgendes umfasst:

    wenigstens einen Prozessor (300);

    wenigstens einen Speicher (301), der einen Computerprogrammcode für ein oder mehrere Programme beinhaltet; und

    einen Sender (305) für drahtloses Übertragen;

    wobei der wenigstens eine Speicher und der Computerprogrammcode konfiguriert sind, um mit dem wenigstens einen Prozessor die Einrichtung zu veranlassen, wenigstens ein Verfahren nach einem der Ansprüche 1-5 durchzuführen.


     
    13. System (120), das Folgendes umfasst:

    wenigstens einen Prozessor (300);

    wenigstens einen Speicher (301), der einen Computerprogrammcode für ein oder mehrere Programme beinhaltet; und

    einen Sender (130, 305) für drahtloses Übertragen;

    wobei der wenigstens eine Speicher und der Computerprogrammcode konfiguriert sind, um mit dem wenigstens einen Prozessor das System zu veranlassen, wenigstens ein Verfahren nach einem der Ansprüche 1-5 durchzuführen.


     
    14. Navigationsvorrichtung (122), die Folgendes umfasst:

    eine Anzeige (211);

    wenigstens einen Prozessor (200);

    wenigstens einen Speicher (204), der einen Computerprogrammcode für ein oder mehrere Programme beinhaltet; und

    einen Empfänger (205) für drahtloses Übertragen;

    wobei der wenigstens eine Speicher und der Computerprogrammcode konfiguriert sind, um mit dem wenigstens einen Prozessor die Navigationsvorrichtung zu veranlassen, wenigstens ein Verfahren nach einem der Ansprüche 6-11 durchzuführen.


     


    Revendications

    1. Procédé mis en œuvre par ordinateur destiné à transmettre des images cartographiques à un dispositif de navigation dans un environnement à bande passante limitée dans lequel le dispositif de navigation est au moins temporairement dans l'incapacité de recevoir ou de transmettre des données à un débit d'au moins 200 kilobits/s, le procédé comprenant :

    la détermination ou la prédiction (S101) d'un état du trafic pour un emplacement sur la base d'une analyse de données de trafic en temps réel, historiques ou prédictives ;

    l'élaboration (S103) d'une image cartographique représentant l'état du trafic ;

    la décomposition de l'image cartographique en une pluralité de segments d'image, dans lequel une image cartographique pour un emplacement avec une densité de trafic plus élevée est décomposée en davantage de segments d'image qu'une image cartographique pour un emplacement avec une densité de trafic plus faible ;

    le codage (S105) de la pluralité de segments d'image de l'image cartographique en une pluralité de charges utiles, chaque charge utile comportant un segment d'image de la pluralité de segments d'image ; et

    la transmission (S107) de la pluralité de charges utiles par voie hertzienne au dispositif de navigation (122), dans lequel chaque transmission d'une charge utile est inférieure à une taille de seuil pour le traitement dans l'environnement à bande passante limitée et dans lequel la pluralité de charges utiles sont transmises avec un ordre défini de sorte que la pluralité de segments d'image peuvent être décodés et réassemblés par le dispositif de navigation pour un affichage sous la forme d'une image cartographique unique.


     
    2. Procédé selon la revendication 1, dans lequel l'image cartographique comprend au moins :

    (1) une image cartographique de jour d'une zone métropolitaine, et/ou

    (2) une image cartographique de nuit de la zone métropolitaine, et/ou

    (3) une image cartographique de jour d'un centre-ville d'une ville, et/ou

    (4) une image cartographique de nuit du centre-ville.


     
    3. Procédé selon la revendication 1, dans lequel l'image cartographique est codée avec des données d'en-tête de tampon et de terminaison de tampon, dans lequel les données de terminaison de tampon comportent un contrôle de redondance cyclique.
     
    4. Procédé selon la revendication 1, dans lequel chaque charge utile de la pluralité de charges utiles comprend un numéro de séquence de début et un numéro de séquence de fin, de sorte que la pluralité de segments d'image peuvent être décodés et réassemblés par le dispositif de navigation à l'aide des numéros de séquence de début et de fin.
     
    5. Procédé selon la revendication 1, dans lequel la pluralité de charges utiles sont émises sur un signal radio AM ou FM.
     
    6. Procédé mis en œuvre par ordinateur destiné à recevoir et traiter des données d'image cartographique codées au niveau d'un dispositif de navigation dans un environnement à bande passante limitée dans lequel le dispositif de navigation est au moins temporairement dans l'incapacité de recevoir ou de transmettre des données à un débit d'au moins 200 kilobits/s, le procédé comprenant :

    la réception (S201), par le dispositif de navigation (122), par l'intermédiaire d'un signal de transmission par voie hertzienne, d'une image cartographique codée, l'image cartographique représentant un état du trafic pour un emplacement déterminé ou prédit sur la base d'une analyse de données de trafic en temps réel, historiques ou prédictives, dans lequel l'image cartographique codée est reçue sous la forme d'une pluralité de charges utiles avec un ordre défini, chaque charge utile comportant un segment d'image d'une pluralité de segments d'image de l'image cartographique, dans lequel une image cartographique pour un emplacement avec une densité de trafic plus élevée est décomposée en davantage de segments d'image qu'une image cartographique pour un emplacement avec une densité de trafic plus faible, et dans lequel la transmission de chaque charge utile est inférieure à une taille de seuil pour le traitement dans l'environnement à bande passante limitée ;

    le décodage (S203), à l'aide d'un processeur du dispositif de navigation, d'une image cartographique unique à partir de l'image cartographique codée ; et

    l'affichage (S205) d'au moins une partie de l'image cartographique décodée unique sur un affichage de dispositif de navigation.


     
    7. Procédé selon la revendication 6, dans lequel chaque charge utile de la pluralité de charges utiles comprend un numéro de séquence de début et un numéro de séquence de fin.
     
    8. Procédé selon la revendication 7, dans lequel le décodage comprend la combinaison de la pluralité de charges utiles par ordre de nombres de séquençage de chaque charge utile pour fournir l'image cartographique décodée.
     
    9. Procédé selon la revendication 6, dans lequel l'image cartographique codée est codée avec des données d'en-tête de tampon et de terminaison de tampon, dans lequel les données de terminaison de tampon comportent des données de contrôle de redondance cyclique, comprenant en outre la validation de la qualité de l'image cartographique codée à l'aide des données de contrôle de redondance cyclique.
     
    10. Procédé selon la revendication 9, comprenant en outre le rejet de l'image cartographique codée par le dispositif de navigation si la validation cyclique échoue.
     
    11. Procédé selon la revendication 6, dans lequel la pluralité de charges utiles sont reçues par l'intermédiaire d'un signal radio AM ou FM.
     
    12. Appareil (125) comprenant :

    au moins un processeur (300) ;

    au moins une mémoire (301) comportant un code de programme informatique destiné à un ou plusieurs programmes ; et

    un émetteur (305) par voie hertzienne ;

    l'au moins une mémoire et le code de programme informatique étant configurés pour, à l'aide dudit processeur, amener l'appareil à au moins exécuter un procédé selon l'une quelconque des revendications 1 à 5.


     
    13. Système (120) comprenant :

    au moins un processeur (300) ;

    au moins une mémoire (301) comportant un code de programme informatique destiné à un ou plusieurs programmes ; et

    un émetteur (130, 305) par voie hertzienne ;

    l'au moins une mémoire et le code de programme informatique étant configurés pour, à l'aide dudit processeur, amener le système à au moins exécuter un procédé selon l'une quelconque des revendications 1 à 5.


     
    14. Dispositif de navigation (122) comprenant :

    un affichage (211) ;

    au moins un processeur (200) ;

    au moins une mémoire (204) comportant un code de programme informatique destiné à un ou plusieurs programmes ; et

    un récepteur (205) par voie hertzienne ;

    l'au moins une mémoire et le code de programme informatique étant configurés pour, à l'aide dudit processeur, amener le dispositif de navigation à au moins exécuter un procédé selon l'une quelconque des revendications 6 à 11.


     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description