[Starlink] On FiWi

[David Lang]

any communications infrastructure that you mandate get built into new buildings 
is going to be obsolete long before the building is (especially radio equipment)

I am a big fan of using wire (or fiber) directly to equipment when you can. wifi 
is sexy and 'easy' to setup, but there is only so much airtime available, and 
your radio footprint where you produce intereference to other equipment is much 
larger than the usable footprint (let alone what your requirements are), so it 
is far more work to share reasonably. You also are sending a lot of power places 
where it's not useful, so you are wasting energy compared to having somethign 
hard-wired.

There are times when you need the mobility that radio gives you, and times where 
it's advantages outweigh the disadvantages, but please don't fall into the trap 
of thinking that wires are obsolete and should be discouraged, it's exactly the 
opposite, the more we can hard-wire, the better the mobile devices that can't be 
hard wired can perform.

David Lang

  On Tue, 14 Mar 2023, David Fernández via Starlink wrote:

> Hi Bob,
>
> If you want that FiWi infrastructure on buildings, I am afraid that
> you only get it (in the long term) with a law that makes it mandatory
> to make new buildings with that infrastructure for communications.
>
> In Spain, it should be added to this:
> https://avancedigital.mineco.gob.es/Infraestructuras/Paginas/Index.aspx
>
> Regards,
>
> David
>
>> Date: Mon, 13 Mar 2023 21:27:23 -0700
>> From: rjmcmahon <rjmcmahon at rjmcmahon.com>
>> To: Sebastian Moeller <moeller0 at gmx.de>
>> Cc: dan <dandenson at gmail.com>, Jeremy Austin <jeremy at aterlo.com>, Rpm
>> 	<rpm at lists.bufferbloat.net>, libreqos
>> 	<libreqos at lists.bufferbloat.net>, Dave Taht via Starlink
>> 	<starlink at lists.bufferbloat.net>, bloat <bloat at lists.bufferbloat.net>
>> Subject: [Starlink] On FiWi
>> Message-ID: <bc1cfdf998bb6bb246a632f0dc0fe3a8 at rjmcmahon.com>
>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>
>> 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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