Cellular-system signal-strength analyzer

• US 5,398,276 A
• Filed: 02/09/1993
• Issued: 03/14/1995
• Est. Priority Date: 02/09/1993
• Status: Expired due to Fees

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Safco Corporation
• Inventors: Lemke, Kurt T., Schifferdecker, Joseph A.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): LOOMIS, PAUL A
• Application Number:
  US08/015,576
• Time in Patent Office: 763 Days
• Field of Search: 379/1, 379/21, 379/27, 379/29, 379/32, 379/34, 379/58, 379/59, 455/33.1, 455/67.1, 455/67.3, 455/161.3, 455/226.2, 455/226.4, 375/10, 358/10, 358/139
• US Class Current: 379/21
• CPC Class Codes: G01S 17/86 Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders
• CPC Class Codes: G01S 17/88 Lidar systems specially adapted for specific applications
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements

Abstract

A manually-movable, portable, cellular-system signal-strength analyzer for measuring, recording and displaying geographically-located, downlink, cellular-communication-channel signal strengths in non-vehicular pedestrian areas and also inside buildings. The analyzer has a cellular-telephone scanning receiver housed within a backpack that is worn by a human operator who traverses the areas to be analyzed. A height-adjustable antenna mast formed from a set of telescoping tubes is fixed to the exterior of the backpack. This mast supports a self-resonant antenna of fixed length whose elevation height may be varied to determine signal-strengths at different pedestrian heights. The backpack also houses a controller. A laser rangefinder which has a built-in compass inputs data to the controller concerning the geographic locations of various points traversed by the analyzer. An arm-held computer is also connected to the controller. The computer has a display and a "pen" for manual writing on the display to input data and instructions to the analyzer. The computer records and displays the signal strengths of the selected cellular-communication channels for various geographically located points throughout the areas traversed.

Claims

1. A method of measuring and recording a plurality of geographically-located, downlink, cellular-communication-channel signal strengths in a pedestrian area using a signal-strength analyzer incorporated as part of a human-supported backpack with the analyzer having an antenna, a receiver, a controller, a timer, a computer, and a self-contained navigation system using a gun having an integral laser rangefinder and a fluxgate compass operating in a dead-reckoning mode with reference to a target point positioned in or adjacent the pedestrian area under analysis to report the respective geographic positions of a sequence of timed signal-strength measurements as the analyzer is moved throughout the pedestrian area in a straight-line path, in which the method comprises the steps of:

a) selecting a straight-line path segment having a starting point and an end point along which the analyzer is to be moved within the pedestrian area under analysis,

b) inputting to the controller assigned values which establish an arbitrary or exact geographic position of the starting point,

c) positioning the analyzer at the starting point which is at the beginning of the straight-line path segment,

d) selecting a distant target point in or adjacent the pedestrian area in the direction of travel along the straight-line path segment which target point is beyond the end point of the straight-line path segment and in alignment with the segment,

e) specifying a time interval by which successive and time-based, signal-strength measurements are to be taken by the signal-strength analyzer,

f) aiming the gun at the distant target point to take a bearing measurement of the straight-line path segment,

g) momentarily activating the gun to take a range measurement from the starting point to the distant target point,

h) reporting the range and bearing measurements of the starting point to the backpack controller,

i) moving the signal-strength analyzer at a uniform velocity by human-operator pacing along the straight-line path segment immediately upon the reporting of the range and bearing measurements of the starting point to the backpack controller,

j) resetting the timer to zero and then starting the timer immediately upon starting movement of the signal-strength analyzer along the straight-line path segment,

k) recording the time as timed by the timer required to move the analyzer along the straight-line path segment immediately upon arrival at the end point of the straight-line segment,

l) aiming the gun at the distant target point upon arrival at the end point of the straight-line path segment to measure a lesser range to the distant target point,

m) computing the distance traveled along the straight-line path segment by subtracting in the computer the range measurement for the end point of the straight-line path segment from the range measurement of the starting point of the straight-line path segment,

n) taking cellular system signal-strength measurements using the antenna and receiver at each specified time interval as the signal-strength analyzer is moved at a uniform velocity along the straight-line path segment from the starting point to the end point,

o) timestamping each signal strength measurement taken during movement of the signal-strength analyzer from the starting point to the end point of the straight-line path segment to position geographically each such measurement along the straight-line path segment,

p) computing upon arrival at the end point the geographic location of each signal-strength measurement taken along the straight-line path segment, using the distance traveled as computed in the computer, the recorded time required to traverse the straight-line path segment, the reported bearing measurement and the specified time interval,

q) and placing in the computer memory the geographic location and signal strength of each measurement taken on and along the straight-line path segment.

2. The method of claim 1 comprising repeating steps a) through q) with respect to a second straight-line path segment which starts at the end point of the first straight-line path segment and which has a bearing which differs from the bearing of the first straight-line path segment by using a second distant target point in or adjacent the pedestrian area in the direction of travel along the second straight-line path segment and which distant target point is beyond the end point of the second straight-line path segment and in alignment with the second segment.

3. A method of measuring and recording a plurality of geographically-located, downlink, cellular-communication-channel signal strengths in a pedestrian area using a signal-strength analyzer incorporated as part of a human-driven pack with the analyzer having an antenna, a receiver, a controller, a timer, a computer, and a self-contained navigation system using a rangefinder emitting an electromagnetic ray and a bearing-reporting compass operating in a dead-reckoning mode with reference to one or more target points positioned in or adjacent the pedestrian area under analysis to report the respective geographic positions of a sequence of timed signal-strength measurements as the analyzer is moved throughout the pedestrian area in a straight-line path segment, in which the method comprises the steps of:

a) selecting a straight-line path segment having a starting point and an end point along which the analyzer is to be moved within the pedestrian area under analysis,

b) inputting to the controller assigned values which establish an arbitrary or exact geographic position of the starting point,

c) positioning the analyzer at a starting point which is at the beginning of the straight-line path segment,

d) selecting a first distant target point in or adjacent the pedestrian area in the direction of travel along the straight-line path segment which target point is beyond the end point of the segment and in alignment with the segment,

e) specifying a time interval by which successive and time-based, signal-strength measurements are to be taken by the signal-strength analyzer,

f) taking a bearing measurement of the straight-line path segment from the starting point,

g) activating the rangefinder to take a range measurement from the starting point to the distant target point,

h) reporting the range and bearing measurements of the starting point to the controller,

i) moving the signal-strength analyzer at a uniform velocity by human-operator pacing along the straight-line path segment after the taking of the range and bearing measurements,

j) initiating a time measurement immediately upon starting movement of the signal-strength analyzer along the straight-line path segment,

k) concluding the time measurement immediately upon arrival at the end point of the straight-line segment,

l) aiming the rangefinder at the target point after arrival at the end point of the straight-line path segment to measure a lesser range to the target point,

m) computing the distance traveled along the straight-line segment by subtracting in the computer the range measurement for the end point of the straight-line path segment from the range measurement of the starting point of the straight-line path segment,

n) taking cellular system signal-strength measurements using the antenna and receiver at each specified time interval as the signal-strength analyzer is moved at a uniform velocity along the straight-line path segment from the starting point to the end point,

o) timestamping each signal strength measurement taken during movement of the signal-strength analyzer from the starting point to the end point of the straight-line path segment to position geographically each such measurement along the straight-line segment,

p) computing after arrival at the end point the geographic location of each signal-strength measurement taken along the straight-line path segment

q) and placing in the computer memory the geographic location and signal strength of each measurement taken along the straight-line path segment.

4. The method of claim 3 comprising repeating the steps a) through q) with respect to a second straight-line path segment which starts at the end point of the first straight-line path segment and which has a bearing which differs from the bearing of the first straight-line path segment by using a second target point in or adjacent the pedestrian area in the direction of travel along the second straight-line path segment which second target point is beyond the end point of the second straight-line path segment.

5. A method of measuring and recording a plurality of geographically-located, downlink, cellular-communication-channel signal strengths in a pedestrian area using a signal-strength analyzer incorporated as part of a portable pack with the analyzer having a self-contained navigation system using a gun having a rangefinder and a compass operating in a dead-reckoning mode with reference to a target point positioned in or adjacent the pedestrian area under analysis to report the respective geographic positions of a sequence of timed signal-strength measurements as the analyzer is moved throughout the pedestrian area in a straight-line path segment, in which the method comprises the steps of:

a) selecting a straight-line path segment along which the analyzer is to be moved within the pedestrian area under analysis,

b) inputting to the analyzer assigned values which establish an arbitrary or exact geographic position of the starting point,

c) positioning the analyzer at a starting point which is at the beginning of the straight-line segment,

d) selecting a first distant target point in or adjacent the pedestrian area in the direction of travel along the straight-line path segment which target point is beyond the end point of the segment,

e) specifying a time interval by which successive and time-based, signal-strength measurements are to be taken by the signal-strength analyzer,

f) taking a bearing measurement of the straight-line path segment,

g) taking a range measurement from the starting point to the first distant target point,

h) reporting the bearing of the straight-line path segment to the analyzer and reporting the range measurement of the starting point to the analyzer,

i) moving the signal-strength analyzer at a uniform velocity by human-operator pacing along the straight-line path segment upon the reporting of the range measurement of the first starting point to the analyzer,

j) initiating a time measurement immediately upon starting movement of the signal-strength analyzer along the straight-line path segment,

k) concluding the time measurement immediately upon arrival at the end point of the straight-line path segment,

l) measuring a lesser range to the target point upon arrival at the end point of the straight-line path segment,

m) computing the distance traveled along the first straight-line segment by subtracting in the analyzer the range measurement for the end point of the straight-line path segment from the range measurement of the starting point of the straight-line path segment,

n) taking cellular system signal-strength measurements at each specified time interval as the signal-strength analyzer is moved at a uniform velocity along the straight-line path segment from the starting point to the end point,

o) timestamping each signal strength measurement taken during movement of the signal-strength analyzer from the starting point to the end point of the first straight-line path segment to position geographically each such measurement along the first straight-line segment,

p) and placing in the analyzer the geographic location and signal strength of each measurement taken along the straight-line path segment.

6. The method of claim 5 comprising repeating steps a) through p) with respect to a second straight-line path segment which starts at the end point of the first straight-line path segment and which has a bearing which differs from the bearing of the first straight-line path segment by using a second target point in or adjacent the pedestrian area in the direction of travel along the second straight-line path segment which target point is beyond the end point of the second straight-line path segment.

7. A manually-movable, portable, cellular-system signal-strength analyzer for measuring and recording geographically-located, downlink, cellular-communication-channel signal strengths in a pedestrian area, comprising a portable pack capable of human-driven movement throughout the pedestrian area, a downlink cellular-communication-channel scanning receiver carried by the pack for reporting information relating to signal strength measurements for selected cellular communication channels, a height adjustable antenna-supporting mast fixed to the pack, an antenna having an active receiving section of fixed length and electrical reception characteristics connected to the receiver and attached to the mast with the mast being capable of adjustment as to height relative to the pack to detect cellular system signals at, above, and below the usual heights at which pedestrians utilize portable cellular transceivers in the pedestrian areas, a controller carried by the pack and connected to the receiver to effect scanning of the selected communication channels and to extract signal-strength information reported to the controller by the receiver for the selected communication channels whose signal strengths are to be measured and recorded and also for receiving navigation information concerning the geographic locations for the signal strengths extracted by the controller, a laser rangefinder and a bearing-reporting fluxgate compass both of which generate an electrical output which is inputted to the controller to determine the positions of the portable pack by dead reckoning with reference to one or more laser-beam target objects positioned in or adjacent the pedestrian areas under analysis as the analyzer is moved in one or more straight-line path segments with each target object being located beyond an associated straight-line path segment and in extended alignment with that segment, and a computer connected to the controller for recording and displaying geographically-located signal strengths with respect to identified communication channels.

8. The signal strength analyzer of claim 7 comprising a timer which measures the elapsed time it takes to move the portable pack at a uniform velocity along each straight line path segment with each segment having a starting point and an end point and in which the timer also timestamps each of the signal-strength measurement information reported to the controller along each straight-line path segment.

9. The signal-strength analyzer of claim 8 including means for taking periodic signal-strength measurements at uniform predetermined time intervals as the analyzer is moved at a uniform velocity along each straight-line path segment.

10. The signal strength analyzer of claim 8 in which the portable pack is a back pack.

11. A manually-movable, portable, cellular-system signal strength analyzer for measuring and recording geographically-located, downlink, cellular-communication-channel signal strengths in pedestrian areas, comprising a portable pack capable of human-driven movement throughout the pedestrian areas, a downlink cellular-communication channel scanning receiver carried by the pack for reporting information relating to the signal strengths for selected cellular communication channels, a height adjustable antenna-supporting mast fixed to the pack, an antenna having an active receiving section of fixed length and electrical reception characteristics connected to the receiver and attached to the mast with the mast being capable of adjustment as to height relative to the pack to detect cellular system signals at the height at which pedestrians utilize portable cellular transceivers in the pedestrian areas, a controller carried by the pack and connected to the receiver to effect scanning of the selected communication channels and to extract signal-strength information reported to the controller by the receiver for the selected communication channels whose signal strengths are to be measured and recorded and also for receiving navigation information concerning the geographic locations for the signal strengths extracted by the controller, a rangefinder and a bearing-reporting compass both of which generate an electrical output which is inputted to the controller to determine the positions of the portable pack by dead reckoning with reference to one or more target objects positioned in or adjacent the pedestrian areas under analysis as the analyzer is moved in one or more straight-line path segments with each target object being located beyond an associated straight-line path segment and in extended alignment with that segment, and a computer connected to the controller for recording and displaying geographically-located signal strengths with respect to identified communication channels.

12. The signal strength analyzer for claim 11 comprising a timer which measures the elapsed time it takes to move the portable pack at a uniform velocity along each straight line path segment with each path segment having a starting point and an ending point which points are geographically located by the rangefinder and the compass and in which the timer also timestamps each of the signal-strength measurement information reported to the controller along each straight-line path segment.

13. The signal strength analyzer of claim 12 including means for taking periodic signal-strength measurements at uniform predetermined time intervals as the analyzer is moved at a uniform velocity along each straight-line path segment.

14. A method of measuring and recording a plurality of geographically-located, downlink, cellular-communication-channel signal strengths in a pedestrian area using a signal-strength analyzer incorporated as part of a human-operator-driven pack with the analyzer having an antenna, a receiver, a controller, and a computer, in which the method comprises the steps of:

selecting a straight-line path segment having a starting point and an end point along which the analyzer is to be moved within the pedestrian area under analysis,

positioning the analyzer at the starting point at the beginning of the straight-line path segment,

inputting the length of the human-operator'"'"'s pace to the computer,

reporting the bearing of the straight-line path segment to the controller,

moving the signal-strength analyzer at a uniform velocity along the first straight-line path segment by having the human operator walk the distance of the straight-line path segment,

counting the number of paces required to traverse the distance of the straight-line path segment,

measuring and recording periodically signal-strength measurements taken during the course of the walk of the straight-line path segment,

inputting the number of paces required to travel the distance of the straight-line path segment,

computing the distance traveled along the straight-line path segment by multiplying the number of paces by the pace length inputted to the computer,

geographically positioning each periodic signal strength measurement taken as the signal-strength analyzer was moved along the straight-line path segment,

and reporting each such geographically-located signal-strength measurement to the computer.

15. A manually-movable, portable, cellular-system signal strength analyzer for measuring and recording geographically-located, downlink, cellular communication-channel signal strengths in pedestrian areas, comprising a portable pack capable of human driven movement throughout the pedestrian areas, a downlink cellular-communication channel scanning receiver carried by the pack for reporting information relating to the signal strengths for selected cellular communication channels, a mast, an antenna having an active receiving section of fixed length and electrical reception characteristics connected to the receiver and attached to the mast, a controller carried by the pack and connected to the receiver to effect scanning of the selected communication channels and to extract signal-strength information reported to the controller by the receiver for the selected communication channels whose signal strengths are to be measured and recorded and also for receiving navigation information concerning the geographic locations for the signal strengths extracted by the controller, means for effecting a dead-reckoning system to determine the positions of the portable pack within the pedestrian areas under analysis, and a computer connected to the controller for recording and displaying geographically-located signal strengths with respect to identified communication channels.

16. The signal strength analyzer of claim 15 in which the mast is capable of adjustment as to height relative to the pack to detect cellular system signals at the height at which pedestrians utilize portable cellular transceivers in the pedestrian areas.

17. The signal strength analyzer of claim 15 in which the means for effecting a dead-reckoning navigation system utilizes a rangefinder and a compass for measuring both of which generate an electrical output which is inputted to the controller to determine the positions of the portable pack by dead reckoning with reference to one or more target objects positioned in or adjacent the pedestrian areas under analysis.

18. The signal strength analyzer for claim 17 comprising a timer which measures the elapsed time it takes to move the portable pack at a uniform velocity along a straight line path having a starting point and an ending point which points are geographically located by the rangefinder and the compass, and in which the timer also timestamps each signal-strength measurement taken while the signal-strength analyzer is moved between the starting point and the end point.

19. The signal strength analyzer of claim 18 in which a laser rangefinder is utilized as the rangefinder.

20. The signal strength analyzer of claim 19 in which a fluxgate bearing-reporting compass is utilized as the bearing-reporting compass.