Section 6.
Coverage Acceptance Test Plan
6.1 Bit Error Rate Coverage Acceptance Test Plan for Voice
6.2 Overview
This Coverage Acceptance Test Plan (CATP) is designed to verify that the voice
radio system implemented by Motorola meets or exceeds the required coverage
reliability within DuPage County ETSB’s service area as indicated on Motorola’s
coverage maps. The CATP defines the coverage testing method and procedure, the
coverage acceptance criterion, the test documentation, and the responsibilities of both
Motorola and DuPage County ETSB.
Coverage Acceptance Testing is based upon a coverage prediction that accurately
represents the implemented infrastructure and parameters that are consistent with the
contract agreements. If the implemented system varies from the design parameters,
then a revised coverage map will be prepared. New test maps will reflect the
measured losses and gains associated with the implemented infrastructure and
subscribers. These will be used to define the test configuration and potential areas
from which test locations may be included in the evaluation process. To verify that
the radio coverage reliability is met, the indicated coverage area within DuPage
County ETSB’s operating area will be divided into equally sized test grids.
The following text provides a detailed description of the CATP:
6.3 CATP Definitions
Several definitions are needed to accurately describe the coverage test method.
Where cited, these terms or methods are defined in TSB-88A-11.
1 Wireless Communications Systems --- Performance in Noise- and Interference-Limited Situations ---
Recommended Methods for Technology-Independent Modeling, Simulation, and Verification, Technical Service
Bulletin TSB-88A-1, Telecommunications Industry Association (TIA), Arlington VA, 1999 & 2002.
Motorola Confidential Restricted Emergency Telephone System Board of DuPage County
Use or disclosure of this proposal is DuPage ETSB Radio Interoperability Project
subject to the restrictions on the title page June 17, 2010
Coverage Acceptance Test Plan 6-1
6.3.1 Coverage Area
The coverage area is the geographical region in which communications will be
provided which meets or exceeds the specified Channel Performance Criterion at the
specified reliability for the specified equipment configuration(s). Radio systems are
typically designed to maximize the coverage area within the customer’s service area
(users’ operational area, jurisdictional boundaries, etc.) {TSB-88A, clause 4.1} The
predicted coverage area for this system is indicated on Motorola’s coverage map(s)
supplied with this proposal.
6.3.2 Channel Performance Criterion (CPC):
The CPC is the specified minimum design performance level in a faded channel.
{TSB-88A, clause 4.2} For DuPage County’s system, the CPC is a Delivered
Audio Quality of DAQ-3.0. The DAQ definitions are provided in Table 1. {TSB-
88A, §4.5.1, Table 1}. Given the static reference sensitivity of a receiver, the faded
performance threshold for the specified CPC is determined by using the projected
CPC requirements for different DAQs listed in TSB-88A, Annex A, Table A-1] For
digital voice systems, the faded performance threshold is for a Bit Error Rate (BER)
that provides the specified CPC. The CATP pass / fail criterion for each test location
is the Delivered Audio Quality of DAQ-3.0.
Table 6-1: Delivered Audio Quality Definitions
DAQ (Delivered
Audio Quality) Subjective Performance Description
1 Unusable, speech present but unreadable.
2 Understandable with considerable effort. Frequent repetition due to
noise / distortion.
3 Speech understandable with slight effort. Occasional repetition
required due to noise / distortion.
3.0 Speech understandable with repetition only rarely required. Some
noise / distortion.
4 Speech easily understood. Occasional noise / distortion.
4.5 Speech easily understood. Infreq nuent noise / distortion.
5 Speech easily understood.
6.3.3 Reliability
The reliability is the percentage of locations within the coverage area that meet or
exceed the specified CPC. Motorola’s coverage map(s) indicate the area within which
this system is predicted to provide at least 95% reliability of meeting or exceeding
the CPC of DAQ-3.0. {TSB-88A, subclause 4.4.2; not regulatory contour reliability}
Motorola Confidential Restricted Emergency Telephone System Board of DuPage County
Use or disclosure of this proposal is DuPage ETSB Radio Interoperability Project
subject to the restrictions on the title page June 17, 2010
Coverage Acceptance Test Plan 6-2
6.3.4 Equipment Configurations
These are the types and configurations of radio network and field unit equipment
upon which coverage acceptance is based. Motorola’s coverage maps for this system
indicate the coverage area for the following equipment configuration:
♦ Receiver voting coverage from 2.5 Watt ASTRO narrow pulse portables inside
12dB loss buildings. The APX7000 portable at hip, with half-wave antenna, in a
swivel case with Remote Speaker Microphone (RSM).
6.3.5 In-Building Coverage
Motorola’s coverage maps for portable in-building equipment configurations are
predictions of coverage inside 12dB loss buildings as specified by the DuPage
County ETSB. The definitions of different building types is in Table 2.
Since building loss varies significantly depending on the construction of buildings,
Motorola’s coverage maps do not predict coverage within any specific building.
Rather, the in-building coverage maps indicate the area within which this system is
predicted to provide 95% reliability of meeting or exceeding the CPC of DAQ-3.0
within buildings that have up to the specified Building Loss.
The in-building coverage maps apply only to the above ground portions of buildings.
The coverage maps do not apply to in-building locations that are shielded from radio
penetration, such as elevators, basements below ground level, tunnels, bank vaults, x-
ray rooms, nuclear facilities, and other locations shielded by metal walls or with
heavy construction and with no external windows or doors.
6.4 CATP Method
The method used to test coverage is statistical sampling of the predicted coverage
area to verify that the CPC is met or exceeded at the required reliability for each of
the defined equipment configurations. It is impossible to verify every point within a
coverage area, because there are infinite points; therefore, coverage reliability will be
verified by sampling a statistically significant number of randomly selected locations,
quasi-uniformly distributed throughout the predicted coverage area.
Motorola Confidential Restricted Emergency Telephone System Board of DuPage County
Use or disclosure of this proposal is DuPage ETSB Radio Interoperability Project
subject to the restrictions on the title page June 17, 2010
Coverage Acceptance Test Plan 6-3
This CATP provides a method of tracking test tile location using Motorola’s
Voyager℠hardware and software. A GPS receiver will provide location information
indicating when a valid test tile is available for testing. The method follows TIA
TSB-88A section 7.0, “Performance Confirmation” for statistical sampling.
6.4.1 Determine the required number of test tiles in the
coverage area
The predicted service area will be divided into a grid pattern to produce at least the
number of uniformly sized test locations (or tiles) required by the Estimate of
Proportions formula. {TSB-88A, subclause 7.2.1, equation 52} The minimum
number of test tiles required varies for different systems, from a hundred to many
thousands, depending on the size of the coverage area, desired confidence in results,
type of coverage test, and the predicted versus required reliability.
6.4.2 Constraints on test tile sizes
The minimum tile size is 100 by 100 wavelengths; however, the minimum practical
tile size is typically about 400 by 400 meters (about 0.25 by 0.25 miles). The
minimum practical tile size for any system is determined by the distance traveled at
the speed of the test vehicle while sampling, GPS error margin, and availability of
road access within very small tiles. A related consideration is the time, resources, and
cost involved in testing very large numbers of very small tiles. The maximum test tile
size is 2 by 2 km (1.25 by 1.25 miles). {TSB-88A, subclause 7.4.3}. In some wide-
area systems, this constraint on maximum tile size may dictate a greater number of
test tiles than the minimum number required by the Estimate of Proportions formula.
For DuPage County’s Declared Service Area, 0.25 by 0.25 miles tiles are
used to a total of 7093 tiles.
6.4.3 Accessibility to test tiles
Prior to testing (if possible) or during the test, Motorola and DuPage County ETSB
will determine whether any test tiles are inaccessible by road for the coverage test
(due to lack of roads, restricted land, etc. Any tile that is found to be inaccessible by
vehicle at the point of the drive test will not be counted in the CATP pass/fail count.
Motorola and the driver will use commercially reasonable efforts to drive all tiles that
are part of the gridded coverage area, which includes contacting local forest preserve
officers to request access to non-public roads and going as far as reasonably possible
in the vehicle in residential and commercial neighborhoods.
Motorola Confidential Restricted Emergency Telephone System Board of DuPage County
Use or disclosure of this proposal is DuPage ETSB Radio Interoperability Project
subject to the restrictions on the title page June 17, 2010
Coverage Acceptance Test Plan 6-4
6.4.4 Randomly Select a Test Location Within Each Tile
Using Voyager℠, the actual test location within each tile will be randomly selected
by the test vehicle crossing into the tile at an arbitrary point, with an arbitrary speed
and direction.
6.4.5 Perform Measurements in Each Tile
In each test tile, a series of sequential measurements (subsamples) will be made. This
test location measurement, containing a number of subsamples, constitutes the test
sample for this location. The test sample will establish the local mean BER within the
test tile. The distance over which the subsamples are measured will be 40
wavelengths. A mean of multiple BER subsamples is used rather than a single
measurement to ensure that the measurement is not biased by taking a single sample
that might be at a peak or null point on the radio wave.
6.4.6 Determine If Each Tile Passes or Fails the CPC
Requirement
For each test tile, the pass / fail criterion is the Bit Error Rate (BER) that provides the
specified CPC. To measure BER, the coverage test will be performed with the
appropriate attenuator value installed in the test receiver’s antenna line, to establish
an equivalent signal level performance for each configuration. Coverage for the
portable in-building equipment configurations will be verified for acceptance by
attenuation of the test receiver for BER tests. The attenuation will be the difference
between the mobile test receiver’s antenna system and the additional loss used in
Motorola’s coverage prediction to account for portable antenna performance and in-
building penetration. The attenuator values calculation is provided below. This
provides an objective method of verifying that the radio system provides the faded
performance threshold (BER) for the specified CPC for each of the defined
equipment configurations.
6.4.7 Determine the Coverage Area Reliability for Acceptance
After all accessible tiles in the coverage area have been tested; the coverage area
reliability (%) will be determined by dividing the number of tiles that pass by the
total number of tiles tested. {TSB-88A, clause 7.1, equation 51} The coverage test
acceptance criterion is that the tested coverage area reliability must be equal to or
greater than the required reliability.
Motorola Confidential Restricted Emergency Telephone System Board of DuPage County
Use or disclosure of this proposal is DuPage ETSB Radio Interoperability Project
subject to the restrictions on the title page June 17, 2010
Coverage Acceptance Test Plan 6-5
6.5 Responsibilities and Preparation
This information will help set the expectations of DuPage County ETSB and
Motorola regarding requirements for equipment, personnel, and time during the
coverage test.
DuPage County ETSB will provide the following for the duration of the coverage
test:
♦ At least two test vehicles that are representative of the vehicles used by DuPage
County ETSB
♦ At least two DuPage County ETSB representatives, to drive each test vehicle
and/or to be the customer representatives for the test teams
Motorola will provide the following for the duration of the coverage test:
♦ At least one Motorola representative, to navigate and to operate Voyager℠ per
test vehicle
♦ At least one calibrated Motorola Voyager℠ coverage testing package per test
vehicle
♦ At least one laptop computer equipped with Voyager℠ software per test vehicle
Coverage acceptance testing will be performed throughout DuPage County ETSB’s
declared service area, as indicated on the coverage map. Motorola will determine the
minimum number of test tiles required, as described in the Method section of this
CATP. Motorola and DuPage County ETSB will plan the route for the test vehicles
through the coverage test area, to ensure that at least the minimum required number
of tiles are tested. If possible, any tiles not accessible to the test vehicle(s) will be
identified while planning the route.
Motorola will calibrate the test receivers used with the Voyager℠ coverage testing
package. Depending on the system, the test receivers may be provided by either
Motorola or DuPage County ETSB. Motorola will provide the attenuator values
required to evaluate each equipment configuration from the outbound BER
measurements.
Motorola will conduct this test only once. If any portion of the test is determined to
be unreliable because of proven equipment malfunctions or failures, Motorola will
repeat the portion of the test affected by the equipment malfunction or failure.
DuPage County ETSB will have the option to accept the coverage at any time prior to
completion of the coverage test. Before starting the test, DuPage County ETSB and
Motorola will agree upon the time frame for Motorola’s submission of a report
containing the coverage test results.
Motorola Confidential Restricted Emergency Telephone System Board of DuPage County
Use or disclosure of this proposal is DuPage ETSB Radio Interoperability Project
subject to the restrictions on the title page June 17, 2010
Coverage Acceptance Test Plan 6-6
6.6 CATP Procedures
A quantitative coverage acceptance test will be performed using Motorola’s
Voyager℠ package, to provide objective verification that the system provides the
faded performance threshold for the specified CPC.
Voyager℠ consists of the following:
♦ A calibrated digital voice test receiver, connected to an antenna installed in a
representative location on the test vehicle. The test receiver will monitor
transmissions from the fixed network radio site(s).
♦ A Global Positioning System (GPS) receiver, which will provide the computer
with the location and speed of the test vehicle.
♦ A laptop computer with Voyager℠ software and a mapping database, which
includes highways and local streets political boundaries, rivers, and railroads.
♦ Coverage acceptance will be based on demonstrating that at least 95% of the tiles
in the coverage test area for each equipment configuration are measured to
provide a mean level of 2.6% BER or better at the test receiver input. A 2.6%
BER value corresponds to the system target DAQ (Delivered Audio Quality)
value of DAQ-3.0. The system coverage acceptance criterion will be the
successful passing of each of the equipment configurations.
♦ Any tile that fails the objective Voyager℠ BER test described above will be re-
tested using a subjective Delivered Audio Quality (DAQ) test. Any tile that fails
the objective test, but passes the subjective re-test will be declared passed.
♦ If a coverage test, or a portion thereof, is suspected by Motorola to have failed
due to external interference, those tiles suspected of being affected by an
interferer may be retested. If the test tiles re-tested are confirmed to have failed
due to interference beyond the control of Motorola, those test tiles will be
excluded from all acceptance calculations and Motorola will work with DuPage
County ETSB to identify potential solutions to the interference issues.
6.7 CATP Documentation and Coverage Acceptance
During the coverage acceptance test, Voyager℠ generates computer files that include
the Reference Tile Levels for each test tile. A copy of this raw data will be provided
to DuPage County ETSB at the conclusion of the coverage test. Motorola will
process this data to determine whether the coverage test was passed for each
equipment configuration, and to produce a map detailing the coverage test results.
Motorola will submit to DuPage County ETSB a report detailing the coverage test
results.
Motorola Confidential Restricted Emergency Telephone System Board of DuPage County
Use or disclosure of this proposal is DuPage ETSB Radio Interoperability Project
subject to the restrictions on the title page June 17, 2010
Coverage Acceptance Test Plan 6-7
