Hi Shane, Your description sounds pretty good! So it's quite ready-2-use, isn't it?
I can give it a try on CB radio... I was just thinking of using such an encoder/decoder system for another project - with the exeption that it uses the bitstream directly, (The FDMDV-modem is not used!) in order to process it otherwise... (NOTE: This is not hamradio - related, but as it takes profit of the work of the Codec2 project, I think it is important to link the original developers and the projects that are based upon their work!) You mave heard about the Cryptofon/Cryptron? ( https://en.wikipedia.org/wiki/Crypto_phone ). A german cypherpunk, known as TRON ( https://en.wikipedia.org/wiki/Tron_(hacker) ) developed it in the past - but since he was killed, there has been no maintainer of the project. [More info can be found on http://tronland.net/ (german languaged) ] I want to restart it, but the long duration of inactivity (approx. 15 years (!) ) really encourage a complete new development from scratch, as getting the original parts becomes more and more challenging (e.g. the ISDN-Controller is not produced anymore!), and bandwith needs are changing. Codec2 would enable a better usage of narrowband connections, even allowing usage with self-made acoustic-coupler (adaptors) on public phones - which means that they mostly do not enable connections with more than 9600 bit/s - or sometimes even just 2400 bit/s when using a standard V.92-modem! As a new implementation of the Cryptofon requires more flexibility (the first and only prototype made by tron only worked on ISDN lines by concept and suffered from a bug that makes it impossible to run it on a regular ISDN phone system as offered by telephony providers!), Codec2 may offer much more efficient bandwith usage as well as a higher robustness against frame-/packet loss than any other codec available w/o propietary licensing or patents. Codec2 seems unbeatable at 1200bit/s - having only MELP as serious competitor. So just a plain example of the usage of Codec2 in terms of Telephony: Even if you just have an analog-only modem connection, you can get up to 32kbit/s total bandwith. Even when using 50% for a simple (yet effective) error correction (like Viterbi-FEC 3/4 & 2/3 in a chain), you still have 16kbit/s payload - enough for 6 (12) parallel voice transmissions @ 2400 bit/s (1200bit/s) (14,4kbit/s) or 1 voice channel (1200bit/s) and 1 data channel (14,4kbit/s). As you see, there are still a few hundred bit/s unused (but may be used for dTDMA ( https://en.wikipedia.org/wiki/Time_division_multiple_access#Dynamic_TDMA ) of the streams using channel identifiers)... When using ISDN (64kbit/s) - you can tunnel 53 (!) conversations @ 1200 bit/s - that's quite impressive! [GSM developed in the opposite direction (see https://en.wikipedia.org/wiki/Adaptive_Multi-Rate_Wideband )] If my short description gained your interest, feel free to contact me via eMail. Yours sincerely, Netzblockierer Am 02.04.2013 17:43, schrieb Shane Burrell: > Specs: > All codec2 rates. Wow! Mostly, the 1200bit/s and 2400 bit/s - mode are interesting > Ability to use external AMBE board. Well... AMBE is patent pending and not allowed on for hamradio according to FCC rule 97.309(b) as ''unspecified digital code''. Besides, it may be subject to restriction according to the ''Wassenaar Treaty'' as well as export regulations (e.g. U.S. ITAR 120-125 ) due to it's ''dual-use functionality''. Nevertheless, the ability to use an external board for encoding/decoding makes it possible to create a more modular and open device... > FV Modem and GSMK Nice! > > Connectivity: > I have a test project that I I started with when the ST32F4 Discovery > came out. I then went to a china manufacture for a STMF4 development > board with additional memory and raw I2S connectivity to a codec > better suited for a real mic/speaker with output/input to a radio. I > on REVB (first working) of my own prototype based on the STM32F4. It > has a 6 pin DIN for my TM-710A and a modular connector for the mic > that comes with that radio. Nice... I've taken a look on the model... Seems to be pretty useful, as it has two tuners that can be used - making duplex transmissions possible w/o the need of a secondary device. I would have tried it on two CB-Radios, using different data transmission channels for Tx and Rx. As my CB also has controls on the DIN microphone connector, it can be used to control the radio without the need to modify it - as this is not even allowed to hams w/ licensing regarding 27MHz CB radio devices (at least in Germany, it is the case...)! > > > > > > > On Tue, Apr 2, 2013 at 11:20 AM, Netzblockierer > <[email protected] > <mailto:[email protected]>> wrote: > > Sounds fine. > Do you have any specifications or at least concept (e.g. supported > encoding/decoding bandwith; connectivity; needed electronics) or > are you > just begginig from scratch? > > @ 20130402,1357CET, Shane Burrell wrote: > > I have a working codec2 project on bare metal hardware. Working on > > combined FV and GSMK version. > > ------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. 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