Mission critical wireless communication is not segregated solely to law enforcement and emergency first responders. Any industry that relies on digital wireless communication, from energy/utilities, to large university campuses or transportation systems, or manufacturing facilities and even amateur radio demand high quality voice and intelligibility. It is considered mission critical to them. These communication systems employ different standards such as DMR, DpMR, Globastar, Terrastar, Full Rate and Half Rate P25, NXDN at various data rates. However, the one thing they have in common is they all implement the AMBE® Vocoder technology. When there is a need to expand or communicate between any of these systems, the best way to avoid the detrimental effect of encoder/decoder tandeming is to employ a parametric rate converter/repeater.
To facilitate the delivery of innovative products that support AMBE® vocoder communication systems DVSI developed the USB-3000™ RC. The USB-3000™ RC is a USB device that incorporates a parametric rate converter, a vocoder repeater and frame analyzer. The parametric rate converter promotes seamless interoperability between AMBE® vocoder communication networks such as, wireless radio or satellite links, wire connected phone lines, and Ethernet networks including the Internet. The USB-3000™ RC vocoder repeater function can extend the effective transmission range and avoid gaps in coverage area as well as remove unwanted errors in data stream. Its frame analyzer function helps propagate efficient data transmission.
DVSI’s patented AMBE+2™ Voice Compression technology is the heart of USB-3000™ RC. It has the flexibility to convert to/from or repeat virtually any data rate between 2000 bps and 9600 bps. The versatility of speech and/or FEC rates permits optimization within custom system requirements while delivering and maintaining excellent voice quality along with superior robustness to bit errors without adding significant delays.
The USB-3000™ RC uses the same technology as the successful USB-3000™. The USB-3000™ has been implemented into critical applications such as digital mobile radio, satellite communication systems and in other wireless communication devices for more than ten years. Both devices allow user to connect to a USB port on a Windows or Linux based PC, to transmit/receive speech and compressed data packets, as well as configure vocoder repeater / rate converter and FEC options and monitor status information.
Like the USB-3000™ the USB-3000™ RC is configured so that all speech and channel data to/from USB port is formatted into packets. This packet-mode interface allows the USB-3000™ RC to process the incoming packets as soon as they are received and output the resulting response packet with minimal delay. The fast baud rate of the USB-3000™ RC helps keep the delay as small as possible. The algorithmic delay of the repeater is zero. There are other non-zero processing and buffering delays caused by the PC hardware and the OS, as well as what drivers are employed by the system.
Efficiently and effectively expanding digital mobile radio communication networks depends greatly on the voice compression vocoder capabilities and how it handles wireless transmission conditions and background environmental noise. DVSI is continuously advancing voice compression technology and its ability to provide high quality intelligible voice in a variety of conditions and background noise environments. With DVSI’s parametric rate converter / repeater technology there is no need to employ encoding/decoding tandeming that could result in severe degradation in performance, increased processing delays and losses in voice quality and intelligibility.
DVSI’s USB-3000™ RC can play and integral role in expanding communication networks by providing a parametric rate converter, a vocoder repeater and frame analyzer that satisfies the needs of its users. The USB interface of the USB-3000™ RC provides the design engineer and the manufacturer with a low-cost method to implement AMBE® Vocoder technology and rate converter into their products.
The USB-3000™ provides a low cost alternative to a fully customized software implementation because it is available off the shelf and requires no up-front licensing fees or royalties. Now product designers, communication engineers and original equipment manufacturers can implement DVSI's AMBE-3000™ vocoder into customized high performance, low-bitrate communication systems, without risks and high development costs associated with DSP implementations.
The simplistic design of the USB-3000™ RC along with its USB interface makes it an ideal component in the production of low-volume military and commercial communication equipment that is cost effective to manufacture, affordable and inexpensive to operate. In addition, the USB-3000™ RC can be used to create multi-channel systems by connecting more than one USB-3000™ RC to a single PC.
USB-3000™ RC is inter-operable with the following Vocoders:
|AMBE-2000™ Chip Rates
|AMBE-3000™ Chip Rates
|APCO Project 25 Half Rate
|APCO Project 25 Full Rate
USB-3000™ Rate Converter Drivers
The USB-3000™ Repeater is configured to use generic drivers offered by Future Technology Devices International Ltd. (FTDI). FTDI has USB drivers for several operating systems. Please visit the FTDI website for more information.
The USB-3000™ RC’s parametric rate converter processes the incoming data bit stream without converting it to speech as part of the conversion process (i.e., it does not use tandeming). Instead, the MBE model parameters are used as the intermediate stage between bit rates. The synthesis and the analysis of speech is not performed. This approach avoids multiple stages of tandeming where in most situations leads to the loss of voice quality, intelligibility, and delay.
Similar to the parametric rate converter feature the “Repeater function” in the USB-3000™ RC does not convert the incoming data bit stream to speech as part of the process. The data bit stream input to the USB-3000™ RC can be FEC Decoded to fix bit errors and then FEC encoded before re-transmitting the repaired frame. Without the need to process MBE model parameters and voice-decode or voice-encode there is no tandeming and no algorithmic delay that can degrade voice quality and hamper network performance. Additionally, the repeater function can be set to ‘FEC decode only’ to give access to transmitted data or ‘FEC Encode only’ for the injection of data into network data stream.
USB-3000™ RC has the flexibility to convert or repeat to/from at virtually any data rate between 2000 bps and 9600 bps. The versatility of speech and/or FEC rates permits optimization within custom system requirements while delivering and maintaining excellent voice quality along with superior robustness to bit errors without adding significant delays.
The USB-3000™ RC uses the same technology as the successful USB-3000™. The USB-3000™ family of products have been implemented into critical communication applications for more than ten years. All of these devices allow user to connect to a USB port on a Windows based PC, and transmit/receive speech and compressed data packets, as well as configure vocoder repeater / rate converter options and monitor status information. Integration of the USB-3000™ USB Device is simplified since drivers are available for a variety of operating systems.
Key benefits of the USB-3000™ RC are:
- Interoperability with DVSI's AMBE® Vocoder Technology via USB.
- Eliminates Encoder / Decoder Tandeming issues (No need to voice synthesis to PCM and re-encode).
- Convert between any two AMBE® Vocoder rates (including custom rates).
- Minimizes delays.
- The USB Repeater device comes with sample control software and reference documentation.
- Compatible with Window XP and Vista operating systems (other driver options available).
- Multi channel capability.
||2.5 X 1.0 X 0.5 inches
The USB-3000™ RC is a complete hardware package available with software and documentation that allows the user to quickly install and begin to process speech data. Technical documentation includes a USB-3000™ Users manual and the AMBE-3000™ USB User's Manual.