25G is a per channel/Lane protocol which is being driven by InfiniBand (EDR), Ethernet (100G 4x25) and Fibre Channel QSFP28. There is quite a bit of development work being done today across all 3 standards. It is anyone's guess what the adoption rate and cost will look like. This development willl likely fuel the need for many new intermediaries to allow 25G switch equipment to efficiently interop with existing servers and storage. Additionally, there are still many signal integrity challenges related to development and deployment of the 25G datacom architecture.
That shouldn't be a problem either. WiFi 802.11n goes up to 600 Mb/s in the 5 GHz band (although ours tops out at 270 Mb/s), which should be enough even for 4K with H.264 compression, and certainly enough for 4K with H.265 compression (which theoretically won't require much more bit rate than HD using H.262 compression, say on the order of 25 Mb/s for 60p). And now WiFi 802.11ad is moving up to the 60 GHz band, for up to 7 Gb/s capacity.
I haven't heard of 25Gig Ethernet, so I asume the 25Gig is for Inifiband, which is used with some storage switches (Infiniband also has 2.5Gig).
As mentioned, the other place you see 25G is 4x25Gig (100Gig, either 4 separate fibers or four mulitplexed frequencies), but I don't think that would show up in the chart as 25G.
The reason you don't see too much of 100Gig at one frequency (called coherent 100Gig), is cost. But, as with all things in the electronics industry, costs go down in time as they integrate more and can produce in volume.
I agree, 4k TV will happen in 15 years...but who cares?...it is a very increamental improvement that will take very long time to sell, spatial resolutionis limuted by your eyes afterall...we need to get a sense of smell and touch in the living room, that would be something interesting to write about
We are not talking about long lines, that is a whole different market. The connections between ethernet switches in a DC do not use FDM or other expensive, physically large devices. Hence the long stall at 2.5Gbps since that was until recently the practical limit on how many bits a semiconductor could modulate or demodulate on one beam. Now Intel and partners are promising 25 Gbps devices.
Actually, multiple frequencies/colors would be just fine too, if you could meet the cost and packaging limits of an ethernet socket.
Sorry @krisi, but I humbly disagree. 3D isn't dead either, but that is outside of the scope of this discussion. So you reckon we won't be at 4K in the next decade and a half (assuming that is how long it takes you to get to your next two TV's)?