OREGON WIRELESS INTEROPERABILITY NETWORK (OWIN) PROJECT. Coverage Verification And Northwest County Analysis Deliverable 1-A-2

OREGON WIRELESS INTEROPERABILITY NETWORK (OWIN) PROJECT Coverage Verification And Northwest County Analysis Deliverable 1-A-2 Prepared by: Federal ...
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OREGON WIRELESS INTEROPERABILITY NETWORK (OWIN) PROJECT

Coverage Verification And Northwest County Analysis Deliverable 1-A-2

Prepared by:

Federal Engineering, Inc. 10600 Arrowhead Dr, Suite 160 Fairfax, VA 22030 703 359-8200

July 25, 2008 

OWIN Coverage Verification and Northwest County Analysis

Executive Summary In 2007, Oregon Wireless Interoperability Network (OWIN) personnel conducted an internal coverage analysis of seven northwest Oregon counties. The goal of the analysis was to examine available radio sites within each county and then to determine if there is an optimum set of sites that would meet OWIN coverage goals while minimizing the overall number of sites required. Those sites providing this level of coverage, irrespective of site ownership, would be considered to be viable candidates for the OWIN statewide radio system. OWIN acquired the services of Federal Engineering, Inc. (FE) to verify the OWIN coverage estimates, and then to perform an FE, county-by-county comparison between OWIN’s estimates and a previous study of that FE had done of the State’s existing radio coverage. This document presents the results of that analysis. In particular, OWIN requested that FE comment on whether OWIN’s selection of radio transmitting/receiving sites in the seven northwest Oregon counties would be impacted differently by a future radio system design that would use VHF or 700 MHz radio spectrum.

Summary of OWIN Verification The internal OWIN coverage analysis examined mobile and portable radio coverage in both the VHF and 700 MHz frequency bands. The radio equipment modeled was digital, narrowband, Project 25 (P25)-compliant equipment. OWIN predicted coverage in the talk-out path, which examines the radio signals being broadcast from a radio site’s antenna to a user’s radio. OWIN supplied FE with the technical parameters used in their analysis, as well as a list of 71 radio sites they considered candidates for the OWIN system in this region. A detailed list of parameters and site information is provided in Appendix A of this document. Using the supplied information, FE performed an analysis similar to the one performed by OWIN. With radio propagation prediction software, FE analyzed the VHF and 700 MHz projected signal strength from several of the supplied radio sites and made comparisons to the OWIN results. Both the OWIN and FE analyses examined signal strengths at a calculated Delivered Audio Quality (DAQ) of 3.4. DAQ 3.4 is a widely-used standard for signal quality in public safety land mobile digital radio systems, and is recommended in the TIA document TSB-88-C, Wireless Communication Systems – Performance in Noise and Interference-Limited Situations as the minimum DAQ level for modeling public safety communications systems. July 25, 2008  Page 2 of 18   

OWIN Coverage Verification and Northwest County Analysis

Concurrent with this analysis, OWIN and FE personnel conducted drive-testing of VHF and 700 MHz P25 equipment at three northwestern Oregon sites. This area was chosen for analysis, as its rugged terrain provided the most rigorous challenges in computer modeling of expected radio propagation. FE has processed and examined the data from these tests and applied the results to its propagation software to increase the accuracy of the predicted VHF and 700 MHz coverage for a digital P25 system. Upon a thorough examination of recalibrated coverage estimates, FE determined that the OWIN estimate for VHF coverage was more conservative when compared to those performed by FE. However, in the 700 MHz band, the OWIN coverage estimates were found to be less conservative and indicate greater coverage than those performed by FE. Alternatively stated, the OWIN’s computerized analysis predicted less radio signal coverage at VHF and more radio signal coverage at 700 MHz than field testing demonstrated. Continuing to move forward without additional prediction tool calibration would result in a state system design that over predicts the number of VHF sites necessary and under predicts the 700 MHz sites necessary to meet the “same or better than existing performance” requirement. See section 1.3 for a table detailing statistics of both the FE and OWIN coverage analysis. Based upon our analyses, FE determined that if there is a difference in either the location or the number of radio transmitting/receiving sites based upon whether OWIN chooses to implement a radio system in the VHF or in the 700 MHz band, the difference will be minimal.

Summary of County-by-County Analysis Results In 2006, FE performed an analysis of the existing radio coverage of three State agencies: the Oregon State Police (OSP), the Oregon Department of Transportation (ODOT), and the Oregon Department of Forestry (ODF). For the current project, FE was asked to determine if the candidate sites supplied by OWIN could be used to provide radio coverage to each of the individual counties to the same extent or better than the best-serving agency did according to the 2006 analysis. Using radio propagation software, FE performed coverage analysis on 71 individual radio sites in northwest Oregon identified by OWIN as potential candidate sites for the statewide system. For comparison purposes, FE calculated the percentage of the county that received a signal which exceeded a calculated DAQ of 3.4. FE then compared those results with the same percentage of each of the State agencies with a calculated DAQ of 3.4 from the 2006 analysis.

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OWIN Coverage Verification and Northwest County Analysis

While FE evaluated both talk-in and talk-out coverage for this analysis, the coverage percentages selected for this comparison are for the mobile talk-in path only, as the FE 2006 coverage analysis evaluated this path. A complete listing of coverage percentages in talk-in and talk-out, for both mobiles and portables, can be found in Section 3.4 of this document. As stated earlier, the drive-testing effort and the resulting information analysis is ongoing. One trend the data shows is that 700 MHz coverage performs very closely to VHF when evaluated from a Bit Error Rate (BER) standpoint. BER is often used as a parameter for evaluating performance of a digital radio system, and the data seems to show that 700 MHz may be outperforming VHF at comparable signal strength levels. Testing this potential advantage for 700 MHz is still being evaluated through analyzing the drive-test data. For all seven counties, VHF was found to produce radio coverage that met or exceeded that of the best-serving existing agency. For 700 MHz, the analysis showed that the coverage met, exceeded, or came within 5-10 percent of the best agency’s current footprint in six of the seven counties, and often exceeded the current coverage of the other agencies. FE performed additional coverage analyses at 700 MHz using various site modifications such as increasing antenna gain, increasing antenna height, and improving performance of tower-top amplifiers. The goal of these supplemental analyses was to determine if judicious RF site engineering could reduce the need for additional 700 MHz coverage radio sites versus the predicted fewer VHF number of sites. The analyses showed that 700 MHz coverage levels could be augmented to meet the coverage requirement when several of these measures are implemented together. This reduces the need to add supplemental sites in these counties. A detailed breakdown of the county-by-county analysis can be found in Section 2 of this document.

 

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Table of Contents Executive Summary .............................................................................................. 2 1. OWIN Coverage Verification .......................................................................... 6 1.1. OWIN Coverage Analysis Procedures ..................................................... 6 1.2. FE Verification Methodology .................................................................... 6 1.3. Results ..................................................................................................... 8 1.4. Impacts .................................................................................................... 9 2. Analysis of Seven Counties .......................................................................... 10 2.1. Coverage Requirements ........................................................................ 10 2.2. Analysis Methodology ............................................................................ 11 2.3. Site and Subscriber Equipment ............................................................. 12 2.4. Results ................................................................................................... 12 2.5. Enhancements ....................................................................................... 12 2.6. Signal Strength vs. BER ........................................................................ 13 3. Conclusion.................................................................................................... 15 Appendix A ......................................................................................................... 16    

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OWIN Coverage Verification and Northwest County Analysis

1. OWIN Coverage Verification 1.1. OWIN Coverage Analysis Procedures For its internal coverage analysis, OWIN evaluated the coverage from various potential radio sites throughout seven counties in northwestern Oregon. The counties examined were: • • • • • • •

Clackamas Clatsop Columbia Multnomah Tillamook Washington Yamhill

OWIN used SoftWright’s Terrain Analysis Package (TAP) to perform its coverage analysis. The focus of the analysis was on the downlink, or talk-out, direction of communication, which refers to the outbound signals being broadcast from radio sites to users’ radios. OWIN specified the following technical parameters used in their analysis: • • • • •

Frequency Band – VHF and 700 MHz Mobile Radio Receiver Height – 5 ft. Propagation Model – TAP’s implementation of Bullington/Inflection Data Resolution – As fine as 1 Arc-Second (approximately 30 meters) when applicable Delivered Audio Quality (DAQ) of 3.4 as a minimum threshold - the TIA document TSB-88-C, Wireless Communication Systems – Performance in Noise and Interference-Limited Situations recommends DAQ 3.4 as a minimum level for modeling public safety communications systems.

OWIN provided FE with plots showing the coverage footprints from the sites used in its analysis, as well as percentages of the respective county that met the minimum coverage threshold. Technical parameters regarding sites and subscriber units were identified on some of the coverage plots. Where information was unavailable, FE made estimations based on assumptions from engineering best practices. For a detailed list of provided technical parameters and assumptions made, see Appendix A of this document.

1.2. FE Verification Methodology To verify the OWIN coverage estimates, FE performed a coverage study of ten individual radio sites used in the OWIN analysis. These sites were selected for July 25, 2008  Page 6 of 18   

OWIN Coverage Verification and Northwest County Analysis

their variety in terrain and frequency, as well as the availability of information regarding parameters (i.e., coverage plots of several of these sites contained detailed technical parameters, and fewer assumptions were required). As another component of this verification effort, FE and the State of Oregon conducted drive-testing for three sites in northwestern Oregon. The three sites tested were Nicolai Mountain, Wilson River, and Megler Mountain. At all three of these locations, VHF and 700 MHz digital P25 repeaters were installed with the antennas at the same height above ground. Multiple drive-test teams then measured the signal strengths and Bit Error Rates (BER) of the transmitted signals throughout each transmitter location’s coverage area. Using the data from these drive tests, FE personnel calibrated their internal radio prediction software package, ATDI’s ICS Telecom, to better represent the realworld results collected in the field. As of this writing, the three sites have completed testing, and the data is being processed. In addition, other drive tests may occur in other portions of the State to collect additional data to be used for calibration. Using the drive-test data, along with engineering best practices for radio propagation prediction, FE determined the ATDI ICS Telecom implementation of propagation models and associated parameters best suited for the coverage verification at each frequency band for OWIN are as follows: •



VHF o Propagation Model – Longley-Rice Irregular Terrain Model o Confidence/Reliability Factors – F50/95 - Industry standard for Longley-Rice predictions o Ground Type – Average Ground o Conductivity – .005 o Relative Permittivity –15 o Radio Climate – Continental Temperate 700 MHz o Propagation Model – International Telecommunication Union Recommendation 525 (ITU-525) o Diffraction – Deygout 94 o Subpath Attenuation – Standard (Fresnel Zone Clearance – 0.6)

The Longley-Rice propagation model is a model used throughout the telecommunications industry that incorporates many individual factors into its calculations such as ground type, radio climate, and permittivity. After importing the VHF drive-test data into ATDI’s ICS Telecom and comparing it with predictions made using various models, FE determined that the Longley-Rice was the most accurate when predicting VHF propagation. The same process was repeated for 700 MHz, and the ITU-525 model with Deygout 94 diffraction was found to best replicate the signals measured in the drive tests. July 25, 2008  Page 7 of 18   

OWIN Coverage Verification and Northwest County Analysis

1.3. Results Just as with the OWIN internal analysis, FE used a DAQ level of 3.4 as the minimum acceptable signal. The drive-test data provided a statistical method for analyzing where this subjective threshold should be set for both VHF and 700 MHz predictions. FE entered this threshold into ATDI’s ICS Telecom, which then output a coverage percentage for each county based on that minimum threshold. These percentages were compared to the numbers provided by OWIN. Table 1.3.1 shows both the OWIN and FE coverage percentages for each of the ten sites examined.

OWIN Predicted Coverage %

FE Predicted Coverage %

% Difference

61.1

50.5

-17

60.2

51.8

-14

70.3

58.2

-17

Mobile Talk-Out

36.8

56.3

53

VHF

Mobile Talk-Out

53.6

81.2

51

Clatsop

VHF

Mobile Talk-Out

42.5

51.7

22

Tillamook

VHF

Mobile Talk-Out

18.22

39.4

116

Salmonberry

Clatsop

VHF

Mobile Talk-Out

23

40

74

Tillamook Head

Clatsop

VHF

Mobile Talk-Out

18.2

52.1

186

Wickiup

Clatsop

VHF

Mobile Talk-Out

59.8

66.6

11

Site Name

County

Band

Biddle Butte

Multnomah

700 MHz

Council Crest

Multnomah

700 MHz

Lookout Point

Multnomah

700 MHz

Cape Lookout

Tillamook

VHF

Clatsop

Humbug Mountain Megler Mountain Neahkahnie Mountain

Path Portable TalkOut Portable TalkOut Portable TalkOut

Table 1.3.1 Coverage Percentages from OWIN and FE Analyses As the table shows, the VHF coverage tends to be significantly higher in the FE analysis, and the 700 MHz tends to be somewhat less. The following are possible reasons for the disparity in coverage estimates: •

The OWIN analysis was performed using SoftWright’s Terrain Analysis Package (TAP), and OWIN did not incorporate land clutter data into its site analyses. Land clutter data contains a code for each parcel of land in a program’s database that corresponds to a certain type of landscape (e.g. residential, urban, agricultural, forest land, etc.). Each of these clutter types has a recommended decibel value for attenuation, or signal dampening. The prediction tool FE uses incorporates clutter data with attenuation values recommended in TSB-88-C, and FE incorporated these losses into its analyses. These values tend to be high for certain clutter

July 25, 2008  Page 8 of 18   

OWIN Coverage Verification and Northwest County Analysis





codes at 700 MHz, and appear to explain the bulk of the disparity between the two analyses. At the time of the OWIN analysis, real-world data was not available to OWIN with which to calibrate its prediction tool. FE used the drive-test data to perform calibrations that helped model results that were closer to actual measurements taken in the field with vendor equipment. FE assumed some of the technical parameters used in the analysis when specific information could not be obtained from OWIN.

1.4. Impacts There are myriad variables and numerous factors to be considered when performing radio propagation analysis. FE feels that the propagation techniques used in its analysis represent the most accurate method for coverage prediction using currently available information. To that end, FE decided to continue with analyzing the coverage from all OWIN-supplied sites using the coverage modeling techniques outlined in this section. The complete results of the analysis are detailed in the Section 3 of this document.

July 25, 2008  Page 9 of 18   

OWIN Coverage Verification and Northwest County Analysis

2. Analysis of Seven Counties 2.1. Coverage Requirements In 2006, FE performed an analysis of existing statewide coverage for three State of Oregon agencies: the Oregon State Police (OSP), the Oregon Department of Transportation (ODOT), and the Oregon Department of Forestry (ODF). Subsequently, OWIN decided that the coverage goal of the statewide radio system should be to provide coverage in each county that is at least as good as the best existing, state agency VHF coverage footprint in each county. For example, if OSP’s present coverage is the highest in a given county, that coverage percentage is used as the coverage requirement for the replacement statewide system in that county. Table 2.1.1 shows the talk-in coverage percentages for these seven, northwest counties calculated as part of the 2006 FE analysis. The focus of the 2006 analysis was on talk-in coverage, as it represented the limiting path (i.e. talk-out coverage was determined to be stronger than talk-in, so the system was designed to talk-in standards to represent the worse-case scenario). The bolded numbers represent the highest estimated percentage in each county.

County Name Clackamas Clatsop Columbia Multnomah Tillamook Washington Yamhill

Existing VHF Talk-In Coverage OSP ODOT ODF Mobile Portable Mobile Portable Mobile Portable 72 60 58 40 35 78 74 54 33 43 26 91 88 82 56 84 61 98 88 85 80 71 56 91 46 39 24 25 13 77 90 86 77 91 77 96 92 88 78 86 70 98

Table 2.1.1 Existing Talk-In Coverage Percentages from 2006 FE Analysis As the table shows, the OSP mobile talk-in numbers represent the best existing footprint, so they are used as the benchmark for the OWIN coverage analysis. In general, OSP tends to have more transmitter/receiver sites in each county than either ODOT or ODF has.

July 25, 2008  Page 10 of 18   

OWIN Coverage Verification and Northwest County Analysis

2.2. Analysis Methodology As stated in Section 1 of this document, , FE used the drive test measured results to improve the calibration of its radio prediction software package, ATDI’s ICS Telecom, in order to improve the correlation of the predicted and measured VHF and 700 MHz coverage. FE used the calibrated techniques for modeling the coverage of the 71 radio sites in this analysis. The propagation model characteristics are as follows: •



VHF o Propagation Model – Longley-Rice Irregular Terrain Model o Confidence/Reliability Factors – F50/95 - Industry standard for Longley-Rice predictions o Ground Type – Average Ground o Conductivity – .005 o Relative Permittivity –15 o Radio Climate – Continental Temperate o TSB-88-C land use clutter 700 MHz o Propagation Model – International Telecommunication Union Recommendation 525 (ITU-525) o Diffraction – Deygout 94 o Subpath Attenuation – Standard (Fresnel Zone Clearance – 0.6) o TSB-88-C land use clutter

OWIN required the use of the TSB-88-C (Wireless Communication Systems – Performance in Noise and Interference-Limited Situations) document in Amendment 3 of the FE Statement of Work. Propagation analyses were then performed for both the talk-in and talk-out paths and all equipment was modeled as digital, narrowband, and P25-compliant. As with the OWIN northwest counties verification phase, FE used a DAQ level of 3.4 as the minimum acceptable signal. The drive-test data provided a statistical method of correlating signal strength and Bit Error Rate to subjective DAQ 3.4 threshold for both VHF and 700 MHz predictions. FE entered this threshold into its ICS Telecom propagation estimation program, and obtained estimates of coverage percentage for each county based on that minimum threshold. See Section 3.4 of this document for a table detailing the resultant percentages for each county. A full list of the 71 sites evaluated is located in Appendix A of this document.

July 25, 2008  Page 11 of 18   

OWIN Coverage Verification and Northwest County Analysis

2.3. Site and Subscriber Equipment FE used a uniform set of technical parameters for the radio sites and subscriber equipment in this analysis. Where possible, the parameters were based on information culled from OWIN’s coverage analysis and the OWIN provided coverage plots. Where information was unavailable, FE used information according to engineering best practices. For a detailed list of the technical parameters that OWIN provided and any assumptions that were made, see Appendix A of this document.

2.4. Results After the adjustments based on the drive-testing results were made to the computerized analysis tool, predictions were again run for the seven Oregon Counties. Table 2.4.1 shows the percentages of FE’s analysis, as well as the existing OSP mobile talk-in numbers, which represent the benchmark for OWIN coverage. All percentages listed are indicative of predicted coverage that meets or exceeds a DAQ level of 3.4.

County Name

Existing OSP Mobile Talk-In Percentage

FE Predicted VHF Coverage Percentages Mobile

FE Predicted 700 MHz Coverage Percentages

Portable

Mobile

Portable

TalkIn

TalkOut

TalkIn

TalkOut

TalkIn

TalkOut

TalkIn

TalkOut

Clackamas

78

95

95

73

83

81

79

50

70

Clatsop

91

99

99

76

92

87

83

42

66

Columbia

98

99

99

87

96

94

92

57

80

Multnomah

91

95

95

83

88

91

90

71

85

Tillamook

77

92

92

50

67

62

58

29

45

Washington

96

99

99

90

95

96

95

77

89

Yamhill

98

99

99

87

95

94

93

64

82

Table 2.4.1 Predicted VHF and 700 MHz Coverage vs. Existing OSP Mobile Talk-In Coverage As the table shows, the predicted VHF mobile talk-in coverage meets or exceeds all seven counties’ existing OSP mobile talk-in percentages. 700 MHz mobile talk-in coverage meets or exceeds three of the seven counties, and is within five percent of three of the remaining four counties.

2.5. Enhancements The 700 MHz predicted coverage shows that some moderate enhancements may be required to elevate the mobile talk-in coverage to the required benchmark. As the majority of the counties that fall short only do so by five July 25, 2008  Page 12 of 18   

OWIN Coverage Verification and Northwest County Analysis

percent or less, FE feels some minor technical modifications can be made to improve the coverage to acceptable levels. These suggested modifications are: • • •

Higher-gain antennas – The current model uses 9 dBd gain antennas, and there are 12 dBd gain antennas available at 700 MHz, which could provide the necessary boost in coverage percentage. Higher receive/transmit antennas - Should site logistics permit, increasing the height of the antenna at the radio sites could elevate coverage. Increased tower-top amplifier performance – The current model uses tower-top amplifiers to nullify any cable and connector loss on the receive side at the radio site. It is possible to increase the level of gain on these amplifiers to provide additional gain for the talk-in path. At 700 MHz, this becomes more feasible than with VHF due to the lower, ambient electrical noise floor.

Should these modifications not elevate the coverage percentages to acceptable levels, additional enhancements may be required. Another alternative is the addition of radio sites which is a costly measure. When comparing 700 MHz mobile talk-in coverage versus the existing OSP VHF mobile talk-in coverage, the 700 MHz shortfall in most counties (with the exception of Tillamook) is less than five percent as shown above in table 2.4.1 , FE recommends that all other suggested enhancements be employed prior to considering additional sites. In the case of Tillamook County, additional radio sites may need to be considered if more cost effective alternative enhancements cannot adequately increase mobile coverage to an acceptable level. As the VHF mobile talk-in coverage percentage is predicted to meet or exceed the existing OSP mobile talk-in footprint in all seven of the counties of interest, no enhancements are required to meet the coverage requirement. Lastly, it is important to note that the portable talk-in coverage percentages in both bands are significantly less than the mobile talk-in percentages. This is to be expected, with portable transmit power being much less than mobile transmit power, much less efficient portable radio antenna systems, and portable signal degradation due to body loss.

2.6. Signal Strength vs. BER The end result of coverage is how well the subscriber unit is able to effectively communicate with the base station equipment. How well the units communicate with each other is dependent on the strength of the received signal and in the digital world on the Bit Error Rate (BER) in the over-the-air digital bit stream. BER refers to the percentage of bits that a radio fails to resolve or are resolved incorrectly, compared to the total bits from a received digital signal, and it is often July 25, 2008  Page 13 of 18   

OWIN Coverage Verification and Northwest County Analysis

considered to represent a more accurate measurement of a digital system’s performance than received signal strength is. A threshold of 5% BER is often used to represent the maximum BER that a Project 25 (P25) radio can withstand prior to losing the ability to present the user with public safety grades of audio. As part of the analysis of the drive-test data, FE has seen that BER levels for VHF and 700 MHz are not necessarily linked to their signal strengths. Preliminary analysis of the data seems to indicate that 700 MHz radios may have a lower BER than VHF radios have at comparable signal strengths. To that end, additional analyses are showing that BER is often comparable between the bands at most of the areas being drive-tested, in spite of the somewhat large gap in signal strength between VHF and 700 MHz. What this data suggests to FE is that when evaluating the viability of a particular frequency band for use in a digital radio system, the foremost technical consideration is the BER performance Observations during testing appear to demonstrate that the lower noise floor and probably a much different multipath condition at 700 MHz allows 700 MHz radios and VHF radios to have very similar coverage areas because of their almost equivalent BER even in the presence of much different signal strengths between the two bands. As the drive-test data analysis continues, there will be more data from varied types of terrain that should give a more verifiable determination regarding 700 MHz performance. This possibility should not be discounted, as the evaluation of digital system performance should not be limited to signal strength alone. Bit Error Rate (BER) may prove to be the best determining factor as to an acceptable user experience with the radio system.

July 25, 2008  Page 14 of 18   

OWIN Coverage Verification and Northwest County Analysis

3. Conclusion FE used the results of the extensive drive tests to refine its internal propagation tools used to establish the OWIN, northwest counties’ coverage estimates. Applying this refined propagation tool to the OWIN internal coverage analysis demonstrated a more conservative signal strength performance at VHF frequencies, and slightly increased signal strength at 700 MHz. After completing the OWIN verification tests, FE performed an analysis of 71 OWIN-identified radio sites using similar modeling techniques. The results of the analysis showed that the OWIN recommended radio sites in the seven northwest Oregon counties can meet or exceed the OWIN coverage requirement at VHF, and six of the seven counties meet, exceed, or are within five percent of the requirement at 700 MHz. FE identified several viable cost effective modifications or enhancements that could be explored at 700 MHz for use at the 71 sites in order to equalize the estimated coverage differences between the two frequency bands. It was further found that Bit Error Rate (BER) may be a better predictor of actual radio system performance rather than is Received Signal Strength Indication (RSSI). Continued analysis of the data may provide additional engineering processes utilizing this effect which could impact overall radio site count.

July 25, 2008  Page 15 of 18   

OWIN Coverage Verification and Northwest County Analysis

Appendix A Site Information and Technical Parameters OWIN-Provided Information – The following parameters were culled from coverage plots provided by OWIN for verification, and are indicative of parameters used by OWIN in their internal coverage analysis. These parameters were applied by FE to both the verification and seven-county analysis phase of this task. • • • • • •

Base Station Transmit Frequencies o VHF: 155.000 MHz o 700 MHz: 776.000 MHz Antenna Model o VHF: Sinclair SRL224NM*6om (6 dBd gain) Antenna Heights at Radio Site o 100’ AGL System Technology o Digital, Narrowband Project 25 Phase 1-Compliant Mobile Antenna Height (both bands): 5 ft AGL Minimum Usable Signal: DAQ 3.4

July 25, 2008  Page 16 of 18   

OWIN Coverage Verification and Northwest County Analysis

Technical Assumptions – When information was unavailable, FE assumed parameters based on industry experience and coverage prediction best practices. • • • • • • • • • • • • • • • •

Base Station Receiver Sensitivity o VHF: -121 dBm o 700 MHz: -122 dBm Antenna Model o 700 MHz: Andrew DB589-A (9 dBd gain) Terrain/Clutter Data Resolution o 30 meters Signal Reliability – 95% Base Station Power Out o VHF: 100 Watts o 700 MHz: 100 Watts Transmission Line Type / Loss o VHF: LDF 5-50A 7/8” (1.57 dB loss / 100 meters at 160 MHz) o 700 MHz: LDF 5-50A 7/8” (3.55 dB loss / 100 meters at 776 MHz) 30 feet of additional cable is budgeted into transmission system above the listed antenna height. Connector Loss: 1 dB Multicoupler/Tower-Top Gain (700 MHz talk-in side only: Assumed to balance losses from connectors and cables at radio site (no net losses or gains) Combiner loss (talk-out path only): 3 dB Mobile Power Out o VHF: 50 Watts o 700 MHz: 35 Watts Mobile Antenna Gain o VHF: 0 dBd o 700 MHz: 3 dBd Portable Antenna Height (both bands): 1 meter AGL Portable Power Out o VHF: 6 Watts o 700 MHz: 2.5 Watts Portable Estimated Body Attenuation: 4 dB Portable Antenna Correction Factor (from TSB-88) o VHF: 10 dB o 700 MHz: 5 dB

July 25, 2008  Page 17 of 18   

OWIN Coverage Verification and Northwest County Analysis

OWIN-Supplied Radio Sites The following table shows the 71 sites used in the coverage analysis and their respective geographic coordinates. Latitude (WGS84, D M S)

Longitude (WGS84, D M S)

Arrowood

45 26 08.3

-122 42 45.7

Bald Mountain West

45 16 59.4

Bald Peak

45 23 21.4

Biddle Butte Boulder Crest

Latitude (WGS84, D M S)

Longitude (WGS84, D M S)

Mount Defiance

45 38 56.0

-121 43 21.0

-123 25 54.4

Mount Hebo

45 12 48.5

-123 45 20.3

-123 03 1.3

Mount Hood

45 20 00.4

-121 41 51.3

45 34 50.0

-122 12 27.0

Mount Lowe

44 57 36.0

-121 58 32.0

45 05 49.4

-123 08 14.4

45 27 15.9

-122 32 53.3

Burntwood

45 28 23.9

-122 50 35.6

45 32 12.4

-122 51 34.3

Buxton Lookout

45 44 38.2

-123 08 07.0

45 20 36.8

-122 35 52.0

45 44 37.4

-123 56 27.5

46 05 9.85

-123 27 8.10

Site Name

Site Name

Canterbury

45 24 48.3

-122 47 01.0

Mount Scott Mountain Top (Chehalem) Mountain View (In Oregon City) Neahkahnie Mountain

Cape Lookout

45 21 43.8

-123 55 48.7

Nicolai

CCOM

45 19 49.3

-122 35 57.6

Oak Point

46 11 01.0

-123 11 54.0

Cedar Hill

45 30 26.5

-122 46 51.5

45 19 21.4

-122 51 52.3

Chehalem

45 21 15.4

-122 59 23.4

45 20 38.9

-122 41 36.9

Clatskanie Mountain

46 03 57.0

-123 16 55.0

Parret Mountain Petes Mountain (West Linn) Polivka Hill (Wally Road)

45 26 3.1

-122 23 22.7

Clatskanie PUD

46 09 19.8

-123 24 43.0

Portland Building

45 30 56.4

-122 40 43.3

Clear Lake Butte

45 09 23.0

-121 43 07.0

Prune Hill

45 35 29.1

-122 26 20.0

Columbia Dixie

45 44 07.0

-122 56 51.0

Pumpkin Ridge

45 41 26.2

-123 02 20.7

Cooper Mountain

45 26 53.4

-122 51 17.7

Rainier Hill

46 02 57.9

-122 55 14.02

Corey Hill

45 51 52.0

-123 12 36.0

45 46 16.3

-123 41 46.4

Council Crest

45 29 56.3

-122 42 29.6

45 18 54.1

-122 27 56.5

Doane creek

45 01 13.4

-123 30 43.4

Rector Ridge Redland Road (Polehn Road) River Road (Hillsboro)

45 29 39.5

-122 56 42.7

Double Peak

45 51 23.9

-123 57 24.0

Rock Creek

45 10 08.6

-123 26 40.0

Flag Point Freedom Road (So. Columbia) Gales Peak

45 19 04.0

-121 28 03.0

Roundtop

45 40 37.9

-123 21 44.8

45 49 20.8

-122 57 6.8

Salmonberry

45 49 10.5

-123 30 5.0

45 32 15.4

-123 12 37.4

South Saddle

45 32 42.4

-123 22 55.4

Goat Mountain

45 07 53.1

-122 17 46.9

Stacker Butte

45 42 49.0

-121 06 04.0

Green Mountain

46 00 53.0

-122 46 24.0

Tillamook Head

45 57 10.3

-123 56 18.1

Hickman Butte

45 24 45.0

-121 54 41.0

Timberline Lodge

45 19 52.0

-121 42 41.0

High Heaven

45 15 59.4

-123 18 34.5

45 45 35.1

-123 12 49.9

Humbug Mountain

45 55 32.3

-123 41 33.4

45 24 57.2

-122 37 02.8

45 21 00.9

-122 10 01.3

45 31 24.4

-122 59 19.3

45 25 19.3

-122 42 09.4

Linhart Butte (5.5 mi SE of Sandy) Little Hebo

45 08 39.0

-123 45 9.0

Top Hill View Acres (Water tanks) Washington County Courthouse Wembley Park

LOCOM

45 25 10.2

-122 40 03.0

Whale Head

45 06 14.0

-122 07 17.0

Lookout Point McMinnville Fire Station Meissner

45 29 0.80

-122 07 45.7

Wickiup

46 06 19.4

-123 35 11.5

45 12 33.4

-123 11 54.4

Willatin Tank

45 34 51.4

-122 47 44.4

45 58 13.1

-122 59 57.6

Wilson River

45 31 23.9

-123 39 10.1

Mill Creek Buttes

45 26 47.0

-121 31 24.0

  July 25, 2008  Page 18 of 18   

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