[Starlink] On FiWi

[Steve Stroh]

Bob:

Three technologies have come together in the past few years to make
(close to what you're proposing) a reality.

1. Airvine just announced a product that they posit is indoor fiber
backhaul... without the fiber. They use 60 GHz mesh to achieve up to 2
Gbps.

2. Wi-Fi 6E makes use of not just the 5 GHz band, but the 6 GHz band
to be able to use more than 1.5 GHz of spectrum for Wi-Fi. That allows
lots of demanding Wi-Fi users to stay out of each other's way,
especially if you shrink the range of the AP to basically just an
apartment.

3. CBRS allows private use of 3.5 GHz spectrum by individuals,
businesses and venues.

Run fiber to where it makes sense - such as down hallways to a fiber /
60 GHz transition point such as Airvine offers. Finish the last
hundred feet (into the apartment) with 6 GHz.

In commercial buildings such as apartments, smoke detectors are
generally wired to power. Install a combo smoke detector / Wi-Fi AP /
6 GHz end point.

Then the venue, such as an apartment building, can easily offer
Broadband Internet service, on a par with Comcast.

CBRS allows private phone service in buildings for internal use -
tightly managed, Internet of things that prefer cellular. Eventually
this will evolve to the point where if a building is "wired" with
CBRS, the cellcos will pay the building to act as a neutral carrier
for them, saving them the expense of having to "light up the building"
themselves, either internally with pico / microcells, or painting it
externally.

There's money to be made deploying these technologies, especially for
third parties to deploy and manage these systems. Venue owners
desperately want "only one neck to wring" when things go wrong. They
hate having to figure out if something is a Comcast problem, a telco
problem, a Wi-Fi problem, etc.

Steve Stroh




On Mon, Mar 13, 2023 at 9:27 PM rjmcmahon via Starlink
<starlink at lists.bufferbloat.net> wrote:
>
> To change the topic - curious to thoughts on FiWi.
>
> Imagine a world with no copper cable called FiWi (Fiber,VCSEL/CMOS
> Radios, Antennas) and which is point to point inside a building
> connected to virtualized APs fiber hops away. Each remote radio head
> (RRH) would consume 5W or less and only when active. No need for things
> like zigbee, or meshes, or threads as each radio has a fiber connection
> via Corning's actifi or equivalent. Eliminate the AP/Client power
> imbalance. Plastics also can house smoke or other sensors.
>
> Some reminders from Paul Baran in 1994 (and from David Reed)
>
> o) Shorter range rf transceivers connected to fiber could produce a
> significant improvement - - tremendous improvement, really.
> o) a mixture of terrestrial links plus shorter range radio links has the
> effect of increasing by orders and orders of magnitude the amount of
> frequency spectrum that can be made available.
> o) By authorizing high power to support a few users to reach slightly
> longer distances we deprive ourselves of the opportunity to serve the
> many.
> o) Communications systems can be built with 10dB ratio
> o) Digital transmission when properly done allows a small signal to
> noise ratio to be used successfully to retrieve an error free signal.
> o) And, never forget, any transmission capacity not used is wasted
> forever, like water over the dam. Not using such techniques represent
> lost opportunity.
>
> And on waveguides:
>
> o) "Fiber transmission loss is ~0.5dB/km for single mode fiber,
> independent of modulation"
> o) “Copper cables and PCB traces are very frequency dependent.  At
> 100Gb/s, the loss is in dB/inch."
> o) "Free space: the power density of the radio waves decreases with the
> square of distance from the transmitting antenna due to spreading of the
> electromagnetic energy in space according to the inverse square law"
>
> The sunk costs & long-lived parts of FiWi are the fiber and the CPE
> plastics & antennas, as CMOS radios+ & fiber/laser, e.g. VCSEL could be
> pluggable, allowing for field upgrades. Just like swapping out SFP in a
> data center.
>
> This approach basically drives out WiFi latency by eliminating shared
> queues and increases capacity by orders of magnitude by leveraging 10dB
> in the spatial dimension, all of which is achieved by a physical design.
> Just place enough RRHs as needed (similar to a pop up sprinkler in an
> irrigation system.)
>
> Start and build this for an MDU and the value of the building improves.
> Sadly, there seems no way to capture that value other than over long
> term use. It doesn't matter whether the leader of the HOA tries to
> capture the value or if a last mile provider tries. The value remains
> sunk or hidden with nothing on the asset side of the balance sheet.
> We've got a CAPEX spend that has to be made up via "OPEX returns" over
> years.
>
> But the asset is there.
>
> How do we do this?
>
> Bob
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-- 
Steve Stroh N8GNJ (he / him / his)
Editor
Zero Retries Newsletter - https://zeroretries.substack.com