This forum has been created to foster the discussion on future and cutting edge technology. This discussion is not limited or restricted to Motorola. Examples of allowed discussion are open source hardware (GNU Radio for example) and software (Open source P25, Asterisk, ROIP, etc). Discussion is also permitted where older technology could be applied to areas where it had previously not been used (Example: Trunking on amateur radio).

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Posts: 169
Joined: Fri Dec 22, 2006 11:38 am


Post by gopher »


This idea I had is to create an affordable software defined radio control system that is extremely versatile and scalable. Applications could range from simple digital speech decoding, to remote HF gateways, to complex multi-site, multi-mode repeater networks.

Hardware designs as well as software are to be free and open source, allowing end users to have ultimate flexibility to build and control their own equipment. This will allow the user to dynamically interface newer DSP technology to existing RF equipment across IP, providing an affordable, interoperable communications system without geographic restriction.

The system could be developed in phases, with an effort to preserve functionality on older designs to prevent them from becoming outdated or obsoleted.

Phase I – Initial system design, running on commodity x86 hardware, sound card A/D D/A, Home brew interfaces for specific radios. This is where the system will start. Completely non-standardized. Software will be designed around hardware. Eventually start to Design hardware and software interfaces to support range of consumer and commercial equip, new and old. Design radioctl API and frontends. must be free, open source, and end user friendly. Programmable via FPP, web, serial, etc. Software is kept up to date via online community maintained version system. Layered to accommodate future changes in hardware.

Phase II - Home brew custom designed hardware PCB's, embedded processing, FPGA, custom A/D – D/A
This is were we will start design something suitable for mass production. SBC? Atom? FPGA? ? No idea where this road will go. experiment custom interfaces or use per-manufactured modules?

Phase III – Commercially produced hardware
final decision on hardware,create standard reference, port software over.
Made affordable for wide range of applications by offering multiple levels / models with different features

Main controller with high level of user interface options via front control panel.
Must have front panel controls either in the form of physical buttons or via touch screen menus. A minimal amount of physical buttons should still exist if touch screen is implemented. IE: power button and vol / selector knob.
Front panel can be mounted remotely?
Must have a internal speaker and microphone, as well as connections for external speaker / mic.
Pair of full duplex analog inputs and outputs capable of discriminator, mic, line or speaker level connection to DSP.
Perhaps direct serial interface for slicer circuits
Must have a large front display, either back lit LCD, or VFD.
Ability to control basic functions on a wide range of radio equipment. Standardized multi pin connector with different custom dongles for various radios.
Possible to do advanced radio controls such as on the fly tuning, programming
2x rj45 Ethernet networking interface to allow daisy chaining multiple devices without switchgear.
Direct software repeater interfacing via echolink, irlp, ipsc, custom hardware wireline interfaces?
Remotely controllable via IP
Houses the AD,DA, CPU, RAM, SSD, etc.

Same as level 1 but with a minimal level of user interface. No local user audio mic or speaker. All programming is done via network or serial port. Designed for permanent install. Otherwise same inputs and output as full featured version. Able to operate remotely and interface with other controller units via IP.

Slave controller with minimal level of user interface options. Bidirectional dsp samples and control messages are sent over IP to the Main Controller. Reduced cost? Higher Delay?

Not sure why I add this but why not? Standardized connections to controller, different modules provide different RF? eh... ettus ? eh.... U$RP? eh......


Main modes of operation, Support for different hardware, and dsp should be easy to change simply by downloading a online profile. user community database of profiles avail at no charge. Design your own profile via pc or touch screen, save and share online.

Decoding or encoding CW signals- On screen display of decoded CW, User could use mic PTT or accessory to TX.

Decoding digital -. Simply connect police scanner discriminator tap.

IP/echolink/irlp remote station. High feature model would require 0 additional hardware to function as a node on these networks.

Mobile Controller. Mount multiple radios out of view in vehicle, and control them with 1 full feature unit on dash. Think KVM

Mobile repeater. Connect 2 mobile radios with minimal unit to form a cross band repeater. Remotely controllable via DTMF, IP, etc.

Multi-mode operation – SDR can be programmed to decode or encode any analog or digital signal. AM, FM, DSTAR, P25. Only limitation is at what point in the radios RF chain you sample and if the closed source codec you want to operate on has been reversed engineered yet.

Complex Repeater – imagine a repeater system with 3 input and output pairs. Pair one is FM, pair 2 is P25, pair 3 is trbo. All real time interconnected.

Multi Band – Frequency is only limited to your selection of radio front ends. Link a VHF p25 to a 1.2 p25?. Its possible!

Remote Links- Controllers have an integrated Ethernet port with full IP communication stack. Either full time dedicated repeater links over VPN or dialing home to do HF while on the road.

IN REALITY - Im just some joe blow that drank too much coffee this morning and had a crazy idea. software and hardware will require thousands of hours of engineering. Not much profit to be made here. Whats your thoughts?

Posts: 169
Joined: Fri Dec 22, 2006 11:38 am


Post by gopher »

Anyone ? Perhaps someone could recommend an alternate forum?
I have been thinking about the beagle board OMAP3530 SBC. small fast (relatively) and cheap.
Only negatives about this i can foresee is it will requires an additional module for analog IO
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