Category Archives: VHF

(some of) the power of Radio over IP

Lately, in the lab, we have been tinkering with Radio Over IP Gateways.  Since we love standards, we spent a significant amount of time with Icom America’s VE-PG3, because it “speaks” the Session Initiation Protocol (SIP).

Just like most other Radio Over IP Gateways in the marketplace, the VE-PG3 can connect two or more radio sites over an IP network.  In this configuration, received radio audio is bridged to opposing radio sites of the network.  This bridge mode can connect dispersed radio sites over the network and can provide cross band, cross category communication.

This technology is already in use by the Virginia State Police.  They call it COMLINC (Commonwealth’s Link to Interoperable Communications).  It enables adjoining jurisdictions totally different radio systems (such as Hanover County’s 800 MHz system and Powhatan County’s VHF system) to be connected.  This is how they are going to catch you if you go speeding from Hanover into Powhatan!

I believe that we will see this technology being used even more in the near future.  One example I can think of is Virginia’s electric cooperatives.  If Northern Neck Electric Cooperative (IDAS on 153MHz) needs to talk to Rappahanock Electric Cooperative (TaitNet MPT 1327 on 217MHz), this is a great way to make it happen.

But, going beyond connecting two or more radio sites is where the VE-PG3 really starts to shine, because it can convert radio audio into SIP.

These were some of the immediate benefits that we were able to see in the lab:

  1. Eliminate EXPENSIVE virtual radio/dispatcher software on PCs by using any SIP softphone/hard phone. (Hint, here are 20 FREE SIP Softphones.)
  2. Use a SIP softphone on any device (think Android, iPhone, etc.) to talk to your radios.
  3. Use a SIP Trunk to talk to your radios. Anyone with any phone can call a telephone number and talk to your radios.
  4. Use all of the features of Asterisk on your radio system. Imagine the literally endless possibilities:
  • Get Call Detail Records for all of your radio traffic
  • Record all of your radio traffic
  • (Conference Bridging.) Bridge any mix of any number of PCs, Androids, iPhones, analog phones, radio systems, paging systems, etc.

If you couldn’t tell, we are excited to see standards coming to the Radio over IP marketplace.

If you are looking to take advantage of Radio over IP, please contact us at (804) 625-4233 or sales AT richmondrf DOT com.

License free radio options

People frequently like to ask us what their license free radio options are for personal use.  Basically, there are three license free radio options other than Citizens’ Band radio:

One could easily argue that FRS is the most common license free radio option.  This is because FRS radios are sold in retail channels (such as Best Buy, etc.) and FRS has been around since 1996.  However, FRS radios are limited to an ERP of 500 milliwatts (half a watt).  FRS manufacturers generally claim exaggerated range. Because FRS is in the ultra high frequency (UHF) band, the presence of large buildings, trees, etc., will reduce range.  Under normal conditions, with line of sight blocked by a few buildings or trees, FRS has an actual range of about 0.5 to 1.5 km (0.3 to 1 mile).

MURS was established by the U.S. Federal Communications Commission in the fall of 2000.  MURS transmitter power output is limited to 2 watts.  This higher power output limit and the fact that MURS is in the very high frequency (VHF) band makes MURS have an increased range.  Also, MURS allows for external antennas, which FRS does not allow for.  Ranges of 10 miles or more are possible.

Both FRS and MURS do not allow for encryption.  On the other hand, radios on the ISM band frequently use Frequency Hopping Spread Spectrum, which enhances communications privacy.  This means that transmissions cannot be picked up on a radio scanner that someone might purchase from an electronics store.  Also, whereas FRS and MURS radios offer only one-to-many group communications, ISM band radios are capable of one-to-one as well as one-to-many.  These radios also offer enhanced capabilities due to their ability to transmit and receive data as well as voice; they can offer Caller ID and even Short Message Service (SMS) text messaging.

So, as you can see, there are many options for license free radio.  For the best “range”, you might choose MURS.  For the most privacy, you might choose Frequency Hopping Spread Spectrum radios on the ISM band.  If you have any questions about what radio might fit your personal license free radio needs, please don’t hesitate to contact us at (804) 625-4233 or sales AT richmondrf DOT com.