Has anyone ever tried using Radiating Coaxial Cable to provide 2.4ghz coverage indoors - in corridors such as in hotels, tunnels etc?
I have just found out about this kind of cable, which is mainly used along train lines and tunnels. It seems like it would be a good solution for the hotel industry, lowering the amount of APs required indoors.
Reading about the cable, it seems that you can order it with varying amounts of apertures, so for instance on long runs, you increase the number of apertures as the length of the cable increases and after joins to counteract signal loss.
I can’t find the link for the newsletter that I saw this in, but it was talking about the Channel Tunnel section 2 and how they provided the comms for it.
I have used such cable in the ‘golden age’ of paging, but it was on much lower frequencies, the buildings (hospitals) did have such a cable run up to the top floor. And these where TX only setups.
The issue I see is that VHF/UHF has much better wall penetration, greater transmit power is used, apertures are quite big, and, most important, the cable has less losses for those frequencies (think of some 6-10 dB/100m).
On 2.4 GHz on the other hand the losses of the cable become significant, a low loss cable like the LMR400 having some 25dB/100m at 2.4 GHz.
So I am not sure if such a setup, powered by a low power AP (less than 1W/30dBm) would be enough to ensure proper coverage over longer runs, so probably some special equipment may be needed (costs, costs, costs…).
Even considered ideal, these apertures will split the transmit power. reducing the apparent power by 3dB for each doubling of the number of apertures.
On the other hand, the gain characteristics of an aperture are not spectacular (i would say around at most 2-3dBi gain), they are not omnidirectional, and adding the cable losses on the receive side will bring received signals further down (LNAs?).
I am really curious to here about real life tests on this topic.