Digital Voice Systems Net-2000-P25 Specifications

Digital Voice Systems, Inc.
The Speech Compression Specialists
Features
Flexibility and Performance
Network enabled voice codec unit interfaces APCO P25
vocoders with Analog 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.
DVSI Half-Rate Vocoder Performance
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00
0 % BER 1 % BER 3 % BER
0 mph 5 mph 5 mph
Channel Condition
7200 bps IMBE™ Full-Rate Vocoder (MOS, HD-FEC)
3600 bps AMBE+2™ Half-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)
Net-2000
The Net-2000™-P25 Voice Codec Unit (VCU) represents Digital Voice Systems,
Inc. (DVSI) latest advancement in voice compression technology. The Net-2000™-
P25 VCU hardware incorporates DVSI's patented vocoder software for voice
compression applications geared toward the next generation of APCO Project 25
(P25) digital mobile radio communication systems. The Net-2000™-P25 VCU
includes two vocoder modes, the standard Full-Rate APCO P25 vocoder and DVSI's
new 3600 bps Half-Rate vocoder that has been proposed to APCO Project 25
system in order to double public safety communication channels. The Net-2000™-
P25 VCU is designed for flexibile integration into a variety of other OEM digital
communication applications including Voice Over Internet Protocol (VoIP), wireless
telephony and voice monitoring / recording systems.
The key element of the Net-2000™-P25 VCU is DVSI's new Half-Rate Vocoder
that operates at 2450 bps and adds 1150 bps of integrated forward error correction
(FEC). This low-bit-rate technology maximizes communications system resources
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.
The new Half-Rate vocoder is an extension of the current 7200 bps standard Full-
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
that codes speech using a set of MBE model parameters for each frame of speech.
However, the new Half-Rate vocoder includes a number of enhanced features
3 % BER 5 % BER
60 mph 60 mph
such as high performance FEC (capable of up to eight bits of soft decision decoding)
built-in Voice/Silence detection (DTX), adaptive comfort noise generation, tone
detection and generation of DTMF / KNOX tone and North American call progress
Digital Voice Systems, Inc.
tones.
The Speech Compression Specialists
TM
-P25 Voice Codec Unit
The Net-2000™-P25 Voice Codec Unit
combines AMBE
Ethernet network connectivity!
®
Vocoder Technology with