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Saturday, January 11, 2014

Digital Migration Radio System

7:50 PM

  •   Analog radios do not have a vocoder, Which does analog-to-digital and digital- To-analog conversion (A/D and D/A).
  •   Vocoder - A special DSP device that converts the analog voice signal into a special digital code that uses less digital data than standard analog-to-digital converters.
  •   Modulation - a radio design that transmits digital data more efficiently within a specified bandwidth (25 or 12.5 khz).
Summary – Benefits of going Digital
  •   RF spectrum efficiency getting more channels from the same RF spectrum
  •   25 khz channel split into two 12.5 khz channels in APCO
  •   Future migration to 6.25 khz (4:1 improvement) in APCO
  •   25 khz channel split into four time slots (equivalent to four channels)
  •   Provides a 4:1 improvement
  •   Inherit privacy with digital transmission over analog
  •   Improved digital audio quality over analog
  •   Maintaining the same coverage for apco digital system providing greater consistency in voice quality
  •   No degradation in encrypted voice quality
  •   Provide integrated voice and data capability
Why digital radio? Spectrum efficiency
  •   Spectrum efficiency - You are able to put more radio users onto one radio channel than ever before!
  •   analog radio channel supports one conversation
  •   Improved Voice Quality over same area - Voice transmissions are now clearer than ever before!
Why digital radio? Integrated Voice & Data, Enhanced signaling
  •   Integrated Voice & Data
  •   You can now have both voice and data on one terminal today!
  •   Enhanced signaling features
  •   Embedded signaling offers enhanced communication features
Why digital radio? Voice privacy, improved encrypted voice quality
  •   Voice Privacy
  •   Voice transmissions are transmitted digitally, so casual eavesdroppers cannot listen to conversations
  •   Improved Encrypted Voice Quality
  •   Digital voice transmissions can also be encrypted, thereby providing additional security, but with the same voice quality as unencrypted voice
Digital Trunking Radio Technologies Today
  •   Only OPEN Standards available today:
  •   TETRA
  •   Terrestrial Trunked Radio
  •   Standard defined by ETSI, Europe
  •   APCO-25
  •   Association of Police Communication Officers Project 25
  •   Standard defined in US by TIA
  •   De-facto Industry Standards for Public Network
  •   iDEN (Motorola)
  •   Endorsed by ITU
  •   Several Proprietary Systems also available today:
  •   Tetrapol FDMA (Matra)
  •   OpenSky (MA/Coms)
APCO-25 Contributors
  •   Association of Public Safety Communications Officials International
  •   APCO Project 25 Steering Committee
  •   National Association of State Telecommunications Directors
  •   U.S. Department of Defense
  •   National Communications System
  •   National Security Agency
  •   The Telecommunications Industry Association
  •   Communications manufacturers
  •   Users, associations, government agencies worldwide
APCO-25 Key Objectives
  •   Public Safety focus
  •   Ensure competition through open architecture
  •   Allow effective inter/intra-agency communications
  •   Maximize spectrum efficiency
  •   Compatibility with existing equipment
  •   Gradual "migration-in-place" using existing spectrum
  •   Integrated voice and data services
What is APCO Project 25?
  •   Project 25 defines several open interfaces for two-way radio communications systems
APCO COMMON AIR INTERFACES
  •   The Common Air Interface is the Foundation for Digital Communication for both Conventional and Trunked Systems
  •   Most of the basic Functionality for Data Communications is already included in the CAI. 
  •   APCO-25 has Selected the Data Encryption Standard, or DES, and the U.S.Federal government is providing the Development effort for OTAR or Over the Air Re-keying.
  • Common Air Interface (CAI)
  •   The Major Goal of the APCO 25 System Standard is the Common Air Interface.
  •   Mobile and Portable equipment from any Manufacturer may be Freely Combined in any APCO 25 system. 
  •   A Base Line of Radio Features will be Guaranteed from any System to Work through any Manufacturer's radio.
Common Air Interface (C.A.I.)
  •   Modulation . . . QPSK-C
  •   Channel Access. . . .FDMA
  •   Bandwidth. . . 12.5 kHz
  •   Channel Bit Rate . . .     9.6kbps
  •   Vocoder . . .IMBE
  •   Signaling Format. . . Protocol Adopted
Embedded Signalling Summary
  •   APCO-25 Signalling:
  •   16,000,000 Unit ID's
  •   64,000 Group ID's
  •   4,000 Network  ID's
  •   Source & Destination ID's
  •   Embedded Emergency
  •   Data Busy Bits
  •   Crypto Key & Algorithm ID's
  •   Manufacturer’s ID
  •   Reserve Bits For New Features
ASTRO 25 System Portfolio
  •   ASTRO 25
  •   Fully Compliant with APCO P25
  •   ASTRO Conventional Systems
  •   Single Site
  •   Multiple Single Sites
  •   Receiver Voting
  •   Multicast Voting
  •   Simulcast
Console Operator Features
  •   Emergency Call
  •   Group Call
  •   Voice Selective Call
  •   PTT ID
  •   Console Patch
  •   Console Multi-Select
  •   APB Transmission
  •   Console Intercom
  •   Monitor
ASTRO 25 InfrastutreSubscriber  Product Portfolio
  •   Infrastructure:
  •   Quantar Base/Repeater
  •   Gateway
  •   Astrotac Comparator
  •   Packet Data Gateway
  •   Key Management Facility
ASTRO Subscriber- Product Portfolio
  •   Mobiles:
  •   ASTRO SPECTRA Mobile
  •   ASTRO Spectra Plus
  •   XTL5000
  •   Portables:
  •   ASTRO Saber
  •   XTS 3000
  •   XTS 2500
  •   XTS 5000
Modulation Mode Select in Subscriber
  •   CLEAR           
  •   Analog                  
  •   ASTRO 25 clear (digital)         
  •   Encrypted
  •   Securenet DVP-XL
  •   ASTRO AES Coded
Subscriber Unit Channel Access Features
  •   Channel Mode Select
  •   Modulation Mode Select
  •   Auto ASTRO/Analog Receive
  •   Transmit Power Select
  •   Non-Priority Channel Scan
  •   Dual Priority Channel Scan
  •   Busy Indicator
  •   Channel Busy Transmit Inhibit
  •   Timeout Timer
  •   Emergency Channel Revert
  •   Talkaround
Digital Migration Proposal
  •   Phase 1 : Upgrade Analog DVP-XL Securenet to ASTRO with DVP-XL
  •   Analog-only
  •   ASTRO-only
  •   Mixed mode
  •   Securenet Transparent
  •   Analog-only
  •   ASTRO-only
  •   Mixed mode
  •   Securenet Transparent
Summary
  •   Phase 1 – Upgrade Analog DVP-XL Securenet to ASTRO with DVP-XL
  •   Phase 1 – Link all sites to the HQ console
  •   Phase 1 – Upgrade with AVLS for GPS tracking





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