Raster-to-vector conversion operations adapted to modeling of RF propagation

• US 7,047,014 B1
• Filed: 11/05/2004
• Issued: 05/16/2006
• Est. Priority Date: 11/05/2004
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Airespace, Inc. (Cisco Systems, Inc.)
• Inventors: Friday, Robert J., Davi, Gregg Scott, Dietrich, Paul F.
• Primary Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US10/982,153
• Time in Patent Office: 557 Days
• Field of Search: 445/63.1, 445/63.2, 445/418, 445/446, 445/524, 445/525, 382/113, 382/165, 382/177, 345/443, 345/581, 345/82, 345/600, 345/619, 345/625, 345/631, 707/1, 707/10, 707/101, 703/22
• US Class Current: 455/446
• CPC Class Codes: H04W 16/18 Network planning tools
• CPC Class Codes: H04W 4/18 Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

Methods, apparatuses and systems directed to optimizing vector models for use in modeling RF propagation in desired physical environments. In one embodiment, the present invention can operate on pre-existing vector models. In other implementations, the present invention facilitates the conversion of raster images of buildings and other physical locations to vector formats for use in connection with the computational modeling of radio-frequency (RF) propagation. According to certain embodiments, the present invention is implemented within the context of a location diagram editing application that supports a line recognition filter, a snap filter and a merge filter which a user may individually select and configure. As discussed more fully below, the line recognition filter operates on the vector objects to adjust near-vertical lines (as defined by a configurable threshold angle) to vertical, and near-horizontal lines to horizontal. In some configuration modes, the line recognition filter may also delete lines that are oriented at an angle greater than a threshold from the x-axis and y-axis to, for example, clean up vector objects corresponding to text and other elements that are usually analytically irrelevant to modeling RF propagation. The snap filter, in one implementation, operates to extend closely spaced objects that are oriented within a threshold distance from each other. The merge filter operates, in one implementation, to merge closely spaced parallel lines to, for example, adjust the vector file to correctly model a wall with a single vector object. In one implementation, the output resulting from the invention is a vector file that has each wall accorded a given wall type, and is optimized for use in connection with an RF prediction engine.

Claims

1. A method facilitating the optimization of vector models for modeling RF propagation, comprising

storing a vector file in a computer-readable medium, wherein the vector file models a physical environment and comprises a plurality of vector objects, each vector object including a set of parameters defining the location and orientation of a physical element relative to a location coordinate system including a horizontal axis and a vertical axis;

applying a line recognition filter to a vector object in the vector file, wherein the line recognition filter is operative to

compare the length of the vector object to a threshold recognition length;

compare the angle of orientation of the vector object, relative to the horizontal and vertical axes, to corresponding vertical and horizontal threshold recognition angles; and

automatically delete the vector object, if the length of the vector object is less than the threshold recognition length.

2. The method of claim 1 wherein the line recognition filter is further operative to automatically delete the vector object, if the angle of orientation of the vector object, relative to the corresponding horizontal and vertical axes, is greater than the vertical and horizontal threshold recognition angles.

3. The method of claim 1 wherein the line recognition filter is further operative to automatically adjust the vector object to a horizontal orientation if the angle of orientation of the vector object relative to the horizontal axis is less than the horizontal threshold recognition angle.

4. The method of claim 1 wherein the line recognition filter is further operative to automatically adjust the vector object to a vertical orientation if the angle of orientation of the vector object relative to the vertical axis is less than the vertical threshold recognition angle.

5. The method of claim 1 further comprising applying a snap filter to the vector file, wherein the snap filter is operative to conditionally extend a first vector object to intersect a second vector object.

6. The method of claim 1 further comprising applying a snap filter to the vector file, wherein the snap filter is operative to

determine whether a first vector object can be extended to intersect, or currently intersects, a second vector object;

determine whether an endpoint of the first vector object is within a snap threshold distance of the second vector object; and

modify the first vector object to extend to the second vector object.

7. The method of claim 1 further comprising applying a merge filter to the vector file, wherein the merge filter is operative to merge parallel vector objects within a threshold merge distance.

8. The method of claim 1 wherein the vector object contains a first endpoint location and a second endpoint location.

9. The method of claim 1 wherein the vector object contains an endpoint location, a magnitude, and a direction.

10. The method of claim 1 further comprising

receiving and storing, prior to storing the vector file, a raster image file of the physical environment;

and

converting the raster image file to the vector file.

11. An apparatus facilitating the optimization of vector models for modeling RF propagation comprising:

a processor;

a memory;

a software application, physically stored in the memory, comprising instructions operable to cause the processor and the apparatus to;

store a vector file in the memory, wherein the vector file models a physical environment and comprises a plurality of vector objects, each vector object including a set of parameters defining the location and orientation of a physical element relative to a location coordinate system including a horizontal axis and a vertical axis;

apply a line recognition filter to a vector object in the vector file, wherein the line recognition filter is operative to

compare the length of the vector object to a threshold recognition length;

compare the angle of orientation of the vector object, relative to the horizontal and vertical axes, to corresponding vertical and horizontal threshold recognition angles; and

automatically delete the vector object, if the length of the vector object is less than the threshold recognition length.

12. The apparatus of claim 11 wherein the line recognition filter is further operative to automatically delete the vector object, if the angle of orientation of the vector object, relative to the corresponding horizontal and vertical axes, is greater than the vertical and horizontal threshold recognition angles.

13. The apparatus of claim 11 wherein the line recognition filter is further operative to automatically adjust the vector object to a horizontal orientation if the angle of orientation of the vector object relative to the horizontal axis is less than the horizontal threshold recognition angle.

14. The apparatus of claim 11 wherein the line recognition filter is further operative to automatically adjust the vector object to a vertical orientation if the angle of orientation of the vector object relative to the vertical axis is less than the vertical threshold recognition angle.

15. The apparatus of claim 11 wherein the software application is further operative to cause the processor and the apparatus to apply a snap filter to the vector file, wherein the snap filter is operative to conditionally modify a first vector object to extend to a second vector object.

16. The apparatus of claim 11 wherein the software application is further operative to cause the processor and the apparatus to apply a snap filter to the vector file, wherein the snap filter is operative to

determine whether a first vector object can be extended to intersect, or currently intersects, a second vector object;

determine whether an endpoint of the first vector object is within a snap threshold distance of the second vector object; and

modify the first vector object to extend to the second vector object.

17. The apparatus of claim 11 wherein the software application is further operative to cause the processor and the apparatus to apply a merge filter to the vector file, wherein the merge filter is operative to merge parallel vector objects within a threshold merge distance.

18. The apparatus of claim 11 wherein the vector object contains a first endpoint location and a second endpoint location.

19. The apparatus of claim 11 wherein the vector object contains an endpoint location, a magnitude, and a direction.

20. The apparatus of claim 11 wherein the software application is further operative to cause the processor and the apparatus to

receive and store a raster image file of the physical environment;

and

convert the raster image file to the vector file.

21. A computer program product, physically stored on a machine-readable medium, for facilitating the optimization of vector models for modeling RF propagation, comprising instructions operable to cause a programmable processor to:

store a vector file in a computer-readable memory, wherein the vector file models a physical environment and comprises a plurality of vector objects, each vector object including a set of parameters defining the location and orientation of a physical element relative to a location coordinate system including a horizontal axis and a vertical axis;

apply a line recognition filter to a vector object in the vector file, wherein the line recognition filter is operative to

compare the length of the vector object to a threshold recognition length;

compare the angle of orientation of the vector object, relative to the horizontal and vertical axes, to corresponding vertical and horizontal threshold recognition angles; and

automatically delete the vector object, if the length of the vector object is less than the threshold recognition length.

22. The computer program product of claim 21 wherein the line recognition filter is further operative to automatically delete the vector object, if the angle of orientation of the vector object, relative to the corresponding horizontal and vertical axes, is greater than the vertical and horizontal threshold recognition angles.

23. The computer program product of claim 21 wherein the line recognition filter is further operative to automatically adjust the vector object to a horizontal orientation if the angle of orientation of the vector object relative to the horizontal axis is less than the horizontal threshold recognition angle.

24. The computer program product of claim 21 wherein the line recognition filter is further operative to automatically adjust the vector object to a vertical orientation if the angle of orientation of the vector object relative to the vertical axis is less than the vertical threshold recognition angle.

25. The computer program product of claim 21 wherein the instructions are further operative to cause the programmable processor to apply a snap filter to the vector file, wherein the snap filter is operative to conditionally modify a first vector object to extend to a second vector object.

26. The computer program product of claim 21 wherein the instructions are further operative to cause the programmable processor to apply a snap filter to the vector file, wherein the snap filter is operative to

determine whether a first vector object can be extended to intersect, or currently intersects, a second vector object;

determine whether an endpoint of the first vector object is within a snap threshold distance of the second vector object; and

modify the first vector object to extend to the second vector object.

27. The computer program product of claim 21 wherein the instructions are further operative to cause the programmable processor to apply a merge filter to the vector file, wherein the merge filter is operative to merge parallel vector objects within a threshold merge distance.

28. The computer program product of claim 21 wherein the vector object contains a first endpoint location and a second endpoint location.

29. The computer program product of claim 21 wherein the vector object contains an endpoint location, a magnitude, and a direction.

30. The computer program product of claim 21 wherein the instructions are further operative to cause the programmable processor to

receive and store a raster image file of the physical environment;

and

convert the raster image file to the vector file.