digital radio

[rochele1]

hi guys,

i'm newbie in the frequency and radio technology , but from experts guys i have a question ,what is the different between digital mobile radio and analog radio ?

 

[n5ims]

hi guys,

i'm newbie in the frequency and radio technology , but from experts guys i have a question ,what is the different between digital mobile radio and analog radio ?

A digital radio encodes the analog voice frequencies into a digital data stream and sends it out using digital modulation of the radio. An analog radio simply sends out the voice frequency directly by modulating the analog radio signal.

An analog radio will generally have good audio that gets noisier as the signal gets weaker. This noise is often like static or bacon frying. As the signal gets weaker and weaker, the audio gets weaker and the noise gets stronger until you can't make out the audio any longer. A digital signal is noise free (although it may not sound as good as an analog one to some) until there isn't enough signal to piece back the audio from the data stream and then it simply drops to nothing.

The range of the two are often said to be the same, although many will argue that a true analog signal is often understood through the noise while the equivalent digital signal has dropped out. Be aware that there's a difference between "understood" and "easily understood" in that statement. It may be that only half or even a third of the transmission is copyable, but if proper procedures are used, it's often possible to make out what is being said. Something like this:

"Subj......For....50, lic.....524-JF...Eastbo...35 past exit 19..." Fairly easy to fill in the blanks to another officer that's familiar with the procedures and area to get "Subject is driving a Ford F-150, License # 524-JF<something>. Eastbound on interstate 135 past exit 193"

 

[pyro424]

hi guys,

i'm newbie in the frequency and radio technology , but from experts guys i have a question ,what is the different between digital mobile radio and analog radio ?

Well digital radio is where you speak into the microphone and the radio turns your voice into numbers and digits and sends those digits over the air. Then another radio receives those digits and converts them back into audio that you can understand. - Analog radio on the other hand simply transmits your voice out over the air without changing it into digits and numbers. Another radio receives your voice without having to do any kind of conversion as it is simply "analog". Not sure if this explains your question but basically digital is where your voice gets converted into numbers and then converted back to voice at the other end. Basically the digital radio has a computer to process your audio. Where as analog does not. It just uses a transmitter and receiver to send your voice over the air. Out of these two types analog is superior and more reliable.

 

[ladn]

Here's another analogy. DIGITAL radio is very much like Magic Jack or Vonage phone services. ANALOG radio is like Plain Old Telephone System dial up.

That said, there are basically two versions of ANALOG radio, AM and FM which dictate how the audio is modulated with the carrier. AM is usually used only on the aircraft bands, and FM is used everywhere else. Because of increasing channel congestion (think parking lot running out of spaces), the FCC has mandated that most FM services narrow their bandwidth (make the parking spaces smaller). Some have gone to narrow band FM (NBFM) while others have gone DIGITAL.

Unlike analog FM, there are multiple digital standards, and none are cross-compatible. Many law enforcement agencies have gone to the P25 digital mode, which "digital capable" scanners can decode. Other digital modes such as NXDN, MOTOTRBO and OPEN SKY can't be decoded by scanners.

 

[DickH]

hi guys,

i'm newbie in the frequency and radio technology , but from experts guys i have a question ,what is the different between digital mobile radio and analog radio ?

It's just a different way to send voice - like AM vs FM radio.