Digital Voice Systems Net-2000-P25 User manual

Net-2000TM-P25 Voice Codec Unit
The Speech Compression Specialists
Digital Voice Systems, Inc.
The Net-2000™-P25 Voice Codec Unit
combinesAMBE®Vocoder Technology with
Ethernet network connectivity!
Flexibility and Performance
•Network enabled voice codec unit interfacesAPCO P25
vocoders withAnalog I/O and Ethernet networks.
•Real-time, full-duplex communications to other Net-
2000™-P25 units via UDP Ethernet or RS-422
interface.
•Both voice and channel data can be transmitted over
the Ethernet interface at the same time.
•Encode/Decode files across a Local Area Network.
•High performance audio using 16-bit linear codec.
•4-wire and 2-wire analog input/outputs.
Half-Rate Vocoder Mode
•Easily switch between Full-Rate and Half-Rate modes.
•Built-in FEC with capability to decode up to 8 bits of soft
descision error correction delivers robust performance
over channels degraded by bit errors and/or
background noise.
•Half-Rate Vocoder Mode can detect and transmit
DTMF and Knox tones, single tones, and North
American Call Progress tones DTX capability, Voice
Activity Detection, Comfort Noise Insertion,
Easy to Integrate and Operate
•Built-in web server User Interface provides access from
any PC on the LAN.
•RS-232 serial port provides system setup and control.
•Built-in DHCP capability simplifies network setup.
•The embedded system software is field upgradeable.
•Rack mountable aluminum chassis design.
The Net-2000™-P25 Voice Codec Unit (VCU) represents Digital Voice Systems,
Inc.(DVSI)latestadvancementinvoicecompressiontechnology. TheNet-2000™-
P25 VCU hardware incorporates DVSI’s patented vocoder software for voice
compression applications geared toward the next generation ofAPCO Project 25
(P25) digital mobile radio communication systems. The Net-2000™-P25 VCU
includestwovocodermodes,thestandardFull-RateAPCOP25vocoderandDVSI’s
new 3600 bps Half-Rate vocoder that has been proposed to APCO Project 25
systeminordertodoublepublicsafetycommunicationchannels. TheNet-2000™-
P25 VCU is designed for flexibile integration into a variety of other OEM digital
communicationapplicationsincludingVoiceOverInternetProtocol(VoIP),wireless
telephony and voice monitoring / recording systems.
The key element of the Net-2000™-P25 VCU is DVSI’s new Half-Rate Vocoder
thatoperatesat2450bpsandadds1150bpsofintegratedforwarderrorcorrection
(FEC). Thislow-bit-ratetechnologymaximizescommunicationssystemresources
by improving channel efficiency up to 2-3 times that of vocoders currently used in
most mobile radio and cellular systems. The new Half-Rate Vocoder advances
even further by incorporating DVSI’s latest quantization and FEC technology to
provide optimum voice comprehension even in degraded channel conditions due
to significant bit errors or acoustic background noise conditions. These superior
performance characteristics make the Half-Rate Vocoder ideal for use in digital
communication applications where bandwidth is at a premium and high quality
voice is imperative.
Thenew Half-Ratevocoderisanextension ofthecurrent7200 bpsstandardFull-
Rate IMBE™ Vocoder that is used throughout P25. Both the new Half-Rate and
the older Full-Rate are based on DVSI’s Multi-Band Excitation (MBE) technology
thatcodesspeechusingasetofMBEmodelparametersforeachframeofspeech.
However, the new Half-Rate vocoder includes a number of enhanced features
suchashighperformanceFEC(capableofuptoeightbitsofsoftdecisiondecoding)
built-in Voice/Silence detection (DTX), adaptive comfort noise generation, tone
detectionandgenerationofDTMF/ KNOXtoneandNorthAmericancallprogress
tones.
Channel Condition
7200 bps IMBE™ Full-Rate Vocoder (MOS, HD-FEC)
3600 bps AMBE+2™ Half-Rate Vocoder (computed MOS, SD-FEC)
3300 bps AMBE+2™ Half-Rate Vocoder (computed MOS, SD-FEC)
3600 bps AMBE+2™ Half-Rate Vocoder (MOS, HD-FEC)
0 % BER
1 % BER
3 % BER
3 % BER
5 % BER
5 mph
0 mph
5 mph
60 mph
60 mph
0.00
0.50
1.00
1.50
2.00
2.50
3.00
3.50
4.00
MOS
DVSI Half-Rate Vocoder Performance
Digital Voice Systems, Inc.
The Speech Compression Specialists
Features

Rear Panel Connections
Serial Port DB9s
LAN RJ-45
RS-422 Synchronous DB-15HD
RS-422Asynchronous RJ-45
2 Wire I/O RJ-11
Analog Line In RCAJack
Analog Line Out RCAJack
Handset RJ-14
AC Line In Pwr. Recp.
Mechanical Specifications
Dimensions: 17.25 X 3.5 X 7.25 inch
Weight: 4.5 pounds
AC Power Requirements
Voltage: 100 - 240 V ~
Frequency: 50 / 60 Hz.
Power: 28 W
AMBE is a registered trademark of Digital Voice Systems, Inc. AMBE+2 is a trademark of Digital Voice Systems, Inc. © Copyright Digital Voice Systems, Inc. 2003 All Rights Reserved. (2/03-
Specifications subject to change.
Ethernet Connectivity
TheNet-2000™-P25VCUgoesbeyondjustimplementingDVSI’spatentedHalf-
Rate Voice Compression Software, it also integrates an Ethernet interface for
remoteaccessandcontrol. The10Base-TEthernetconnectionontheNet-2000™-
P25 VCU allows full-duplex real-time or half-duplex non-real time voice
compressionapplicationsoveraLocalArea Network (LAN). Using the LAN, two
Net-2000™-P25VCU’scancommunicatetocreateaVoiceOverInternetProtocol
(VOIP)Ethernetbasedvocodercommunicationsystem. Communicatingbetween
twoNet-2000™-P25VCUis aseasyasenteringtheIPaddress(orhostname)of
the Net-2000™-P25 VCU units, selecting the desired voice interface and the
Full-Rate or Half-Rate Vocoder mode.
When two Net-2000™-P25 VCU communicate, each converts the input analog
speechintodigitalspeechsamples,encodesthespeechusingtheselectedAPCO
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 VCU is read in from the
Ethernetinterfaceanddecoded back in to digitalspeechsamples. Thedecoded
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. Since the
channel data is a packet based UDP Ethernet protocol users can develop their
own customized controls and user interfaces so that the Net-2000™-P25 VCU
can fit into an endless array of applications.
TheEthernetLANconnectioncanalsobeusedtoencode/decodefilesfromaPC
makingtheNet-2000™-P25VCUidealforcompressed-voicestorageapplications
or non-real-time testing. Alternatively, the Net-2000™-P25 VCU can loop back
theVoIPinformationbacktoitselfforvoicemonitoringandevaluationapplications.
TheEthernet connection to aLAN provides the abilityfor any PC onthe network
to use a standard web browser to control the Net-2000™-P25 VCU. The user-
friendly web server built-into the Net-2000™-P25 makes it easy to select analog
audio I/O interfaces, select the vocoder mode and to establish communication
acrosstheEthernetconnection. Inadditiontothecontrol,thewebpagesdisplay
information about network settings, operating mode and system status. Since
the Net-2000™-P25 uses Ethernet, its web page can even be accessed from
notebook or tablet PC via wireless network.
Fast and Easy Set-up
Initialset-up of the Net-2000™-P25 VCU is straightforward and fastthanks to its
Ethernet network connection. It is equipped to handle IP address information
from a DHCP server when available on the LAN. Alternatively, the Net-2000™-
P25VCU’sRS-232serialportcanbeusedasaconsoleterminal
toallowlow-levelnetworksetupandselectionamongthevarious
input and output audio interfaces.
Variety of I/O
To meet a wide range of communication system requirements
the Net-2000™-P25 Voice Codec Unit hosts a variety of inputs
andoutputs. ForuncompressedanalogvoiceI/OtheNet-2000™-
P25VCUsupports2-wire,4-wireandhandsetanaloginterfaces.
For compressed voice data communication across a channel,
digitized speech can be transmitted and received through either
the Ethernet or RS-422 serial interface. A unique feature of the
Net-2000™-P25VCUisthatbothvoiceandchanneldatacanbe
transmitted over the Ethernet interface at the same time.
DVSIdeveloped the Net-2000™-P25 VCU to package thelatest
softwareinto a hardwareplatformthatdoes notrequirelicensing
fees or royalties. With off-the-shelf availability the Net-2000™-
P25 VCU provides cost effective voice compression without the
risks and engineering expenses associated with new product
development.
Contact Us
Digital Voice Systems, Inc. is the accepted leader in the
development of low-bit-rate, high quality voice compression
technology. DVSI provides both software and hardware based
voice coding solutions to equipment manufacturers throughout
theworld. DVSI’shighperformancevocodertechnologycombined
with innovative designs and advanced features, benefit a wide
range of digital communications and voice storage applications.
For additional information or to learn more about DVSI and its
products visit us on-line at www.dvsinc.com.
The Speech Compression Specialists
Digital Voice Systems, Inc.
234 Littleton Road
Westford, MA 01886
Tel: [phone]
Fax: [phone]
Web: www.dvsinc.com
Built-In Web Server User Interface