Course Welcome
Welcome to IS-0951 DHS Component Radio Interoperability Training.  This training is based on information contained in the DHS Joint Wireless Program Communications Interoperability Policy #TB-15-001.0.  The training establishes a common plan for interoperability and radio programming across DHS agencies.
Course Objectives
Objectives: At the end of this course, participants will be able to:
  • Explain the capabilities of land mobile radios and radio systems
  • Determine which interoperability channels are programmed into DHS radios
  • Locate interoperability channels on portable and mobile radios
  • Identify when and how to use interoperability channels in an operational environment

Lesson 1: Radio Basics

Lesson Objectives

Upon completion of this lesson, students will:

  1. Explain common terminology relating to radio equipment and systems.
  2. Identify which radio frequency bands DHS agencies utilize and how this relates to interoperability with other agencies.
  3. Explain common radio system functions and how they impact ability to communicate effectively.
  4. Explain basic radio functions and operation in order to increase proficiency when using portable and mobile radio equipment.
  5. Identify how and when to use or update encryption capabilities with DHS land mobile radio equipment.
Radio Proficiency/Training

Users should be as proficient with their radio as they are with their other critical life-safety equipment. Radios are a critical communications lifeline during times when help is needed.

Prior to this course, it is expected that each agency will provide basic radio training that focuses upon the unique aspects of their operation and types of equipment used.

Personnel should contact their agency’s designated communications technical personnel to obtain agency-specific radio information.

Radio Terminology
  • Encryption – Methodology that encodes a voice or data message to protect its content from unauthorized reception.
  • (In the) Clear – Unencrypted radio transmissions that can be heard by all persons who can monitor the frequency, including those with radio scanners and smartphone apps.
  • Hailing Channel (aka Calling Channel) – Channels designated for the purpose of making initial contact when approaching or arriving at an event. May or may not be monitored by dispatchers or other personnel.
  • Keyloader – Device which physically connects to a radio to allow the manual downloading of encryption keys.
  • Over-the-Air-Rekeying (OTAR) – Method to transmit encryption keys over the radio system. Encryption keys are received by the radio, and (normally) automatically updated.
  • Push-To-Talk (PTT) – Refers to the microphone button which is pushed to transmit and released to receive transmissions.
  • Soft Key – Buttons on a radio controlling various functions programmed into the radio. Often found directly adjacent to the display denoting the button’s function.
  • Strapped – Encryption is permanently attached to a channel and is always on, cannot be controlled by the user.
Why Use Radios?
When used properly, radios are a life-safety tool that provide the following:
  • Effective interoperable communications among agencies when managing unplanned events, planned events, or day-to-day operations
  • Ease of use, especially during times of distress. (Select the correct channel and use the push-to-talk button to broadcast a message)
  • Durability and ruggedness that exceeds other non public safety grade communications devices
  • Reliable means of communications without competition from the general public when cellular networks become congested
Real-World Application

Explosive device detonates during a large-scale planned event in an urban area causing chaos and multiple casualties

  • Cellular network overloaded
  • Public safety agencies overwhelmed

If a radio operator is on the scene with a radio, they should be able to immediately accomplish the following:

  • Broadcast or receive critical information such as suspect location/descriptions to users across all federal, state, and local agencies
  • Request medical/EMS response
  • Provide information on potential secondary devices, area closures, etc.
Radio System Components
Portable (handheld) radios
  • Lower power, shorter range
portable (handheld) radio
Mobile (vehicle mounted) radios
  • Greater power, longer range
Mobile (vehicle mounted) radio
Dispatch Centers
  • Offer extensive capabilities to support users in the field, such as patching users together, relaying information, and providing instructions/guidance
Dispatch Center
Frequency Bands

Knowing your agency’s radio frequency band helps determine compatibility or common interoperability options with other agencies.

  • HF = High Frequency: 3-30 MHz 
  • VHF = Very High Frequency: 30-50MHz - Low Band & High Band: 148-174 MHz
  • UHF = Ultra High Frequency: 406-420 MHz and 450-512 MHz
  • 700 MHz: 758-805 MHz
  • 800 MHz: 806-824 MHz and 851-869 MHz

To communicate, the operator's radio must be on a channel in the same frequency band as the other users

Radio System Information
Trunked Analog and Digital Graph - full description available at link.
  • Conventional Systems
    • Conventional radios operate on fixed channels and each user group is permanently assigned a fixed frequency or a set of frequencies
  • Trunked Systems
    • When operating on a trunked radio system, users will hear a “talk permit tone” after keying the mic, and must pause briefly before speaking
  • Analog
    • Gradual deterioration with increasing static or noise as a user moves out of range
  • Digital
    • Very sharp drop-off when a user moves out of range
    • User may hear some digital sounds like “blips and bleeps”, then other user will suddenly disappear

Graph Description

Simplex vs Repeater
  • Simplex (aka “Radio-to-Radio”, “Direct”, “Talkaround”, or “Car-to-Car”)
    • Radios are “off network” and talk directly to each other
    • Shorter/limited distance
    • Best for localized operations, short-range tactical communications, and when out of repeater range
  • Repeater
    • Repeaters receive transmissions from the field and retransmit (repeat) them with greater power and usually from a higher altitude, allowing communications over increased distances
    • Coverage distance greater than Simplex
    • Best for communicating over wide areas
Close-up photograph of the radio display screen on a (Motorola APX model) portable radio. The radio screen shot contains the time, battery strength indicator, zone name, channel name, and three menu items across the bottom. Along the top of the screen is an icon of a small arrow pointing to the right in between two vertical bars indicating the radio is currently selected on a simplex channel. There is a red circle around the arrow icon to highlight it as the key topic from ths slide. The radio display contains the following text: the time of 10:05 in the upper left corner, Zone IO1 in the center with DHSTAC directly underneath representing the Zone and Channel Name. Three menu items across the bottom read Mute, Clck, Zone from left to right.
Simplex and Repeater Diagrams
REPEATER
Example: DHSNET or DHS-RPT
Repeater Diagram - Example: DHSNET or DHS-RPT Tower with 2 down arrows to 2 people and radio. Another person and radio showing up arrow to tower
SIMPLEX
Example: DHSTAC or DHS-SIM
There is a text box with the word "Simplex" at the top. The line underneath reads "Example: DHSTAC or DHS-SIM".
Important Note:
  • Radios contain both Simplex and Repeater channels
  • Know which channels in the radio are simplex and which channels require a repeater
  • Radio users must be in range or within the coverage area of an active repeater to use repeater channels
  • If a repeater is not available, use a Simplex channel as long as you are in range of other users on the same channel
  • Mobile radios have greater range than portable radios
  • A repeater channel has greater range than a simplex channel.
Coverage Range

The coverage range of your radio will depend on many factors:

  • Transmitting power, type of antenna
  • Well maintained radio equipment
  • Terrain (mountainous/hilly vs flat)
  • Environment (urban vs rural)

Radio waves rely on a line-of-sight concept, and can be blocked or absorbed by obstacles, such as buildings or elevated terrain, which can reduce your coverage range

If possible, test radio communications to ensure effective coverage

Basic Radio Functions
By knowing the basic functions of your radio, operators will be able to select the correct zone and channel, and communicate effectively with other users:
  • Zone Selector: allows a user to select the desired zone, which refers to groups of channels in a radio
  • Channel Selector: allows selection of one of the multiple channels found within zones
  • PTT (Push To Talk): the microphone button that is pushed and held, in order to transmit
  • Home Button: when pressed and held down for an extended period (1-2 seconds), normally returns the radio to users’ primary operating channel, pressing the Home Button momentarily vs pressing and holding may also perform different functions. Home button may not be available on all radios and may be programmed differently between agencies or different radios.
  • Orange Button: often used as an “Emergency Call” button, but not always the case, programming varies (it is very important for users to be aware of and understand whether the Emergency Call feature is active on their radios)
Changing Zones

Using an interoperability channel may require the operator to change zones in their radio

Directions:

  1. Press the Soft Button under “ZONE.”
  2. If “ZONE” doesn’t appear on the radio display screen, press the right or left arrows until it does.
  3. Press the arrows to toggle through the zones until the desired zone is identified.
  4. Press the HOME button or the SEL soft button to select the desired zone.
Changing Zones - XTS Radios Transcript
To change zones on the portable radio, press the button, or soft key, underneath the word ZONE on the radio display. The current zone name should now be flashing on the display. Press the left or right arrow keys to scroll through the zones on the radio until the desired zone appears. When the desired zone name appears on the radio display, press the HOME button to select it. Once the correct zone is selected, rotate the channel selector knob on the top of the radio until the desired channel is selected.
Changing Zones - APX Radios Transcript
To change zones on the portable radio, press the button, or soft key, underneath the word ZONE on the radio display. If ZONE does not appear on the display, press the left or right arrow keys until it appears on the screen. A list of available zones will now appear on the display. Press the up or down arrow keys to scroll through the zones on the radio until the desired zone is selected. When the desired zone is highlighted on the radio display, press the soft button underneath SEL on the screen to select the zone. Once the correct zone is selected, rotate the channel selector knob on the top of the radio until the desired channel is selected.
Close-up photograph of the front panel of a portable radio (Motorola XTS model) showing a display screen with buttons underneath. The radio screen shot contains the time, battery strength indicator, zone name, channel name, and three menu items across the bottom. There is a number 1 below the "Zone" menu item on the screen, numbers 2 and 3 above the arrow buttons on the front panel, and a number 4 over the "Home" button on the front panel. The radio display contains the following text: the time of 11:15 in the upper left corner, IO2 DHS-RPT in the center representing the Zone and Channel Name. Three menu items across the bottom read Mute, Clck, Zone from left to right.
Close-up photograph of the front panel of a portable radio (Motorola APX model) showing a display screen with buttons underneath. The radio screen shot contains the time, battery strength indicator, zone name, channel name, and three menu items across the bottom. There is a number 1 below the "Zone" menu item on the screen, numbers 2 and 3 above the arrow buttons on the front panel, and a number 4 next to the left "soft button" on the front panel below the radio display screen. The radio display contains the following text: the time of 10:01 in the upper left corner, Zone IO1 in the center with DHSNET directly underneath representing the Zone and Channel Name. Three menu items across the bottom read Mute, Clck, Zone from left to right.
Additional Radio Features

In addition to the basic functions, radios contain:

  • several buttons
  • switches and knobs
  • added features
  • functions
  • capabilities

Not all radios are alike - each agency programs and configures its radios based on their unique mission and operational needs

Encryption
  • Encryption encodes a voice or data message to protect its content from unauthorized reception
  • Using encryption does not decrease range or coverage area
  • Radios use “encryption keys” which are loaded by attaching a device called a “Keyloader” to the radio, or through “Over the Air Rekeying” (OTAR)
  • Sensitive, but unclassified information, may be transmitted over encrypted channels
Using Encryption
  • To participate in an encrypted conversation, all radios must use the same encryption key
  • When encryption is required, interoperability with other agencies requires coordination to ensure commonality and to prevent any sensitive radio communications from being transmitted in the “clear”
Encryption On/Off

Portable Radio Features

◯ = Clear
∅ = Encrypted

  • ∅ - Icon will appear on radio display when turned on
  • The icon will flash when receiving an encrypted transmission

In some cases, users must use a switch to turn encryption on and off. In other cases, encryption is permanently attached (“strapped”) to a channel and cannot be controlled by the user.

Encryption (APX) arrow pointing to center dial
Encryption (XG-100) Arrow pointing to encryption features on right dial
Encryption (XTS5000) Arrow pointing to center dial clear/encrypted
Lesson Summary

Participants should now be able to:

  1. Explain common terminology relating to radio equipment and systems.
  2. Identify which radio frequency bands DHS agencies utilize and how this relates to interoperability with other agencies.
  3. Explain common radio system functions and how they impact ability to communicate effectively.
  4. Explain basic radio functions and operation in order to increase proficiency when using portable and mobile radio equipment.
  5. Identify how and when to use or update encryption capabilities with DHS land mobile radio equipment.