U.S. patent application number 13/853489 was filed with the patent office on 2013-11-07 for testing voice-based office equipment for immunity to interference from wireless devices.
The applicant listed for this patent is Goldman, Sachs & Co.. Invention is credited to Stephen Berger, Tony Griffiths, Joseph Liguori, Jeff Rodman, Werner Schaefer, Vivek Talwar.
Application Number | 20130295856 13/853489 |
Document ID | / |
Family ID | 38232217 |
Filed Date | 2013-11-07 |
United States Patent
Application |
20130295856 |
Kind Code |
A1 |
Talwar; Vivek ; et
al. |
November 7, 2013 |
Testing Voice-Based Office Equipment For Immunity To Interference
From Wireless Devices
Abstract
According to some embodiments, a method includes placing a
device under test (DUT) in a test chamber and applying a
pulse-modulated RF wireless test signal to the DUT in the test
chamber. The method further includes detecting an acoustic output
of the DUT. In addition or as an alternative to applying the
pulse-modulated test signal, the test signal strength may be at a
level of 30 V/m or 90 V/m. If the DUT is a telephone, it may be
coupled via a voice signal path to another telephone, and an output
of the other telephone may also be detected.
Inventors: |
Talwar; Vivek; (Edgewater,
NJ) ; Berger; Stephen; (Georgetown, TX) ;
Schaefer; Werner; (Novato, CA) ; Rodman; Jeff;
(San Francisco, CA) ; Griffiths; Tony;
(Worcestershire, GB) ; Liguori; Joseph; (Brick,
NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Goldman, Sachs & Co.; |
|
|
US |
|
|
Family ID: |
38232217 |
Appl. No.: |
13/853489 |
Filed: |
March 29, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11636885 |
Dec 11, 2006 |
8412111 |
|
|
13853489 |
|
|
|
|
60750727 |
Dec 15, 2005 |
|
|
|
Current U.S.
Class: |
455/67.12 |
Current CPC
Class: |
H04M 1/24 20130101; H04B
17/16 20150115; G01R 31/002 20130101 |
Class at
Publication: |
455/67.12 |
International
Class: |
H04B 17/00 20060101
H04B017/00 |
Claims
1.-13. (canceled)
14. A method comprising: placing a first telephone in a test
chamber; connecting the first telephone to a second telephone that
is not in the test chamber; applying an RF wireless test signal to
the first telephone in the test chamber; detecting an output of the
second telephone.
15. The method of claim 14, further comprising: detecting an output
of the first telephone.
16. The method of claim 14, wherein the test signal is
pulse-modulated.
17. The method of claim 14, wherein the test signal has a strength
of at least 30 V/m in at least a portion of the test chamber.
18. The method of claim 17, wherein the test signal has a strength
of at least 90 V/m in at least a portion of the test chamber.
19.-20. (canceled)
21.-27. (canceled)
28. A method comprising: using a handheld wireless device to
generate a sample signal; recording the sample signal; placing a
device under test (DUT) in a test chamber; reproducing the recorded
sample signal in the test chamber to apply the reproduced sample
signal to the DUT as a test signal; and detecting an acoustic
output of the DUT.
29. The method of claim 28, wherein: the sample signal is recorded
using a vector signal analyzer; and the recorded sample signal is
reproduced using a vector signal generator.
30. The method of claim 28, wherein the sample signal is stored as
an IQ file.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims benefit from provisional patent
application no. 60/750,727, filed Dec. 15, 2005, which is
incorporated herein by reference.
FIELD
[0002] The present invention relates to electronic equipment. In
some embodiments, the present invention relates to methods and
apparatus for testing electronic equipment for immunity to
interference.
BACKGROUND
[0003] As new kinds of electronic equipment have continued to
proliferate, the opportunities for interference between items of
equipment have increased. One type of interference that is
increasingly a problem is interference experienced by telephones,
wireless headsets or conference room voice amplification
(microphone) systems from portable wireless devices such as the
well-known BlackBerry.RTM. portable electronic mail device. An
aggravating factor in terms of potential interference is the likely
increased proximity of potentially interfering devices to devices
that may suffer interference. For example, one individual may being
speaking on a telephone in his/her cubicle, while another
individual in a neighboring cubicle is using his/her BlackBerry
device or speaking on a cellular telephone. As another example, an
individual may be using his/her BlackBerry in a meeting in a
conference room in close proximity to a microphone that is part of
a voice amplification system for the conference room. In both of
these examples, audible interference may be produced in the
voice-based device, so that voice communication is prevented or
degraded.
[0004] Accordingly, the present inventors have recognized a need
for improved testing of voice-based devices to determine whether
the devices are subject to interference from nearby wireless
devices.
SUMMARY
[0005] To address the foregoing, embodiments of the present
invention concern a method, an apparatus, and a medium storing
processor-executable process steps to place a device under test
(DUT) in a test chamber, apply a pulse-modulated RF wireless test
signal to the DUT in the test chamber and detect an acoustic output
of the DUT. To simulate the proximity of potential interfering
devices in real-world situations, the test signal strength may be
on the order of 30 V/m for some DUTs and on the order of 90 V/m for
other DUTs.
[0006] In some aspects, the DUT in the test chamber may be a
telephone which is coupled to second telephone that is not in the
test chamber. An output of the second telephone may also be
detected to determine whether interference is transmitted from the
DUT telephone in the test chamber to the second telephone
[0007] With these and other aspects of the invention, improved
testing of voice-based electronic devices may be provided to
determine whether the devices are subject to interference in
situations likely to be encountered during real-world use of the
electronic devices.
[0008] With these and other advantages and features of the
invention that will become hereinafter apparent, the invention may
be more clearly understood by reference to the following detailed
description of the invention, the appended claims, and the drawings
attached hereto.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram of a test arrangement consistent
with the present invention.
[0010] FIG. 2 is a flow diagram that illustrates an exemplary
process that may be performed in the test arrangement of FIG.
1.
[0011] FIG. 3 is a block diagram of a test arrangement consistent
with another embodiment of the invention.
[0012] FIG. 4 is a flow diagram that illustrates an exemplary
process that may be performed in the test arrangement of FIG.
3.
[0013] FIG. 5 is a block diagram of one embodiment of a control
device that may be part of the test arrangement(s) of FIG. 1 and/or
FIG. 3.
DETAILED DESCRIPTION
[0014] In general, and for the purposes of introducing concepts of
embodiments of the present invention, voice-based electronic
devices may be subjected to testing for susceptibility to
interference in accordance with test procedures that more
accurately reflect certain potential real-world conditions than
prior art testing has done. For example, the test signal applied to
the electronic devices may be pulse-modulated rather than
amplitude-modulated. Also, the strength of the test signal may be
substantially higher than in prior art practices to reflect the
potentially extreme proximity of sources of interference that may
be experienced in the real world by the devices to be tested.
[0015] Features of some embodiments of the present invention will
now be described by first referring to FIG. 1, where a block
diagram of one embodiment of a test arrangement 100 is shown. As
shown, test arrangement 100 includes a number of different
components which cooperatively operate to perform testing of
electronic devices to determine to what extent, if any, the
electronic devices are vulnerable to interference from certain
wireless devices.
[0016] As depicted, test arrangement 100 includes a test chamber
102. The test chamber 102 may be, for example, any one of a number
of different types of test chambers conventionally employed in
testing of electronic devices. For example, the test chamber 102
may be of a type conventionally employed for testing for
vulnerability to interference. Among other possibilities, the test
chamber 102 may be a GTEM (gigahertz transverse electromagnetic
cell) chamber, a reverberation test chamber, an anechoic test
chamber or a semi-anechoic test chamber. The test chamber need not
be identical to known test chambers but rather may, for example, be
specially designed in accordance with known principles as informed
by the teachings of this invention.
[0017] Reference numeral 104 indicates a device under test (DUT)
which has been placed in the test chamber 102. The DUT 104 may, but
need not, be considered part of the test arrangement 100. The DUT
104 may be any one of a number of different types of electronic
devices. For example, the DUT 104 may be a telephone (e.g., a
conventional fixed telephone and/or speakerphone, a cordless
telephone or a cellular telephone), a wireless headset (including a
microphone and at least one earphone), or a conference room
microphone (e.g., a gooseneck microphone).
[0018] The test arrangement 100 also includes an antenna 106 which
is installed (permanently or temporarily) in the test chamber 102
to radiate a test signal in the test chamber 102, thereby to apply
the test signal to the DUT 104 in the test chamber 102. The antenna
106 may be a conventional off-the-shelf item, and may be a
biconical antenna, a log periodic antenna or may be formed of
standard gain horns.
[0019] The test arrangement 100 further includes a control device
108, which may function as the "brains" of the test arrangement
100. The control device 108 may control operation of the test
arrangement 100 and may tabulate results of tests performed in the
test arrangement 100. As will be seen, the control device 108 may
be constituted, at least in part, by conventional computer hardware
such as a conventional personal computer. Further details of the
control device 108 will be discussed below.
[0020] Still further, the test arrangement 100 may include a test
signal generator 110. The test signal generator is coupled to and
under the control of the control device 108. The test signal
generator 110 may be like or generally similar to conventional test
signal generators for interference immunity testing, except that
the test signal generator may be such as to generate or be driven
or controlled to generate a pulse-modulated test signal. For
example, the test signal generator may be driven/controlled to
generate a signal formed of 100 microsecond pulses, repeated at a
100 Hz repetition rate, of an RF carrier signal. The carrier
frequency may, in some test procedures performed in the test
arrangement, be varied throughout (stepped through) a frequency
range of, say, 800 MHz to 6.0 GHz. In some examples, the frequency
may be increased to traverse the range in steps of 1% of the
current frequency from the low end of the range to the top of the
range. Other frequency ranges and/or step sizes may also or
alternatively be employed.
[0021] In addition, the test arrangement 100 may include a power
amplifier 112 which is coupled to the test signal generator 110 to
amplify the test signal generated by the test signal generator 110.
Although not indicated in the drawing, the power amplifier 112 may
also be coupled to the control device 108 to allow the control
device 108 to control the degree of amplification provided by the
power amplifier 112. Thus the control device 108 may be allowed to
control the power level of the test signal applied to the DUT 104
in the test chamber 102.
[0022] Further, the test arrangement 100 may include a directional
coupler 114 which connects an output of the power amplifier 112 to
the antenna 106 so that the amplified test signal is radiated in
the test chamber 102 by the antenna 106. The directional coupler
114 also couples the output of the power amplifier 112 to a
feed-back path 116. The feed-back path 116 includes a power sensor
118 and a power meter 120 for detecting and measuring the power
level of the amplified test signal output from the power amplifier
112. The feed-back path 116 is coupled to the control device 108 to
provide to the control device 108 an input that indicates the power
level of the amplified test signal. Based on this input, the
control device 108 may be able to control the level of the test
signal so that the test signal is radiated at a desired level in
the test chamber 102.
[0023] Still further, the test arrangement 100 includes a detection
path 122. The detection path 122 includes an amplifier 124 and a
coupler 126 by which the amplifier is coupled to the DUT 104 to
receive a signal or signals output from the DUT 104. As only
schematically indicated in the drawing, in some embodiments
coupling to the DUT 104 may be via an acoustic pickup (e.g., a
microphone) positioned outside of the test chamber 102 to pick up
an acoustic output of the DUT 104. In other embodiments, a suitable
RF-immune microphone may be placed inside the test chamber for
acoustic coupling to the DUT 104, with the electrical signal from
such a microphone coupled to the amplifier 124. A microphone or
other pickup located in or near the test chamber will be considered
associated with the test chamber.
[0024] The detection path 122 further includes a bandpass filter
128 coupled to the amplifier 124 and a multimeter 130 coupled to
the filter 128 to measure the level of the DUT output, as amplified
by the amplifier 124 and filtered by the filter 128. The multimeter
130 is coupled to the control device 108 to provide a measurement
output to the control device 108. The measurement provided by the
multimeter 130 may be indicative of a degree of interference, if
any, experienced by the DUT 104 as a result of the application to
the DUT 104 of the test signal.
[0025] FIG. 2 is a flow diagram that illustrates an exemplary
process that may be performed in the test arrangement 100. At 202
in FIG. 2, the DUT 104 is placed in the test chamber. Before or
after the DUT 104 is placed in the test chamber 102, the DUT 104 is
coupled so that its output is provided to the detection path 122.
At 204, the test signal is applied to the DUT 104 in the test
chamber. That is, the test signal is generated by the test signal
generator 110, amplified by the power amplifier 112 and coupled to
the antenna 106 so that the antenna 106 radiates the test signal in
the test chamber 102. Example frequency and modulation
characteristics of the test signal were described above in
connection with discussion of the test signal generator 110. In
some embodiments, the test signal may be amplified to such a degree
that the field strength of the test signal in at least a portion of
the test chamber 102 is at least 30 V/m. Such a signal strength may
be applied to all types of DUTs, except that for devices connected
to be connected to wireless transmitters (e.g., wireless headsets
or assistive listening devices (amplifier modules)) the test signal
strength may be at least 90 V/m in at least a portion of the test
chamber. The field strength of 30 V/m corresponds to a distance of
about 15 cm between a potentially interfering wireless transmitter
and the device (e.g., a telephone) that potentially may experience
interference. The field strength of 90 V/m corresponds to a
situation in which the potentially interfering device is directly
physically connected to the device (e.g. a headset) that
potentially may experience interference.
[0026] At 206 in FIG. 2, the detection path 122 of the test
arrangement 100 may detect and/or measure the output of the DUT
(e.g., simultaneously with application of the test signal) to
determine whether and/or to what extent the DUT is or may be
vulnerable to interference from wireless devices. The measurements
output from the detection path 122 may be provided to the control
device 108, which may store, tabulate and/or analyze the
measurements to provide an indication as to whether or not the DUT
104 is vulnerable to RF interface.
[0027] In some embodiments, the DUT 104 is operated in each of its
normal operating modes while in the test chamber 102, and the full
range of test signals is applied during each of the operating
modes.
[0028] If the DUT 104 is battery powered, it may be advisable to
install a fresh battery in the DUT for use during testing. It may
be desirable that the battery have a voltage, when no load is
applied, that is within 5% of the battery's rated voltage.
[0029] In a case where the DUT 104 is a telephone that includes a
handset, a sound pressure level that does not exceed 40 dB(A) at
the handset may be considered acceptable.
[0030] In a case where the DUT 104 is arranged to be interfaced to
a headset, the headset should be installed for the test, and a
sound pressure level that does not exceed 40 dB(A) at the headset
may be considered acceptable.
[0031] In a case where the DUT 104 includes a speakerphone, a test
result obtained during speakerphone mode in which the sound
pressure level measured at a distance of 25 cm in the direction of
maximum acoustic output from the speaker does not exceed 46 dB(A)
may be considered acceptable. As to test results obtained with the
DUT 104 not in speakerphone mode, it may be an acceptable
measurement if the sound pressure level measured at a distance of
25 cm in the direction of maximum acoustic output from the speaker
does not exceed 46 dB(A) or the ambient noise level, whichever is
lower (i.e., no detectable acoustic output). In other embodiments,
the measurement may be taken at a distance of less than 25 cm with
adjustments to the above-mentioned thresholds. Such adjusted
thresholds may be determined, for example, by transmitting to the
DUT a tone that produces a sound pressure of 46 dB(A) at 25 cm and
measuring the resulting sound pressure at the alternative
distance(s).
[0032] As for other consideration relating to test results, it may
be determined that the test results are acceptable if the DUT 104
does not suffer a reset, loss of data, change in LED state,
blanking or changing in displayed data, disconnection from a call
or any ongoing disruption of the device operation during the test.
It may be acceptable for the DUT 104 to exhibit momentary,
self-correcting transient events.
[0033] Prior to the test proper, it may be desirable to test the
detection path 122 without the DUT present to assure that the test
signal does not cause a change in the detected sound pressure
levels of other monitoring output.
[0034] During the test, it may be desirable to support the DUT in
the test chamber in such a way that there are not significant RF
reflecting objects within a distance of at least 2 wavelengths of
the frequency of measurement, or at least a distance such that the
total reflections from such objects are kept at least 20 dB below
the desired direct test signal. Support structures such as expanded
foam and very low dielectric constant plastics may be used for
supporting the DUT.
[0035] A check for reflections may be made when calibrating the
field uniformity. To check for reflections, standing waves or other
influence from nearly objects, an isotropic probe may be moved 1/4
wavelength relative to the support structure. The frequency band
may then be rescanned to compare the results.
[0036] It may be desirable that the RF ambient and acoustic noise
floor be more than 20 dB below the intended test field
strength.
[0037] In a case where the test chamber is an anechoic chamber, one
of the following procedures may be used.
[0038] If the DUT is large and has many cables, the DUT and the
cables may be divided into test sections, with each section tested
separately.
[0039] In other cases, the test may be reiterated for each of
vertical and horizontal orientations of the illuminating antenna
and for three positions of the DUT, with the DUT rotated
120.degree. between the three positions, so that a total of six
test iterations are performed.
[0040] In other cases, the antenna may be oriented with a diagonal
(ortho-angle) of a cube that contains the test volume, and the DUT
may be rotated 120.degree. among three test positions, with the
test iterated once for each DUT position.
[0041] For test frequencies that are less than or equal to 2 GHz,
the calibration technique described in International
Electrotechnical Commission standard IEC 6100-4-3 may be employed.
For test frequencies over 2 GHz, one of the following calibration
methods may be used.
[0042] The first method is suitable for relatively large DUTs or
for DUTs with extensive cable harnesses. For this method, the test
area is divided into two sections and a plane is defined at the
leading edge of each section. Calibration is performed for each
section in turn. A first plane is located at the face of the first
section, which includes the location for the DUT housing and its
immediate area. An isotropic probe and (subsequently) the DUT will
be positioned with the leading edge at the first plane. A second
plane is located at the leading edge of the cable harness area,
which is the second section. The second plane is at the midpoint of
the wiring loom between the DUT and any ancillary or support
equipment.
[0043] A transmitting antenna is placed so that its tip is no
closer than 1 meter from the first plane. The height of the antenna
above the floor of the test chamber is at least 1 meter. A field
probe is placed in the first section and power is applied to the
transmitting antenna. Controlled measurements are made to establish
the required forward power into the antenna to give the required
unmodulated test field at the first plane. The calibration is
performed with the antenna both vertically and horizontally
oriented. The same procedure then follows for the second plane and
second section.
[0044] The second method may be appropriate when the DUT can be
moved to ensure that each defined section of the DUT is tested in
turn. In this method, a transmitting antenna is placed so that its
tip is no closer than 1 meter from the predefined test plane. The
antenna height above the floor of the test chamber is at least 1
meter. A field probe is placed in the test plane and power is
applied to the transmitting antenna. Controlled measurements are
made to establish the required forward power into the antenna to
give the required unmodulated test field. The calibration is
performed with the antenna both vertically and horizontally
oriented.
[0045] In another test technique, the test signal is applied with a
dipole antenna in close proximity to the DUT. To calibrate the test
set up, an isotropic RF probe is placed on the circumference of a
circle of rotation at the point closest to the dipole antenna. The
dipole antenna is illuminated and is raised and lowered to find the
point of maximum field strength. The power feed level required for
the desired field strength is determined for each frequency.
[0046] During the actual testing, the DUT is placed in the intended
test position and connected to the monitoring and support
equipment. The dipole antenna is in the position determined during
calibration and is energized. The required frequency range is
scanned, with adjustments in power level as indicated during
calibration. The dipole antenna is raised or lowered so that at
least one tip and the center of the dipole antenna traverse the
height of the DUT. The frequency range is scanned during the
vertical scan. The DUT is rotated twice through 120.degree. with
the vertical scan by the dipole antenna repeated for each new
position of the DUT. The polarization of the dipole antenna is then
changed and the vertical scans and rotations of the DUT are
repeated.
[0047] FIG. 3 is a block diagram of a test arrangement 300
consistent with another embodiment of the invention. In the test
arrangement 300, it is assumed that all of the components of the
arrangement 100 (FIG. 1) are present, with the further assumption
that the DUT 104 is a telephone. A purpose of the test arrangement
300 is to determine whether the DUT telephone 104 is vulnerable to
transmitting interference signals to a remote or "far-end"
telephone 302 with which the DUT telephone 104 is linked by a voice
signal path 304. One or more line simulators and/or a telephone
impairment test set may be used to form the voice signal path 304
between the DUT telephone 104 and the far-end telephone 302. The
far-end telephone 302 is located outside of the test chamber 102
and is preferably located/shielded so that it is not exposed to the
test signal applied to the DUT telephone 104.
[0048] The test arrangement 300 further includes a detection path
122' that is coupled to receive and monitor the output of the
far-end phone 302 and may be similar to the detection path 122 that
is coupled to the DUT telephone 104. The detection path 122'
includes an amplifier 124' and a coupler 126' by the which the
amplifier 124' is coupled to the far-end telephone 302 to receive a
signal or signals output from the far-end telephone 302. The
detection path 122' further includes a bandpass filter 128' coupled
to the amplifier and a multimeter 130' coupled to the filter 128'
to measure the level of the far-end phone output, as amplified by
the amplifier 124' and filtered by the filter 128'. The multimeter
130' is coupled to the control device 108 to provide a measurement
output to the control device 108. The measurement provided by the
multimeter 130' may be indicative of an interference signal, if
any, transmitted to the far-end telephone 302 from the DUT
telephone 104 in response to the test signal applied to the DUT
telephone 104. The components of the detection path 122' may be
similar to, or even identical in construction to, the components of
the detection path 122.
[0049] FIG. 4 is a flow diagram that illustrates an exemplary
process that may be performed in the test arrangement 300 of FIG.
3. At 402 in FIG. 4, the DUT telephone 104 is placed in the test
chamber 102. Before or after the DUT telephone 104 is placed in the
test chamber 102, the DUT telephone 104 is coupled so that its
output is provided to the detection path 122. At 404, the voice
signal path 304 is established between the DUT telephone 104 and
the far-end telephone 302. This is also done either before or after
placing the DUT telephone 104 in the test chamber 102. At 406, the
test signal is applied to the DUT telephone 104 in the test
chamber. This may be done in the same manner described above in
connection with the process of FIG. 2.
[0050] At 408 in FIG. 4, the detection path 122 of the test
arrangement 300 may detect and/or measure the output of the DUT
telephone 104 and may provide resulting measurements to the control
device 108. Further, the control device 108 may receive, analyze,
etc. the measurements from the detection path 122. These activities
may be performed in the same manner as in the process of FIG.
2.
[0051] Further, at 410, the detection path 122' of the test
arrangement 300 may detect and/or measure the output of the far-end
telephone 302 (e.g., simultaneously with application of the test
signal) to determine whether and/or to what extent interference
signals are transmitted from the DUT telephone 104 to the far-end
telephone 302 as a result of the application of the test signal to
the DUT telephone 104. The measurements output from the detection
path 122' may be provided to the control device 108, which may
store, tabulate and/or analyze the measurements to provide an
indication as to whether or not the DUT telephone 104 is vulnerable
to RF interference of a sort which causes the DUT telephone 104 to
transmit audible interference to another telephone to which it is
linked by a voice communication path. A transmission impairment
measurement set (TIMS--not separately shown) may be employed as
part of the detection path 122'.
[0052] In some embodiments, it may be considered that the results
of the test are acceptable if any interference received at the
far-end telephone 302 does not exceed 30 dBmC.
[0053] Reference is now made to FIG. 5, where an example embodiment
of the control device 108 is shown. As depicted, control device 108
includes a processor 500 operatively coupled to a communication
device 502, a storage device 504, an output device 508 (e.g., a
display and/or a printer), and one or more input devices 506. Some
or all of the hardware constituting the control device 108 may be
conventional personal computer (PC) hardware. Thus the processor
500 may be a conventional Pentium.RTM. processor, for example, and
the communication device 502 may be a conventional communication
port which enables the control device 108 to exchange data with the
test signal generator 110 and/or the multimeter(s) 130 (and/or
130') via, e.g., an Ethernet connection. The storage device 504 may
include a conventional hard disk drive or other mass storage device
and/or other types of memory such as random access memory (RAM)
and/or read only memory (ROM).
[0054] The input devices 508 may include a conventional keyboard
and/or a conventional pointing device such as a mouse or trackball.
The ROM, if present, may store basic input/output instructions and
instructions used during boot-up of control device 108. The RAM may
provide fast data storage and retrieval and thus may function as
working memory for processor 500. In addition, the RAM may
temporarily store instructions corresponding to
processor-executable process steps being executed by processor
500.
[0055] Storage device 504 stores one or more programs for
controlling processor 500. The programs include an operating system
510, a program 512 to allow the control device 108 to control
generation of the test signal, a program 513 to allow the control
device to receive and analyze test measurement information from the
detection path(s) 122 (and/or 122'), and possibly other
applications as well, which are not separately indicated. The
programs comprise processor-executable process steps of control
device 108. The programs may also include, for example, device
drivers. Storage device 504 may also store one or more databases
514.
[0056] Under control of the programs stored in the storage device
504, the control device 108 may control the over-all operation of
the test arrangements described above, and may perform the
functions described in connection with the processes of FIGS. 2 and
4.
[0057] A testing procedure or procedures like those described above
may make it possible to identify potential vulnerability of office
equipment to interference from wireless devices. The use of
pulse-modulated and/or high-powered signals may reflect more
accurately than conventional testing procedures sources of
potential interference that may be encountered in the real world in
view of the proliferation of wireless devices in offices and
conference rooms. Application of the procedures of the present
invention may allow manufacturers to trouble-shoot equipment
designs and to revise designs so that equipment that is actually
sold may be substantially immune to types of interference that may
be encountered in actual use.
[0058] Embodiments described herein call for testing for
interference exhibited by the DUT or for testing both for such
interference and for interference transmitted to a far-end
telephone. Other embodiments, however, may test only for
interference transmitted to a far-end telephone, so that the
near-end detection path may be omitted.
[0059] In embodiments described hereinabove, the test signal
applied to the DUT in the test chamber is generated by a test
signal generator. However, in other embodiments, the test signal
may be generated in an alternative manner. For example, a sample RF
transmission may be generated from a cellular telephone or other
handheld wireless device. The sample RF transmission may be
captured as a sample signal with a vector signal analyzer and
stored as an IQ file or in some other manner. (As is known to those
who are skilled in the art, an "IQ file" is a data file that is
produced by IQ modulation, i.e., by modulation of both in-phase and
quadrature components of a waveform.) During test operations, the
stored sample signal may be reproduced in the test chamber as a
test signal. Reproduction of the stored sample signal may utilize a
vector signal generator.
[0060] The flow diagrams and other descriptions of processes herein
are not meant to imply a fixed order of steps. Rather, the process
steps may be performed in any order that is practicable.
[0061] The present invention has been described in terms of several
embodiments solely for the purpose of illustration. Persons skilled
in the art will recognize from this description that the invention
is not limited to the embodiments described, but may be practiced
with modifications and alterations limited only by the spirit and
scope of the appended claims.
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