Comment by lxgr
1 month ago
Both not true.
Both European PMR446 and the US FRS are limited to 0.5 W; GSM uses four times that. There are walkie-talkies with very small antennas too. The limiting factor is line-of-sight, in any case.
If you're fine with less than real-time audio, you can get much, much smaller and low power.
1) LTE frequencies are in the frequency intervals 600—900Mhz, or over the Ghz. Higher frequency means smaller antennas.
2) 5G cells are small and very dense, this means less power consumption.
3) LTE and 5G are based on CDMA, a technology that is way more efficient in term of bandwidth efficiency than the FM modulation used by a walkie talkie
> 5G cells are small and very dense
Not necessarily. In rural areas and using low frequencies, I believe they can even be larger than GSM.
> LTE and 5G are based on CDMA
No, the last CDMA based cell standards were 3G/UMTS and the Qualcomm equivalent (CDMA2000 or what it was). From then on, it’s all been OFDM.
> In rural areas and using low frequencies, I believe they can even be larger than GSM.
In Europe GSM is going to be dismantled. And techniques like beamforming and radio resource management reduce the power consumption for 5G base station and phones.
> No, the last CDMA based cell standards were 3G/UMTS and the Qualcomm equivalent (CDMA2000 or what it was). From then on, it’s all been OFDM.
Even if 5G is using more advanced modulations like OFDMA or NONA, the concept is the same if you compare the with FM used by walkie talkie: those are modulations way more effective in term of energy and information effiency than a traditional FM transmission