45 ms·
The problem with this technology is that at a 3.5dB/KM loss, it's only really good for about 10KM. At such short distances, the latency difference would only be
by hhw 14y ago
The problem with this technology is that at a 3.5dB/KM loss, it's only really good for about 10KM. At such short distances, the latency difference would only be about 0.0167ms. Given all the other latencies involved between two end-to-end hosts, that's hardly worth laying new fiber for. Unless they manage to reduce the loss to within a reasonably small multiple of more traditional fiber, this new technology isn't going to have much adoption.
At only 37 channels, compared to the 80 that more traditional fiber can carry using DWDM, it also carries less than half the capacity. And that's assuming that it's capable of the same bandwidth capacity per channel; the article states 40Gbps per channel, whereas you can already go as high as 100Gbps over a single wave using DWDM, which means it may only be able to carry 18.5% as much.
- aortega 14y agoAlso, I don't see this technology being compatible with erbium-doped fiber amplifiers. See, even the best glass fiber is good only up to 80 km, that's not enough, but by placing a piece of erbium-doped fiber it acts as a laser-amplifier and the fiber lenght can go up to 4000 km. Now that's useful. IMHO the EDFA is the technology that really enabled high-speed internet.
- alokv28 14y agoWhy couldn't these fibres work with EDFAs? As long as the fibres are designed to operate in the C-band (~1.55 micron wavelength), there shouldn't be a problem running them through an amplifier.
- aortega 14y agoNo physicist here but I think there may be losses in the interface air/glass. Also, air contains water and other elements that may present too much attenuation at 1550 nm. I suspect the different lambda is one of the reasons of the limited bandwidth of the hollow fiber. I should try to RTFA.
- timthorn 14y agoIt's overcoming the losses in the interfacing that's the innovation here - holey fibres have been around for a while. Note that it's the same research lab doing this work as invented the EDFA in the first place.
- alokv28 14y agoIs the capacity limit of 37 channels a fundamental limit due to the design, or a consequence of fabricating these fibres in a university lab? I'm honestly asking since I can't access the full text at home, but I suspect it's the latter reason.
- timthorn 14y agoThis isn't a limit of the lab. They've a full fibre drawing tower and develop new techniques for industrialisation.