Generally, downlink freq. > uplink freq. in mobile communications. I was able to gather some answers as to why is so. But my seniors (in my company) seem not to be satisfied with the below answers.

  1. High frequency means higher attenuation. So lets suppose that BTS (as in case of GSM) transmits using low frequency on the downlink. So, that means lower attenuation. Hence, data is received as it should be (without attenuation). So, MS (mobile) has to transmit on uplink using higher freq. in order to avoid interference. But high freq. means higher attenuation. So, in order to overcome the attenuation, MS has to transmit on high power. But due to the constraint on the amount of energy available on the MS battery, this approach is not feasible. Hence, downlink frequency should be greater than uplink frequency.
  2. This point is from user perspective. Generally, people download more than upload (however, its converging now). So, we require more bandwidth in DL than in UL and it can be attained only if DL freq. > UL freq. Hence DL freq. > UL freq.

I have searched almost everything (however, that's not possible). If you could help me regarding the same, it would be very kind.

  • $\begingroup$ A mobile transmission tower, or even a large solar-powered satellite, has a much bigger power source than a hand held phone. I suspect that, plus point 2, are more important than the "lower attenuation" argument in point 1. This asymmetric speed also applies to wired internet connections (ADSL) - for example, the service guarantee from my ISP is 55 Mb/s download, 10 MB/s upload. $\endgroup$ – alephzero Jul 27 '17 at 21:29

In Mobile communication (unlike in satellite communication where source doesn't seems to have much battery (similar to UE in mobile communication)there are 2 devices one is mobile & other is mobile tower here mobile tower is in continue/adequate supply of power while mobile power will goes zero soon so here as per the requirement load can be put on on mobile tower hence high power(some one needs to be more) high frequency higher frequency higher throughput (throughput is secondary issue) hence concluded


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