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Laser-delivered Netflix and backyard data centers!
The conversation continues with optical communications guru, Stefan Loeffler. In this episode, Daniel Bogdanoff and Mike Hoffman discuss optical infrastructure today and what the future holds for optics.
Audio Version:
Discussion Overview:
Optical Communication Infrastructure 00:30
Optics = Laser-driven Netflix delivery system
Line-side is the network that transports the signals from the supplier to the consumer
Client-side is the equipment that is either a consumer or business, accepting the data from the network provider.
Yellow cables in your wall indicate presence of fiber 1:40
Technically, optics is communication using radiation! But it is invisible to us as humans. 2:20
Getting fiber all the way to the antenna is one of the major new technologies 2:30
But this requires you to have power at the antenna 2:45
However, typically there is a “hotel” or base station at the bottom of the antenna where the power is and where fiber traditionally connects, instead of up to the antenna
Really new or experimental antennas have fiber running all the way up the pole 3:28
Network topologies- star, ring, and mesh 3:42
Base stations are usually organized in star-form, or a star network pattern. A star network starts at a single base station and distributes data to multiple cells
Rings (ring networks) are popular in metro infrastructure because you can encircle an entire area 4:20
Optical rings are like traffic circles for data.
Is ring topology the most efficient or flexible? 6:20
An advantage of ring and mesh topologies is built-in resilience
Mesh topologies have more bandwidth but require more fiber optic cable 7:10
How often is the topology or format of a network defined by geography or regulations? 8:30
How consumers get fiber 9:20
Business or academic campuses typically utilize mesh networks on the client side, subscribing to a fiber provider
Fiber itself or a certain bandwidth using that fiber can be leased
If you’re a business, like a financial institution, and latency or bandwidth is critical, leasing fiber is necessary so you have control over the network 9:45
What’s the limiting factor of optical?
What are the limitations of the hardware that’s sending/receiving optical signals? 11:08
Whatever we do in fiber, at some point, it is electrical 11:27
There will be a tipping point where quantum computing and photon-computing (optical computing) comes into play 11:40
Will optical links ever compete with silicon? Maybe we will have optical computers in the future 12:02
The limiting factor is the power supply 12:40
What’s costing all this energy? 12:58
The more data (bits and bytes) we push through, the more energy in the form of optical photons or electrons we are pushing through. We also must use a DSP for decoding which costs energy
One of the first 100 Gb links between two clients was between the New York Stock Exchange and the London Stock Exchange 14:00
The evolution of the transmission of data 14:45
Will we ever have open-air optical communication? 15:50
RF technology uses open-air communication today, but it is easy to disturb
The basic material fiber is made of is cheap (silica, quartz), and can be found on any beach 16:08
Whereas copper has a supply problem and, thus, continues to increase in price
Other uses for optical 16:33
Crystal fiber and multicore fiber is being experimented with to increase the usable bandwidth
Optical, as waveguides, can be built into small wafer sections 17:15
Optics is used in electrical chips when photons are easier to push through than electrons
Cross-talk can happen with optical, too 18:13
Testing is done with optical probing, which works because of optical coupling
Optical-to-electrical converter solution
Optical satellite communication 19:48
Hollow-fiber could be used in a vacuum, such as space
The refractive index of the fiber’s core is higher than the cladding, which guides the optical signal through 21:05
A hollow-fiber would be like a mini mirror tube
Optical data transmission 21:25
Higher carrier frequencies means you can modulate faster, but there’s more loss and dispersion
This means optical communication could be harder in open-air vs. in traditional fiber 22:45
70-80% headroom is typical
The congested part of a network drives the change in technology. 24:25
Mega data centers vs. distributed data centers
Cooling and power is important so big data centers are being built by Google, Facebook, Netflix in places where cheap, cool water is abundant 24:30
Distributed data centers are becoming more popular than mega-data centers 24:55
All images on Facebook have “cdn” in the URL because the image is hosted on a content distribution network, or cloud
Data centers are described by megawatts (MW) of power, not size or amount of data processed 26:20
Internal data center traffic takes up about 75% of the traffic 27:47
Distributed networks utilize a mesh network and require communication between networks
Telecom starts using faster fiber when about 20% of the fiber is used 28:55
This 20% utilization is also common in CAN busses because of safety-critical data communication
Uptime guarantees require the Telecom industry to keep this number at 20%
Keysight optical resources and solutions 31:00
Predictions 31:45
Also, check out our previous conversations with Stefan about Optical Communication 101 and Optical Communication Techniques.
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