Supporting Standards for In-Building Radio Communication Systems Amplifications

Table of Contents

1.0 Purpose
2.0 General Radio Communications Coverage
      2.1 Definitions
3.0 General Policy
4.0 Amplification Systems Allowed
5.0 Evaluation Process
      5.1 Pre-Construction Phase
      5.1.1 New Building Information
      5.1.2 Existing System Information
      5.1.3 Need Determination-Signal Strength Measurements
      5.2 Construction Phase
      5.3 Acceptance/Implementation
6.0 Cost Evaluation
      6.0.1 Fiber Optic Based System
      6.0.2 Off-Air Repeater
      6.1 Vendor Request
      6.2 Testing and Acceptance
7.0 Acceptance Test Plan (ATP)
8.0 Additional System Testing
      8.1 Qualification of Testing Personnel
      8.2 UC Davis Outdoor RF Survey Report
      8.3 Annual Tests
      8.4 Five-Year Tests
      8.5 Field Testing
Appendix

1.0 Purpose

 

The purpose of this document is to establish the policies and procedures regarding the needs assessment, specifications, type, cost evaluation, testing and acceptance of an in-building radio system required in new campus buildings.

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2.0 General Radio Communications Coverage

 

All buildings require the capability to support radio communications of the local public safety entities (Fire, Police etc.) Since each building is unique in its location, construction, and interior design, this document provides guidance in support of the formal UCD Directive XXX-2000, Radio System Coverage Evaluation / In-Building Radio Communication Systems which requires consideration of funding appropriations for specific radio system coverage of each newly constructed facility and/or consideration for existing facilities that may be impacted by the new construction. In many cases, a placeholder is to be used for in-building amplification costs; based on historical data, a recommendation of $35,000 should be used for capital projects exceeding 5000 square feet or multi-level structures. (Refine estimate during cost evaluation)

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2.1 Definitions

 

BTS - Base Transceiver Station, also known as the donor site.
dBm - dB, decibels, in milli-watts. A unit of measure for RF signal level.
Distributive Antenna - A system of non-radiating cable connected to an array of passive antenna.
Donor - Base Transceiver Station, also known as the BTS.
Donor channel - The frequency in which the donor site transmits digital control information.
Grade of Service - Typical service is stated as 95% coverage, 95% calls received and transmitted at Circuit Merit Level 3 (CM3).
Fiber Optic - Optical transport of radio signals over fiber optic cable.
Off-Air Repeater - A repeater that receives frequencies from an antenna and amplifies and retransmits those frequencies.
NPSPAC - National Public Safety Planning and Advisory Committee.
FCC - Federal Communications Commission.

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3.0 General Policy



Except as otherwise provided, no person shall, erect, construct, change the use of or provide an addition of more than 20% to, any building or structure or any part thereof, or cause the same to be done which fails to support adequate radio coverage for the clients of the University of California, Davis 800 MHz Trunked Communications System, (including but not limited to Firefighters, Police Officers, or Emergency Response Personnel). For purposed of this section, adequate radio coverage shall include all of the following:

A minimum signal strength of -95 dBm available in 95% of the area of each floor of the building or structure when transmitted from the campus Central Transceiver of the University of California, Davis 800 MHz Trunked Communications System;

A minimum signal strength of -95 dBm received at the campus Central Transceiver of the University of California, Davis 800 MHz Trunked Communications System when transmitted from 95% of the area of each floor of the building;

The frequency range which must be supported shall be 821-823 MHz and 866-868 MHz; and

A 100% reliability factor.

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4.0 Amplification Systems Allowed

 

Buildings and structures which cannot support the required level of radio coverage shall be equipped with either (A) an internal multiple antenna system with or without FCC type accepted bi-directional 800 MHz amplifiers as needed or (B) radiating cable system (leaky coax). If any part of the installed system or systems contains an electrically powered component, the system shall be capable of operating on an independent battery and/or generator system for a period of at least twelve (12) hours without external power input. The battery system shall automatically charge in the presence of an external power input. If used, bi-directional amplifiers shall include filters to reduce adjacent frequency interference at least 35 dB below the NPSPAC band. The filters shall be tuned to 825 MHz and to 870 MHz so that they will be 35 dB below the NPSPAC frequencies of 824 MHz and 869 MHz respectively. Other settings may be used provided that they don't attenuate the NPSPAC frequencies and further provided that they are not more than one MHz from the NPSPAC frequencies.

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5.0 Evaluation Process

 

The evaluation process for determining the need for in-building amplification is conducted in a minimum of three phases: Pre-construction, construction, and acceptance/implementation.

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5.1 Pre-construction Phase

 

Before the construction of the new building, basic information can be gathered to begin the process of determining the need, type and actual implementation of augmentation to the radio system. In most cases, the following information must be known to properly design and cost estimate an in-building radio system.

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5.1.1 New Building Information

 

Type/Size of building - single story, multi-level, square foot

If multi-level, number of stories

Orientation of building - above/below ground, line of sight

Construction of the outer and inner walls. - Plaster, drywall, brick.

Proposed equipment locations - Equipment rooms, cableways, conduits.

Building location - Longitude and latitude coordinates.

Local building code requirements and special requirements.

Building Blueprints or drawings.

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5.1.2 Existing System Information

 

BTS location - Longitude and latitude coordinates.

Donor channel frequency - Specific digital channel to enhance radio coverage.

Grade of Service required meeting objective.

Type of subscriber unit.

Number of channels and their frequencies.

Signal strength of donor site at the building location.

With the information above, the following steps can establish determining the potential need for an in-building radio system.

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5.1.3 Needs Determination-Signal Strength Measurements



At the planned construction site, measure (or have measured) the signal strength of the donor control channel:

If the signal strength of the donor is -95 dBm or less on the outside of the building, the probability of additional in-building coverage is high.

If the signal strength of the donor is greater than -95 dBm, determine the expected signal strength of the donor by subtracting the sum of the interior losses due to walls, doors and windows from the ambient signal outside the building. (See Table 1)

If a signal strength of -95 dBm or greater is calculated at the inner most point of the building, an in building system may not be required.

If the signal strength is calculated at -95 dBm or less, an in-building system is warranted.

To determine signal strengths for specific areas on campus and evaluate the impact of the facility on existing structures, consult the latest UC Davis Outdoor RF Survey report.

If determined that In-building amplification is required for either the proposed site or existing structures impacted by the proposed construction, provide placeholder in budget for cost of communication system based on results of the above.

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5.2 Construction Phase

 

As the construction progresses, refinements to the placeholder budget should be made to ensure adequate funds are available to cover the cost of providing in-building amplification to the new facility and to re-evaluate the impact on existing structures. Re-visiting the specifications from the initial evaluation will fine-tune the proposed cost line item.

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5.3 Acceptance/Implementation Phase

 

Using criteria from Section 7, the Project Manager will accept the In-Building amplification measurements, ensuring they are within design specification. The budget line item may be closed out upon final acceptance.

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6.0 Cost Evaluation/RFSP

 

Once a determination has been made that in-building amplification is required for the proposed facility or as an augmentation to existing facilities impacted by the new facility, cost estimating an in building coverage system is mostly an academic process. The first step in this process is to determine if the system should be fiber based or an Off- air system. Each system has it own unique advantages and disadvantages. (Table 2 identifies several cost considerations that may be quantified in the planning stage)

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6.0.1 Fiber Optic Based System

 

If there is dark fiber present or can be economically installed from the Network Operations Center (NOC) to the proposed building, then a fiber based solution is viable. Fiber based systems have typically better performance than an off-air system. This is due to the reduction of out of band interference that an off-air system is exposed. Fiber based systems are typically more expensive than off air system, but once installed are easily expanded and maintained. Fiber systems typically have multiple antennas that transmit low power RF (0 dBm typical). An antenna transmitting 0 dBm can cover approximately a 75 foot radius. Therefore, by breaking up the coverage area into 75 foot sections and multiplying the number of section by the cost per antenna installed can give you an approximate system price.

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6.0.2 Off-Air Repeater

 

If dark fiber is not present or too expensive to route to the building, in building coverage can be provided through the use of Bi-Directional Amplifiers and distributed antenna system or leaky feeder radiating cable. Off - Air Repeater systems are simple and reliable and typically cost less than fiber-based solutions. They are however, susceptible to interference caused by large level signals that are close to the pass band of the amplifier. Extra RF filtering can be engineered into the system design to reject the unwanted signals. Typical applications have a central head end amplifier, which drives the distributed antenna or leaky feeder cable and the remainder of the antenna system. Adding the cost of the amplifier installed plus the cost of the distributed cable system can determine a budgetary cost estimate of an Off-Air Repeater system.

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6.1 Vendor Request



Request for Survey and Proposal (RFSP) should be created to provide to multiple wireless system vendors. The format of the RFP can be mandated or left open to each vendor. However, the RFSP should at the minimum include the following sections:

Cover Letter stating overall system price

Company Capabilities

Statement of Work

System Description

System Block Diagram

General Schedule

Turnkey Pricing 4

Conditions of Quotation

Acceptance Test Plan (ATP)

Maintenance, Service and Warranty


The RFSP should clearly state the areas where coverage is needed, the grade of service expected (GOS), and construction schedule of the building in process. Additionally, the RFP should include the information gathered in the pre-construction assessment phase of this policy.

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6.2 Testing and Acceptance

 

Once implemented, the RF coverage system should be tested via the pre-determined Acceptance Test Plan (ATP). The ATP should include personnel from Information and Educational Technology, Police, Fire, Safety and Vendor. A walk through test should be completed and any discrepancies noted and resolved by the vendor.

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7.0 Acceptance Test Plan (ATP)



When an in-building radio system is required, and upon completion of project installation, it will be the Project Manager's responsibility to have the radio system tested to ensure that two-way coverage on each floor of the building are within General policy requirements as prescribed below:

Each floor of the building shall be divided into a grid of approximately twenty (20) equal areas.

The test shall be conducted using a Motorola MTS 2000, or equivalent, portable radio, talking through the campus Central Transceiver of the University of California, Davis 800 MHz Trunked Communications System.

A spot located approximately in the center of a grid area will be selected for the test.

The radio will be keyed to verify two-way communications to and from the outside of the building through the campus Central Transceiver.

Once the spot has been selected, prospecting for a better spot within the grid area will not be permitted.

Each grid area will be tested for transmission/reception; minimum signal strength of -95 dBm. If signal strength fails to meet the requirement, the grid area shall be marked as a fail.

A maximum of two (2) non-adjacent areas will be allowed to fail the test. In the event that three (3) of the areas fail the test, in order to be more statistically accurate, the floor may be divided into forty (40) equal areas.

In such event, a maximum of four (4) nonadjacent areas will be allowed to fail the test.

After the forty (40)-area test, if the system continues to fail, the project Manager shall have the system altered to meet the 95% coverage requirement.


The gain values of all amplifiers shall be measured and the test measurement results shall be kept on file with Communications Resources, a Division of Information and Educational Technology, so that the measurements can be verified each year during the annual tests. In the event that the measurement results became lost, the building owner will be required to rerun the acceptance test to reestablish, the gain values.

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8.0 Additional System Testing

 

Communications Resources will periodically test in-building amplification systems. Results of the testing will be compared to designed specifications and corrective action taken if required maintaining the system within the desired design specification.

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8.1 Qualification of Testing Personnel

 

Communications Resources shall be responsible for conducting or contracting system testing. All tests shall be conducted, documented and signed by a person in possession of a current FCC license, or a current technician certification issued by the Associated Public-Safety Communications Officials International (APCO) or the Personal Communications Industry Association (PCIA). All test records shall be retained on the inspected premises and a copy submitted to Communications Resources and to the Police/Fire Department officials.

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8.2 UC Davis Outdoor RF Survey Report

 

At the discretion of Communications Resources, but no less than semi-annually, the campus shall conduct an Outdoor RF Survey mapping the campus footprint for RF energy. The report should specify specific frequencies, coverage with relative signal strength highlight those areas of signal strength below standards.

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8.3 Annual Tests

 

When an in-building radio system are installed, Communications Resources shall test all active components of the system, including but not limited to amplifiers, power supplies and backup batteries, a minimum of once every twelve (12) months. Amplifiers shall be tested to ensure that the gain is the same as it was upon initial installation and acceptance. Backup batteries and power supplies shall be tested under load for a period of one (1) hour to verify that, they will properly operate during an actual power outage. If within the one (1) hour test period, in the opinion of the testing technician, the battery exhibits symptoms of failure, the test shall be extended for additional one (1) hour periods until the /testing technician confirms the integrity of the battery. All other active components shall be checked to determine that they are operating within the manufacturer's specifications for the intended purpose.

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8.4 Five-Year Tests

 

In addition to the annual test, Communications Resources shall perform a radio coverage test a minimum of once every five (5) years to ensure that the radio system continues to meet the requirements of the original acceptance test. The procedure set forth above shall apply to such tests.

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8.5 Field Testing

 

Police and fire personnel, after providing reasonable notice to Communications Resources, shall have the right to enter property to conduct field-testing to be certain that the required level of radio coverage is present. Discrepancies from field-testing and recorded tests shall immediately be brought to the attention of Communications Resources. Communications Resources will provide corrective action in response to reported discrepancies.

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Appendix


Table 1 - RF Loss Characteristics

ItemLoss (DB)Losses From Structural Components Ceiling Duct
Metal Pole (small)
Metal Catwalks
Large I Beams
Concrete block wall
One floor
One floor and one wall
1-8
3
5
8-10
13-20
20-30
40-50
Machinery
Light machinery
Metallic Hoppers
General Machinery (10-20 sq ft)
Heavy Machinery (>20 sq ft)
1-4
3-6
5-10
10-15
Inventory
Light Textile
Empty Cardboard
Metal Inventory
Heavy Textile
3-5
3-6
4-7
8-11

 

Table 2 - In-building RF Coverage System Cost Estimating

ItemCostCoax Cable Installed
Antenna Installed
Amplifier Low Power Installed
Amplifier High Power installed
Fiber Antenna Installed
Fiber Support Equipment Installed
number x
number x
number x
number x
number x
number x

 

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