Drive Test Critique

Draft A — 1/15/2021 @ 10:00 am, PST

ctc technology & energy

Review of Verizon Coverage

Prepared for the City of Petaluma, California

December 2020

1. Executive Summary

Columbia Telecommunications Corporation (CTC) is an independent telecommunications consulting firm that has been retained by the City. CTC performed a technical review and analysis of Verizon’s communications and engineering materials, and performed tests to determine the overall functionality of the existing Verizon commercial wireless transmission facilities. This report describes the information that we received from the City and documents our analysis and conclusions related to the data collected during the site visit in mid-November 2020.

Our analysis is confined to the technical aspects of the existing Verizon service and includes:

1. An evaluation of the coverage and network maps submitted by the applicant to determine whether such existing and potential coverage projections can be confirmed
2. Network measurement data collected during multiple drive tests throughout the City of Petaluma, particularly in the southwestern quadrant of the City and in the vicinity of the proposed new macro site on top of the Petaluma Creamery building at 611 Western Avenue.

Accordingly, our conclusions are based on

• an evaluation of the technical characteristics of the existing Verizon network,
• the data collected, and best engineering design practices common to the wireless carriers and the hardware they deploy, based on Verizon’s existing FCC wireless licensed spectrum.

1.1 Overview of Analysis

This report documents CTC’s findings relative to Verizon’s existing 4G LTE network.

In November 2020, CTC’s engineers performed the following tasks:

• Reviewed all pertinent materials submitted by Verizon, including:
  • Coverage maps (showing the target area and vicinity)
  • RF exposure level analysis in the vicinity of the proposed site
  • Photo simulations of the proposed new macro site at the Creamery
• Conducted a site visit to visually inspect the existing macro site, the proposed site at the
• Creamery and vicinity, and to verify the documentation provided in the applications is
  consistent with our observations.
• Conducted on-site drive tests to measure Verizon’s wireless signal strength to verify practical, real-world Verizon subscriber coverage (network connectivity) and capacity (quantity of data throughput as a function of time) throughout the target area
• Conducted on-site speed tests to determine wireless signal capacity which simulates realworld Verizon subscriber experience with critical broadband applications. These tests measure signal capabilities in both an upload and download manner, addressing not only streaming audio and video consumption but two-way applications like video conferencing, large file transfers, Virtual Private Networking (VPN) for remote office connections, and gaming.

1.2 Findings

• The current Verizon network provides reliable in-vehicle coverage for traditional voice, text messaging and email services throughout the entire area of the testing we conducted.
• While no in-building testing was conducted, typically signal levels of at least an additional 10 dB of signal power level over the in-vehicle signal power level is required to provide the same level of service, performance and reliability in typical residential buildings.¹

• Download/upload throughput data transmission rate measurements confirm that the download links operate at or near full utilization. During peak periods, the limitation in network capacity reduces download speed and functionality. The capacity limitations are typically most pronounced with high demand services such as video streaming, virtual learning and video meetings.

• Addition of the proposed Creamery site would essentially double the network capacity and increase signal levels to enhance in-building coverage within Petaluma.

2. Brief Background on Cellular Antenna Issues

The following brief discussion presents a framework for understanding our analysis of Verizon’s application and our findings.

2.1 Wireless Coverage and Target Signal Levels

Wireless coverage for modern 4G technology broadband services is determined by a carrier’s RF signal amplitude and signal quality within a desired service area. Signals need to be at a minimum amplitude to override noise and, in many cases, interference from other wireless facilities. Signal levels also need to be maintained at a power level such that user devices are not constantly connecting and reconnecting (either because of a loss of signal or because an existing connection is overpowered by another wireless access point).

Handing off a user from one access site to another is part of the mechanics of dealing with users who are in motion—particularly in an urbanized area with multiple signal paths and tower sites. Further, modern 4G technologies as employed by Verizon and other carriers operate with sophisticated encoding technology that permits higher transmission speeds in areas where signal levels are higher than those required for minimum data rate transfers.

While the FCC has no technical standards for the services provided by commercial wireless carriers, the industry and equipment manufacturers have generally established target signal levels for various service environments.

Typically referenced service environments include

• outdoor coverage,
• in-vehicle coverage, and
• in-building coverage.

For 4G technology, target levels are specified in terms of the ratio of decibels (dB) to milliwatts (mW) of signal power,

with a reference level of 0 dBm being equal to 1 milliwatt of signal power. Modern cellular equipment is extremely sensitive and can operate at signal levels as low as -120 dBm RSRP.²

2.2 FCC Guidelines for Human Exposure to Radio Frequency Fields

The FCC’s guidelines for evaluating human exposure to RF signals were first established in 1985. The current guidelines were adopted in August 1997 in FCC OET Bulletin 65.³ The guidelines are expressed in terms of Maximum Permissible Exposure (MPE) to electric and magnetic field strength and power density. The guidelines cover the frequency range of 300 kHz to 100 GHz.

The guidelines cover two separate tiers of exposure:

1. Occupational/controlled exposure limits apply to situations in which persons are exposed as a consequence of their employment and in which those persons who are exposed have been made fully aware of the potential for exposure and can exercise control over their exposure.
2. General population/uncontrolled exposure limits apply to situations in which the general public may be exposed or in which persons who are exposed as a consequence of their employment may not be made fully aware of the potential for exposure or cannot exercise control over their exposure.

Figure 1 is a plot of MPE as a function of RF.⁴

Figure 1: FCC Limits for Maximum Permissible Exposure4 (mW/cm2)

[image – oet]

Figure 2 illustrates the areas where the greatest RF exposure is present—specifically, at or near the base of the antenna mounting structure and horizontally at an elevated location near the antenna.

Maximum energy at antenna height parallel to ground (e.g., multi-story building)

Lower toward the base of mounting structure

Area where a pedestrian might be near the pole’s base

We have independently reviewed the proposed Verizon design and computed the RF emission exposure for all antennas using the proposed wireless bands and radio equipment.

Based on our analysis, performed consistent with FCC guidelines, we find the site to be fully compliant with the current federal RF standards for uncontrolled public exposure in areas accessible to the public. It is assumed that suitable warning signage and access controlled consistent with FCC guidelines will be installed on the Creamery property as required.

3. Overview of Current and Planned Verizon Service in the City

Verizon Wireless currently provides commercial wireless service throughout the City with antennas mounted on buildings and towers. These traditional wireless facilities, which are designed to serve users in a 1- to 2-mile radius, are often referred to as “macro” sites.

Verizon Wireless delivers service in three wireless bands (Table 1). However, while Verizon and other commercial wireless carriers’ existing sites cover the City, many areas of the City receive service only in the lower-capacity 700 and 800 MHz bands. The substantially greater network bandwidth/capacity resources are found in the higher-frequency PCS and AWS bands.

Current Frequencies/Bandwidths transmitted by Commscope NHH-45B-R2B Antennas

1. 746-757 MHz
2. 776-787 MHz
3. 835-845 MHz
4. 846.5-849 MHz
5. 880-894 MHz
6. 891.5-894 MHz
7. 1895-1910 MHz
8. 1975-1990 MHz
9. 1720-1730 MHz
10. 2120-2130 MHz
11. 1770-1780 MHz
12. 2170-2180 MHz

Future Frequencies/Bandwidths Verizon Could Add

1. 32 | P1 | PEA | 3550-3650
2. 54 | P2 | PEA | 3550-3650
3. 205 | P3 | PEA | 3550-3650
4. 226 | P4 | PEA | 3550-3650
5. 209 | P5 | PEA | 3550-3650
6. 122 | P6 | PEA | 3550-3650
7. 1699 | L1 | BTA | 27500-27925
8. 1618 | L2 | BTA | 27925-28350
9. 3142 | M1 | PEA | 37600-37700
10. 3142 | M2 | PEA | 37700-37800
11. 3142 | M3 | PEA | 37800-37900
12. 3142 | M4 | PEA | 37900-38000
13. 3142 | M5 | PEA | 38000-38100
14. 3142 | M6 | PEA | 38100-38200
15. 3142 | M7 | PEA | 38200-38300
16. 3132 | M8 | PEA | 38300-38400
17. 2894 | M9 | PEA | 38400-38500
18. 2894 | M10 | PEA | 38500-38600
19. 371 | M10 | PEA | 38500-38600

3.1 On-Site Field Tests

Over two days we measured the Verizon signals using an LG Android phone (to simulate an experience of a typical wireless customer) at 1,082 locations driving throughout principal roads in the southwest quadrant of the City of Petaluma. Additionally, we conducted multiple upload/download data throughput speed tests at 5 locations to obtain an overview picture of the data throughput speeds which can be anticipated by Verizon 4G users with the existing network.

Our signal intensity measurements confirm that Verizon’s existing network delivers a signal power level that is mostly adequate to support a high level of connectivity and service (i.e., the network provides adequate in-vehicle coverage).⁵

This finding matches our experience in other communities in California where Verizon LTE sites that are not subjected to the demands of a large concurrent user base (i.e., user demand does not overload the network’s transmission capacity) consistently deliver reliable download speeds in the range of 30 Mbps to 40 Mbps and upload speeds ranging from 10 Mbps to 25 Mbps (i.e., performance typically achievable with the current generation of 4G LTE transmission equipment).[^5] This is consistent with the FCC’s position established back in 2015 that set the benchmark for what is considered broadband speed at 25 Mbps for download and 3 Mbps for upload.

That said, the data transmission rates we measured for calibration, near Bob’s Beach facing the existing macro site downtown atop the Dairyman’s Feed and Supply performed in that range at the various times of our sampling over the two days. For example, our measurements there were at a best range of

• download speeds of 35-41 Mbps with
• upload speeds of 15-19 Mbps providing good throughput speeds and good latency times.

Alternately, at other times when capacity is limited, the
– download speeds were more like 17-25 Mbps and the
– upload speeds were more like 11-14 Mbps.

This shows the real-world best-case scenarios for broadband throughput at these specific times, the experience for subscribers who are farther from the antennas would typically see lower throughputs.

Table 2: Data Transmission Test Measurements near Bob’s Beach (facing Existing Macro Site)

3 Different Instances

[Table 2 Data Transmission Image]

At locations further from the existing macro site, the data throughput speeds were significantly lower in all but one spot, which was the closest to the existing site at 501 Petaluma Blvd. Those speed tests (see Table 3) showed download speeds around 30 Mbps and uploads around 21 Mbps with good latency.

[Table 3 Data Transmission Image]

In areas with higher traffic and density, there was a significant drop off in performance. At the location for the proposed Verizon macro site at the Creamery — where
– download speeds were around 8 Mbps and
– upload speeds were around 15 Mbps (see Table 4)

. . . and at City Hall – where the

• download speeds never reached 5 Mbps and
• upload speeds were around 12 Mbps,

. . . the Verizon network was still functional but clearly lacked capacity to properly serve their customers with speeds defined by the FCC as broadband (25 Mbps down/3 Mbps up).

[Table 4 Data Transmission Image]

[Table 5 Data Transmission Image]

In a less dense, residential environment, the speed test point at 512 Howard Street showed a less severe drop in speed. Table 6 shows download speeds from
– 16-21 Mbps and
– upload speeds of around 13 Mbps.

[Table 6 Data Transmission Image]

In addition to the on-site speed tests, we conducted drive test measurements of signal levels on primary roads in and near the proposed small cell deployment areas. Figure 3 (on the following page) is a map illustrating the signal levels we recorded. During the days in which testing was conducted, we experienced no disconnects and no interruption in the connection to the 4G LTE network service.

• The green spots indicate excellent signal of -80 dBm or better which corresponds to excellent in building coverage. ⁶
• The yellow locations show a signal of between -81 and -90 dBm indicating generally acceptable residential in-building coverage⁷ and good in-vehicle coverage.
• The orange dots equate to a signal power level of -100 dBm or lower. Most devices will operate in a vehicle up to about -105 dBm and outside vehicles to -108 dBm.

A majority of the orange locations in Figure 3 fall within the 100 to 105 dBm range with scattered lower signal levels recorded in the farther western test points, where the terrain begins to climb more quickly.

Figure 4 (on the following page below) is the exhibit that Verizon provided to indicate their understanding of existing signal strength. The colors and signal levels are consistent from Figure 3 to Figure 4 for comparison purposes.

[Figure 3 Image]

[Current Coverage image]

Appendix A: Verizon Spectrum Chart

Appendix B: Existing Macro Cell Conditions – Spectrum Analyzer Scans of Operating Bands

700 MHz Petaluma Verizon

[image]

800 MHz Petaluma Verizon

[image]

1700 MHz Petaluma Verizon

[image]

1900 and 2100 MHz Petaluma Verizon

[image]

Appendix C: Speed Test Sites

512 Howard Street
[image]

501 Petaluma Blvd

[image]

Petaluma City Hall

[image]

Petaluma Creamery

[image]

Existing Macro at Dairyman’s Feed and Supply

[image]

Data Pages 17-40

Need a no read bandwidth (don’t know what you are looking at)

Automatic speed (less precision on scans) — not the right

reported — absolutely critical and number of sample points

Can’t do any averaging

SDR Receiver

Peak or average — scanning are not reliable (skip a frequency in use)

values in the waterfall

Pointless (none of the data is calibrated)

Appendix E: Field Software and Test Equipment (Antenna is not calibrated nothing is usable)

• RF Spectrum Analysis was performed using RF Explorer Handheld Spectrum Analyzer using RF Explorer for Windows
• LG Model K20 V using Android version 7.0
• Ookla – Speedtest
• Kaibits -– Network Signal Info Pro