With Google's acquisition of Motorola Mobility Solutions, do you think that an open-source iDEN scanner will be available in the future? Theoretically, it's possible.

Thank you Alex and Jim for the feedback!

Sincerely,

TVZ

Hi folks! I noticed when my friend calls (using interconnect telco call mode) me across the coffee shop he sounds like a robot! It seems like the "Swedes" reconfigured the base station to use interleave 6:1 AMBE vocoder for interconnect calls which used to be 3:1 VSELP (which sounded much ...

Just curious.. Does the m370 support AMBE vocoders as well?

Any updates on this? I now have an Ettus WBX transceiver to work with.. Just need some source code to start playing with now.. Sorry for the delay folks, so many things surfaced unexpectedly. However, things are finally moving along. Purchasing USRP WBX repeater boards soon to experiment with and b...

Hello folks! Has anyone published a comprehensive vocoder matrix spreadsheet out there for two-way radio systems? For example, AMBE, AMBE+2, IMBE, ProVoice, VSELP, EDACS, NXDN, etc. with corresponding bit rates, frame, forward error correction, etc. with associated trunking system(s) ? I thought I'd...

Thank you, wavetar! Going through the SPR vocoder specs proposed in the blog, it reminds me of a Russian Company that developed a similar technique using TI DSP's: DSP Innovations Inc. (dispini.com) Slavi 4, Penza 440000 Russian Federation David Rowe's work may potentially be a viable option. Howeve...

MattSR, That's GREAT to hear that you have a USRP as well -- Do you need TVRO daughter boards? I am actually waiting for the DC-1GHz boards from Ettus Research (not sure if they are available yet). On another matter, I currently do not have any alpha code yet to release via SVN -- Hopefully, in the ...

Hi folks! I am in the early planning stages of building an Open-Source Digital Mobile Radio (DMR) like MotoTRBO following the ETSI specs. The system will be designed using Software Defined Radio (SDR) test platforms, such as the USRP and SSRP. The frequency band will be virtually unlimited -- I thin...

Fatboy, Thank you for your response. Yes, that is correct. I am using SDR front-ends and SCR Preselector to get by for now. Due to it's limited capability, I am designing a new high-performance SDR receiver with a much larger bandwidth of at least 160MHz with an onboard FPGA for DSP with either a Xi...

Hi Folks! My problem is this: I found a very good digital-controlled preselector (via USB) that works in the lower VHF bands (30MHz) for my homebrew mixed-signal scanner. However, I would like to move a specified band, for example iDEN 851-870, down to the preselector's operating range with the leas...

WowBagger,

Thank you very much for sharing! Now, I think I am in love with those Aeroflex/IFR 3920 Beauties! Gotta get one of those soon!

Sincerely,

TVZ

Hi ALL!

As a hobby, I like making homebrew scanners. I was wondering if you can do a raw L2 data dump from an R8000 or IFR 3920(nice!). If so, are there L3 messages can you extract from that?

Just curious..

Thanks all in advance!

TVZ

The other day when I was doing an RF survey for my little iDEN EBTS tracking project, I noticed that a couple of transmitters are not exactly on the designated Hex frequencies. For example, if you look in your iDEN handset diagnostic mode, you should see a Hex code like 2AC which is 684 in decimal o...

Bill_G, Thank you for your response! It's been helpful to me. In fact, you gave me an idea of building a multi-pole preselector with cascaded digitally controlled potentiometers for the receiver. On the transmitter side, I will also attempt to implement it with an additional closed-loop RF PA with d...

Hi folks! I need to know if anyone knows of a digital controlled preselector specifically for the 801-824MHz band (or a similar solution). I would like to improve my uplink reception from a radio handset. Apparently, I receive a lot of 800MHz trunking interference which affects the frame error rates...

Hi folks! I am not businessman, I am really just a design engineer and hobbyist. But if I am to charge for two-way radio repair services, what are the ways to charge for it? I have seen companies charge from $90 to $125 per hour plus parts? Also, as low as, $45 per hour plus cost of parts, or even s...

I suppose to further explain my request, here's my current and proposed setup: (For example, let's take iDEN 800MHz Band 2 from my current setup) Receive Omni Antenna (806-870, 2.5dBi)---> Diplexer (806-928MHz) ----> Two Receive Paths: (A) Forward/Outbound Base Station Frequency 851-866MHz (B) Rever...

So you're going to build (presumably) a "commercial" single-band scanner that will decode P25, iDEN (both codecs?), LTR, and more... and you don't have a basic understanding of what RF conditioning components you'd need to get started? I'd say you have a lot more to worry about than a few...

Hi ALL, I am planning to build a hybrid digital/analog ESMR scanner front-end receivers that will work between 806-870 MHz. What combination of antennas, preselectors, diplexers, and/or LNA that I could use to improve the signal and reduce interference? I would like the capability to receive Astro, ...

Thank you very much for your reply, wavetar!
It's awesome to have knowledgeable people in this forum!
My primary goal is always been to learn from the "hands-on" people from the field to design better products and systems.

Thank you all for sharing, I am learning a lot!

Sincerely,

TVZ

Hi, Just curious.. 1. Will MotoTRBO have encryption? If so, what is it? AES, DES, RC4? I head there's a Basic Privacy and "Advanced" Privacy Option. 2. Are there manufacturers (3rd party?) making voice scramblers that will work on MotoTRBO? 3. I was listening to a MotoTRBO vs. Moto Analog ...

Hi Einstein, I think there's a way to use an iDEN handset with Windows Mobile 23K (i920/i930) to retrieve that info. You may have to write a little software app using the API's to read the MCC, DLA, LAC, CI, etc. But I am sure the code is lurking out there somewhere and it should work for GSM, CDMA,...

Hi all,

Is there anyone here have experience with R8000A with MotoTRBO option?

Also, I am wondering if all the vocoder tests work well.

Thanks,

TVZ

Hi Resq22,

What CPS version are you using? What firmware version?

Sincerely,

-- TVZ

Hi David, The very least you can do is a perform a drive test (along with an associate)with a RF Service Monitor connected to your laptop (via serial or USB port) to collect RF signal strengths (dB) data along with a GPS receiver and data collection software (or make your own!). Later you can calcul...

In addition, someone already made their own open-source GSM base stations (OpenBTS) and Base Station Controllers (OpenBSC). The new system will be demonstrated at this years http://www.burningman.com Prior to that, our engineering team designed Cellular/two-way radio interoperability via an open-sou...

Hi, When I consulted for Verizon/AirTouch/Vodafone, I combined aerial maps and USGS maps for RF Propagation Surveys. However, you can use the http://www.acme.com/mapper and make your own coverage maps. Make sure you define all your RF specifications for test and measurement though. I have also had g...

Hi folks! Anyone here working on DMR equipment for the recently allocated (or released?) White Space RF spectrum. I heard of broadband wireless communications are currently being developed, but I have not heard much about other DMR projects. Just wondering, if someone is interested in building a Ope...

Hi, Sorry, I forgot to mention the I/Q modulation scheme. iDEN uses what Moto calls "M16-QAM", what it is really 4 x subchannels using Phase-Amplitude Modulation (PAM) per TX and another set for RX. On the top of that is a 6-slot, 15ms per slot, TDMA layer. The voice (dispatch radio and in...

Tom, Thank you for the quick response. Yep, I been there already. Actually, I had been Googling the ETSI specs for a few hours already. I had already been to China and back -- I saw the pdf's there, but I could not read the Chinese writing.. haha Any help will be GREAT! Thank you all in advance for ...

Hi,

Anyone here have the MotoTRBO ETSI specs handy?

Particularly, ETSI TS 102 361-2? For some reason, the link is broken at the ETSI website.

Thanks in advance!

-- TVZ

[quote="billlayton"]Is it possible to monitor a Nextel channel using an old Motorola VSELP radio? The only Moto radio models I know that could do that were Astro Sabers at the 800MHz band. Unless you workout some kind of down converter RF front-end to translate the narrowband frequencies t...