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Something here doesn’t make sense to me. The retired 3G spectrum will be used for 4G and 5G (per the FCC article) so the antennas could be reused as the carrie

Something here doesn’t make sense to me. The retired 3G spectrum will be used for 4G and 5G (per the FCC article) so the antennas could be reused as the carrier frequency will not change. For a concrete example, if you’re running 3G at 900 MHz, why would running 5G at 900 MHz require a different antenna? On that note, saying the antennas don’t go up to true 5G frequencies is a bit…misleading? Because while the frequency goes up, the wavelength goes down so the antenna should shrink.

rubylark 5y ago
That's fair. Unfortunately I don't know the specifics of the hardware involved, and I wasn't there long enough to get a good understanding. I hope someone with more knowledge or industry experience can chime in. All I know that the company I worked for sold a completely new antenna assembly that supported 5G and that our customers were moving to using those antennas. As far as the size, all of the units we sold have been approximately the same size for quite a while. E.g. all the chasses varied by maybe 6-10" max between the old assemblies and the new. The new ones were larger (maybe more room for power electronics?) I don't know if there was any effort on our part to support 5G transition without replacing our antennas. Edit: I believe we were pushing new hardware because the services wanted to utilize the high frequency band of FR2 24-56Gz [1] (what I meant by "true 5G") that our old antenna assemblies couldn't support. I assume they couldn't support it because they weren't optimized for those bands at a high enough fidelity for good data transmission. [1] https://en.wikipedia.org/wiki/5G#Frequency_range_2_(24%E2%80%9354_GHz) https://en.wikipedia.org/wiki/5G#Frequency_range_2_(24%E2%80...
- darksaints 5y ago
  The FR2 hardware requires phased array antennaes for beamforming capability. While it technically could be used without beamforming, it would be extremely inefficient and have even less range than their already limited range. And those MIMO phased array antennaes are crazy expensive...it's still a technology with several active patent encumbrances.
darksaints 5y ago
Antennaes can be reused, but radio units and baseband units cannot, and those are by far more expensive. For example, a C-band array of radio units and baseband unit can cost upwards of $80k, while the antennae are a few thousand at most.

rubylark 5y ago

That's fair. Unfortunately I don't know the specifics of the hardware involved, and I wasn't there long enough to get a good understanding. I hope someone with more knowledge or industry experience can chime in. All I know that the company I worked for sold a completely new antenna assembly that supported 5G and that our customers were moving to using those antennas. As far as the size, all of the units we sold have been approximately the same size for quite a while. E.g. all the chasses varied by maybe 6-10" max between the old assemblies and the new. The new ones were larger (maybe more room for power electronics?) I don't know if there was any effort on our part to support 5G transition without replacing our antennas. Edit: I believe we were pushing new hardware because the services wanted to utilize the high frequency band of FR2 24-56Gz [1] (what I meant by "true 5G") that our old antenna assemblies couldn't support. I assume they couldn't support it because they weren't optimized for those bands at a high enough fidelity for good data transmission. [1] https://en.wikipedia.org/wiki/5G#Frequency_range_2_(24%E2%80%9354_GHz) https://en.wikipedia.org/wiki/5G#Frequency_range_2_(24%E2%80...

darksaints 5y ago
The FR2 hardware requires phased array antennaes for beamforming capability. While it technically could be used without beamforming, it would be extremely inefficient and have even less range than their already limited range. And those MIMO phased array antennaes are crazy expensive...it's still a technology with several active patent encumbrances.

darksaints 5y ago

Antennaes can be reused, but radio units and baseband units cannot, and those are by far more expensive. For example, a C-band array of radio units and baseband unit can cost upwards of $80k, while the antennae are a few thousand at most.