Page 1
The Speech Compression Specialists
Net-2000™-P25
Voice Codec Unit
User’s Manual
Version 2.0.0
December 2003
Page 2
Net-2000™-P25 Voice Codec Unit
User’s Manual
Version 2.0.0, December 2003
Copyright, 2003
Digital Voice Systems, Inc
234 Littleton Road
Westford, MA 01886
This document may not, in whole or in part be copied, photocopied, reproduced, translated, or reduced
to any electronic medium or machine readable form without prior consent in writing from Digital Voice
Systems, Incorporated.
Every effort has been made to ensure the accuracy of this manual. However, Digital Voice Systems,
Inc. makes no warranties with respect to the documentation and disclaims any implied warranties of
merchantability and fitness for a particular purpose. Digital Voice Systems, Inc. shall not be liable for
any errors or for incidental or consequential damages in connection with the furnishing, performance, or
use of this manual or the examples herein. The information in this document is subject to change
without notice.
Trademarks
Net-2000™- P25 VCU Voice Codec Unit, AMBE+2™ and AMBE+™ are trademarks of Digital Voice
Systems, Inc. AMBE® is a registered trademark of Digital Voice Systems, Inc. Other product names
mentioned may be trademarks or registered trademarks of their respective companies and are the sole
property of their respective manufacturers.
All Rights Reserved
Data subject to change
Page 3
Net-2000™- P25 Voice Codec Unit END USER License Agreement
1.0 Preliminary Statements and Definitions
1.1 "Voice Codec Unit" shall mean the hardware,
software and associated documentation referred to in the
invoice or shipping papers accompanying this agreement for
which END USER has requested a license, and any
derivative works thereof, including modifications,
enhancements and extensions made by or for Digital Voice
Systems, Inc. (DVSI) and including circuit diagrams, timing
diagrams, programmable logic software, logic diagrams,
layouts, operating instructions and user manuals.
"AMBE™ Software" shall mean the speech coding software
and/or firmware provided as part of the Voice Codec Unit.
This software is contained in the Read Only Memories
(ROMS, EPROMS, EEPROMS, etc...) which are included as
part of the Voice Codec Unit. This software includes any
derivative works which have as their source the software
contained in the Read Only Memories, and it includes the
software contained in any future Read Only Memories which
DVSI may provide END USER for use in the Voice Codec.
1.3 "Designated Site" shall mean the location of the
Voice Codec Unit.
1.4 "Proprietary Information" shall mean the information
which DVSI desires to protect against unrestricted disclosure
or competitive use and which is designated as such in writing
by DVSI or is disclosed orally and within thirty (30) days
thereafter is reduced to tangible form pursuant to this
License.
DVSI represents that it owns certain “Proprietary Rights” in
the Technology and in the AMBE and AMBE+2™ Voice
Compression Software, including patent rights in the
Technology, and patent rights, copyrights, and trade secrets
in the AMBE and AMBE+2™ Voice Compression Software.
2.0 License Granted
2.1 Subject to the conditions herein and upon initial use
of the AMBE™ and AMBE+2™ Software within the Net2000™-P25 Voice Codec Unit, DVSI hereby grants to END
USER a non-exclusive, limited license to use the AMBE® and
AMBE+™ Voice Compression Software internal to the Net2000™-P25 Voice Codec Unit. Title to the AMBE® Voice
Compression Software remains with DVSI. No license is
granted for use of the AMBE® AMBE+™ Voice Compression
Software on other than the Net-2000™-P25 Voice Codec
Unit. No license, right or interest in any trademark, trade
name or service mark of DVSI is granted under this
Agreement.
2.2 END USER shall not copy, extract, de-compile,
reverse engineer or disassemble the AMBE® and AMBE+™
Voice Compression Software contained in the Net-2000™P25 Voice Codec Unit.
2.3 Transfer of License
(a) END USER may transfer the Net-2000™-P25 Voice
Codec Unit with the AMBE® and AMBE+™ Software and all
rights under this agreement to a third party together with a
copy of this Agreement provided that END USER provides
DVSI with a written notification of the transfer and provided
that the third party agrees in writing to accept all the terms
and conditions of this agreement. Upon any such transfer,
END USER's rights under this Agreement shall terminate
pursuant to Section 3.0.
DVSI Confidential Proprietary
(b) END USER may relocate the Net-2000™-P25 Voice
Codec Unit, and the subsequent location shall then be
considered the Designated Site.
(c) Except as provided in this Section 2.2, this
Agreement, the AMBE® and AMBE+™ Software and any other
information provided by DVSI to END USER and any licenses
and rights granted hereunder, may not be sold, leased,
assigned, sublicensed or otherwise transferred, in whole or in
part, by END USER.
2.4 END USER shall not de-compile, reverse engineer or
disassemble the Net-2000™-P25 Voice Codec Unit, AMBE®
and AMBE+™ Software.
3.0 Term and Termination
3.1 This Agreement is effective upon initial use of the
AMBE® and AMBE+™ Software on the Net-2000™-P25 Voice
Codec Unit and shall remain in effect until terminated in
accordance with this agreement.
3.2 This Agreement shall terminate automatically without
notice from DVSI if END USER fails to comply with any of the
material terms and conditions herein. END USER may
terminate this Agreement at any time upon written notice to
DVSI certifying that END USER has complied with the
provisions of Section 3.3.
3.3 Upon termination of this Agreement for any reason,
END USER shall: (i) have no further rights to the Net-2000™P25 Voice Codec Unit and AMBE® and AMBE+™ Software; (ii)
discontinue all use of the Net-2000™-P25 Voice Codec Unit
and AMBE® and AMBE+™ Software; and (iii) destroy or, at
DVSI's option, return the Net-2000™ Voice Codec Unit and
AMBE® and AMBE+™ Software.
4.0 Payments
4.1 In consideration of the hardware, software, and
associated materials provided as part of the Net-2000™-P25
Voice Codec Unit and AMBE® and AMBE+™ Software, and in
consideration of the license and rights in the AMBE® and
AMBE+™ Software granted by DVSI, and in consideration of
DVSI's performance of its obligations hereunder, END USER
agrees to pay to DVSI the fee specified in DVSI's invoice.
5.0 Proprietary Notices
5.1 END USER shall not remove any copyright or
proprietary notice on the on the Net-2000™-P25 Voice Codec
Unit and AMBE® and AMBE+™ Voice Compression Software.
6.0 Proprietary Information
6.1 The parties agree that the Net-2000™-P25 Voice
Codec Unit and AMBE® and AMBE+™ Software, Voice
Compression Software shall be considered Proprietary
Information.
6.2 Except as otherwise provided in this Agreement,
END USER shall not use, disclose, make, or have made any
copies of the Proprietary Information, in whole or in part,
without the prior written consent of DVSI.
6.3 END USER shall make reasonable efforts to notify
and inform its employees having access to the Proprietary
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Net-2000™ Voice Codec Unit
User’s Manual
Information of END USER's limitations, duties and obligations
regarding nondisclosure and copying of the Net-2000™-P25
Voice Codec Unit and AMBE® and AMBE+™ Software,.
Proprietary Information shall be used only by employees of
END USER and only at the Designated Site, except as
provided under this agreement.
6.4 END USER shall have no obligations for disclosure
or use of Proprietary Information which: (i) is already known to
END USER, at time of disclosure by DVSI; (ii) is or becomes
publicly known through publication, inspection of product or
otherwise through no wrongful act of END USER; (iii) is
received from a third party without restriction and without
breach of this Agreement; (iv) is independently developed by
END USER; (v) is disclosed to a third party by or on behalf of
DVSI without restriction; or (vi) is approved for release or use
by written authorization of DVSI.
6.5 Notwithstanding any termination pursuant to
Section 3.0, the obligations set forth in this Section 6.0 shall
survive termination of this Agreement.
7.0 Limited Warranty
7.1 DVSI warrants the Net-2000™-P25 Voice Codec
Unit and AMBE® and AMBE+™ Software, to be free from
defects in materials and workmanship under normal use for a
period of ninety (90) days from the date of delivery. DVSI
further warrants that the Net-2000™-P25 Voice Codec Unit
and AMBE® and AMBE+™ Software, operate in accordance
with the written specifications delivered to END USER with
the Net-2000™-P25 Voice Codec Unit,.
7.2 Except as stated in Section 7.1, the Net-2000™P25 Voice Codec Unit and AMBE® and AMBE+™ Software,
are provided "as is" without warranty of any kind. DVSI does
not warrant, guarantee or make any representations
regarding the use, or the results of the use, of the Net2000™-P25 Voice Codec Unit and AMBE® and AMBE+™
Software, with respect to its correctness, accuracy, reliability,
correctness or otherwise. The entire risk as to the results and
performance of the Net-2000™-P25 Voice Codec Unit and
AMBE® and AMBE+™ Software, is assumed by the END
USER. After expiration of the warranty period, END USER,
and not DVSI or its employees, assumes the entire cost of
any servicing, repair or correction of the Net-2000™-P25
Voice Codec Unit and AMBE® and AMBE+™ Software,.
7.3 DVSI warrants that it has the right to enter into this
Agreement and to grant a license to use the Net-2000™-P25
Voice Codec Unit and AMBE® and AMBE+™ Software, to
END USER.
7.4 Except as specifically set forth in this Section 7.0,
DVSI makes no express or implied warranties including,
without limitation, the warranties of merchantability or fitness
for a particular purpose or arising from a course of dealing,
usage or trade practice, with respect to the Net-2000™-P25
Voice Codec Unit and AMBE® and AMBE+™ Software,.
Some states do not allow the exclusion of implied warranties,
so the above exclusion may not apply to END USER. No oral
or written information or advice given by DVSI or its
employees shall create a warranty or in any way increase the
scope of this warranty, and END USER may not rely on any
such information or advice. The limited warranties under this
section 7.0 give END USER specific legal rights, and END
USER may have other rights which vary from state to state.
Information – Section
8.0 Limitation of Liability
8.1 In no event shall DVSI be liable for any special,
incidental, indirect or consequential damages resulting from the
use or performance of the Net-2000™-P25 Voice Codec Unit
and AMBE® and AMBE+™ Software, whether based on an
action in contract, tort (including negligence) or otherwise
(including, without limitation, damages for loss of business
profits, business interruption, and loss of business information),
even if DVSI or any DVSI representative has been advised of
the possibility of such damages.
8.2 Because some states do not allow the exclusion or
limitation of liability for consequential or incidental damages,
the above limitations may not apply to END USER.
8.3 DVSI's maximum liability for damages arising under
this Agreement shall be limited to 20% (twenty percent) of the
fees paid by END USER for the particular Net-2000™-P25
Voice Codec Unit which caused the damages or that is the
subject matter of, or is directly related to, the cause of action.
9.0 Taxes
9.1 All payments required under Section 4.0 or otherwise
under this Agreement are exclusive of taxes and END USER
agrees to bear and be responsible for the payment of all such
taxes (except for taxes based upon DVSI's income) including,
but not limited to, all sales, use, rental receipt, personal
property or other taxes which may be levied or assessed in
connection with this Agreement.
10.0 Export
10.1 United States export laws and regulations prohibit the
exportation of certain products or technical data received from
DVSI under this Agreement to certain countries except under a
special validated license. As of May 20, 1996 the restricted
countries are: Libya, Cuba, North Korea, Iraq, Serbia,
Montenegro, and Iran. The END USER hereby gives its
assurance to DVSI that it will not knowingly, unless prior
authorization is obtained from the appropriate U.S. export
authority, export or re-export, directly or indirectly to any of the
restricted countries any products or technical data received
from DVSI under this Agreement in violation of said United
States Export Laws and Regulations. DVSI neither represents
that a license is not required nor that, if required, it will be
issued by the U.S. Department of Commerce. Licensee shall
assume complete and sole responsibility for obtaining any
licenses required for export purposes.
11.0 Governing Law
11.1 This Agreement is made under and shall be
governed by and construed in accordance with the laws of the
Commonwealth of Massachusetts, except that body of law
governing conflicts of law. If any provision of this Agreement
shall be held unenforceable by a court of competent
jurisdiction, that provision shall be enforced to the maximum
extent permissible, and the remaining provisions of this
Agreement shall remain in full force and effect.
12.0 Notices
12.1 Any notices to DVSI which may be given hereunder
shall be sent in writing to: Digital Voice Systems Inc., 234
Littleton Road, Westford, MA, 01886 USA
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
User’s Manual
Information – Section
Safety Instructions
Safety Precautions
1. Read Instructions - All the safety and operating instructions should be read before operating the
Net-2000™- P25 VCU unit. Failure to exercise reasonable care and to follow all instructions and
heed all warnings may result in injury to property or to individuals.
2. Retain Instructions - The safety and operating instructions should be retained for future reference.
3. Heed Warnings - Adhered to all warnings and cautions on the unit and in the operating
instructions.
4. Follow Instructions - All operating and use instructions should be followed.
5. Water and Moisture - The appliance should not be used near water - for example, near a
washbowl, sink, laundry tub, or in a wet or damp location. Moisture may form inside the unit it is
brought from cool surroundings into a warm room or if the room temperature suddenly rises. To
prevent this, let the Net-2000™- P25 VCU unit stand in its new surroundings for about an hour
before switching it on, or make sure the room temperature rises gradually. Condensation may also
form if the unit is exposed to the breeze from an air conditioner. In these situations, change the
location of the Net-2000™- P25 VCU .
6. Carts and Stands - The Net-2000™- P25 VCU unit should be used only with a cart or stand that is
suitable for the units size and weight. The unit and cart combination should be moved with care.
Quick stops, excessive force, and uneven surfaces may cause the cart to overturn.
7. Wall or Ceiling Mounting - The Net-2000™- P25 VCU unit is not intended to be mounted to a wall
or the ceiling.
8. Ventilation - The Net-2000™- P25 VCU unit should be situated so that its location or position does
not interfere with proper ventilation and air circulation around the unit. For example, the unit
should also not be placed in a built-in installation, such as an sealed cabinet or bookcase that may
impede the flow of air around the unit.
9. Heat - The Net-2000™- P25 VCU unit should be situated away from heat sources such as
radiators, heat registers, ovens, or other appliances (including amplifiers) that produce heat.
10. Power Sources - The Unit should be connected to an AC power source only of the type described
in the operating instructions or as marked on the Net-2000™- P25 VCU unit. The Net-2000™P25 VCU unit uses AC voltages which can cause death or serious injury if used improperly.
Extreme care must be taken when connecting or disconnecting from power sources and in no
event should the user remove the cover or back of the unit.
11. Grounding and Polarization - Precautions should be taken to insure that the grounding or
polarization means of the Net-2000™- P25 VCU unit is not defeated.
12. Power-Cord Protection - Power-supply cords should be routed so that they are not likely to be
walked on or pinched by items placed upon or against them. Pay particular attention to cords at
plugs, convenience receptacles, and the point where they connect to the Net-2000™- P25 VCU
unit. Handle the power-cord by the plug. Do not pull out the plug by tugging the cord.
13. Cleaning - Unplug the Net-2000™- P25 VCU unit from the AC power source before cleaning. The
unit should be cleaned only with a polishing cloth or soft dry cloth. Never clean the unit with
furniture wax, benzene, insecticides, or other volatile liquids.
14. Nonuse Periods - The AC power cord of the Net-2000™- P25 VCU unit should be unplugged
from the wall outlet when left unused for long periods of time.
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
User’s Manual
Information – Section
15. Object and Liquid Entry - Care should be take so that objects do not fall and liquids are not spilled
onto the enclosure.
16. Damage Requiring Service - The Net-2000™- P25 VCU unit should be serviced by qualified
service personnel when:
• The power-supply cord or plug has been damaged.
• Objects have fallen, or liquid has been spilled into the unit; or
• The unit has been exposed to rain; or
• The unit does not appear to operate normally or exhibits a marked change in performance;
or
• The unit has been dropped, or the enclosure damaged.
Rear Panel Caution Description
The lightning flash with arrowhead symbol, within an equilateral triangle, is intended to alert the user to
the presence of insolated “dangerous voltage” within the product’s enclosure that may be sufficient
magnitude to constitute a risk of electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert the user to the presence of
important operating and maintenance (servicing) instructions in the literature accompanying the
appliance.
CAUTION:
To prevent the risk of electric shock, do not remove cover.
No user-serviceable parts are inside.
Refer servicing to qualified service personnel.
Servicing
The user should not attempt to service the Net-2000™- P25 VCU unit beyond that described in the
operating instructions. All other servicing should be referred to qualified personnel.
WARNING
The power switch is secondary connected and therefore does not
separate the unit from mains power in the OFF position.
WARNING
To prevent fire or shock hazard, do not expose this unit to rain or
moisture. If this equipment is used in a manner not specified in this
manual, the protection provided by the equipment may be impaired.
Important Note: The serial number for this equipment is located on the rear panel. Please write this
serial number in this manual and keep it in a secure area for future reference.
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
User’s Manual
SAFETY INSTRUCTIONS............................................................... III
SAFETY PRECAUTIONS..........................................................................................III
REAR PANEL CAUTION DESCRIPTION.....................................................................IV
SERVICING ...........................................................................................................IV
NET-2000
NET-2000
TM
GENERAL INFORMATION........................................................................................ 1
FEATURES............................................................................................................ 1
INTERFACES .........................................................................................................1
SET-UP ................................................................................................................ 2
CONTROL............................................................................................................. 2
PROTOCOL...........................................................................................................2
TM
OVERVIEW ...........................................................................................................3
NET-2000™- P25 VCU CONNECTIONS ................................................................3
RACK MOUNT INSTALLATION..................................................................................6
Section – Table of Contents
Table of Contents
VCU INTRODUCTION................................................1
- P25 VCU INSTALLATION .......................................3
Connecting AC Power................................................................................4
Voice Audio I/O Connections......................................................................4
Channel Communication............................................................................4
RS-232 Serial Port......................................................................................5
NET-2000™ - P25 VCU SETUP & CONTROL...............................7
OVERVIEW ...........................................................................................................7
VCU FRONT PANEL..............................................................................................7
Power On Switch........................................................................................ 7
INITIAL SET-UP – (RS-232 SERIAL CONNECTION) ..................................................7
NET-2000™- P25 VCU WEB CONTROL INTERFACE..............................................9
Home Page.................................................................................................9
Net-2000™ -P25 VCU Status................................................................... 10
Voice Source............................................................................................10
APCO Vocoder Selection.........................................................................11
Communication Channel Selection .......................................................... 12
Control Buttons......................................................................................... 13
INTERFACE PROTOCOL..............................................................16
INTRODUCTION ...................................................ERROR! BOOKMARK NOT DEFINED.
PROTOCOL PACKET DESCRIPTION.......................................................................16
DECODE PACKET................................................................................................17
PACKET HEADER ................................................................................................ 16
PACKET PARAMETERS ........................................................................................ 18
len............................................................................................................. 18
type........................................................................................................... 18
seq............................................................................................................ 18
rate[5] ....................................................................................................... 18
cmode....................................................................................................... 19
tone [2]......................................................................................................20
ws.............................................................................................................22
format ....................................................................................................... 22
channel [192]............................................................................................ 23
C-LANGUAGE HEADER FILE.................................ERROR! BOOKMARK NOT DEFINED.
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
User’s Manual
SPECIFICATIONS.......................................................................37
INTRODUCTION....................................................................................................37
REAR PANEL CONNECTIONS ................................................................................37
AUDIO I/O CONNECTIONS....................................................................................37
ELECTRICAL INPUT ..............................................................................................38
MECHANICAL.......................................................................................................38
ENVIRONMENTAL.................................................................................................38
NET-2000™- P25 SUPPORT ....................................................39
UPGRADE PROCEDURE........................................................................................39
DVSI TECHNICAL SUPPORT.................................................................................39
LIST OF TABLES
TABLE 1 REAR PANEL CONNECTORS......................................................................................3
TABLE 2 SERIAL PORT TERMINAL SET-UP...............................................................................7
TABLE 3 DHCP SET-UP COMMAND ARGUMENTS.....................................................................8
TABLE 4 DHCP SETUP EXAMPLE...........................................................................................8
TABLE 5 HOME PAGE DEFAULTS LIST...................................................................................15
TABLE 6 DECODER PACKET .................................................................................................17
TABLE 7 PACKET HEADER....................................................................................................16
TABLE 8 LEN HEADER PARAMETER.......................................................................................18
TABLE 9 TYPE HEADER PARAMETER.....................................................................................18
TABLE 10 SEQ HEADER PARAMETER ....................................................................................18
TABLE 11 VOCODER RATE PARAMETER................................................................................19
TABLE 12 CMODE PARAMETER.............................................................................................19
TABLE 13 TONE.IDX PARAMETER ..........................................................................................21
TABLE 14 TONE.AMP PARAMETER ........................................................................................22
TABLE 15 WS PARAMETER ...................................................................................................22
TABLE 16 FORMAT PARAMETERS..........................................................................................22
TABLE 17 CHANNEL PARAMETERS ........................................................................................23
TABLE 18 RS-232 SERIAL PORT PIN OUT ............................................................................37
LIST OF FIGURES
FIGURE 1 NET-2000™- P25 VCU REAR PANEL.....................................................................3
FIGURE 2 CONNECTING TWO NET-2000™- P25 VCU’S TOGETHER.........................................5
FIGURE 3 RACK MOUNT INSTALLATION...................................................................................6
FIGURE 4 NET-2000™- P25 VCU FRONT PANEL...................................................................7
FIGURE 5 NET-2000™- P25 VCU HOME PAGE .....................................................................9
FIGURE 6 NET-2000™-P25 STATUS INFORMATION ..............................................................10
FIGURE 7 VOICE SOURCE ....................................................................................................11
FIGURE 8 RATE SELECTION .................................................................................................11
FIGURE 9 COMMUNICATIONS CHANNEL.................................................................................12
FIGURE 11 SOFTWARE VERSION INFORMATION POP-UP WINDOW .........................................13
FIGURE 13 NET-2000™- P25 VCU NETWORK SETTINGS POP-UP WINDOW .........................14
FIGURE 14 HOME PAGE RESET MAIN PAGE TO DEFAULTS ....................................................15
FIGURE 15 START AND STOP BUTTONS................................................................................15
Section – Table of Contents
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
User’s Manual
Section 1 – Net-2000™ VCU Introduction
Net-2000TM VCU Introduction
General Information
The Net-2000™-P25 voice codec unit (VCU) incorporates Digital Voice Systems, Inc. (DVSI) latest
advancement in voice compression technology to bridge analog speech I/O to an Ethernet network.
The Net-2000™-P25 VCU supports both the standard Full-Rate APCO P25 vocoder as well as
DVSI’s new Half-Rate voice compression vocoder proposed to APCO. This makes it an ideal
evaluation module for a variety of digital mobile radio communication systems.
DVSI’s new Half-Rate Vocoder operates at 2450 bps and includes integrated forward error
correction (FEC) to raise the total channel rate to only 3600 bps. DVSI designed the 3600 bps HalfRate Vocoder as an extension to the standard 7200 bps Full-Rate IMBE™ Vocoder that is currently
used throughout P25.
Features
• Net-2000™ VCU incorporates both the current APCO standard Full-Rate vocoder and the
proposed Half-Rate voice compression vocoder
• Real-time, full-duplex communications via the Ethernet interface to another Net-2000™P25 VCU unit.
• A built-in web server for easy selection and control of the audio I/O
• The Net-2000™- P25 VCU’s RS-232 serial port can be used as a console terminal to allow
low-level system setup.
• The Net-2000™- P25 VCU can handle information from a DHCP server when available on a
Local Area Network (LAN).
• The embedded user interface allows the operation software to be field upgradeable.
Interfaces
To meet a wide variety of communication system requirements the Net-2000™- P25 VCU contains
two interfaces for speech input and output and an Ethernet connection for the channel data
interface. The Net-2000™-P25 VCU analog interface includes a 4-wire and a handset for input and
output of uncompressed speech. The speech I/O is easily managed with the Net-2000™- P25
VCU’s built-in web server control.
For a channel connection, the Net-2000™ VCU provides a 10Base-T Ethernet interface for
connecting directly to a Local Area Network (LAN). This configuration can be used to create a realtime full duplex Voice Over Internet Protocol (VOIP) Ethernet based vocoder communication system
between two Net-2000™ VCUs. Alternatively, the Net-2000™ VCU can Loopback the VOIP
information back to itself for voice monitoring and evaluation applications.
When two Net-2000™-P25 communicate, each converts the input analog speech into digital speech
samples, encodes the speech using the selected APCO Full-Rate or Half-Rate mode and then
sends the compressed bit stream out as UDP packets over the Ethernet interface. Simultaneously,
the compressed bit stream of UDP packets from the other Net-2000™-P25 are read in from the
Ethernet interface and decoded back in to digital speech samples. The decoded samples are
converted back into analog speech via the AIC-10 codec whose output is sent to both the handset
and line-level output connections.
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
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Section 1 – Net-2000™ VCU Introduction
Set-up
The Ethernet interface is equipped to handle IP address information from a DHCP server so that
initial set-up of the Net-2000™-P25 VCU is fast and straightforward. Alternatively, the RS-232 serial
port can be used via telnet as a console terminal to allow low-level network setup.
Control
When connected on a LAN — any PC on the network can use a standard web browser to control the
Net-2000™-P25 VCU through the use of a PC web browser. The user-friendly web pages built-into
the Net-2000™-P25 make it easy to select analog audio interfaces, select the vocoder mode and to
establish real-time, full-duplex communication across the Ethernet connection. In addition to the
control, the web pages display information about network settings, operating mode and system
status. Since the Net-2000™-P25 uses Ethernet, its web page can even be accessed over a
wireless network through a wireless notebook or tablet PC.
Protocol
The Net-2000™ VCU uses DVSI’s own UDP interface described in section 4. This allows users to
develop their own application controls and user interfaces for an endless array of customized
applications.
Before using the Net-2000™- P25 VCU, read through this user’s manual in its entirety, paying
careful attention to the safety instructions beginning on page ii.
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
User’s Manual
Section 2 – Net-2000™ VCU Installation
Net-2000TM - P25 VCU Installation
Overview
The Net-2000™- P25 VCU hosts a variety of inputs and outputs that provide you with flexibility in
system integration. The Net-2000™- P25 VCU is designed to be controlled through the use of a PC
and to communicate over an Ethernet network. This manual assumes that the user has a working
networked PC before the Net-2000™- P25 VCU is installed.
Net-2000™- P25 VCU Connections
See Section 5 Specifications for more detailed technical information about each of the connections.
Figure 1 Net-2000™- P25 VCU Rear Panel
Rear Panel Connections
Item No. Name Connector Type Status
1 Serial Port DE9s Active
2 LAN RJ-45 Active
3 RS-422 Synchronous DB-15HD Not Active
4 RS-422 Asynchronous RJ-45 Not Active
5 2 Wire I/O RJ-11 Not Active
6 Analog Line In RCA Jack Active
7 Analog Line Out RCA Jack Active
8 Handset RJ-11 Active
9 No Connection SMA Not Active
10 AC Line In Power Cord Receptacle Active
Table 1 Rear Panel Connectors
In order to install the Net-2000™- P25 VCU connections must be made to a voice audio source and
output, channel communications and control. In Target IP Mode, the Net-2000™- P25 VCU can be
connected to another Net-2000™- P25 VCU located anywhere on the LAN. This configuration can
support a real-time, full-duplex channel over Ethernet connection. This mode can be controlled via
the built-in web page.
DVSI Confidential Proprietary
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Net-2000™ Voice Codec Unit
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Section 2 – Net-2000™ VCU Installation
Connecting AC Power
The Net-2000™- P25 VCU unit will automatically adjust to both European and US voltage levels.
There are no user settings. Just plug in the AC power cord provided into the AC receptacle on the
back of the unit (See Table 1 Rear Panel Connectors item 9) and plug the other end into an AC
power outlet.
Voice Audio I/O Connections
4-Wire
Connecting the Net-2000™- P25 VCU to analog audio components is fairly self explanatory. At
typical connection would be to connect the audio output of an audio component such as a Mic, a
Digital Tape, player or even a PC sound card output to the Analog Input jack of the Net-2000™- P25
VCU (audio cables not included). Next connect the Analog Output jack of the Net-2000™ VCU to an
amplifier or Audio In jack on a PC sound card.
Handset
If you are using a handset instead of the 4 wire interface, use a standard telephone handset
(included) to connect to the RJ11 handset connector. Use a handset with a cord that is about a foot
long (included) when not stretched. This will help reduce noise from being introduced into the voice
signal.
Channel Communication
Ethernet
The Net-2000™- P25 VCU uses Ethernet to for control (using a web browser), to transmit channel
data in VOIP Mode, and to transmit both voice and channel data in File Mode. A special protocol
designed by DVSI must be used to exchange voice and channel data with the VCU. This UDP
streaming protocol allows for real-time full-duplex communication with another Net-2000™- P25
VCU box (VOIP Mode) and for bit-exact testing (File Mode). To run in VOIP mode the operator
selects the voice interface (4-wire, handset), the IP address of the unit to send channel data to, and
the vocoder (Standard APCO, Half-Rate APCO, or Half-Rate APCO with bit-stealing). When
running in VOIP Mode the VCU encodes a frame of speech from the specified voice interface and
transmits a packet containing the encoded data to the specified target IP address. At the same time
the VCU expects to receive channel data packets from the specified target IP address. The VCU
decodes these packets and sends the decoded speech to both the handset and line-out speech
outputs.
In File Mode the Net-2000™- P25 VCU responds to incoming voice packets by encoding the voice
data in them and transmitting a channel data packet to the sender, and to incoming channel data
packets by decoding them and transmitting synthesized voice data packets to the sender. Only one
user can access the VCU at a time in File Mode. Transmitting data packets to the VCU from more
than one source will produce undesired results.
Connecting the Ethernet Network
Make sure the Ethernet cable is connected to the Ethernet port in the back of the NET-2000™- P25
VCU before applying AC power. Note that if you are going to use a direct Ethernet connection from
your PC to the NET-2000™- P25 VCU you should use a crossover cable. If your NET-2000™- P25
VCU is connected to a hub, a straight-through Ethernet cable should be used.
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Section 2 – Net-2000™ VCU Installation
The VCU has a 10 Mbps Ethernet interface for network communication. It can operate on a 100
Mbps LAN when connected to a 10/100 Ethernet hub or router. The default network configuration
for the VCU assumes that a DHCP server is available on the LAN to provide it with valid network
address information. If a DHCP server is not available on the LAN, static IP address information will
need to be entered via the serial port in order to access the VCU over the network.
RS-232 Serial Port
Connecting to RS-232
The RS-232 serial port located on the back of the Net-2000™- P25 VCU unit provides low level setup functions. The interface itself consists of a simple command/response ASCII text protocol. You
can use a terminal or terminal emulator on a personal computer to type commands at a keyboard as
your user interface.
To connect the serial interface, to a Terminal or PC plug a straight-through modem cable (see pin
outs in Table 35 RS-232 Serial Port Pin Out) into the serial port DE-9s connector and plug the other
end into your terminal (or one of the serial ports on your PC if you are using an emulator). Set the
terminal as shown in Table 2 Serial Port Terminal Set-up.
Figure 2 Connecting two Net-2000™- P25 VCU’s together
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Rack Mount installation
When a rack mount kit is purchased with the Net-2000™- P25 VCU the assembly is installed at the
factory prior to shipping. If the rack mount, needs to be removed there are three flat head Philips
screws on each side that secures the rack mount plate to the Net-2000™- P25 VCU chassis as
shown below. To avoid scratching the sides of the Net-2000™- P25 VCU when removing the rack
plate push down on the front of the plate so that it slips out from underneath the unit. When reinstalling the rack mount slip it up from underneath and push it back to be flush with front face. Use
the same six screws to secure the rack mount back on the chassis.
Figure 3 Rack Mount Installation
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Section 3 – Net-2000™ VCU Control
Net-2000™ - P25 VCU Setup & Control
Overview
The Net-2000™- P25 VCU may be set-up from the serial RS-232 interface and controlled through
the use of the built-in web sever. Both of these interfaces may be used and connected at the same
time to provide the flexibility required to integrate to most system configurations.
Connecting to the RS-232 interface allows for low level set-up of the NET-2000™- P25 VCU. When
connected on a LAN -- any PC on the network can use a standard web browser to configure the
unit’s mode of operation, I/O interfaces and selection of vocoder mode. Input and output gain
settings for the voice codec can be also specified.
In addition to the control, the web pages also display information about network settings, operating
mode and system control. Connecting two Net-2000™- P25 VCU units together can be done by
entering the IP address (or hostname) of the other Net-2000™- P25 VCU unit and selecting the
desired voice interface.
VCU Front Panel
Figure 4 Net-2000™- P25 VCU Front Panel
Net - 2000
Net - 2000
V
C U
oice odec nit
Power On Switch
The Net-200™ VCU’s power is turned ON /Off through the switch on the left side of the front panel.
Press the top of the switch (I) to turn ON. Press the bottom of the switch (0) to turn OFF. When
powering off the unit always wait a few seconds before turning the unit back on.
Initial Set-up – (RS-232 Serial Connection)
The RS-232 interface is used for command line style set-up. It is used when the Net-2000™ VCU
is installed on a network where there is no DHCP Server or when the user wants to customize the
network configuration.
Serial Port Settings
Bits per second: 9600
Data bits: 8
Parity: None
Stop bits: 1
Flow control: None
Table 2 Serial Port Terminal Set-up
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Note:
The Ethernet MAC address and default hostname of the VCU is derived from the serial
number of the VCU. The MAC address will begin with 00:01:FD followed by the last six
digits of the serial number. The hostname is VCU followed by the last six digits of the
serial number. For example, if the last six digits of the serial number are FF1234, the
MAC address is 00:01:FD:FF:12:34 and the hostname is VCUFF1234.
When no DHCP server is available on a LAN the VCU’s RS-232 serial port can be used as a
console terminal for low-level network setup. With the serial cable connected and the terminal
running type a few carriage returns from the PC’s keyboard. The Net-2000™- P25 VCU will respond
with the console prompt as shown below:
adsh>
At the adsh prompt the VCU’s network settings can be configured or changed using the terminal
console command “network” as follows:
adsh>network [-dhcp] [-h hostname] [-w workgroup] [-i ipaddress] [-m
netmask] [-g gateway] [-n nameserver][-d domainname]
The arguments to the network command are described below:
Arguments Use Result
-dhcp when DHCP is available on LAN DHCP is enabled
-h Sets the hostname of the VCU
-w
anytime
Sets the Windows workgroup of the VCU
-i Sets the static IP address
-m Sets the IP address of the netmask
-g Sets the IP address of the gateway
use only when DHCP is disabled
-n Sets the IP address of the nameserver
-d
Sets the domain name of the VCU.
Table 3 DHCP Set-up command Arguments
The following command example results are show in the table below
adsh>network –h net2k1 -w lab -i 192.168.1.100 -m 255.255.255.0 -g
192.168.1.250 -n 192.168.1.1 -d domain.com
Arguments VCU Result Example
DHCP is NOT enabled
-h HOSTNAME net2k1
-w Windows WORKGROUP lab
-I STATIC IP address 192.168.1.100
-m NETMASK IP address 255.255.255.0
-g GATEWAY IP address 192.168.1.250
-n NAMESERVER IP address 192.168.1.1
-d VCU DOMAIN NAME domain.com
Table 4 DHCP Setup Example
NOTE: Do not mix the -dhcp argument with the -i -m –d -g -n arguments.
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Use the -i -m -g -n and -d options to set up a static IP address. The argument following the -i -m -g
and -n options should in the form of a dotted IP address (e.g. “192.168.0.1"). If a DHCP server
becomes available at a later time, it can be enabled by issuing the network command with the -dhcp
option.
After setting or changing the network settings, the VCU should be rebooted by typing “shutdown" at
the console terminal adsh> prompt.
adsh>shutdown
Net-2000™- P25 VCU Web Control Interface
Home Page
The Net-2000™- P25 VCU can be controlled remotely by accessing the unit’s built-in web server
using a PC's web browser as the graphical user interface. To connect to the Net-2000™ VCU web
server home page, first open up the web browser software on a PC and type the IP address (or
hostname if the LAN has a name server) of the VCU you want to control in the URL address bar.
The VCU web server will respond with a Welcome Page. Select the “Click Here to Continue” and
you will go to the VCU Home Page as shown in Figure 1.
Figure 5 Net-2000™- P25 VCU Home Page
The Net-2000™- P25 VCU’s built-in web server provides I/O configuration, system control and
displays information about the operational mode and network settings. The left portion of the page
is where the system settings are selected. The right side of the page displays the current system
and connection settings.
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Net-2000™ -P25 VCU Status
The Net-2000™ -P25 VCU Status window is designed to conveniently display the current conditions
for Audio I/O, vocoder and communications channel to the operator. The light blue portion of the
window gives the operator a quick view of all the parameters for the transmission of the encoded
speech. The darker blue section provides information from the incoming voice source.
The top two lines of the NET-2000™- P25 VCU status screen indicate the current running condition.
Figure 6 Net-2000™-P25 Status Information
Net-2000™ is Active / Idle
The Net-2000™ VCU is active when the unit is processing data through the encoder or decoder.
The Net-2000™ VCU is idle when the unit is stopped. In this condition the unit is not ready to
process data through the encoder or decoder.
VOIP Mode
VOIP mode indicates that the Net-2000™ VCU is in Target IP address communications mode and
sending data over the Ethernet interface. VOIP mode is also displayed when Loopback
communications mode is selected because the Net-2000™ VCU sends data over the internal
loopback Ethernet address of 127.0.0.1
FILE Mode
FILE mode indicates that the Net-2000™ VCU is waiting to receive voice or data packets over the
Ethernet interface and encoder or decode them, respectively. The Ethernet address of the target is
set to 0.0.0.0 to indicate that it should be ignored and the voice source is displayed as “Ethernet”.
Voice Source
The Voice Source menu provides the user the choice to select which input source will be used on
the Net-2000™- P25 VCU in VOIP Mode only. The default source is set to 4-wire. Only one source
may be selected at a time. After switching from one voice source to the other it is necessary to
select the start button in order to initiate the change. Note that in File Mode this menu is ignored.
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Figure 7 Voice Source (VOIP Mode Only)
4-Wire
When the 4-Wire voice source interface is selected, the Net-2000™ VCU expects the analog voice
signal input on the RCA jack (Item 7 in Table 1 Rear Panel Connectors). The unit outputs the
analog signal on the output RCA jack (Item 6 Table 1 Rear Panel Connectors). The Net-2000™
VCU always outputs the audio to both the 4-Wire and Handset output regardless of which voice
source is selected.
Handset
When the Handset voice source interface is selected, the Net-2000™ VCU expects the analog voice
signal input and output on the RJ11 jack (Item 8 in Table 1 Rear Panel Connectors). The output will
also be on the output RCA jack (Item 6 Table 1 Rear Panel Connectors). The Net-2000™ VCU
always outputs the audio to both the 4-Wire and Handset output regardless of which voice source is
selected.
APCO Vocoder Selection
The APCO Vocoder selection window allows the operator to select between the Full-Rate and HalfRate APCO Vocoders. Only one rate can be selected at a time. After switching from one rate to the
other it is necessary to select the start button in order to initiate the change.
Figure 8 Rate Selection
Full-Rate Vocoder Mode
The Full-Rate mode is compatible with the current APCO P25 Standard. The Full-Rate vocoder has
a total data bit rate of 7200 bps. Of these bits 4400 bps is voice data and 2800 bps is Forward Error
Correction (FEC).
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Half-Rate Vocoder Mode
Net-2000™- P25 VCU Half-Rate Mode offers built-in Soft Decision Forward Error Correction (FEC)
detection, DTMF / Knox Tone Detection and generation and DTX Comfort Noise Insertion.
The Half-Rate Vocoder is DVSI’s new low data rate vocoder technology. The Half-Rate vocoder in
the Net-2000™- P25 VCU has a total data rate of 3600 bps. This new Half-Rate includes 2450 bps
of data and 1150 bps of FEC. It is designed to be particularly robust and perform exceptionally well
even under the presence of bit errors and acoustic background noise conditions.
Bit Stealing Half-Rate Vocoder Mode
This mode is identical to Half-Rate Vocoder Mode except that 300 bps of the channel data stream
can be used to transmit user data in-band.
Half Rate Vocoder Additional Features
As part of Half-Rate vocoder mode the Net-2000™ VCU offers the ability to decode up to 8 bits of
Soft Decision Forward Error Correction. This feature is ideal for testing and evaluating degraded
channel conditions and/or significant bit errors.
In addition to the enhanced FEC capability the Net-2000™ VCU Half-Rate vocoder provides voice
activity detection and DTMF Knox Tone detection and regeneration. See Section 4 Protocol for
more information.
Communication Channel Selection
The Net-2000™-P25 can be configured to encode / decode speech from either one of two
communications channel sources. The default channel is loopback. Only one communication mode
may be selected at a time. After switching from one communications mode to the other it is
necessary to select the start button in order to initiate the change.
Figure 9 Communications Menu
Loopback (Local)
In loopback communications mode the Net-2000™- P25 VCU will encode speech received on the
selected voice source input (4-Wire or Handset) and play out the encoded/decoded speech on the
handset and Line-Out interface. This channel selection is useful when encoding / decoding
recorded voice samples as a quick analysis of the selected vocoder. This selection enables VOIP
mode on the VCU.
When Loopback communications mode is selected the Net-2000™ VCU sends data over the
internal loopback Ethernet address of 127.0.0.1. Loopback can also be accessed by entering in the
IP or host name of the Net-2000™ VCU in the Target IP address box.
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Target IP Address
The Net-2000™- P25 VCU can communication with another NET-2000™-P25. To communicate
(encode and decode to / from) to another Net-2000™ VCU via Ethernet first select the target IP
address radio button. Next enter the IP address or host name of the remote unit you are connecting
to, in the address box located under the Radio Button. This selection also enables VOIP mode on
the VCU.
File Mode
This selection enables File Mode on the VCU. The Voice Source menu is ignored.
Control Buttons
The Net-2000™ VCU home page provides five buttons for selection of additional settings and
information.
Info Section
Selecting the Info Page will display a pop-up window with the current software version of the Net2000™- P25 VCU. There are no user definable settings on this page. Selecting CLOSE will close
the pop-up screen.
Figure 10 Home Page Information Button
Figure 11 Software Version Information Pop-up Window
Network Settings
Selecting the Network Setting button will display a pop-up window with the current network and I/O
gain information of the Net-2000™- P25 VCU. There only user definable settings on this page are
Port number and Gain I/O. Selecting CLOSE will close the pop-up screen.
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Figure 12 Home Page Setting Button
Note:
Input gain is set at 0 dB and is not configurable.
Output gain should normally be left at 0 dB, but
can be set to –3 dB or –6 dB.
Figure 13 Net-2000™- P25 VCU Network Settings Pop-Up Window
The network settings pop-up window allows the operator to change the network port number for the
communication channel. The default port number is Port 4000. If a different port number is required
enter in the desired port number and select the configure button. Valid port numbers are greater
than 1024 and less than 65535. Port numbers 4001, 4002 and 4003 are reserved by the Net2000™ VCU and must not be used.
Output Gain
The output gain setting for the voice codec can be set by the user, however, the default values
should be sufficient for most applications. The gain can be set to 0 dB, -3 dB, or –6 dB. To set a
gain other than zero enter the number into the Output Gain setting box and then select Configure to
initiate the new setting. To lower the I/O gain below zero enter a negative number using a minus
sign in front of the value.
Configure Button
Selecting this button will load the displayed network and gain settings into the VCU. Once loaded
the VCU will automatically switch to the new settings.
Reset to Defaults Button
The reset to default button on the Network Setting Pop-up window resets the value of the Port
number to 4000 and sets the I/O gain setting to zero.
Close
Selecting CLOSE will close the network setting pop-up window.
Reset To Defaults Button
The Default button on the main control page resets the Net-2000™- P25 VCU and puts the vocoder
settings to their default values. Network settings such as Hostname and IP address are not affected
by this Reset to Default button activation.
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Figure 14 Home Page Reset Main Page to Defaults
Default vocoder values page are as follows:
Home Page Defaults Settings
Item Value
Voice Source 4-Wire
Vocoder Mode Full-Rate Vocoder
Target IP 127.0.0.1
Data Source Loop-Back
Table 5 Home Page Defaults List
NOTE: At power-up the VCU automatically starts up with the default settings. You do not need to
use the web interface unless you want to change these settings.
Start and Stop Buttons
Upon power up the Net-2000™- P25 VCU loads the default settings and runs the half-rate decoder
in loopback over the 4-wire interface. Click the Stop button to put the Net-2000™- P25 VCU into idle
mode. In idle mode the VCU is not active and will not respond to voice or channel data packets.
Changes to the settings can be made while the unit is active. However, the new settings will not
take affect until the Start button is clicked.
Note: The “Start" button will automatically stop and restart the Net-2000™- P25 VCU. It is not
necessary to click on the “Stop" button and then click the Start button to restart the Net-2000™- P25
VCU with a new setting.
Figure 15 Start and Stop Buttons
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Section 4 – Net-2000™ VCU Interface Protocol
Interface Protocol
Protocol Packet Description
The UDP Ethernet protocol of the Net-2000™ VCU’s uses port 4000. Byte order for all 16-bit data
types (“short” in the C-language data structure) is network order (big endian), so bytes with lower
indexes are the most significant. Since PC’s are little endian machines it is necessary to byte-swap
when using this protocol with a PC.
There are four packets defined for the VCU protocol: a Channel packet, a Voice packet, a Reset
packet, an Ack packet and a Nack packet. Channel packets contain channel data (coded speech)
that is sent to the decoder to synthesize speech. Voice packets contain voice data that is sent to the
encoder to compress into channel data. The Reset packet is used to re-initialize the encoder and
decoder state data structures so that repeatable results can be generated for a given input. Ack
packets are sent in response to Reset packets. Nack packets are sent in response to anything else.
When the VCU is in VOIP Mode it exchanges Channel packets with another VCU in real time to
provide a full duplex communication channel. The decoder in the VCU synthesizes the channel data
into speech and sends it out the handset and 4-wire voice interfaces. Only Channel packets are
transmitted in VOIP mode. Voice, Reset, and Acknowledge packets are not used.
When the VCU is in File Mode is monitors UDP port 4000 (or a different port if one has been
selected using the web interface) for incoming packets. If a Reset packet is received the VCU
resets the encoder and/or decoder as specified in the packet and responds to the packet sender
with an ACK packet. If an Voice packet is received the VCU encodes the data in the packet and
responds to the sender with a Channel packet containing the encoded data. If a Channel packet is
received the VCU decodes the packet and responds to the sender with an Voice packet containing
the synthesized speech. In File Mode it is possible to produce bit-exact, repeatable results for
vocoder quality testing.
PC source code is provided on the CD included with the VCU that implements the protocol and can
be used with the VCU in File Mode to encode and decode speech.
Packet Header
Each packet in the protocol starts with a six-byte header containing a 16-bit integer indicating the
overall length of the packet in bytes, a 16-bit integer indicating the type of the packet, and a 16-bit
sequence number. The six-byte packet header for all data packets is shown in Table 2. An “x” is
used in all the tables in this description to indicate that a bit can take a value of 0 or 1.
Packet Header
Bytes
(msb-lsb)
0 – 1 0 0 0 0 0 0 0 0 x x x x x x x x len
2 – 3 0 0 0 0 0 0 0 0 x x x x x x x x type
Header
Table 6 Channel Packet Header
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4 – 5 x x x x x x x x x x x x x x x x seq
Bits
7 6 5 4 3 2 1 0
Bits
7 6 5 4 3 2 1 0
Parameter Name
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Channel Packet
Channel packets contain the channel data for one frame of voice with the control flags and data
needed to run the decoder. They are also transmitted in response to Voice packets when the VCU is
in File Mode.
Channel Packet (218 bytes)
Bytes
(msb-lsb)
0 - 1 0 0 0 0 0 0 0 0 1 1 0 1 1 0 1 0 len
2 - 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 type
Header
4 - 5 X x x x x x x x x x x x x x x x seq
6 - 7 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 x rate [0]
8 - 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [1]
10 - 11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [2]
12 - 13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [3]
14 - 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [4]
16 - 17 0 x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cmode
18 - 19 0 0 0 0 0 0 0 0 1 0 x x x x x x tone.idx
20 - 21 X 0 0 0 0 0 0 0 0 x x x x x x x tone.amp
22 - 23 0 0 0 0 0 0 0 0 1 0 x x x x x x ws
24 - 25 0 0 0 0 x x x x 0 0 0 x 0 0 x x format
26 - 27 x x x x x x x x x x x x x x x x channel [0-1]
28 - 29 x x x x x x x x x x x x x x x x channel [2-3]
30 - 31 x x x x x x x x x x x x x x x x channel [4-5]
… … … …
216 - 217 x x x x x x x x x x x x x x x x channel [191-192]
Bit
7 6 5 4 3 2 1 0
Bit
7 6 5 4 3 2 1 0
Parameter Name
Table 7. Channel Packet
Channel packets are always 218 bytes and have the following format described Table 6 and Clanguage data structure below:
struct channel_packet_t {
short len;
short type;
short seq;
short rate[5];
short cmode;
short tone[2];
short ws;
short format;
char channel[192];
};
Note that each bit of channel data occupies one byte of the channel[] buffer in the packet and
that the actual number of channel bits in the buffer is 144 for the Standard APCO vocoder and 72 for
the APCO Half-Rate vocoder. The remaining bytes in the channel[] buffer are ignored. The
elements of the Decode packet are described in detail in the following sections.
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Channel Packet Parameters
len
The len parameter (bytes 0 and 1) hold the 16-bit length of the packet (Table 3). The packet length
is always 218 bytes.
len = Length (in bytes) of total packet (including header)
Data Packet Size 0 0 0 0 0 0 0 0 1 1 0 1 1 0 1 0 218 bytes
Table 8 len header parameter
Byte 0
7 6 5 4 3 2 1 0
type
The type parameter (bytes 2 and 3) is 16-bits packet type and is always 0x003 for channel data.
type = Packet type
Channel Data 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0x0003
Byte 2
7 6 5 4 3 2 1 0
Byte 1
7 6 5 4 3 2 1 0
Byte 3
7 6 5 4 3 2 1 0
Decimal
Hex Value
Value
Table 9 type header parameter
seq
Bytes 4 and 5 hold the 16-bit sequence number (see Table 5). The sequence number is used as a
method to detect if and when data packets are dropped, so it is important to ensure that consecutive
sequence numbers are transmitted for channel data packets during operation.
seq = Sequence number*
Minimum Value 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -32768
Maximum Value 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 32767
Table 10 seq header parameter
*Note: Sequence numbers should be incremented by one every time a packet is transmitted. When
the sequence number reaches 32767, the next valid sequence number is -32768.
Byte 4
7 6 5 4 3 2 1 0
Byte 5
7 6 5 4 3 2 1 0
Decimal
Value
rate[5]
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The AMBE APCO coder runs in either one of two rates. The Full-Rate at 7200 bps including 4400
bps voice and 2800 FEC. The Half-Rate coder runs at 3600 including 2450 data and 1150 FEC.
rate [5] vocoder rate
rate [0] Packets
Byte 6
7 6 5 4 3 2 1 0
Byte 7
7 6 5 4 3 2 1 0
APCO Full-Rate Vocoder (7200bps) 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 0 0x00C2
APCO Half-Rate Vocoder (3600bps) 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 1 0x00C3
APCO Half-Rate Vocoder + Bit Stealing
(3600 bps)
0 0 0 0 0 0 0 0 1 1 0 0 0 1 0 0
Table 11 Vocoder Rate Parameter
For the APCO Full-Rate vocoder
(rate[0] & 0x00ff) == 0x00c2
For the APCO Half-Rate vocoder
(rate[0] & 0x00ff) == 0x00c3
For the APCO Half-Rate vocoder with bit-stealing
(rate[0] & 0x00ff) == 0x00c4
Hex
Value
0x00C4
cmode
The cmode element of the Channel packet contains the input flags to the decoder when it is
transmitted to the VCU and the output flags of the encoder when it is transmitted by the VCU. The
value of cmode also depends on the vocoder in use. Tables 12a and 12b list values for the decoder
input and encoder output flags of the Channel packet.
Cmode parameter
Decoder Input Flags
Byte 16
7 6 5 4 3 2 1 0
Nominal Value 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x0000
Lost Frame 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0x0004
Mute 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0x0008
Tone Signaling 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x4000
Table 12a. cmode Parameter (Decoder Input Flags)
The nominal value for the cmode parameter should be zero when transmitting Channel packets to
the VCU. To get the decoder to perform a frame repeat set the Lost Frame flag. To generate
comfort noise (i.e., mute) set the Mute flag. The Tone Signaling Flag can be set to get the APCO
Half-Rate vocoder to ignore the channel data in the packet and generate a tone. The index and
amplitude of the tone should be set in the tone[] parameter of the Channel packet. The Standard
APCO decoder does not support tone signaling and ignores this flag.
Cmode parameter
Half-Rate Encoder Output Flags
Byte 16
7 6 5 4 3 2 1 0
Voice Active 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0x0002
VAD 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0x0400
Tone Frame 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x8000
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Byte 77
7 6 5 4 3 2 1 0
Byte 77
7 6 5 4 3 2 1 0
Hex Value
Hex Value
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Table 13b. cmode Parameter (Encoder Output Flags)
When the VCU transmits Channel packets in response to Voice packets it sets the cmode
parameter with the flags returned by the encoder. For the Standard APCO encoder this value is
always zero. For the Half-Rate encoder the flags are listed in Table 12b. The Voice Active flag is
set when the packet must be transmitted to the decoder (otherwise, if DTX is in use the frame does
not need to be transmitted). If the VAD flag is set the packet contains voice data (otherwise the
frame is a silence frame). If the Tone Frame flag is set the packet contains tone data. The
amplitude and index of the tone are set in the tone[] parameter of the Channel packet.
tone [2]
Appropriate values for tone.idx and tone.amp, are listed in Tables 8 and 9. When tone signaling is
inactive tone.idx should be set to NO TONE and tone.amp should be set to zero. Note that tone
signaling is possible only when using the Half-Rate vocoder. These values are ignored if the
Standard APCO vocoder is in use.
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tone.idx
Tone Type
Invalid n/a n/a n/a 0 – 4
Single Tones
Not used n/a n/a n/a
DTMF “0” 1336 941 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 128
DTMF “1” 1209 697 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 129
DTMF “2” 1336 697 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 130
DTMF “3” 1477 697 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 131
DTMF “4” 1209 770 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 132
DTMF “5” 1336 770 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 1 133
DTMF “6” 1477 770 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 0 134
DTMF “7” 1209 852 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 1 135
DTMF “8” 1336 852 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 136
DTMF “9” 1477 852 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 1 137
DTMF “A” 1633 697 0 0 0 0 0 0 0 0 1 0 0 0 1 0 1 0 138
DTMF “B” 1633 770 0 0 0 0 0 0 0 0 1 0 0 0 1 0 1 1 139
DTMF “C” 1633 852 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 0 140
DTMF “D” 1633 941 0 0 0 0 0 0 0 0 1 0 0 0 1 1 0 1 141
DTMF “*” 1209 941 0 0 0 0 0 0 0 0 1 0 0 0 1 1 1 0 142
DTMF “#” 1477 941 0 0 0 0 0 0 0 0 1 0 0 0 1 1 1 1 143
KNOX “0” 1162 820 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 0 144
KNOX “1” 1052 606 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 1 145
KNOX “2” 1162 606 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 0 146
KNOX “3” 1279 606 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 1 147
KNOX “4” 1052 672 0 0 0 0 0 0 0 0 1 0 0 1 0 1 0 0 148
KNOX “5” 1162 672 0 0 0 0 0 0 0 0 1 0 0 1 0 1 0 1 149
KNOX “6” 1279 672 0 0 0 0 0 0 0 0 1 0 0 1 0 1 1 0 150
KNOX “7” 1052 743 0 0 0 0 0 0 0 0 1 0 0 1 0 1 1 1 151
KNOX “8” 1162 743 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 0 152
KNOX “9” 1279 743 0 0 0 0 0 0 0 0 1 0 0 1 1 0 0 1 153
KNOX “A” 1430 606 0 0 0 0 0 0 0 0 1 0 0 1 1 0 1 0 154
KNOX “B” 1430 672 0 0 0 0 0 0 0 0 1 0 0 1 1 0 1 1 155
KNOX “C” 1430 743 0 0 0 0 0 0 0 0 1 0 0 1 1 1 0 0 156
KNOX “D” 1430 820 0 0 0 0 0 0 0 0 1 0 0 1 1 1 0 1 157
KNOX “*” 1052 820 0 0 0 0 0 0 0 0 1 0 0 1 1 1 1 0 158
KNOX “#” 1279 820 0 0 0 0 0 0 0 0 1 0 0 1 1 1 1 1 159
Call Progress 440 350 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 160
Call Progress 480 440 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 1 161
Call Progress 620 480 0 0 0 0 0 0 0 0 1 0 1 0 0 0 1 0 162
Call Progress 490 350 0 0 0 0 0 0 0 0 1 0 1 0 0 0 1 1 163
Invalid n/a n/a n/a 164-254
NO TONE n/a 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 255
Frequency (Hz)
Freq #2 Freq #1
156.25 to 3812.5 Hz
(31.25 * tone.idx)
Section 4 – Net-2000™ VCU Interface Protocol
Byte 18
7 6 5 4 3 2 1 0
Byte 19
7 6 5 4 3 2 1 0
Decimal
Value
0 0 0 0 0 0 0 0 0 x x x x x x x 5 – 122
123 –
127
Table 14 tone.idx parameter
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Valid range for tone.amp is: +3 to -90 (signed twos complement integer, units are dBm0)
tone.amp = tone amplitude
Description
Byte 20
7 6 5 4 3 2 1 0
Byte 21
7 6 5 4 3 2 1 0
Decimal Value
Max Amplitude 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 +3
… … … …
Zero Amplitude 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
… … … …
Min. Amplitude 1 1 1 1 1 1 1 1 1 0 1 0 0 1 1 0 -90
Table 15 tone.amp Parameter
ws
The ws element of the packet contains the number of samples that should be synthesized by the
decoder when transmitted to the VCU and the number of samples that were used to encode the
channel data when transmitted by the VCU. Appropriate values for ws are listed in Table 10.
Ws = Number of voice samples.
Description
Byte 22
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0 1 0 0 1 1 1 1 1 159
0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 160
0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 1 161
Byte 23
7 6 5 4 3 2 1 0
Decimal
Value
Table 16 ws Parameter
format
Format include both the number of soft decision bits in the channel data and the format of the voice
data to synthesize. This number of soft decision bits should be between 1 (hard decision) and 8
(maximum soft decision capability). The number of soft decision bits is determined by the top 8 bits
of the format element.
(format >> 8) & 0x00ff
The format element of the channel packet also indicates the format of the voice data to be
generated by the decoder. Appropriate values for the number of soft decision bits and voice data
type in the format element is listed in Table 11.
format = Soft decision & voice data
Voice Data Formats
Byte 24
7 6 5 4 3 2 1 0
Linear 16-bit PCM 0 0 0 0 x x x x 0 0 0 0 0 0 0 0 0xXX00
Soft-Decision Bits
Byte 24
7 6 5 4 3 2 1 0
1 0 0 0 0 0 0 0 1 0 0 0 x 0 0 x x 0x01XX
2 0 0 0 0 0 0 1 0 0 0 0 x 0 0 x x 0x02XX
3 0 0 0 0 0 0 1 1 0 0 0 x 0 0 x x 0x03XX
4 0 0 0 0 0 1 0 0 0 0 0 x 0 0 x x 0x04XX
5 0 0 0 0 0 1 0 1 0 0 0 x 0 0 x x 0x05XX
6 0 0 0 0 0 1 1 0 0 0 0 x 0 0 x x 0x06XX
7 0 0 0 0 0 1 1 1 0 0 0 x 0 0 x x 0x07XX
8 0 0 0 0 1 0 0 0 0 0 0 x 0 0 x x 0x08XX
Byte 25
7 6 5 4 3 2 1 0
Byte 25
7 6 5 4 3 2 1 0
Hex Value
Hex Value
Table 17 format Parameters
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a
d
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The voice data format to synthesize is as follows:
The voice data to be synthesized is 16 bit PCM
(format & 0x00ff) == 0x00
All other formats are invalid.
channel [192]
For simplicity, and since channel data packets are small compared to nominal Ethernet frames all
192 Channel Data bytes are ALWAYS transmitted regardless of the actual bit-rate of the vocoder.
Each byte of the channel [] array contains one channel data “bit”.
Channel [192]
Bytes
(msb-lsb)
… … … …
26 - 27 X x x x x x x x x x x x x x x x channel [0-1]
28 – 29 X x x x x x x x x x x x x x x x channel [2-3]
30 – 31 X x x x x x x x x x x x x x x x channel [4-5]
… … … …
216-217 X x x x x x x x x x x x x x x x channel [191-192]
Bit
7 6 5 4 3 2 1 0
Bit
7 6 5 4 3 2 1 0
Parameter Name
Table 18 channel parameters
If channel[] contains hard decision data (no soft decision error detection)
channel[i] == 0x01 is a one,
channel[i] == 0x00 is a zero
If 8 bit soft decision error detection is used then,
channel[i] == 0xff is the most confident one
channel[i] = 0x00 is the most confident zero
Other values for the number of soft-decision bits are coded in a similar manner. For transmitting
DTX frames a channel data packet must contain all ones in the channel[] array. To signal no data
and force a frame repeat the channel[] array data packet must contain all zeros.
Voice Packet
Voice packets contain the voice data for one frame of voice with the control flags and data needed to
run the encoder. They are also transmitted by the VCU in response to Channel packets when in File
Mode and contain the synthesized speech output by the decoder.
Voice Packet
Bytes
(msb-lsb)
0 – 1 0 0 0 0 0 0 0 0 1 1 0 1 1 0 1 0 len
Bit
7 6 5 4 3 2 1 0
Bit
7 6 5 4 3 2 1 0
Parameter Name
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2 – 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 type
4 – 5 x x x x x x x x x x x x x x x x seq
6 – 7 0 0 0 0 0 0 0 0 1 1 0 0 0 0 1 x rate [0]
8 – 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [1]
10 – 11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [2]
12 – 13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [3]
14 – 15 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 rate [4]
16 – 17 0 x 0 0 0 0 0 0 0 0 0 0 0 0 0 0 cmode
18 – 19 0 0 0 0 0 0 0 0 1 0 x x x x x x tone.idx
20 – 21 x 0 0 0 0 0 0 0 0 x x x x x x x tone.amp
22 – 23 0 0 0 0 0 0 0 0 1 0 x x x x x x ws
24 – 25 0 0 0 0 x x x x 0 0 0 x 0 0 x x format
26 – 27 x x x x x x x x x x x x x x x x voice [0]
28 – 29 x x x x x x x x x x x x x x x x voice[1]
30 – 31 x x x x x x x x x x x x x x x x voice [2]
… … … …
344 – 345 x x x x x x x x x x x x x x x x voice[159]
Table 18 Encode Packet
Voice packets have the following format described Table 18 and C-language data structure below:
struct voice_packet_t {
short len;
short type;
short seq;
short rate[5];
short cmode;
short tone[2];
short ws;
short format;
short voice[160];
};
The size of the Voice packet can vary depending on the number of samples in the voice[] buffer.
The actual number of elements in the voice[] buffer can vary between 159 and 161 for the APCO
Standard and Half-Rate vocoders. The nominal number of samples is 160. The ws and len
elements of the Voice packet should be adjusted to indicate the actual number of samples in
voice[]. The elements of the Voice packet are described in detail in the following sections.
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Voice Packet Parameters
len
The len parameter (bytes 0 and 1) hold the 16-bit length of the packet (Table 3). The packet length
can vary from 344 to 348 bytes.
len = Length (in bytes) of total packet (including header)
Data Packet Size 0 0 0 0 0 0 0 0 x x x x x x x x
Table 19 len header parameter
Byte 0
7 6 5 4 3 2 1 0
Byte 1
7 6 5 4 3 2 1 0
Decimal
344 - 348
Value
bytes
type
The type parameter (bytes 2 and 3) is 16-bits packet type and is always 0x002 for voice data.
type = Packet type
Voice Data 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0x0002
Table 20 type header parameter
Byte 2
7 6 5 4 3 2 1 0
Byte 3
7 6 5 4 3 2 1 0
Hex Value
seq
Bytes 4 and 5 hold the 16-bit sequence number (see Table 5). The sequence number is used as a
method to detect if and when data packets are dropped, so it is important to ensure that consecutive
sequence numbers are transmitted for channel data packets during operation.
seq = Sequence number*
Minimum Value 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -32768
Maximum Value 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 32767
Byte 4
7 6 5 4 3 2 1 0
Byte 5
7 6 5 4 3 2 1 0
Decimal
Value
Table 21 seq header parameter
*Note: Sequence numbers should be incremented by one every time a packet is transmitted. When
the sequence number reaches 32767, the next valid sequence number is -32768.
rate[5]
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The rate[] array is used to indicate the vocoder type and is identical to the rate[] array in the
Channel packet discussed in the previous section.
cmode
The cmode element of the packet contains the input flags to the encoder when it is transmitted to
the VCU and the output flags of the decoder when it is transmitted from the VCU. The value of
cmode also depends on the vocoder in use. Tables 12a and 12b lists the input flags to the encoder
and the output flags of the decoder for the cmode element of Voice packets.
cmode parameter
Half-Rate Encoder Input Flags
Byte 16
7 6 5 4 3 2 1 0
Noise Suppression Enable 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0x0040
DTX Enable 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0x0400
Tone Detection Enable 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0x1000
Tone Signaling 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x4000
Table 22a cmode Parameter (Half-Rate Encoder Inputs)
Byte 77
7 6 5 4 3 2 1 0
Hex Value
The values in Table 12a apply only to the Half-Rate encoder. The value of cmode should always be
zero for the Standard APCO encoder.
cmode parameter
Decoder Output Flags
Byte 16
7 6 5 4 3 2 1 0
Byte 77
7 6 5 4 3 2 1 0
Hex Value
Voice Active 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0x0002
Data Invalid 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0x0020
Tone Frame 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x8000
Table 23b cmode Parameter
The Data Invalid flag is set by the Decoder if the data that was received in the Channel packet used
to generate the Voice packet was invalid, or if the Lost Frame or Mute flag was set in the cmode
element of the Channel packet. The Half-Rate decoder sets the Voice Active flag if the packet is not
a silence frame. The Half-Rate decoder sets the Tone Frame flag if the packet contains a tone.
The values of the tone element of the packet contain the index and amplitude of the tone. The
Standard APCO decoder does not use the Voice Active or Tone Frame flags.
tone [2]
Appropriate values for tone.idx and tone.amp are the same as the tone.idx and tone.amp values for
Channel packets and are listed in Tables 8 and 9. When tone signaling is inactive tone.idx should
be set to NO TONE and tone.amp should be set to zero.
ws
The ws element of the packet contains the number of voice samples that the voice packet contains.
Appropriate values for ws are listed in Table 10.
ws = Number of voice samples.
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Description
Byte 22
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0 1 0 0 1 1 1 1 1 159
Byte 23
7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 160
0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 1 161
Table 24 ws Parameter
format
The format element of the voice packet also indicates the format of the voice data in the voice[]
array. Appropriate values voice data type in the format element is listed in Table 11.
format = Soft decision & voice data
Voice Data Formats
Byte 24
7 6 5 4 3 2 1 0
Linear 16-bit PCM 0 0 0 0 x x x x 0 0 0 0 0 0 0 0 0xXX00
Table 25 format Parameters
The voice data format to synthesize is as follows:
The voice data to be synthesized is 16 bit PCM
(format & 0x00ff) == 0x00
All other formats are invalid.
Byte 25
7 6 5 4 3 2 1 0
Hex Value
Decimal
Value
voice [ ]
The number of elements in the voice[] array can vary between 159 and 161. The nominal number of
elements should be 160. The voice format is 16 bit PCM each element of the voice array should
contain one linear 16 bit voice sample.
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Reset Packet
The Reset packet is used to reset the encoder and decoder state when the VCU is in File Mode. In
order to get reproducible, bit-exact results in File Mode the state of the vocoder must be reset before
sending Channel or Voice packets to the VCU.
Reset Packet
Bytes
(msb-lsb)
0 – 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 len
2 – 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 type
Header
4 – 5 x x x x x x x x x x x x x x x x seq
6 – 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 x x which
Table 18 Reset Packet
Reset packets have the following format described Table 18 and C-language data structure below:
struct reset_packet_t {
short len;
short type;
short seq;
short which;
};
The size of the Reset packet is eight bytes. The elements of the Reset packet are described in
detail in the following sections.
Bit
7 6 5 4 3 2 1 0
Bit
7 6 5 4 3 2 1 0
Parameter Name
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Reset Packet Parameters
len
The len parameter (bytes 0 and 1) hold the 16-bit length of the packet (Table 3). The packet length
is eight bytes.
len = Length (in bytes) of total packet (including header)
Reset Packet Size 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 8 bytes
Table 26 len header parameter
Byte 0
7 6 5 4 3 2 1 0
type
The type parameter (bytes 2 and 3) is 16-bits packet type and is always 0x0000 for reset packets.
type = Packet type
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x0000
Byte 2
7 6 5 4 3 2 1 0
Byte 1
7 6 5 4 3 2 1 0
Byte 3
7 6 5 4 3 2 1 0
Decimal
Hex Value
Value
Table 27 type header parameter
seq
Bytes 4 and 5 hold the 16-bit sequence number (see Table 5). The sequence number is used as a
method to detect if and when data packets are dropped, so it is important to ensure that consecutive
sequence numbers are transmitted for channel data packets during operation.
Seq = Sequence number*
Minimum Value 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -32768
Maximum Value 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 32767
Table 28 seq header parameter
*Note: Sequence numbers should be incremented by one every time a packet is transmitted. When
the sequence number reaches 32767, the next valid sequence number is -32768.
Byte 4
7 6 5 4 3 2 1 0
Byte 5
7 6 5 4 3 2 1 0
Decimal
Value
which
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The which element is used to indicate which vocoder state to reset. If bit zero is set the encoder
state is reset. If bit one is set the decoder state is reset. To reset both the encoder and decoder
state set both bits zero and one.
Which parameter
Reset Flags
Byte 16
7 6 5 4 3 2 1 0
Byte 77
7 6 5 4 3 2 1 0
Hex Value
Encoder Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0x0001
Decoder Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0x0002
Table 19. which parameter.
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Ack Packet
The Ack packet is used to acknowledge the Reset packet when the VCU is in File Mode.
Ack Packet
Bytes
(msb-lsb)
0 – 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 Len
2 – 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Type
Header
4 – 5 x x x x x x x x x x x x x x x x Seq
6 – 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cmd
Table 18 Ack Packet
Ack packets have the following format described Table 18 and C-language data structure below:
struct ack_packet_t {
short len;
short type;
short seq;
short cmd;
};
The size of the Ack packet is eight bytes. The elements of the Ack packet are described in detail in
the following sections.
Bit
7 6 5 4 3 2 1 0
Bit
7 6 5 4 3 2 1 0
Parameter Name
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Ack Packet Parameters
len
The len parameter (bytes 0 and 1) hold the 16-bit length of the packet (Table 3). The packet length
is eight bytes.
len = Length (in bytes) of total packet (including header)
Ack Packet Size 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 8 bytes
Table 29 len header parameter
Byte 0
7 6 5 4 3 2 1 0
type
The type parameter (bytes 2 and 3) is 16-bits packet type and is always 0x0000 for ack packets.
type = Packet type
Ack 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x0000
Byte 2
7 6 5 4 3 2 1 0
Byte 1
7 6 5 4 3 2 1 0
Byte 3
7 6 5 4 3 2 1 0
Decimal
Hex Value
Value
Table 30 type header parameter
seq
Bytes 4 and 5 hold the 16-bit sequence number (see Table 5). The sequence number is used as a
method to detect if and when data packets are dropped, so it is important to ensure that consecutive
sequence numbers are transmitted for channel data packets during operation.
Seq = Sequence number*
Minimum Value 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -32768
Maximum Value 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 32767
Table 31 seq header parameter
*Note: Sequence numbers should be incremented by one every time a packet is transmitted. When
the sequence number reaches 32767, the next valid sequence number is -32768.
Byte 4
7 6 5 4 3 2 1 0
Byte 5
7 6 5 4 3 2 1 0
Decimal
Value
cmd
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The cmd element is used to indicate the packet type being acknowledged. Since Reset packets are
the only packets acknowledged this value is always zero.
Cmd parameter
Packet Type Ack’ed
Byte 16
7 6 5 4 3 2 1 0
Byte 77
7 6 5 4 3 2 1 0
Hex Value
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0x0000
Table 19. cmd parameter.
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Nack Packet
The Nack packet is used to respond to badly formatted or unrecognized packets.
Ack Packet
Bytes
(msb-lsb)
0 – 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 len
2 – 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 type
Header
4 – 5 x x x x x x x x x x x x x x x x seq
6 – 7 X x x x x x x x x x x x x x x x cmd
8 – 9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 reason
Table 18 Nack Packet
Nack packets have the following format described Table 18 and C-language data structure below:
struct nack_packet_t {
short len;
short type;
short seq;
short cmd;
short reason;
};
The size of the Nack packet is ten bytes. The elements of the Nack packet are described in detail in
the following sections.
Bit
7 6 5 4 3 2 1 0
Bit
7 6 5 4 3 2 1 0
Parameter Name
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Nack Packet Parameters
len
The len parameter (bytes 0 and 1) hold the 16-bit length of the packet (Table 3). The packet length
is ten bytes.
len = Length (in bytes) of total packet (including header)
Ack Packet Size 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 10 bytes
Table 32 len header parameter
Byte 0
7 6 5 4 3 2 1 0
type
The type parameter (bytes 2 and 3) is 16-bits packet type and is always 0x0001 for nack packets.
type = Packet type
Nack 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0x0001
Byte 2
7 6 5 4 3 2 1 0
Byte 1
7 6 5 4 3 2 1 0
Byte 3
7 6 5 4 3 2 1 0
Decimal
Hex Value
Value
Table 33 type header parameter
seq
Bytes 4 and 5 hold the 16-bit sequence number (see Table 5). The sequence number is used as a
method to detect if and when data packets are dropped, so it is important to ensure that consecutive
sequence numbers are transmitted for channel data packets during operation.
Seq = Sequence number*
Minimum Value 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 -32768
Maximum Value 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 32767
Table 34 seq header parameter
*Note: Sequence numbers should be incremented by one every time a packet is transmitted. When
the sequence number reaches 32767, the next valid sequence number is -32768.
Byte 4
7 6 5 4 3 2 1 0
Byte 5
7 6 5 4 3 2 1 0
Decimal
Value
cmd
The cmd element is used to indicate the packet type being Nack’ed.
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Section 4 – Net-2000™ VCU Interface Protocol
Cmd parameter
Packet Type Nack’ed
Byte 16
7 6 5 4 3 2 1 0
Byte 77
7 6 5 4 3 2 1 0
Type x x x x x x x x x x x x x x x x 0xXXXX
Table 19. cmd parameter.
reason
The reason element is used to indicate the reason for the Nack. This value is currently always
0xFFFF (invalid packet). Other values are reserved for future expansion.
Cmd parameter
Packet Type Nack’ed
Byte 16
7 6 5 4 3 2 1 0
Packet Invalid 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0xFFFF
Table 19. reason parameter.
Byte 77
7 6 5 4 3 2 1 0
Hex Value
Hex Value
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Section 5 – Net-2000™ VCU Specifications
Specifications
Introduction
This section contains hardware Specifications of the VCU. Any interfaces listed as “inactive" require
firmware and software upgrades to activate. NOTE: All values are typical unless noted otherwise.
All specifications subject to change.
Rear Panel Connections
Serial Port
Type RS-232
Connector DE9s
Net-2000™- P25 VCU RS 232 Serial Port Pin Out
(as viewed from the back of the unit)
Pin Number Name
1, 4, 6 Connected together internally
2 Tx
3 Rx
5 Ground
7 CTS
8 RTS
9 No Connection
Table 35 RS-232 Serial Port Pin Out
LAN
Type 10-BaseT Ethernet
Connector RJ-45
RS-422 Synchronous (Inactive)
Type RS-422 differential
Connector DB-15HD
RS-422 Asynchronous (Inactive)
Type RS-422 differential
Connector RJ-45
Audio I/O Connections
2-Wire (Inactive)
Analog 2 Wire Input / Output:
Type: Deferential
Connector: RJ-11 6P2C
Input /Output Impedance: 600 Ohms
Bandwidth: 300 Hz to 3300 Hz
A/D,D/A Resolution: 16 bits
A/D,D/A Sampling Rate: 8 kHz
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Line In
Type Single-ended 4 Wire Input
Connector female RCA
Maximum Input Level: +/- 2.45 Volts
Input Impedance 10 kOhms
Bandwidth 20 Hz to 4 kHz
D/A Resolution 16 bits
D/A Sampling Rate 8 kHz
Note: A 1.414 V signal on the line input produces digital max when the codec
input gain is 0 dB.
Line Out
Type: Single-ended 4 Wire Output
Connector: female RCA
Maximum Output Level +/- 1.5 Volts
Output Impedance: <10 Ohms
Bandwidth: 20 Hz to 4 kHz
A/D Resolution: 16 bits
A/D Sampling Rate: 8 kHz
Minimum Load 600 Ohms
Note: A digital max produces 1.414 V signal on the line output when the
codec output gain is 0 dB.
Handset:
Type: Single-ended
Connector: RJ 4P4C
Bandwidth: 20 Hz to 4 kHz
A/D Sampling Rate: 8 kHz
A/D Resolution: 16 bits
Section 5 – Net-2000™ VCU Specifications
Electrical Input
AC Power
Input Voltage 110/220 Volts AC
Input Current @ 110V AC 250 ma
Input Current @ 220V AC 125 ma
Rated Input Frequency 50/60 Hz
Mechanical
Mechanical
Weight 4.25 lbs.
Size (W X D X H) 17.25"X7.25"X3.5"
Environmental
Environmental
Operating Temperature 5 to 35 degrees C
Humidity 5 to 80% RH non-condensing
Storage Temperature -30 to 60 degrees C
Installation Category (II)
Pollution Degree (2)
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Section 6 – Net-2000™ VCU Support
Net-2000™- P25 Support
Upgrade Procedure
Future upgrades to the Net-2000™- P25 VCU VCU’s internal software may become available to
provide for additional features and capabilities or to remedy unforeseen issues. In order to upgrade
the Net-2000™- P25 VCU VCU’s internal software the following equipment is required.
A PC (Windows OS) with network access to the same LAN the VCU is on,
and a terminal connected to the VCU console serial port.
The VCU upgrade image file located on a shared folder on the PC
First. Telnet to the VCU. Open a DOS window and telnet to the VCU using its IP address or host
name:
telnet 192.168.1.100
Next, at the adsh> prompt of the VCU console shell, give the VCU access to the shared folder by
typing the following commands:
adsh>mkdir /var/upgrade
adsh>smbmount //<host>/<share> /var/upgrade
where <host> is the PC's host name and <share> is the name of the shared folder.
Note: If the shared folder on your PC requires a user name and password to gain access, add -U
<user> and -P <password> to the smbmount command where <user> is the user name and
<password> is the user's password.
Now change directories to the shared folder on the PC and download the upgrade:
adsh>cd /var/upgrade
adsh>cat <imagefile> | flash - /dev/all
where <imagefile> is the file name of the upgrade image. After up upgrade is loaded into the VCU,
reboot it by with the following command.
adsh>shutdown
DVSI Technical Support
If you have any problems with the Net-2000™- P25 VCU Voice Codec Unit or have questions about
its operation, please contact:
Digital Voice Systems, Inc.
234 Littleton Road
Westford, MA 01886 USA
Phone: (978) 392-0002
Fax: (978) 392-8866
email: info@dvsinc.com
web: www.dvsinc.com
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NOTES
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