[196145] in North American Network Operators' Group
Re: Hurricane Maria: Summary of communication status - and lack of
daemon@ATHENA.MIT.EDU (Mike Hammett)
Fri Oct 6 06:57:55 2017
X-Original-To: nanog@nanog.org
Date: Thu, 5 Oct 2017 18:11:44 -0500 (CDT)
From: Mike Hammett <nanog@ics-il.net>
Cc: nanog@nanog.org
In-Reply-To: <a53253ec-9f0b-e907-5c99-8ec40074d2a0@vaxination.ca>
Errors-To: nanog-bounces@nanog.org
Broadcast towers that you ruled out often have cell companies on them. Buil=
dings often have cell sites on them. DAS really isn't all that common.=20
There's usually two, three, four providers on a given tower. My ASR search =
of Arecibo, PR gives me 19 constructed. Six of them are on known multi-tena=
nt tower owners.=20
All towers over 200' and some towers meeting various other requirements mus=
t be listed in ASR. The tower companies usually list many of them in ASR, b=
ut not always.=20
Crown Castle has 299 sites in Puerto Rico and lists 196 "alternative" sites=
. These are likely options on various retail rooftops, open land, etc.=20
American Tower lists 175 sites with about 2/3 of them being typical towers =
and the other third being random other things that may or may not be develo=
ped.=20
SBA lists 97 sites.=20
PTI lists 19 sites.=20
There are likely other tower companies down there as well. My AT&T Towers l=
ogin isn't working and they appear to have their own sites down there.=20
It probably adds up with some margin of error.=20
-----=20
Mike Hammett=20
Intelligent Computing Solutions=20
Midwest Internet Exchange=20
The Brothers WISP=20
----- Original Message -----
From: "Jean-Francois Mezei" <jfmezei_nanog@vaxination.ca>=20
To: nanog@nanog.org=20
Sent: Thursday, October 5, 2017 4:50:39 PM=20
Subject: Re: Hurricane Maria: Summary of communication status - and lack of=
=20
got curious about the FCC's definition of "cell site" in the Maria=20
outages reports in Puerto Rico.=20
In the Oct 4 report: Arecibo is reported as having 68 cell sites served,=20
65 being out. (95.2% outage)=20
The FCC has an "ASR" (Antenna Structure Registration) search for cell=20
sites, and this points to actual masts (which I assume need some permit=20
above certain height).=20
For ARECIBO, there are 31 entries,=20
1 dismantled,=20
4 granted=20
2 cancelled=20
That leaves 24 "constructed".=20
These registrations do not mention which carrier(s) uses the mast. And=20
include some owners such as Caribbean Broadcasting Corporation which=20
isn't likiely being used for cellular.=20
For all of Puerto Rico, it reports 930 ASR registrations. (haven't done=20
the parsing to see how many are "Constructed" vs Cancelled, granted,=20
dismantled). Lets assume 900 for sake of discussion.=20
So the ~1600 quoted by another organisation would have to include more=20
than just registered antenna masts.=20
Except for water towers, what other structures would be amenable to=20
having multiple carrier's antennas?=20
What is also not clear from such statistics is the fact you could have a=20
town with an high antenna broadcasting 850 to the whole area, and then=20
lots of DAS antennas at telephone pole height in the town at 1900 or 1700.=
=20
Having the 850 up and running at the top of the hill might cover the=20
whole town, even if it would represent only 1 of say 50 cell sites in=20
the area.=20
Similarly, covering a windy road in a canyon might be done with lots of=20
DAS anetnnas on telephone poles along the way. They may all be down, but=20
would normally serve 0 population, so is this number of "down" antennas=20
relevant?=20
During the 1998 ce storm in Qu=C3=A9bec, Hydro Qu=C3=A9bec was overwhelmed =
and=20
asked cities to identify priority sites inside their territories.=20
It's fancy "point to where the break is based on where everyone reports=20
an outage" software was useless because many breaks continued to happen=20
after power had been lost.=20
So it had to start from where there was power and work its way, fixing=20
breaks along the line towards those priority sites. (and once done, fan=20
out from there to power the non priority areas).=20
In many rural areas, this involved planting new poles for long=20
distances, rebuilding from scratch. (And only once the poles are up can=20
the telco restring its wiring).=20
What the media doesn't show after a disaster is what is still standing,=20
what is still working. It could be that a large portion of telephone=20
poles are still standing and intact and only require minor individual=20
fixes. Or it could be that large swaths ave seen the poles toppled and=20
new ones needed with new power and telco wiring done from scratch.=20
Statistics may look bad showing 100,000 without power. But if it is a=20
single break by a branch it is easy to fix compared to having 1000=20
breaks by 1000 branches. So again, statistics don't give the full story=20
on the real extent of damage.=20
