UHF Radio Communication System Design and Installation

UHF Radio Communication System Design and Installation

Trunked Repeater Station

• The output power shall be adjusted to 75 watts.
• Channel spacing shall be 12.5/25 KHz.
• Receiver sensitivity shall be equal or better than -116 dBm.
• All interconnection cables shall be low-loss, flexible coaxial cables and shall comply with SESX05-S01 requirements.
• All transceiver equipment shall be housed in standard EIA 19-inch racks.
• The design of transmitter shall comply with the following typical information as a minimum:
  a. Output power: 25-100 Watts adjustable.
  b. Frequency Range: 403-433 MHz, or 433-470 MHz (depends on approved operating frequency range that may fall under either category)
  c. Modulation: FM              d. Audio distortion: less than 3 percent at 1000 Hz
• The design of receiver shall comply with the following typical information as a minimum:
  a. Input impedance: 50 ohms
  b. Audio distortion: less than 3 percent at 1000 Hz.

Base Station

• Estimate the base stations minimum one for each of the operator console.
  Base station requirements within the same building where the main trunked radio system is located shall use dispatcher units only, i.e. direct feeds to the trunked radio system. This shall
  eliminate the need for additional transceiver units.
• The design of transmitter shall comply with the following typical information:
  a. Output power: 15-25 Watts,
  b. Frequency Range: 403-470 MHz
  c. Modulation: FM
  d. Audio distortion: less than 3 percent at 1000 Hz;
• The design of receiver shall comply with the following typical information as a minimum:
  a. Input impedance: 50 ohms
  b. Audio distortion: less than 3 percent at 1000 Hz
• The following options shall be provided with each base station:
  a. Tone Remote Adaptor (Junction Box)
  b. Desktop microphone with push-to-talk (PTT) button
  c. Telephone handset type speaker/microphone, with PTT

Portable Radios

• Portable radios shall be handheld type, with top mounted antenna and channel selector, battery and side mounted push-to-talk button with the typical transmitter and receiver characteristics as mentioned below.
  a. Output power: 1-4 Watts
  b. Frequency Range: 403-470 MHz
  c. Modulation: FM
  d. Audio distortion: less than 3 percent at 1000 Hz.
• The design of receiver shall comply with the following typical information as a minimum:
  a. Sensitivity @ 12 db SINAD: 0.25 µv
  b. Oscillator stability: 2.5 PPM
  c. Audio distortion: less than 3 percent at 1000 Hz
• Handheld radios shall be provided with noise cancelling headsets with boom type noise suppression microphones, for operations in high noise areas for hands free operation. In addition to hand held radios, all audio accessories shall be certified by FM and CSA.
• The radio equipment shall be capable of supporting multiple talk groups as required for the site. Talk groups shall be indicated with an alphanumeric display. Portable radios shall be suitable for immediate use on simplex frequencies.

Mobile Radios

• Mobile radios are recommended for vehicles, forklifts, cranes users if specified.
• Requirements of mobile radio shall be similar to those mentioned in transmitter and receiver requirements of base station.
• Additional features like fixing kits for dash board mount, power unit suitable for 12 Vdc or 24 Vdc, and vehicle mount antenna fixing kit with feed cable shall be provided.
• Mobile radios shall have the same selection capabilities as portable radios supporting point to point communication and talk group capabilities.

System Manager

• A computer based, system maintenance and configuration station shall be provided that is fully user configurable. It shall monitor the radio main equipment repeater, controller, power
  supply etc. System manager shall display system malfunction alarm and status information about any critical component.
• The system manager shall allow user to add, delete or modify units of the system and it shall provide continuous monitoring of the system. This shall be done with menu driven software
  provided within the system.

System Interface

• An interface capability between the radio system and the plant Paging, Public address and telephone system should be provided. This interface shall allow base stations, mobile and
  handheld radio units to receive or place calls through these systems.

Communication Tower and Antennas

• The design of a self supporting communication tower shall be based on the site coverage requirement determined by a specialist agency and, its installation shall comply with all local
  codes and standards for lightning, wind loading, color, grounding etc.
• The tower design shall comply with TIA-222-G requirements.
• The tower shall be located in a designated non hazardous area.
• Towers greater than 30 m in height shall have resting platforms at 20 m intervals. These platforms shall be arranged such that personnel must leave the section ladder to get access
  to the next section ladder.
• The tower shall be located within 30 m of the building that houses the associated radio equipment.
• The tower lightning protection shall follow recommendations and guidelines provided in SESE11-E02 and TIA-607-B.
• The contractor shall provide lightning protection design for SABIC review.
• Pure copper cable insulated with green PVC, 28 strand, 2 AWG, rope-lay and tinned shall be buried 1 m deep to form a continuous ground ring around each tower base. Each tower leg ground electrode and the building entrance plate shall be bonded to this ground ring.
• Apex of the tower shall be mounted with a lightning terminal as finial, which shall be connected to the ground ring by green PVC, 28 strands, 2 AWG, rope-lay and tinned copper conductor. The copper conductor shall run down one leg of the tower and be bonded to the tower at least every 3 m. The lightning terminal shall be at least 2.0 cm in diameter, highly polished solid copper with pointed nickel tip. The terminal shall project at least 60 cm above the highest point of the tower and tower accessories including antennas.
• Cables connecting the antennas mounted on tower to the building shall be installed through over head cable trays.

Power Supply to Radio Equipment 

• Power supply shall be evaluated as per the equipment manufacturer’s requirement.
• A dedicated UPS shall be designed to support the main radio equipment for 12 hours under normal load when the main AC source is cut off as per HCIS directive SEC-08. Single UPS System with Alternate Supply’ as per SES-E13-S01 is recommended.
• For DC power requirement refer to SES-E12-C01 and SES-E12-E01 and SES-E12-S01.
• The designer shall estimate the consumption load of the whole system and specify the UPS backup requirements in accordance with HCIS directive SEC-08.

Power distribution

a. The rectifier/charger shall provide a circuit breaker distribution panel.
b. Each rack equipment load shall be connected through an appropriate circuit breaker for

Cabling protection

• Cable pathways installation between the repeaters, base stations and end user equipment shall conform to TIA-569-B.
• All communication cables installation and termination shall conform to the TIA-568-C.
• Coaxial cables used for interconnecting antennas and the repeaters, base stations and end user equipment shall conform to SES-X05-S01.

Labeling and Tagging 

• All equipment and cables shall be labeled and tagged for the environment for which they are installed. The tagging material shall be permanent, visible and readable. Tagging materials shall comply with industry standards. Refer to the TIA-606-A for more information on tagging and labeling.
• Factory Acceptance Test (FAT)
• Simulation and validation of system setup, its total functionality test, programming andconfiguration shall be done at factory as per the FAT procedures approved by SABIC.
• Configuration and programming of pre defined talk groups shall be done and tested at factory.
• TIA-603-D shall be referred for the test conditions and methods of measurement to ascertainthe performance of equipment.
• FAT documents shall be provided to HCIS for review as per HCIS directive SEC-01.

Inspection and Site Acceptance Test (SAT) 

• Following field tests as minimum shall be performed:
  a. Verify operating frequencies of transmitters and receivers.
  b. Verify RF power of transmitter and confirming coverage area of base station.
  c. Check SNR and SINAD for receiver systems.
  d. Check RF cable and antenna matching and voltage standing wave ratio (VSWR).
  e. Check lightning protection devices are bonded properly to the outside building ground grid.
  f. Ensure that all the necessary certificates and approvals are available for radio system equipment and its frequencies.
  g. Verify that calibration certificates for all the testing equipment are valid.
  h. SAT documents shall be provided to HCIS for review as per HCIS directive SEC-01.