Message-ID: <404d8128-5205-a23e-429b-3fcd5f566176@ionary.com>
Date: Sat, 2 Apr 2022 12:14:14 -0400
From: Fred Goldstein <invalid@see.sig.telecom-digest.org>
Subject: Re: FirstNet is Connecting More First Responders Across
South Carolina
On 4/1/2022 8:28 PM, Telecom Digest Moderator wrote:
> ...
> One of the things that happens when I take a vacation from the Digest
> is that I come to work with "new eyes" - I notice things that weren't
> grabbing my attention before, and I've just realized that I don't know
> as much about radio and Cellular technology as I had thought I did.
>
> Ergo, I'll ask you to give us more detail about the underlying
> technology behind FirstNet
®, and to explain some of the acronyms
> that have been mentioned. I hate to do it, but I'll (respectfully)
> request an "Executive Overview" that gives a layman's view of the
> possibilities and problems.
Happy to oblige.
>> FirstNet is a "broadband" public safety network intended to complement
>> the "narrowband" voice walkie-talkie systems that first responders
>> (police, fire, EMS) typically carry.
>
> OK, here's my first double-take: my only experience with two-way radio
> technology, outside Amateur radio, was fixing the radios in the snow
> plows and staff cars used by the Commonwealth of Massachusetts, back
> in 1972. At that time, "Narrowband" was what we called FM two-way
> radios that were set for plus-and-minus 5KHz deviation. However, I've
> been told that "Narrowband" now refers to radio transmitters using
> ±2.5KHz deviation, and "Wideband" is the older ±5KHz
> system.
>
> Pleae tell us if I'm right, and what that change did to increase the
> available bandwidth in the bands used by First Responders, and why
> FirstNet is considered "Wideband."
"Broadband" in the modern sense means that it supports more than
voice, and supports high-bandwidth applications like video. Think
high-speed Internet access, in this case via smartphones. FirstNet is
a cellular network, just one with special features for first
responders.
>> It's basically a 700 MHz LTE network, where the 700 MHz band has
>> good indoor and cluttered-area coverage. The idea is that AT&T gets
>> to use the spectrum for commercial (cellular) customers, but
>> reserves and prioritizes its use for first responders when they need
>> it. FirstNet's customers, the first responders, pay for the service,
>> which allows them to download images and video, which could help
>> them in their front line work.
>
> IIRC, 700 MHz was the range used for "trunked" two-way push-to-talk
> systems: I thought it was still being used for that. Correct me if I'm
> wrong, though: didn't T-Mobile have it's "Push-To_Talk" service in
> that band as well?
No. 700 MHz was TV channels 51-69, repurposed for mobile use around 15
years ago via the DTV transition. Trunked two-way uses frequencies in
the 800 MHz range (near but not the same ones as cellular) and on the
older UHF band (450-470 MHz). - When the second 700 MHz auction - was
being planned, there was a proposal on the table to reserve some for
first responders, and that ended up in FirstNet.
> And, Ghod forgive me, I have to ask what "LTE" means in this
> context. Trunked radio systems are now decades old, so if that's what
> AT&T is calling "Long Term Evolution," well, I want my tax money back.
LTE is the name of the "4G" air interface, which has been the standard
for at least a decade. Since the 3G networks are being shut down, your
mobile phone either has LTE or it won't work. "5G" has an air
interface called "NR", for New Radio, but that is really just a set of
evolutionary changes to LTE to support higher frequencies, wider
channels, multi-band aggregation, and similar tweaks. To make a long
story short, LTE uses full-channel OFDM in the downlink (base to
mobile) while the uplink divides the channel into narrower
sub-channels called Resource Blocks and thus allows multiple mobile
units to transmit at once. OFDM means that there are multiple
narrowband carriers, 15 kHz apart in LTE (can be more in NR), across
which the payload is divided. It's a basket of clever ideas (and
maybe some weird ones) thrown together by committee.
>> Not all first responders buy into this; real-world police in many
>> places, for instance, carry ordinary smartphones, which generally work
>> fine. But in some places where cell coverage is spotty, FirstNet gives
>> AT&T an incentive to build out, and it gives local governments an
>> incentive to permit the necessary towers to be built. Whether that's
>> good or bad is a matter of perspective...
>
> Let's pull over into the learning lane for a moment, and I'll ask a
> few questions I hope will clarify what is going on.
>
> 1. Is FirstNet(R) a service that uses single-channel radios, like the
> ones that Police used to have for their exclusive use, or is it for
> "trunked" radios like the ones taxicabs, courier services, and
> delivery trucks use now? Some Police and Fire departments have
> switched to "trunked" systems, because some municipalities have
> cobined all their services into a single "trunked" system in an
> effort to save money.
It uses a conventional cellular phone, so the channels are wide and
allocated using LTE's methods. Trunked systems are voice systems with
a lot of narrowband voice channels assigned on demand. Totally
different.
> 2. If FirstNet is a "Wideband" service that allows First Responders to
> "download images and video," how can it be shared with older
> "narrowband" push-to-talk users? Are there multiple systems with
> different capabilities sharing the FirstNet band(s)?
It is totally separate from old PTT. It may synthesize PTT but that's
an "app". The network is full duplex with paired (frequency division
duplex) channels.
> 3. Unless I misunderstand the FirstNet PR, the system is equipped to
> allow First Responders to interrupt existing "other" users when
> First Responders make a call. Is that correct? Is there any public
> info you can point us to?
LTE supports a lot of simultaneous users per cell, and divides
capacity among them. FirstNet prioritizes first responders, so if
there is a shortage of capacity on a cell, first responders get theirs
first, and ordinary cellular users either get less capacity or in
extreme cases may get thrown off. Basically the license is divided
into a cellular channel and a first responder channel, and the first
responder channel's share of capacity is available to cellular users
when first responders don't need it.
--
Fred R. Goldstein k1io fred "at" ionary.com
+1 617 795 2701
Message-ID: <4AFCBC9C-CB76-42A5-A400-C867DD109747@icloud.com>
Date: 3 Apr 2022 13:14:16 -0400
From: "Julian Thomas" <jtnuage@icloud.com>
Subject: Re: August 2nd, 2022 - The Decommissioning of Copper Gets
Real
I think that Frontier here in Rochester NY (successor to the late
lamented Rochester Tel) may have adopted a different method for
encouraging POTs subscribers to bail in addition to or instead of drip
drip drip rate increases. Residents in our neighborhood are having
periodic loss of service which seems to be coming from the CO. Seems
that they are eliminating equipment (line frames?) as people cancel
service and consolidating subscriber lines on the remaining
frames. Apparently this process frequently doesn't work correctly.
--
jt - jt@jt-mj.net
Those who can make you believe absurdities can make you
commit atrocities. - Voltaire
Message-ID: <20220401150109.4B98CA27@telecom2018.csail.mit.edu>
Date: Fri, 1 Apr 2022 15:01:09 +0000 (UTC)
From: Bill Horne <malQRMassimilation@gmail.com>
Subject: CWA Bargaining Update
AT&T Mobility and DirecTV (Orange)
Just shy of a thousand AT&T Mobility workers joined a town hall call
last Wednesday for an update on contract negotiations and strategies
for strengthening their power at the bargaining table. The call was
also an opportunity for newer members to learn how we have mobilized
to bargain strong contracts at AT&T Mobility, such as waging an
historic strike in 2017.
CWA District 1 Vice President Dennis Trainor, who coordinates
bargaining for the AT&T Mobility Orange contract, kicked off the call
saying, "We don't win our great contracts with just the bargaining
committee, we win when we have every member mobilizing and
participating in every mobilization activity. We have tremendous
support within CWA and from the public. But we need to energize all of
our Mobility workers and send a clear message to AT&T that we want a
fair contract now. AT&T has to know that their employees are ready to
stand up and fight back. We did this in 2017 ... I need all of you to
be ready to send the same message to AT&T in 2022."
https://cwa-union.org/news/bargaining-update-193
--
(Please remove QRM from my email address to write to me directly)
Message-ID: <20220401205444.E89FCA27@telecom2018.csail.mit.edu>
Date: Fri, 1 Apr 2022 20:54:44 +0000 (UTC)
From: Sean Murphy <murphy.s@remove-this.telecomdigest.net>
Subject: Amazon Workers on Staten Island Vote to Unionize in
Landmark Win for Labor
Despite heavy lobbying by the company, workers at the facility voted
by a wide margin for a union. It was seen as a rebuke of the
company's treatment of its employees.
By Karen Weise and Noam Scheiber
It was a union organizing campaign that few expected to have a
chance. A handful of employees at Amazon's massive warehouse on Staten
Island, operating without support from national labor organizations,
took on one of the most powerful companies in the world.
And, somehow, they won.
Workers at the facility voted by a wide margin to form a union,
according to results released on Friday, in a landmark win for a
campaign targeting the country's second-largest employer and one of
the biggest victories for organized labor in a generation.
https://www.nytimes.com/2022/04/01/technology/amazon-union-staten-island.html
