MOTOTRBO_System_Planner_1.6a

Manual Revisions

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Documentation Copyrights

No duplication or distribution of this document or any portion thereof shall take place without the express written permission of Motorola. No part of this manual may be reproduced, distributed, or transmitted in any form or by any means, electronic or mechanical, for any purpose without the express written permission of Motorola.

Disclaimer

The information in this document is carefully examined, and is believed to be entirely reliable.

However no responsibility is assumed for inaccuracies. Furthermore, Motorola reserves the right to make changes to any products herein to improve readability, function, or design. Motorola does not assume any liability arising out of the applications or use of any product or circuit described herein; nor does it cover any license under its patent rights nor the rights of others. Trademarks

MOTOROLA, Stylized M logo, and MOTOTRBO TM are registered in the US Patent & Trademark Office. All other products or service names are property of their respective owners.

?2010 by Motorola, Inc.

The AMBE+2TM voice coding Technology embodied in this product is protected by intellectual property rights including patent rights, copyrights and trade secrets of Digital Voice Systems, Inc.

This voice coding Technology is licensed solely for use within this Communications Equipment.

The user of this Technology is explicitly prohibited from attempting to decompile, reverse engineer, or disassemble the Object Code, or in any other way convert the Object Code into a human-readable form.

U.S. Pat. Nos. #5,870,405, #5,826,222, #5,754,974, #5,701,390, #5,715,365, #5,649,050, #5,630,011, #5,581,656, #5,517,511, #5,491,772, #5,247,579, #5,226,084 and #5,195,166.

Section 1 Introduction

1.1 Welcome to MOTOTRBO TM! (1)

1.2 Software Version (2)

Section 2 System Feature Overview

2.1 MOTOTRBO Digital Radio Technology (3)

2.1.1 Digital Radio Technology Overview (3)

2.1.1.1 Part One: The Analog to Digital Conversion (3)

2.1.1.2 Part Two: The Vocoder and Forward Error Correction (FEC) (3)

2.1.1.3 Part Three: Framing (4)

2.1.1.4 Part Four: TDMA Transmission (4)

2.1.1.5 Standards Compliance (4)

2.1.2 Spectrum Efficiency via Two-Slot TDMA (5)

2.1.2.1 Frequencies, Channels, and Requirements for

Spectrum Efficiency (5)

2.1.2.2 Delivering Increased Capacity in Existing 12.5kHz Channels (5)

2.1.2.3 Two-Slot TDMA Reduces Infrastructure Equipment (6)

2.1.2.4 Two-Slot TDMA Enables System Flexibility (8)

2.1.2.5 Two-Slot TDMA System Planning Considerations (9)

2.1.3 Digital Audio Quality and Coverage Performance (9)

2.1.3.1 Digital Audio Coverage (10)

2.1.3.2 Predicting Digital Audio Coverage (11)

2.1.3.3 User Expectations for Digital Audio Performance (12)

2.1.3.4 Audio Balancing (13)

2.2 Basic System Topologies for Digital and Analog Operations (14)

2.2.1 Repeater and Direct Mode Configurations (14)

2.2.2 MOTOTRBO Supports Analog and Digital Operation (20)

2.2.3 MOTOTRBO Channel Access (20)

2.2.3.1 Impolite Operation (Admit Criteria of “Always”) (21)

2.2.3.2 Polite to All Operation (Admit Criteria of “Channel Free”) (22)

2.2.

3.3 Polite to Own Digital System Operation (Admit Criteria of

“Color Code Free”) (22)

2.2.

3.4 Polite to Other Analog System Operation (Admit Criteria of

“Correct PL”) (22)

2.2.

3.5 Polite or Impolite, or Voice Interrupt While Participating in a Call

(In Call Criteria) (23)

2.2.3.6 Repeater Wake-up Provisioning (24)

2.3 MOTOTRBO Digital Features (25)

2.3.1 Digital Voice Features (25)

2.3.1.1 Group Calls (25)

i

2.3.1.2 Private Calls (26)

2.3.1.3 All Call (27)

2.3.2 Transmit Interrupt (28)

2.3.2.1 Upgrading a System to be Transmit Interrupt Capable (29)

2.3.3 Digital Signaling Features (30)

2.3.3.1 PTT ID and Aliasing (30)

2.3.3.2 Radio Disable (Selective Radio Inhibit) (30)

2.3.3.3 Remote Monitor (31)

2.3.3.4 Radio Check (31)

2.3.3.5 Call Alert (32)

2.3.3.6 Remote Voice Dekey (32)

2.3.4 Digital Emergency (32)

2.3.4.1 Emergency Alarm Only (35)

2.3.4.2 Emergency Alarm and Call (35)

2.3.4.3 Emergency Alarm with Voice to Follow (36)

2.3.4.4 Emergency Voice Interrupt for Emergency Alarm (37)

2.3.4.5 Emergency Voice Interrupt for Emergency Voice (38)

2.4 MOTOTRBO Integrated Data (39)

2.4.1 Overview (39)

2.4.2 Text Messaging Services (41)

2.4.2.1 Built-In Text Messaging Service (41)

2.4.2.2 Services Provided to a Third Party Text Message Application (42)

2.4.3 Location Services (43)

2.4.3.1 Performance Specifications (44)

2.4.3.2 Services Provided to a Radio User (45)

2.4.3.3 Services Provided to a Location Application (45)

2.4.3.4 GPS Revert Channel (47)

2.4.3.5 Data Revert Channel (48)

2.4.4 Telemetry Services (49)

2.4.4.1 Physical Connection Information (50)

2.4.4.2 Telemetry Examples (50)

2.4.5 Data Precedence and Data Over Voice Interrupt (51)

2.5 Scan (52)

2.5.1 Priority Sampling (53)

2.5.2 Channel Marking (54)

2.5.3 Scan Considerations (55)

2.5.3.1 Scanning and Preamble (56)

2.5.3.2 Channel Scan and Last Landed Channel (57)

2.5.3.3 Scan Members with Similar Receive Parameters (58)

2.5.4 Transmit Interrupt and Scan (60)

ii

2.6 Site Roaming (61)

2.6.1 Passive Site Searching (61)

2.6.2 Active Site Searching (62)

2.6.3 Roaming Considerations (64)

2.6.3.1 Configuring a Roam List (64)

2.6.3.2 Scan or Roam (66)

2.6.3.3 Configuring the Roaming RSSI Threshold (66)

2.6.3.4 Setting Beacon Duration and Beacon Interval (71)

2.6.3.5 Emergency Revert, GPS Revert, and Roaming Interactions (73)

2.6.3.6 Performance while Roaming (74)

2.7 Voice and Data Privacy (75)

2.7.1 Types of Privacy (75)

2.7.2 Strength of the Protection Mechanism (76)

2.7.3 Scope of Protection (76)

2.7.4 Effects on Performance (77)

2.7.5 User Control Over Privacy (77)

2.7.6 Privacy Indications to User (78)

2.7.7 Key Mismatch (79)

2.7.8 Keys and Key Management (79)

2.7.9 Multiple Keys in a Basic Privacy System (80)

2.7.10 Data Gateway Privacy Settings (81)

2.7.11 Protecting One Group’s Message from Another (82)

2.7.12 Updating from Basic Privacy to Enhanced Privacy (82)

2.8 Repeater Diagnostics and Control (RDAC) (83)

2.8.1 Connecting Remotely via the Network (85)

2.8.2 Connecting Locally via the USB (85)

2.8.3 Connecting Locally via GPIO Lines (85)

2.8.

3.1 RDAC Local Settings Rear Accessory Port CPS

Programmable Pins (87)

2.8.4 Redundant Repeater Setup (88)

2.8.5 Dual Control Considerations (89)

2.9 Voice Operated Transmission (VOX) (90)

2.9.1 Operational Description (90)

2.9.2 Usage Consideration (90)

2.9.2.1 Suspending VOX (90)

2.9.2.2 Talk Permit Tone (90)

2.9.2.3 Emergency Calls (91)

2.9.2.4 Transmit Interrupt (91)

2.10 Lone Worker (91)

2.11 One Touch Home Revert Button (92)

iii

2.12 Analog Features (92)

2.12.1 Analog Voice Features (92)

2.12.2 MDC Analog Signaling Features (93)

2.12.3 Quik-Call II Signaling Features (93)

2.12.4 Analog Scan Features (94)

2.12.5 Analog Repeater Interface (94)

2.12.5.1 Analog Repeater Interface Settings (94)

2.12.5.2 Recommended Service Aid for the MTR3000 (98)

2.12.5.3 Configuration Summary Table (98)

2.12.5.4 Configuration Considerations (99)

2.12.6 Comparison Chart (103)

2.13 Third Party Application Partner Program (105)

2.1

3.1 MOTOTRBO, the Dealer, and the Accredited

Third-Party Developer (105)

2.13.2 MOTOTRBO Applications Interfaces (105)

2.1

3.3 MOTOTRBO Documents Available via the Third Party

Application Partner Program (107)

2.13.4 Available Levels of Partnership (108)

Section 3 System Components and Topologies

3.1 System Components (111)

3.1.1 Fixed End Components (111)

3.1.1.1 Repeater (111)

3.1.1.2 Radio Control Station (113)

3.1.1.3 MC1000, MC2000, MC2500 Console (114)

3.1.2 Mobile Components (114)

3.1.2.1 MOTOTRBO Portable (115)

3.1.2.2 MOTOTRBO Mobile (121)

3.1.3 Data Applications (126)

3.2 System Topologies (126)

3.2.1 Direct Mode (126)

3.2.1.1 Digital MOTOTRBO Radios in Direct Mode (127)

3.2.1.2 Interoperability between Analog MOTOTRBO Radios and Analog

Radios in Direct Mode (136)

3.2.1.3 Interoperability between Digital MOTOTRBO Radios, Mixed Mode

MOTOTRBO Radios, and Analog Radios in Direct Mode (137)

3.2.2 Repeater Mode (137)

3.2.2.1 Digital MOTOTRBO Radios in Repeater Mode (139)

3.2.2.2 Analog MOTOTRBO Radios in Repeater Mode (150)

3.2.3 IP Site Connect Mode (151)

3.2.3.1 Topologies of IP Site Connect System (152)

iv

3.2.4 Capacity Plus Mode (162)

3.2.4.1 Topologies of Capacity Plus System (162)

Section 4 System Design Considerations

4.1 Purpose (169)

4.2 Migration Plans (169)

4.2.1 Pre-Deployment System Integration (169)

4.2.2 Analog to Digital Preparation and Migration (170)

4.2.3 New/Full System Replacement (171)

4.3 Frequency Licensing (172)

4.3.1 Acquiring New Frequencies (Region Specific) (172)

4.3.2 Converting Existing 12.5/25kHz Licenses (173)

4.3.3 Repeater Continuous Wave Identification (CWID) (173)

4.4 Digital Repeater Loading (174)

4.4.1 Assumptions and Precautions (174)

4.4.2 Voice and Data Traffic Profile (175)

4.4.3 Estimating Loading (Single Repeater and IP Site Connect) (176)

4.4.4 Estimating Loading (For Capacity Plus) (177)

4.4.5 Loading Optimization (For Single Repeater and IP Site Connect) (180)

4.4.5.1 Distribution of High Usage Users (180)

4.4.5.2 Minimize Location Periodic Update Rate (181)

4.4.5.3 Data Application Retry Attempts and Intervals (183)

4.4.5.4 Optimize Data Application Outbound Message Rate (183)

4.4.5.5 GPS Revert and Loading (184)

4.4.6 Loading Optimization (For Capacity Plus) (187)

4.4.6.1 Preference for Using a Frequency (187)

4.4.6.2 Improving Channel Capacity by Adjusting Hang Times (187)

4.4.6.3 Call Priority in Capacity Plus Mode (188)

4.4.6.4 Call Initiation in Capacity Plus Mode (188)

4.5 Multiple Digital Repeaters in Standalone Mode (189)

4.5.1 Overlapping Coverage Area (189)

4.5.2 Color Codes in a Digital System (190)

4.5.3 Additional Considerations for Color Codes (191)

4.6 Multiple Digital Repeaters in IP Site Connect Mode (192)

4.6.1 System Capacity (192)

4.6.2 Frequencies and Color Code Considerations (192)

4.6.3 Considerations for the Backend Network (193)

4.6.3.1 Automatic Reconfiguration (194)

4.6.3.2 Characteristics of Backend Network (195)

4.6.4 Flow of Voice/Data/Control Messages (202)

v

4.6.5 Security Considerations (203)

4.6.6 General Considerations When Setting Up the Network Connection

for an IP Site Connect System (204)

4.6.7 General Considerations When Utilizing the RDAC Application to Set

Up the Network Connection (205)

4.6.8 Considerations for Shared Use of a Channel (206)

4.6.9 Migration from Single Site Systems (207)

4.6.10 Migration from an Older IP Site Connect System (208)

4.7 Multiple Digital Repeaters in Capacity Plus (209)

4.7.1 System Capacity (209)

4.7.2 Frequencies and Color Code Considerations (209)

4.7.3 Considerations for the Backend Network (210)

4.7.4 Behaviors in Presence of Failures (210)

4.7.5 Limiting Interference to Other Systems (211)

4.7.6 Plan for Talkaround Mode (211)

4.7.7 Ways to Improve Battery Life (212)

4.7.8 Considerations for Configuring Mixed Firmware Versions (212)

4.8 Transmit Interrupt System Design Considerations (213)

4.8.1 Interruptible Radios (213)

4.8.2 Voice Interrupt (213)

4.8.3 Emergency Voice Interrupt (214)

4.8.4 Data Over Voice Interrupt (215)

4.8.5 Remote Voice Dekey (215)

4.9 Data Sub-System Design Considerations (216)

4.9.1 Computer and IP Network Configurations (216)

4.9.1.1 Radio to Mobile Client Network Connectivity (216)

4.9.1.2 Radio to Air Interface Network Connectivity (217)

4.9.1.3 Application Server Control Station Network Connectivity (220)

4.9.1.4 Control Station Considerations (221)

4.9.1.5 Multi-Channel Device Driver (MCDD) and Required

Static Routes (223)

4.9.1.6 Application Server and Dispatcher Network Connectivity (223)

4.9.1.7 MOTOTRBO Subject Line Usage (224)

4.9.1.8 MOTOTRBO Example System IP Plan (224)

4.9.1.9 Application Server Network Connection Considerations (226)

4.9.1.10 Reduction in Data Messages (When Radios Power On) (226)

4.9.1.11 Ways to Improve Data Throughput (227)

4.9.1.12 Data Revert Channels for Capacity Plus (228)

4.9.2 Mobile Terminal and Application Server

Power Management Considerations (231)

4.10 Customer Fleetmap Development (232)

vi

4.10.1 Identifying a Functional Fleetmap Design Team (232)

4.10.2 Identifying Radio Users (233)

4.10.3 Organizing Radio Users into Groups (234)

4.10.3.1 Configuration of Groups (235)

4.10.4 Assigning IDs and Aliases (235)

4.10.4.1 Identifying Radio IDs (236)

4.10.4.2 Assigning Radio Aliases (236)

4.10.4.3 Identifying Group IDs (237)

4.10.4.4 Assigning Group Aliases (237)

4.10.5 Determining Which Channel Operates in Repeater Mode

or Direct Mode (238)

4.10.6 Determining Feature Assignments (238)

4.10.6.1 Determining Supervisor Radios (238)

4.10.6.2 Private Calls (238)

4.10.6.3 All Call (239)

4.10.6.4 Radio Disable (239)

4.10.6.5 Remote Monitor (239)

4.10.6.6 Radio Check (240)

4.10.6.7 Call Alert (240)

4.10.6.8 RX Only (240)

4.10.6.9 Remote Voice Dekey (240)

4.10.7 Emergency Handling Configuration (241)

4.10.7.1 Emergency Handling User Roles (241)

4.10.7.2 Emergency Handling Strategies (242)

4.10.7.3 Acknowledging Supervisors in Emergency (244)

4.10.7.4 Extended Emergency Call Hang Time (244)

4.10.7.5 Emergency Revert and GPS Revert Considerations (244)

4.10.8 Channel Access Configuration (249)

4.10.9 Zones and Channel Knob Programming (250)

4.11 Base Station Identifications (BSI) Setting Considerations (251)

4.12 GPS Revert Considerations (For Single Repeater and IP Site

Connect only) (253)

4.13 Failure Preparedness (254)

4.13.1 Direct Mode Fallback (Talkaround) (254)

4.13.2 Uninterrupted Power Supplies (Battery Backup) (254)

4.14 Dynamic Mixed Mode System Design Considerations (255)

4.14.1 Dynamic Mixed Mode System Configuration Considerations (255)

4.14.2 Loading Considerations in a Dynamic Mixed Mode System (257)

4.15 Configurable Timers (258)

vii

Section 5 Sales and Service Support Tools

5.1 Purpose (263)

5.2 Applications Overview (263)

5.3 Service Equipment (263)

5.3.1 Recommended Test Equipment (263)

5.4 Documentation and Trainings (265)

5.4.1 MOTOTRBO Documentation (265)

Section A Control Station Installation

A.1 Data Bearer Service (267)

A.2 Interference (268)

A.3 Control Station Installation Considerations (269)

viii

Introduction1 SECTION 1 INTRODUCTION

1.1 Welcome to MOTOTRBO TM!

Improving workforce productivity and operational effectiveness requires superior communications quality, reliability, and functionality. MOTOTRBO is the first digital two-way radio system from Motorola specifically designed to meet the requirements of professional organizations that need a customizable, business critical, private communication solution using licensed spectrum.

MOTOTRBO combines the best in two-way radio functionality with digital technology to deliver increased capacity and spectral efficiency, integrated data applications and enhanced voice communications.

MOTOTRBO is an integrated voice and data system solution comprising of mobile and portable radios, audio and energy accessories, repeaters, and a third party application partner program.

Figure 1.1 MOTOTRBO System

This system planner will enable the reader to understand the features and capabilities of the MOTOTRBO system, and will provide guidance on how to deploy and configure the system and its components to take advantage of its advanced capabilities.

This system planner is divided into 5 sections, with the first being this introduction. Section 2 provides an overview of system level features. Section 3 describes the system components in more detail. Section 4 provides guidance on system design considerations including configuration of components. Section 5 provides product sales and support information.

This system planner is complementary to additional training and documentation including:

?Radio Customer Programming Software (CPS) and related training

?System workshop/system service training

?Product specification sheets

68007024085March 2010

2Introduction 1.2 Software Version

All the features described in the System Planner are supported by the radio’s software version R01.06.10 or later.

The initial MTR3000 firmware version 1.00.03 released in 2010 does not support MOTOTRBO features introduced in DR 3000 firmware version 1.06.00 onwards.

Example: The Transmit Interrupt feature is not supported in the MTR3000 firmware version

1.00.03.

March 2010 68007024085

System Feature Overview3 SECTION 2 SYSTEM FEATURE OVERVIEW

2.1 MOTOTRBO Digital Radio Technology

This section provides a brief overview of MOTOTRBO digital radio technology. It addresses two of the primary benefits delivered by this technology: spectral efficiency and improved audio performance.

2.1.1 Digital Radio Technology Overview

The digital radio technologies employed by MOTOTRBO can be summarized as follows:

or

1234

Figure 2-1 MOTOTRBO Digital Radio Technology

Figure 2-1 “MOTOTRBO Digital Radio Technology” is broken down into four parts which are described in the following subsections.

2.1.1.1 Part One: The Analog to Digital Conversion

When a radio user presses the Push-To-Talk (PTT) button and begins speaking, his voice is received by the radio microphone and converted from an acoustic waveform to an analog electrical waveform. This voice waveform is then sampled by an analog to digital converter. In typical radio applications, a 16-bit sample is taken every 8kHz, this produces a 128,000bps (bits per second) digital bitstream, which contains far too much information to send over a 12.5kHz or 25kHz radio channel. Therefore some form of compression is required.

2.1.1.2 Part Two: The Vocoder and Forward Error Correction (FEC)

Vocoding (Voice encoding) compresses speech by breaking it into its most important parts and encoding them with a small number of bits, while greatly reducing background noise. Vocoding compresses the voice bitstream to fit the narrow (for MOTOTRBO) 6.25kHz equivalent radio channel. The MOTOTRBO vocoder is AMBE+2TM which was developed by Digital Voice System, Inc. (DVSI), a leader in the vocoding industry. This particular vocoder works by dividing speech into short segments, typically 20 to 30 milliseconds in length. Each segment of speech is analyzed, and the important parameters such as pitch, level, and frequency response are extracted. These parameters are then encoded using a small number of digital bits. The AMBE+2TM vocoder is the 68007024085March 2010

4System Feature Overview first to demonstrate very low bit rates while producing toll-quality speech such as traditionally associated with wireline telephone systems.

Together with the vocoding process, Forward Error Correction (FEC) is also applied. FEC is a mathematical checksum technique that enables the receiver to both validate the integrity of a received message and determine which, if any, bits have been corrupted. FEC enables the receiver to correct bit errors that may have occurred due to radio frequency (RF) channel impairment. This effectively rejects noise that can distort an analog signal and by comparison enables more consistent audio performance throughout the coverage area. At this stage, the vocoder has already compressed the 128,000bps input signal to 3,600bps.

2.1.1.3 Part Three: Framing

In framing, the vocoded speech is formatted for transmission. This includes organizing the voice and any embedded signaling information (such as color code, group ID, PTT ID, call type, etc.) into packets. These packets form a header and payload type of structure – the header contains the call control and ID information, and the payload contains the vocoded speech. This same structure can also relay Internet Protocol (IP) data packets – the IP packets are simply an alternative form of payload to the MOTOTRBO radio. The header information is repeated periodically throughout the transmission, thereby improving the reliability of the signaling information as well as enabling a receiving radio to join a call that may already be in progress – we refer to this condition as “late entry”.

2.1.1.4 Part Four: TDMA Transmission

Finally, the signal is encoded for a Frequency Modulation (FM) transmission. The bits contained in the digital packets are encoded as symbols representing the amplitude and phase of the modulated carrier frequency, amplified, and then transmitted.

TDMA (Time Division Multiple Access) organizes a channel into 2 time slots: a given radio’s transmitter is active only for short bursts, which provides longer battery life. By transmitting only on their alternating time slots, two calls can share the same channel at the same time without interfering with one another, thereby doubling spectrum efficiency. Using TDMA, a radio transmits only during its time slot (i.e. it transmits a burst of information, then waits, then transmits the next burst of information).

2.1.1.5 Standards Compliance

The digital protocols employed in MOTOTRBO (from vocoding and forward error correction to framing, transmission encoding, and transmission via two-slot TDMA) are fully specified by the ETSI1 DMR2 Tier 23 Standard, which is an internationally recognized standard with agreements among its supporting members. Although formal interoperability testing and verification processes for this standard have yet to fully mature, Motorola anticipates that MOTOTRBO radio systems will be interoperable with other solutions that comply to the ETSI DMR Tier 2 standard.

1.European Telecommunications Standards Institute

2.Digital Mobile Radio

3.Tier 2 indicates full power conventional operation in licensed channels for professional and commercial

users.

March 201068007024085

System Feature Overview5 2.1.2 Spectrum Efficiency via Two-Slot TDMA

2.1.2.1 Frequencies, Channels, and Requirements for Spectrum Efficiency

A radio communications channel is defined by its carrier frequency, and its bandwidth. The

spectrum of available carrier frequencies is divided into major bands (such as 800/900 MHz, VHF, and UHF), and the majority of licensed channels in use today have widths of either 25kHz or

12.5kHz. As the airwaves have become increasingly crowded, new standards and technologies

that allow more radio users to share the available spectrum in any given area are needed. The demand for greater spectral efficiency is being driven, in part, by regulatory agencies. In the U.S., for example, the Federal Communications Commission (FCC) requires manufacturers to offer only devices that operate within 12.5kHz VHF and UHF channels by 2011. By the year 2013, all VHF and UHF users are required to operate in 12.5kHz channels.

The next logical step is to further improve the effective capacity of 12.5kHz channels. While there is no current mandate requiring a move to 6.25kHz, such discussions are on-going at the FCC and other agencies. It’s only a matter of time before the ability to carry two voice paths in a single

12.5kHz channel, also known as 6.25kHz equivalent efficiency, becomes a requirement in 800/900

MHz, VHF, and UHF bands. Presently, FCC rules are in place to mandate manufacturers to build radios capable of the 6.25kHz efficiency for 800/900 MHz, VHF, and UHF bands, but the enforcement of these rules are put on hold. In the meantime, MOTOTRBO offers a way to divide a

12.5kHz channel into two independent time slots, thus achieving 6.25kHz-equivalent efficiency

today.

2.1.2.2 Delivering Increased Capacity in Existing 12.5kHz Channels

MOTOTRBO uses a two-slot TDMA architecture. This architecture divides the channel into two alternating time slots, thereby creating two logical channels on one physical 12.5kHz channel.

Each voice call utilizes only one of these logical channels, and each user accesses a time slot as if it is an independent channel. A transmitting radio transmits information only during its selected slot, and will be idle during the alternate slot. The receiving radio observes the transmissions in either time slot, and relies on the signaling information included in each time slot to determine which call it was meant to receive.

68007024085March 2010

6System Feature Overview

March 201068007024085By comparison, analog radios operate on the concept of Frequency Division Multiple Access (FDMA). In FDMA, each transmitting radio transmits continuously on a designated channel, and the receiving radio receives the relevant transmission by tuning to the desired carrier frequency.

TDMA thereby offers a straightforward method for achieving 6.25kHz equivalency in 12.5kHz repeater channels – a major benefit for users of increasingly crowded licensed bands. Instead of dividing channels into smaller slices of decreased bandwidth – which is what would be required to increase spectrum efficiency with FDMA methods, TDMA uses the full 12.5kHz channel bandwidth, but increases efficiency by dividing it into two alternating time slots. Additionally, this method preserves the well-known radio frequency (RF) performance characteristics of the 12.5kHz signal. From the perspective of RF physics – that is, actual transmitted power and radiated emissions – the 12.5kHz signal of two-slot TDMA occupies the channel, propagates, and performs essentially in the same way as today’s 12.5kHz analog signals. With the added advantages of digital technology, TDMA-based radios can work within a single repeater channel to provide roughly twice the traffic capacity, while offering RF coverage performance equivalent to, or better than, today’s analog radio.

2.1.2.3 Two-Slot TDMA Reduces Infrastructure Equipment

As we have seen, two-slot TDMA essentially doubles repeater capacity. This means that one MOTOTRBO repeater does the work of two analog repeaters (a MOTOTRBO repeater supports two calls simultaneously). This saves costs of repeater hardware and maintenance, and also saves on the cost and complexity of RF combining equipment necessary in multi-channel configurations. Just as importantly, the two-slot TDMA signal fits cleanly into a customer’s existing,licensed channels; there is no need to obtain new licenses for the increase in repeater capacity,T i m e Regulatory emissions mask Slot 1

Slot 1

Slot 1

Slot 2

Slot 2

Slot 2

F re q u e n c y F re q u e n c y

MOTOTRBO

System Feature Overview 7

68007024085March 2010and compared to alternative technologies that may operate on different bandwidths, there is no comparative increase in the risk of interference with or from adjacent channels.

Figure 2-3 MOTOTRBO Requires Less Combining Equipment

T x 1

R x 1

T x 2

R x 2

T x

3R x 3

Repeater 1

12.5kHz Analog

Repeater 2Repeater 3

Combining Equipment Frequency Pair 2Groups Frequency Pair 1

Analog 2-Channel System Repeater Tx

Rx 12.5kHz TDMA

MOTOTRBO 2-Channel System

Duplexer

Frequency Pair

Groups

8System Feature Overview

March 2010680070240852.1.2.4 Two-Slot TDMA Enables System Flexibility

The two time slots or logical channels enabled by two-slot TDMA can potentially be used for a variety of purposes. Many organizations deploying MOTOTRBO systems can use these slots in the following manner:

?

Use both the slots as voice channels. This doubles the voice capacity per licensed repeater channel, thereby ?

increasing the number of users the system can accommodate, and ?

increasing the amount of air time the users can consume.?

Use both slots as data channels. This allows the organizations to fully deploy data transactions ?Use one slot as a voice channel, and the other as a data channel. This is a flexible

solution, that allows customers to equip their voice users with mobile data, messaging,

or location tracking capabilities.

In any of these scenarios, additional benefits are realized within the existing licensed repeater channel(s).

Figure 2-4 Example of Two-Slot TDMA

Timeslot 1Timeslot 1Timeslot 1Timeslot 2Timeslot 2Timeslot 2

Voice Call 2 (or Data)

Voice Call 1 (or Data)

System Feature Overview9 NOTE:When used in direct mode without a repeater, two-slot TDMA systems on a 12.5kHz channel do not deliver 6.25kHz equivalent efficiency. This is because the repeater is

necessary to synchronize the time slots to enable independent parties to share them.

Thus, on a direct or talkaround channel, when one radio begins transmitting, the whole

12.5kHz channel is effectively busy, even though the transmitting radio is using only one

time slot. The alternate time slot is unavailable for another, independent voice call.

However, the alternate time slot can potentially be utilized as a signaling path. The ETSI

DMR Tier 2 standard refers to this capability as Reverse Channel signaling, and it is

envisioned to be used to deliver important future benefits to professional users, such as

priority call control, remote-control of the transmitting radio, and emergency call pre-

emption. This future capacity for reverse channel signaling is a unique capability of TDMA

technology and, if supported by your system, may be deployed in both repeater and direct/

talkaround configurations. At this time, the MOTOTRBO system does NOT support

Reverse Channel signaling.

2.1.2.5 Two-Slot TDMA System Planning Considerations

System Planning considerations associated with the increased capacity and the flexibility of the MOTOTRBO two-slot TDMA architecture include:

?Capacity planning:

?How many voice and data users do you have?

?What usage profiles are anticipated?

?How many channels and repeaters are needed?

These questions are addressed in more detail in “System Design Considerations” on page169.

?Fleetmapping:

?How to map users, voice services and data services such as messaging or location tracking to channels.

Voice and data service capabilities are described in more detail in this module and in “System Components and Topologies” on page111. Fleetmapping considerations are addressed in more detail in “System Design Considerations” on page169, in the MOTOTRBO Systems Training, and within the MOTOTRBO radio CPS.

?Migration Planning:

?How to migrate existing channels to digital channels?

?What updates to licensing requirements may be needed?

These questions are addressed in mode detail in Section 4 “System Design Considerations” on page169.

2.1.3 Digital Audio Quality and Coverage Performance

This section describes how digital audio drives coverage performance. It also sets expectations for how digital audio behaves and sounds from the end-user’s perspective.

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10System Feature Overview 2.1.3.1 Digital Audio Coverage

The main difference between analog and digital coverage is how the audio quality degrades throughout the coverage region. Analog audio degrades linearly throughout the region of coverage, while digital audio quality performs more consistently in the same region of coverage. A primary reason for the different degradation characteristics is the use of forward error correction coding used in digital transmissions, which can accurately deliver both audio and data content with virtually no loss over a far greater area.

It is this error protection that allows a MOTOTRBO system to provide consistent audio quality throughout its coverage area. A comparable analog system can never offer such consistency. In the MOTOTRBO system, the audio quality remains at a high level, because the error protection minimizes the noise effect.

The figure below graphically illustrates the relationship of delivered system audio quality, while comparing good to poor audio quality with strong to weak signal strength. Do note that ?In very strong signal areas the analog signal, because there is no processing, may sound slightly better than the digital audio signal.

?Digital signals increase the effective coverage area above the minimally acceptable audio quality level.

?Digital signals improve the quality and consistency of the audio throughout the effective coverage area.

?Digital signals do not necessarily increase the total distance that an RF signal propagates.

Figure 2-5 Comparison of Audio Quality versus Signal Strength for Analog and Digital

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System Feature Overview11 2.1.3.2 Predicting Digital Audio Coverage

Predicting coverage for a radio site can be complicated. There are many factors that affect RF performance prediction, and generally, the more factors that can be considered, the more accurate the prediction of coverage. Perhaps the most influential factor is the selection of the RF propagation model and/or RF prediction software tools.

Coverage prediction techniques for analog and digital systems generally follow the same basic procedures, and require similar sets of input factors. Therefore, if the site’s analog coverage footprint is already known, it is easier to plan the site’s digital coverage footprint. This approach allows the system designer to use their existing analog site coverage prediction techniques, whether simple or complex, and then translate the results of the analog coverage prediction to predict digital coverage.

Delivered Audio Quality (DAQ) is a method to quantify audio quality. It is a measure of the intelligibility and quality of voice transported through a communications system, as defined in TIA TSB-88. DAQ reports audio quality on a 5 point scale, with a DAQ rating of 3 considered as the minimal acceptable level of audio quality for public safety applications. The definition of DAQ 3 is “Speech understandable with slight effort and occasional repetition required due to Noise/ Distortion.”.

When comparing an analog site and a MOTOTRBO site, the relative regions of coverage offering comparable audio quality are illustrated in the figure below.

Figure 2-6 Differences in Analog Coverage

For a DAQ 3 audio quality, MOTOTRBO provides a greater usable range than analog, when all other factors are considered equal (e.g. transmit power level, antenna height, receiver noise figures, IF filter bandwidths, no audio processing – such as Hear Clear – on the analog radios, terrain, antenna combining equipment, etc.).

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