Net-2000™ Voice Codec Unit

Introduction

The Net-2000™ Voice Codec Unit (VCU) combines AMBE® Vocoder Technology with Ethernet network connectivity!

The Net-2000™ voice codec unit (VCU) incorporates Digital Voice Systems, Inc. (DVSI) award winning AMBE® Vocoder technology to bridge analog speech I/O to an Ethernet network. This stand-alone device supports multiple AMBE® vocoder modes that makes it ideally suited for a variety of digital communication systems as well as volume OEM applications such as VoIP, and voice recording products.

The flexibility of the Net-2000™ VCU’s patented AMBE® Vocoder technology maximizes communications system resources and provides optimum voice comprehension even under extreme bit errors or acoustic background noise conditions. The Net-2000™ AMBE® Vocoder modes include bit rates between 2.0 - 9.6 kbps (adjustable in 50 bps increments), built-in Viterbi Decoder 4-bit soft decision FEC, DTMF capability, Voice Activity Detection (VAD), Comfort Noise Insertion (CNI), and echo cancellation.

The Net-2000™ also incorporates the AMBE+2™ Vocoder that sets the standard for speech quality at the low data rate of 4.0 kbps. The superior performance characteristics of AMBE+2™ Vocoder have made it successful in voice communication applications where bandwidth is at a premium and high quality voice is imperative. In fact, the AMBE® vocoder has been proven by numerous independent evaluations, to out perform CELP and other competitive technologies at under half the data rate.

To meet a wide variety of communication system requirements the NET-2000™ Voice Codec Unit offers an array of speech and channel interfaces along with control features that make it easy to set-up and operate. The Net-2000™ includes 2-wire, 4-wire and handset analog interfaces for input and output of uncompressed speech, as well as, Ethernet and RS-422 as its channel data interface. A unique feature of the Net-2000™ is that both voice and channel data can be transmitted over the Ethernet interface at the same time.

The Net-2000™ implements the channel data interface using a special protocol designed by DVSI. This allows real-time, full-duplex communications via the Ethernet or RS-422 interfaces to another Net-2000™ unit. Connecting two Net-2000™ units together is as easy as entering the IP address (or hostname) of the Net-2000™ units and selecting the desired voice interface and AMBE® vocoder mode.

Each Net-2000™ converts the input analog speech into digital speech samples, encodes the speech using the selected AMBE® Vocoder mode and then send 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™ is 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.

Alternatively, the Ethernet interface can connect directly to a Local Area Network (LAN). This configuration can be used to create a real-time Ethernet based vocoder communication system or to record / playback of files using a PC. To encode/decode files stored on a PC the Net-2000™ provides a SMB file I/O mode ideal for compressed-voice storage applications or non-real-time testing and evaluation.

Initial set-up of the Net-2000™ is fast and straightforward thanks 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™’s RS-232 serial port can be used via telnet as a console terminal to allow low-level network setup and selection among the various input and output audio interfaces.

The Net-2000™ is controlled via PC connected through the RS-232 or Ethernet interface. When connected on a LAN — any PC on the network can use a standard web browser to configure and control the unit without requiring custom PC software.

The user-friendly web pages built-into the Net-2000™ make it easy to select analog audio interfaces, configure the AMBE® vocoder mode and to establish real-time, full-duplex communication across the Ethernet or RS-422 connection. In addition to the control, the web pages display information about network settings, operating mode and system status. Since the Net-2000™ uses Ethernet its web page can even be accessed over a wireless network through a wireless notebook or tablet PC.

Features

Stand-alone Design

• Network enabled voice codec unit interfaces AMBE™ vocoders between Analog I/O and Ethernet networks.
• Real-time, full-duplex communications to other Net-2000™ 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 stored on a PC or networked attached storage. 

Flexibility and Performance

• High performance line level audio using 16-bit linear codec. 
• 4-wire and 2-wire analog input/outputs.
• Built-in web server to select audio I/O, gain settings and vocoder mode from any PC on the LAN.
• Supports Variety of AMBE™ Vocoder Modes.
• Flexible bit-rates (2.0 – 9.6 kbps and 4 kbps toll quality) for optimum system performance.
• Built-in FEC delivers robust performance over channels degraded by bit errors and/or background noise.
• AMBE™ Vocoder Modes can also include DTMF capability, Voice Activity Detection, Comfort Noise Insertion, and Echo Cancellation.

Easy to Integrate and Operate.

• The RS-232 serial port can used as a console terminal for system setup and control.
• Easy network set-up with built-in DHCP to handle IP address information when available on LAN.
• The embedded operation software can be field upgradeable.
• Rack mountable aluminum chassis design.

Technical Specifications: