[Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Bob McMahon]

[-- Attachment #1.1: Type: text/plain, Size: 2322 bytes --]

Hi All,

There is a historic building that has 5 floors and no fire alerting
associated with the rear fire escape ladder. I'm considering installing
nest protects in each unit near the rear egress to alert of the fire escape
is compromised by fire. My guess is floor to floor wireless communications
may not work too well.

I'm thinking about cleaning up the communications runs in the rear of the
building. The cable company did a shoddy job of hanging cable for TV
services in the 80s. It seems a good time to add communications conduit and
run more modern cabling.

As part of this, I'm considering running LMR 600 cabling on the exterior
brick wall to act as 2.4Ghz communications wave guides. I was thinking make
a loop but break the loop at each floor with a 2.4Ghz wilkinson power
divider
<https://www.pasternack.com/2-way-n-wilkinson-power-divider-690-mhz-2.7-ghz-10-watts-pe2092-p.aspx?utm_source=google&utm_medium=cpc&adpos=&scid=scplpP74039&sc_intid=P74039&gclid=CjwKCAjwqIiFBhAHEiwANg9szk1JG2oJufz2G2Hylc6oOgOSl-tBN5O39Kn2T1pHV4g8_r8AnkFA7xoCFhUQAvD_BwE>.
Then bore a hole into each unit and install a 2.4Ghz patch antenna
<https://www.l-com.com/wireless-antenna-24-ghz-8-dbi-round-patch-antennas>
pm each rear interior wall. Each unit would then install a Nest protect on
the ceiling from the patch antenna. The ring or loop topology I think gives
a bit of redundancy.

Thoughts on if this would achieve the goals of supporting nest protect
communications for such a building?

Bob

-- 
This electronic communication and the information and any files transmitted 
with it, or attached to it, are confidential and are intended solely for 
the use of the individual or entity to whom it is addressed and may contain 
information that is confidential, legally privileged, protected by privacy 
laws, or otherwise restricted from disclosure to anyone else. If you are 
not the intended recipient or the person responsible for delivering the 
e-mail to the intended recipient, you are hereby notified that any use, 
copying, distributing, dissemination, forwarding, printing, or copying of 
this e-mail is strictly prohibited. If you received this e-mail in error, 
please return the e-mail to the sender, delete it from your computer, and 
destroy any printed copy of it.

[-- Attachment #1.2: Type: text/html, Size: 2517 bytes --]

[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4206 bytes --]

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Aaron Wood]

[-- Attachment #1: Type: text/plain, Size: 3248 bytes --]

I've seen similar techniques used for creating isolated wifi device test
labs.  Each device is locked into a small RF isolation box, with bulkhead
fittings for power and coax.  A 2.4GHz (or 5GHz antenna, or both) is placed
inside the box, and then the boxes are wired to one another in any topology
that is desired.  splitters of course dropping the signal in the coax, but
really not much more than in the air.

You might want to do some test setups with cheap isolation boxes of wire,
to see how much signal you'll get through your antennas and coax.

On Mon, May 17, 2021 at 11:09 AM Bob McMahon via Make-wifi-fast <
make-wifi-fast@lists.bufferbloat.net> wrote:

> Hi All,
>
> There is a historic building that has 5 floors and no fire alerting
> associated with the rear fire escape ladder. I'm considering installing
> nest protects in each unit near the rear egress to alert of the fire escape
> is compromised by fire. My guess is floor to floor wireless communications
> may not work too well.
>
> I'm thinking about cleaning up the communications runs in the rear of the
> building. The cable company did a shoddy job of hanging cable for TV
> services in the 80s. It seems a good time to add communications conduit and
> run more modern cabling.
>
> As part of this, I'm considering running LMR 600 cabling on the exterior
> brick wall to act as 2.4Ghz communications wave guides. I was thinking make
> a loop but break the loop at each floor with a 2.4Ghz wilkinson power
> divider
> <https://www.pasternack.com/2-way-n-wilkinson-power-divider-690-mhz-2.7-ghz-10-watts-pe2092-p.aspx?utm_source=google&utm_medium=cpc&adpos=&scid=scplpP74039&sc_intid=P74039&gclid=CjwKCAjwqIiFBhAHEiwANg9szk1JG2oJufz2G2Hylc6oOgOSl-tBN5O39Kn2T1pHV4g8_r8AnkFA7xoCFhUQAvD_BwE>.
> Then bore a hole into each unit and install a 2.4Ghz patch antenna
> <https://www.l-com.com/wireless-antenna-24-ghz-8-dbi-round-patch-antennas>
> pm each rear interior wall. Each unit would then install a Nest protect on
> the ceiling from the patch antenna. The ring or loop topology I think gives
> a bit of redundancy.
>
> Thoughts on if this would achieve the goals of supporting nest protect
> communications for such a building?
>
> Bob
>
>
>
>
> This electronic communication and the information and any files
> transmitted with it, or attached to it, are confidential and are intended
> solely for the use of the individual or entity to whom it is addressed and
> may contain information that is confidential, legally privileged, protected
> by privacy laws, or otherwise restricted from disclosure to anyone else. If
> you are not the intended recipient or the person responsible for delivering
> the e-mail to the intended recipient, you are hereby notified that any use,
> copying, distributing, dissemination, forwarding, printing, or copying of
> this e-mail is strictly prohibited. If you received this e-mail in error,
> please return the e-mail to the sender, delete it from your computer, and
> destroy any printed copy of it.
> _______________________________________________
> Make-wifi-fast mailing list
> Make-wifi-fast@lists.bufferbloat.net
> https://lists.bufferbloat.net/listinfo/make-wifi-fast

[-- Attachment #2: Type: text/html, Size: 3943 bytes --]

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Bob McMahon]

[-- Attachment #1.1: Type: text/plain, Size: 4625 bytes --]

yeah, thanks for this. I have access to such RF enclosures at work. I'll
likely build it out first here in CA before shipping. I purchased a HackRF
one as well for on premise measurements.

I was also hoping to get API access into the fire alarms for cloud based
remote monitoring, basic things like batteries need replacement or an
unexpected device removal from the mesh. I haven't found a way to do that
yet.

Bob

On Tue, May 18, 2021 at 9:02 AM Aaron Wood <woody77@gmail.com> wrote:

> I've seen similar techniques used for creating isolated wifi device test
> labs.  Each device is locked into a small RF isolation box, with bulkhead
> fittings for power and coax.  A 2.4GHz (or 5GHz antenna, or both) is placed
> inside the box, and then the boxes are wired to one another in any topology
> that is desired.  splitters of course dropping the signal in the coax, but
> really not much more than in the air.
>
> You might want to do some test setups with cheap isolation boxes of wire,
> to see how much signal you'll get through your antennas and coax.
>
> On Mon, May 17, 2021 at 11:09 AM Bob McMahon via Make-wifi-fast <
> make-wifi-fast@lists.bufferbloat.net> wrote:
>
>> Hi All,
>>
>> There is a historic building that has 5 floors and no fire alerting
>> associated with the rear fire escape ladder. I'm considering installing
>> nest protects in each unit near the rear egress to alert of the fire escape
>> is compromised by fire. My guess is floor to floor wireless communications
>> may not work too well.
>>
>> I'm thinking about cleaning up the communications runs in the rear of the
>> building. The cable company did a shoddy job of hanging cable for TV
>> services in the 80s. It seems a good time to add communications conduit and
>> run more modern cabling.
>>
>> As part of this, I'm considering running LMR 600 cabling on the exterior
>> brick wall to act as 2.4Ghz communications wave guides. I was thinking make
>> a loop but break the loop at each floor with a 2.4Ghz wilkinson power
>> divider
>> <https://www.pasternack.com/2-way-n-wilkinson-power-divider-690-mhz-2.7-ghz-10-watts-pe2092-p.aspx?utm_source=google&utm_medium=cpc&adpos=&scid=scplpP74039&sc_intid=P74039&gclid=CjwKCAjwqIiFBhAHEiwANg9szk1JG2oJufz2G2Hylc6oOgOSl-tBN5O39Kn2T1pHV4g8_r8AnkFA7xoCFhUQAvD_BwE>.
>> Then bore a hole into each unit and install a 2.4Ghz patch antenna
>> <https://www.l-com.com/wireless-antenna-24-ghz-8-dbi-round-patch-antennas>
>> pm each rear interior wall. Each unit would then install a Nest protect on
>> the ceiling from the patch antenna. The ring or loop topology I think gives
>> a bit of redundancy.
>>
>> Thoughts on if this would achieve the goals of supporting nest protect
>> communications for such a building?
>>
>> Bob
>>
>>
>>
>>
>> This electronic communication and the information and any files
>> transmitted with it, or attached to it, are confidential and are intended
>> solely for the use of the individual or entity to whom it is addressed and
>> may contain information that is confidential, legally privileged, protected
>> by privacy laws, or otherwise restricted from disclosure to anyone else. If
>> you are not the intended recipient or the person responsible for delivering
>> the e-mail to the intended recipient, you are hereby notified that any use,
>> copying, distributing, dissemination, forwarding, printing, or copying of
>> this e-mail is strictly prohibited. If you received this e-mail in error,
>> please return the e-mail to the sender, delete it from your computer, and
>> destroy any printed copy of it.
>> _______________________________________________
>> Make-wifi-fast mailing list
>> Make-wifi-fast@lists.bufferbloat.net
>> https://lists.bufferbloat.net/listinfo/make-wifi-fast
>
>

-- 
This electronic communication and the information and any files transmitted 
with it, or attached to it, are confidential and are intended solely for 
the use of the individual or entity to whom it is addressed and may contain 
information that is confidential, legally privileged, protected by privacy 
laws, or otherwise restricted from disclosure to anyone else. If you are 
not the intended recipient or the person responsible for delivering the 
e-mail to the intended recipient, you are hereby notified that any use, 
copying, distributing, dissemination, forwarding, printing, or copying of 
this e-mail is strictly prohibited. If you received this e-mail in error, 
please return the e-mail to the sender, delete it from your computer, and 
destroy any printed copy of it.

[-- Attachment #1.2: Type: text/html, Size: 5562 bytes --]

[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4206 bytes --]

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Jannie Hanekom]

[-- Attachment #1: Type: text/plain, Size: 3550 bytes --]

(This contribution is probably drifting a bit off topic significantly.  Apologies for that.)

 

I have to acknowledge: As someone who lacks the expert-level technical knowledge most contributors on this list have, what I say doesn’t carry much weight.  I’m here mostly because I enjoy the content.  But, I have a few concerns I’d like to raise, mostly related to safety… 

*	Fire is a serious matter.  As well-intentioned as it may be, using a prosumer-grade fire alerting product in an commercial or high-density residential setting may not be appropriate.  It’s one thing for the occupant of a residential unit to install their own device.  It’s something quite different to use it as part of the services a building offers to its tenants.
*	Creating a building-sized 2.4Ghz antenna sounds like an interesting experiment, but wouldn’t the noise-floor being prohibitively high?
*	Supporting such an environment on your day off would be a challenge.  That’s important considering the functionality the solution has to deliver.
*	Something I’ve learnt about loops and other redundant systems is that their reliability benefits are only as good as the processes that monitor them for failures.  Passive cable is really hard to monitor.

 

Then, as someone occasionally involved in deployments of commercial off-the-shelf solutions through my $dayjob, I’d argue that the “traditional” route of installing a bunch of CAT6 and one or more APs per unit (if the solution *had* to be Nest Protects) would likely score higher on availability, performance and supportability.  (If you’re talking Zigbee not WiFi then I’m even further out of my depth, but I’d argue the same points still apply.)

 

Jannie

 

 

Van: Make-wifi-fast <make-wifi-fast-bounces@lists.bufferbloat.net> Namens Bob McMahon via Make-wifi-fast
Gestuur: Maandag 17 Mei 2021 20:09
Aan: Make-Wifi-fast <make-wifi-fast@lists.bufferbloat.net>
Onderwerp: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

 

Hi All,

There is a historic building that has 5 floors and no fire alerting associated with the rear fire escape ladder. I'm considering installing nest protects in each unit near the rear egress to alert of the fire escape is compromised by fire. My guess is floor to floor wireless communications may not work too well.

 

I'm thinking about cleaning up the communications runs in the rear of the building. The cable company did a shoddy job of hanging cable for TV services in the 80s. It seems a good time to add communications conduit and run more modern cabling.

As part of this, I'm considering running LMR 600 cabling on the exterior brick wall to act as 2.4Ghz communications wave guides. I was thinking make a loop but break the loop at each floor with a 2.4Ghz wilkinson power divider <https://www.pasternack.com/2-way-n-wilkinson-power-divider-690-mhz-2.7-ghz-10-watts-pe2092-p.aspx?utm_source=google&utm_medium=cpc&adpos=&scid=scplpP74039&sc_intid=P74039&gclid=CjwKCAjwqIiFBhAHEiwANg9szk1JG2oJufz2G2Hylc6oOgOSl-tBN5O39Kn2T1pHV4g8_r8AnkFA7xoCFhUQAvD_BwE> . Then bore a hole into each unit and install a 2.4Ghz patch antenna <https://www.l-com.com/wireless-antenna-24-ghz-8-dbi-round-patch-antennas>  pm each rear interior wall. Each unit would then install a Nest protect on the ceiling from the patch antenna. The ring or loop topology I think gives a bit of redundancy.

Thoughts on if this would achieve the goals of supporting nest protect communications for such a building?

Bob


[-- Attachment #2: Type: text/html, Size: 9283 bytes --]

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Bob McMahon]

[-- Attachment #1.1: Type: text/plain, Size: 6819 bytes --]

Yeah, this whole thread should start with a disclaimer of *no
responsibility nor liability for any opinions expressed*. I'm not a lawyer
and not sure the best way to write such disclaimers, but I fully understand
the seriousness of fire alerting and that a WiFi discussion group is not a
place to go for anything more than discussion and opinions.

As some background, and way off topic for sure, I called the local fire
department and they said there is no current requirement for a floor to
floor alerting system on older buildings. I then asked if they would have
their kids live in such a building and the answer was, "I can't answer
that." And any other following question I had was "google it" because "we,
the fire department, don't want to take liability for something we can't
affect." I also spoke with a person who runs a fire consulting business and
he said not having alerting on the egress escapes was not safe,
particularly for higher level floors.

I found that a professionally installed alerting system would cost $60K to
$100K. This is just alerting, not suppression. Needless to say, the HOA
doesn't have such funds. Each unit has a few chirp alarms which seems to be
sufficient for the fire department w/respect to them not hindering "real
estate transactions" because real estate business is serious too. The fire
dept would get crushed politically if they imposed $100K bills on people
trying to meet their rents. Note: they will get involved when a building
has major improvements but, until then, they're basically trying to avoid
any kind of liability and they only get involved after the building
department asks them too. In other words, the building is not going to be
honestly evaluated for fire safety by anyone in a position of expertise and
responsibility until it undergoes a major remodel - which will force most
people out. I find reality usually is what it is vs what I'd like it to be.

NO RESPONSIBILITY AND NO LIABILITY applies to all from my perspective.

And please don't think I'd trust anyone here for such a system that affects
human life. Not meaning to be disparaging to anyone.

Bob



On Tue, May 18, 2021 at 2:57 PM Jannie Hanekom <jannie@hanekom.net> wrote:

> (This contribution is probably drifting a bit off topic significantly.
> Apologies for that.)
>
>
>
> I have to acknowledge: As someone who lacks the expert-level technical
> knowledge most contributors on this list have, what I say doesn’t carry
> much weight.  I’m here mostly because I enjoy the content.  But, I have a
> few concerns I’d like to raise, mostly related to safety…
>
>    - Fire is a serious matter.  As well-intentioned as it may be, using a
>    prosumer-grade fire alerting product in an commercial or high-density
>    residential setting may not be appropriate.  It’s one thing for the
>    occupant of a residential unit to install their own device.  It’s something
>    quite different to use it as part of the services a building offers to its
>    tenants.
>    - Creating a building-sized 2.4Ghz antenna sounds like an interesting
>    experiment, but wouldn’t the noise-floor being prohibitively high?
>    - Supporting such an environment on your day off would be a
>    challenge.  That’s important considering the functionality the solution has
>    to deliver.
>    - Something I’ve learnt about loops and other redundant systems is
>    that their reliability benefits are only as good as the processes that
>    monitor them for failures.  Passive cable is really hard to monitor.
>
>
>
> Then, as someone occasionally involved in deployments of commercial
> off-the-shelf solutions through my $dayjob, I’d argue that the
> “traditional” route of installing a bunch of CAT6 and one or more APs per
> unit (if the solution **had** to be Nest Protects) would likely score
> higher on availability, performance and supportability.  (If you’re talking
> Zigbee not WiFi then I’m even further out of my depth, but I’d argue the
> same points still apply.)
>
>
>
> Jannie
>
>
>
>
>
> *Van:* Make-wifi-fast <make-wifi-fast-bounces@lists.bufferbloat.net> *Namens
> *Bob McMahon via Make-wifi-fast
> *Gestuur:* Maandag 17 Mei 2021 20:09
> *Aan:* Make-Wifi-fast <make-wifi-fast@lists.bufferbloat.net>
> *Onderwerp:* [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects
>
>
>
> Hi All,
>
> There is a historic building that has 5 floors and no fire alerting
> associated with the rear fire escape ladder. I'm considering installing
> nest protects in each unit near the rear egress to alert of the fire escape
> is compromised by fire. My guess is floor to floor wireless communications
> may not work too well.
>
>
>
> I'm thinking about cleaning up the communications runs in the rear of the
> building. The cable company did a shoddy job of hanging cable for TV
> services in the 80s. It seems a good time to add communications conduit and
> run more modern cabling.
>
> As part of this, I'm considering running LMR 600 cabling on the exterior
> brick wall to act as 2.4Ghz communications wave guides. I was thinking make
> a loop but break the loop at each floor with a 2.4Ghz wilkinson power
> divider
> <https://www.pasternack.com/2-way-n-wilkinson-power-divider-690-mhz-2.7-ghz-10-watts-pe2092-p.aspx?utm_source=google&utm_medium=cpc&adpos=&scid=scplpP74039&sc_intid=P74039&gclid=CjwKCAjwqIiFBhAHEiwANg9szk1JG2oJufz2G2Hylc6oOgOSl-tBN5O39Kn2T1pHV4g8_r8AnkFA7xoCFhUQAvD_BwE>.
> Then bore a hole into each unit and install a 2.4Ghz patch antenna
> <https://www.l-com.com/wireless-antenna-24-ghz-8-dbi-round-patch-antennas>
> pm each rear interior wall. Each unit would then install a Nest protect on
> the ceiling from the patch antenna. The ring or loop topology I think gives
> a bit of redundancy.
>
> Thoughts on if this would achieve the goals of supporting nest protect
> communications for such a building?
>
> Bob
>

-- 
This electronic communication and the information and any files transmitted 
with it, or attached to it, are confidential and are intended solely for 
the use of the individual or entity to whom it is addressed and may contain 
information that is confidential, legally privileged, protected by privacy 
laws, or otherwise restricted from disclosure to anyone else. If you are 
not the intended recipient or the person responsible for delivering the 
e-mail to the intended recipient, you are hereby notified that any use, 
copying, distributing, dissemination, forwarding, printing, or copying of 
this e-mail is strictly prohibited. If you received this e-mail in error, 
please return the e-mail to the sender, delete it from your computer, and 
destroy any printed copy of it.

[-- Attachment #1.2: Type: text/html, Size: 8909 bytes --]

[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4206 bytes --]

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Bob McMahon]

[-- Attachment #1.1: Type: text/plain, Size: 8018 bytes --]

To the technical points,

o) Don't need to monitor the passive cables, they're just acting as wave
guides. I need to monitor they're doing their purpose, provide for the
devices and their ability to reliably communicate with one another. If that
fails, fallback to where things are as today, chirp alarms though add
amazon guard. Also, call somebody and fix the things.
o) Cat 6 and APs require power and WiFi APs really aren't as robust as
people think. I wouldn't connect life support to one. Nor life support to a
cable company that ran cables in a shoddy manner in the 80s that are still
there today.
o) The noise floor is something that needs to be addressed - I assumed
Google would have done some of that before selling them to consumers. Trust
but verify comes to mind.
o) An RF plan could help though a plan with devices and redundancy that
actively measure SINR and alerts seems best. Samples in time don't always
predict.

Bob

On Tue, May 18, 2021 at 4:32 PM Bob McMahon <bob.mcmahon@broadcom.com>
wrote:

> Yeah, this whole thread should start with a disclaimer of *no
> responsibility nor liability for any opinions expressed*. I'm not a
> lawyer and not sure the best way to write such disclaimers, but I fully
> understand the seriousness of fire alerting and that a WiFi discussion
> group is not a place to go for anything more than discussion and opinions.
>
> As some background, and way off topic for sure, I called the local fire
> department and they said there is no current requirement for a floor to
> floor alerting system on older buildings. I then asked if they would have
> their kids live in such a building and the answer was, "I can't answer
> that." And any other following question I had was "google it" because "we,
> the fire department, don't want to take liability for something we can't
> affect." I also spoke with a person who runs a fire consulting business and
> he said not having alerting on the egress escapes was not safe,
> particularly for higher level floors.
>
> I found that a professionally installed alerting system would cost $60K to
> $100K. This is just alerting, not suppression. Needless to say, the HOA
> doesn't have such funds. Each unit has a few chirp alarms which seems to be
> sufficient for the fire department w/respect to them not hindering "real
> estate transactions" because real estate business is serious too. The fire
> dept would get crushed politically if they imposed $100K bills on people
> trying to meet their rents. Note: they will get involved when a building
> has major improvements but, until then, they're basically trying to avoid
> any kind of liability and they only get involved after the building
> department asks them too. In other words, the building is not going to be
> honestly evaluated for fire safety by anyone in a position of expertise and
> responsibility until it undergoes a major remodel - which will force most
> people out. I find reality usually is what it is vs what I'd like it to be.
>
> NO RESPONSIBILITY AND NO LIABILITY applies to all from my perspective.
>
> And please don't think I'd trust anyone here for such a system that
> affects human life. Not meaning to be disparaging to anyone.
>
> Bob
>
>
>
> On Tue, May 18, 2021 at 2:57 PM Jannie Hanekom <jannie@hanekom.net> wrote:
>
>> (This contribution is probably drifting a bit off topic significantly.
>> Apologies for that.)
>>
>>
>>
>> I have to acknowledge: As someone who lacks the expert-level technical
>> knowledge most contributors on this list have, what I say doesn’t carry
>> much weight.  I’m here mostly because I enjoy the content.  But, I have a
>> few concerns I’d like to raise, mostly related to safety…
>>
>>    - Fire is a serious matter.  As well-intentioned as it may be, using
>>    a prosumer-grade fire alerting product in an commercial or high-density
>>    residential setting may not be appropriate.  It’s one thing for the
>>    occupant of a residential unit to install their own device.  It’s something
>>    quite different to use it as part of the services a building offers to its
>>    tenants.
>>    - Creating a building-sized 2.4Ghz antenna sounds like an interesting
>>    experiment, but wouldn’t the noise-floor being prohibitively high?
>>    - Supporting such an environment on your day off would be a
>>    challenge.  That’s important considering the functionality the solution has
>>    to deliver.
>>    - Something I’ve learnt about loops and other redundant systems is
>>    that their reliability benefits are only as good as the processes that
>>    monitor them for failures.  Passive cable is really hard to monitor.
>>
>>
>>
>> Then, as someone occasionally involved in deployments of commercial
>> off-the-shelf solutions through my $dayjob, I’d argue that the
>> “traditional” route of installing a bunch of CAT6 and one or more APs per
>> unit (if the solution **had** to be Nest Protects) would likely score
>> higher on availability, performance and supportability.  (If you’re talking
>> Zigbee not WiFi then I’m even further out of my depth, but I’d argue the
>> same points still apply.)
>>
>>
>>
>> Jannie
>>
>>
>>
>>
>>
>> *Van:* Make-wifi-fast <make-wifi-fast-bounces@lists.bufferbloat.net> *Namens
>> *Bob McMahon via Make-wifi-fast
>> *Gestuur:* Maandag 17 Mei 2021 20:09
>> *Aan:* Make-Wifi-fast <make-wifi-fast@lists.bufferbloat.net>
>> *Onderwerp:* [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects
>>
>>
>>
>> Hi All,
>>
>> There is a historic building that has 5 floors and no fire alerting
>> associated with the rear fire escape ladder. I'm considering installing
>> nest protects in each unit near the rear egress to alert of the fire escape
>> is compromised by fire. My guess is floor to floor wireless communications
>> may not work too well.
>>
>>
>>
>> I'm thinking about cleaning up the communications runs in the rear of the
>> building. The cable company did a shoddy job of hanging cable for TV
>> services in the 80s. It seems a good time to add communications conduit and
>> run more modern cabling.
>>
>> As part of this, I'm considering running LMR 600 cabling on the exterior
>> brick wall to act as 2.4Ghz communications wave guides. I was thinking make
>> a loop but break the loop at each floor with a 2.4Ghz wilkinson power
>> divider
>> <https://www.pasternack.com/2-way-n-wilkinson-power-divider-690-mhz-2.7-ghz-10-watts-pe2092-p.aspx?utm_source=google&utm_medium=cpc&adpos=&scid=scplpP74039&sc_intid=P74039&gclid=CjwKCAjwqIiFBhAHEiwANg9szk1JG2oJufz2G2Hylc6oOgOSl-tBN5O39Kn2T1pHV4g8_r8AnkFA7xoCFhUQAvD_BwE>.
>> Then bore a hole into each unit and install a 2.4Ghz patch antenna
>> <https://www.l-com.com/wireless-antenna-24-ghz-8-dbi-round-patch-antennas>
>> pm each rear interior wall. Each unit would then install a Nest protect on
>> the ceiling from the patch antenna. The ring or loop topology I think gives
>> a bit of redundancy.
>>
>> Thoughts on if this would achieve the goals of supporting nest protect
>> communications for such a building?
>>
>> Bob
>>
>

-- 
This electronic communication and the information and any files transmitted 
with it, or attached to it, are confidential and are intended solely for 
the use of the individual or entity to whom it is addressed and may contain 
information that is confidential, legally privileged, protected by privacy 
laws, or otherwise restricted from disclosure to anyone else. If you are 
not the intended recipient or the person responsible for delivering the 
e-mail to the intended recipient, you are hereby notified that any use, 
copying, distributing, dissemination, forwarding, printing, or copying of 
this e-mail is strictly prohibited. If you received this e-mail in error, 
please return the e-mail to the sender, delete it from your computer, and 
destroy any printed copy of it.

[-- Attachment #1.2: Type: text/html, Size: 9989 bytes --]

[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4206 bytes --]

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[David Lang]

passive repeaters (two antennas connected together with no electronics) work 
much better than most people realize.

I would do floor-by-floor antenna pairs, and if each device going off should 
trigger the one on the next floor, I'd consider spacing them out so that you 
don't have one antenna pair feeding a strong signal to the next pair.

If the only purpose of this is to relay the fire alarm signals, use high-gain, 
narrow beamwidth antennas pointed at the alarms, this will do wonders at 
overcoming the general noise on 2.4GHz

I have too much radio experience to be happy trusting anything wireless for 
critical things, but where the alternative is no connectivity, it's better than 
nothing.

David Lang

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[Bob McMahon]

[-- Attachment #1.1: Type: text/plain, Size: 3747 bytes --]

Thanks, this helps. Yeah, looking for "better than nothing" here for sure.
I also gotta watch out for taking on liabilities myself. Disclaimers of no
responsibility will need to be clear.

I'm not understanding the connecting pairs together in your response.

I was thinking of a single directional antenna per floor connected into a
2.4Ghz Wilkinson power divider with 22 dB isolation for the splits going to
adjacent floors. This way each floor would reach one floor up and one floor
down and no further. (I haven't yet measured the power outputs of the
devices and of a heavily trafficked 2.4Ghz noise floor to make sure 22dB is
sufficient.) I'd connect the bottom floor to the top floor the same way so
basically each floor has one peer up and one peer down.

|--> (3dB less per power split) to floor above
Fire alarm (free space)  Ant--->PD (0.5dB loss) |
                                         -- 22dB isolation between

|--> (3dB less per power split) to floor below

where PD is a Wilkinson power divider, 5 floors for 5 PDs.

Then the LMR connects the Wilkinson's splits to each other. The LMR is
external to the building (along the rear ladder) and the antennas internal.

The floor logical topology becomes 5<-1<->2<->3<->4<->5->1 such that any
single hop failure only impacts that floor. Passive materials will be
military grade, hermetically sealed and inside conduit. The building has
two sets of egress stairs so alerting per one set being compromised can
direct to the other. The internal stairwell is connected floor to floor -
that was required by the fire department (and was costly to the owners.)

I was hoping to be able monitor the devices' topology and detect
any changes using remote servers in the cloud. So far no luck in getting
that information via an API that I can find. I think this is a critical
piece, i.e. having always on servers bugging someone to pay attention to an
unexpected topology change or a need for battery replacements.

I don't think there'd be fire marshal approval for this but, even without
that, I think this meets the "better than nothing" goal and isn't
prohibitively expensive.

Bob

On Tue, May 18, 2021 at 5:09 PM David Lang <david@lang.hm> wrote:

> passive repeaters (two antennas connected together with no electronics)
> work
> much better than most people realize.
>
> I would do floor-by-floor antenna pairs, and if each device going off
> should
> trigger the one on the next floor, I'd consider spacing them out so that
> you
> don't have one antenna pair feeding a strong signal to the next pair.
>
> If the only purpose of this is to relay the fire alarm signals, use
> high-gain,
> narrow beamwidth antennas pointed at the alarms, this will do wonders at
> overcoming the general noise on 2.4GHz
>
> I have too much radio experience to be happy trusting anything wireless
> for
> critical things, but where the alternative is no connectivity, it's better
> than
> nothing.
>
> David Lang
>

-- 
This electronic communication and the information and any files transmitted 
with it, or attached to it, are confidential and are intended solely for 
the use of the individual or entity to whom it is addressed and may contain 
information that is confidential, legally privileged, protected by privacy 
laws, or otherwise restricted from disclosure to anyone else. If you are 
not the intended recipient or the person responsible for delivering the 
e-mail to the intended recipient, you are hereby notified that any use, 
copying, distributing, dissemination, forwarding, printing, or copying of 
this e-mail is strictly prohibited. If you received this e-mail in error, 
please return the e-mail to the sender, delete it from your computer, and 
destroy any printed copy of it.

[-- Attachment #1.2: Type: text/html, Size: 4600 bytes --]

[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4206 bytes --]

Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects

[David Lang]

I would simplify and not mess ith power diverters (you have little enough power 
to start with)

I'd do an antenna on the 1st floor connected to an antenna on the second floor

then a second antenna on the second floor connected to an antenna on the third 
floor

a second antenna on the third floor connected to an antenna on the fourth floor.

etc.

you don't need expensive coax (not dirt cheap, but not super expensive) and you 
can use DIY yagi antennas, simialr to 
https://flylib.com/books/en/2.434.1/hack_85_pringles_can_waveguide.html which 
will help pick up the signal you want, but also ignore the signal from other 
wifi devices in the area

David Lang

On Tue, 18 May 2021, Bob McMahon wrote:

> Date: Tue, 18 May 2021 21:47:06 -0700
> From: Bob McMahon <bob.mcmahon@broadcom.com>
> To: David Lang <david@lang.hm>
> Cc: Jannie Hanekom <jannie@hanekom.net>,
>     Make-Wifi-fast <make-wifi-fast@lists.bufferbloat.net>
> Subject: Re: [Make-wifi-fast] 2.4Ghz hybrid wiring for nest protects
> 
> Thanks, this helps. Yeah, looking for "better than nothing" here for sure.
> I also gotta watch out for taking on liabilities myself. Disclaimers of no
> responsibility will need to be clear.
>
> I'm not understanding the connecting pairs together in your response.
>
> I was thinking of a single directional antenna per floor connected into a
> 2.4Ghz Wilkinson power divider with 22 dB isolation for the splits going to
> adjacent floors. This way each floor would reach one floor up and one floor
> down and no further. (I haven't yet measured the power outputs of the
> devices and of a heavily trafficked 2.4Ghz noise floor to make sure 22dB is
> sufficient.) I'd connect the bottom floor to the top floor the same way so
> basically each floor has one peer up and one peer down.
>
> |--> (3dB less per power split) to floor above
> Fire alarm (free space)  Ant--->PD (0.5dB loss) |
>                                         -- 22dB isolation between
>
> |--> (3dB less per power split) to floor below
>
> where PD is a Wilkinson power divider, 5 floors for 5 PDs.
>
> Then the LMR connects the Wilkinson's splits to each other. The LMR is
> external to the building (along the rear ladder) and the antennas internal.
>
> The floor logical topology becomes 5<-1<->2<->3<->4<->5->1 such that any
> single hop failure only impacts that floor. Passive materials will be
> military grade, hermetically sealed and inside conduit. The building has
> two sets of egress stairs so alerting per one set being compromised can
> direct to the other. The internal stairwell is connected floor to floor -
> that was required by the fire department (and was costly to the owners.)
>
> I was hoping to be able monitor the devices' topology and detect
> any changes using remote servers in the cloud. So far no luck in getting
> that information via an API that I can find. I think this is a critical
> piece, i.e. having always on servers bugging someone to pay attention to an
> unexpected topology change or a need for battery replacements.
>
> I don't think there'd be fire marshal approval for this but, even without
> that, I think this meets the "better than nothing" goal and isn't
> prohibitively expensive.
>
> Bob
>
> On Tue, May 18, 2021 at 5:09 PM David Lang <david@lang.hm> wrote:
>
>> passive repeaters (two antennas connected together with no electronics)
>> work
>> much better than most people realize.
>>
>> I would do floor-by-floor antenna pairs, and if each device going off
>> should
>> trigger the one on the next floor, I'd consider spacing them out so that
>> you
>> don't have one antenna pair feeding a strong signal to the next pair.
>>
>> If the only purpose of this is to relay the fire alarm signals, use
>> high-gain,
>> narrow beamwidth antennas pointed at the alarms, this will do wonders at
>> overcoming the general noise on 2.4GHz
>>
>> I have too much radio experience to be happy trusting anything wireless
>> for
>> critical things, but where the alternative is no connectivity, it's better
>> than
>> nothing.
>>
>> David Lang
>>
>
>