When using the RF what is the difference of Wide band and Narrow band communication?

Most ICs claim to use Narrow band and I have not come across ICs that use wide band communication. Is there a reason for this? What are the applications wide band is more applicable?

Thank you for your opinion.

closed as too broad by Andy aka, PeterJ, nidhin, pjc50, Daniel Grillo Mar 4 '15 at 18:44

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

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    This is a very, very big subject and probably too big for this format. If you could ask a more specific question possibly related to something you need to know most urgently then maybe it can be properly addressed. – Andy aka Mar 4 '15 at 8:40
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    I'm sorry if thIs question seems vague I actually thought it was specific. To be honest I needed a place to start. And the answer leads some distance in the path I wanted to walk although I have a few questions – Dina Mar 4 '15 at 10:49
up vote 7 down vote accepted

The scope of this question is too broad and cannot be answered well but I will try to give you some hints where to look for next:

Wideband communication

Wideband communication uses - as the name states - a wider portion of the spectrum. This has some advantages and disadvantages:

  • Wideband communication allows for a higher bandwidth and therefore for a faster communication
  • Wideband communication allows for spreading the signal to encrypt it (See: Direct Sequence Spread Spectrum and its derivates)
  • wideband communication allows for notching out narrow noise sources in the spectrum (See OFDM)
  • Wideband communication puts high demands on the linearity of filters (also the respective filter bandwidths are higher)
  • It's harder to send and detect wideband signals (You need a high Signal to Noise ratio) as the energy of the signal is distributed across the width of the spectrum which makes the signal weaker the wider it gets (transmitting on a given power level)
  • Wideband communication is almost exclusively done in higher frequencies (I'd say 433MHz+) as it's easier to design integrated circuits which have wider filters
  • Common modulation techniques are OFDM, GMSK, N-PSK and QAM-N in combination with frequency hopping
  • Examples of wideband communication are wireless networks: Wifi, LTE, HSPA

Narrowband communication

Narrowband communication uses a narrow bandwidth.

  • Narrowband signals are used in a slower form of communication where mainly voice or slow datastreams have to be transmitted
  • Narrowband signals usually have a far greater range of reception as narrower filters can be used and therefore cancel out unwanted wideband noise. The transmitted energy also concentrates on a smaller portion of the spectrum.
  • Common uses are FM radio, AM radio, satellite downlinks, morse code (CW), GPS signals and NOAA weather transmissions.
  • Common modulation techniques are AM, FM, SSB, BPSK and CW

Often IC manufacturers do focus on narrowband communication because often you need to flip a switch and propagate the change in signal through the air which does not need a high bandwidth. If you however try to send a x264 packed HD picture with 24MBit over the air you most certainly need a high bandwidth to transmit it in realtime. But according to the frequency usage plans you need to use a higher frequency band to be allowed to use a certain bandwidth (or power level). This is why wideband communication is almost exclusive to hardware used for 1 GHz+ operation.

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    UWB radio? No mention of this? I'm saying this because you can never give a full account of a question such as this. Knowing that the question is nearly impossible to do justice to means that if you do try and answer it, you are open to some criticism because giving a partial answer doesn't answer the question. The question will likely be closed anyway so this is a moot point. – Andy aka Mar 4 '15 at 10:22
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    I didn't include UWB radio because I didn't know about that particular technique! Will read up on that topic and update my answer. Thanks! – Jan Krüger Mar 4 '15 at 10:27
  • Thank you @Jan for giving me a good idea about the subject. Well why would this question be closed? I believe there is a lot of knowledge in it. – Dina Mar 4 '15 at 11:04
  • The Stackexchange format calls for specific questions. Your question is asked in a very general way which can only be answered in a general way and therefore the questions falls under the list of questions one should avoid asking here – Jan Krüger Mar 4 '15 at 11:44
  • Would you want me to delete it? – Dina Mar 4 '15 at 15:29

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