<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:content="http://purl.org/rss/1.0/modules/content/"><channel><title>Telecom on ErrorZap</title><link>https://errorzap.com/tags/telecom/</link><description>Recent content in Telecom on ErrorZap</description><image><title>ErrorZap</title><url>https://errorzap.com/og.png</url><link>https://errorzap.com/og.png</link></image><generator>Hugo</generator><language>en-US</language><copyright>ErrorZap</copyright><lastBuildDate>Sat, 26 Sep 2026 17:07:00 -0600</lastBuildDate><atom:link href="https://errorzap.com/tags/telecom/index.xml" rel="self" type="application/rss+xml"/><item><title>The Phone in the Elevator</title><link>https://errorzap.com/elevators/the-phone/</link><pubDate>Sat, 26 Sep 2026 17:07:00 -0600</pubDate><guid>https://errorzap.com/elevators/the-phone/</guid><description>That little stainless steel phone panel is one of the last things in most buildings still running on a copper POTS line. What the codes require, why the copper is disappearing, and how cellular and IP communicators are taking over.</description><content:encoded><![CDATA[<div class="ez-dossier-lede"><span>ELEVATORS · FLOOR 07 · THE PHONE</span><p>Find the oldest phone line in a modern office building and there's a decent chance it's the one in the elevator.</p></div>
<h2 id="the-short-version">The short version</h2>
<ul>
<li>Elevator codes require a <strong>two-way emergency communication</strong> device in every car. Press the button and you have to reach a real person who can send help.</li>
<li>For decades, that meant an <strong>analog phone on a copper POTS line</strong>, usually one line per elevator bank, auto-dialing a monitoring company.</li>
<li>Carriers are retiring copper. AT&amp;T has said it plans to get out of most traditional landline service <strong>by 2029</strong>.</li>
<li>The replacements are <strong>cellular communicators</strong> (often LTE, with battery backup and the antenna outside the steel shaft) or <strong>IP-based</strong> systems.</li>
<li>The 2019 edition of the elevator code added a <strong>text or video</strong> requirement, so riders who are deaf, hard of hearing, or can&rsquo;t speak can communicate too.</li>
</ul>
<figure class="el-fig el-phone">
  <figcaption><b>FIG. 7</b>The elevator phone, then and now. Same red button, very different path out of the building.</figcaption>
  <svg viewBox="0 0 360 430" role="img" aria-labelledby="el-phone-t">
    <title id="el-phone-t">Two columns. Then: car phone, down a traveling cable, to a copper POTS pair, to the phone company central office, which is crossed out as being retired. Now: car phone and screen, to a battery-backed communicator, out through an antenna outside the shaft over LTE, to a staffed 24/7 monitoring center.</title>
    <rect width="360" height="430" class="bg"/>
    <text x="14" y="26" class="lbl">THEN · COPPER</text>
    <text x="192" y="26" class="lbl new">NOW · CELLULAR / IP</text>
    <g class="node"><rect x="10" y="40" width="160" height="54" rx="8"/><text x="22" y="63">CAR PHONE</text><text x="22" y="81" class="sub">push the button</text></g>
    <g class="node"><rect x="10" y="126" width="160" height="54" rx="8"/><text x="22" y="149">TRAVELING</text><text x="22" y="167" class="sub">cable down the shaft</text></g>
    <g class="node old"><rect x="10" y="212" width="160" height="54" rx="8"/><text x="22" y="235">POTS LINE</text><text x="22" y="253" class="sub">copper pair</text></g>
    <g class="node old"><rect x="10" y="298" width="160" height="54" rx="8"/><text x="22" y="321">CENTRAL OFFICE</text><text x="22" y="339" class="sub">phone company</text></g>
    <path d="M90 94V126M90 180V212M90 266V298" class="wire old"/>
    <path d="M128 304l30 42M158 304l-30 42" class="x"/>
    <text x="14" y="376" class="warn">being retired by</text>
    <text x="14" y="392" class="warn">the carriers</text>

    <g class="node"><rect x="190" y="40" width="160" height="54" rx="8"/><text x="202" y="63">CAR PHONE</text><text x="202" y="81" class="sub">plus a text screen</text></g>
    <g class="node new"><rect x="190" y="126" width="160" height="54" rx="8"/><text x="202" y="149">COMMUNICATOR</text><text x="202" y="167" class="sub">battery backed</text></g>
    <g class="ant"><path d="M270 180v34M258 196l12-10 12 10"/></g>
    <text x="290" y="204" class="sub">antenna</text>
    <text x="290" y="220" class="sub">outside</text>
    <text x="290" y="236" class="sub">the shaft</text>
    <path d="M270 214C270 250 270 262 270 298" class="wire air"/>
    <text x="202" y="266" class="sub">LTE</text>
    <g class="node new"><rect x="190" y="298" width="160" height="54" rx="8"/><text x="202" y="321">24/7 MONITORING</text><text x="202" y="339" class="sub">a human answers</text></g>
    <path d="M270 94V126" class="wire"/>
    <circle r="4" class="pkt"><animateMotion dur="2.6s" repeatCount="indefinite" path="M270 94V180V298"/></circle>
    <text x="192" y="376" class="sub">Code also wants a light</text>
    <text x="192" y="392" class="sub">that shows help is coming,</text>
    <text x="192" y="408" class="sub">plus text or video for</text>
    <text x="192" y="424" class="sub">riders who can't hear.</text>
  </svg>
</figure>

<h2 id="what-the-code-actually-asks-for">What the code actually asks for</h2>
<p>In North America, ASME A17.1 section 2.27 covers emergency communication. The
basics, in plain English:</p>
<ul>
<li>A button in the car that starts a <strong>two-way voice</strong> call, with no handset to
pick up and nothing to dial.</li>
<li>The call goes to <strong>authorized personnel</strong> who can respond around the clock,
typically a monitoring service.</li>
<li>A <strong>visual signal</strong> in the car that lights up when the call is acknowledged,
so a rider who can&rsquo;t hear knows help was reached.</li>
<li>Since <strong>A17.1-2019</strong>, per the National Elevator Industry Inc., the code
spells out requirements aimed at riders who are deaf, hard of hearing, or
speech impaired, which in practice means a <strong>two-way text or video display</strong>
in the car for buildings that fall under that edition.</li>
</ul>
<p>The ADA standards add that the system can&rsquo;t rely on voice alone.</p>
<h2 id="why-the-copper-matters">Why the copper matters</h2>
<p>A POTS line is a very simple, very reliable thing. The phone company feeds it
power from the central office, so it keeps working when the building&rsquo;s power is
out. It has a dial tone you can test, and old elevator phones were designed
around exactly that behavior.</p>
<p>That copper is going away. In late 2024 AT&amp;T said it planned to eliminate
traditional landline service in 20 of its 21 states by 2029, and other carriers
are shrinking their copper networks too. According to emergency-phone vendor
Kings III, an FCC change that took effect in March 2026 means carriers no longer
need the agency&rsquo;s approval before retiring copper, just 90 days&rsquo; notice to
customers. So building owners are
facing a forced upgrade on one of the most safety-critical phone lines they
have.</p>
<h2 id="whats-replacing-it">What&rsquo;s replacing it</h2>
<ul>
<li><strong>Cellular communicators.</strong> A box that presents a phone-line interface to
the elevator phone and connects over LTE instead. Since steel and concrete
shafts kill cell signal, the antenna usually goes on top of the car, in the
machine room, or outside the hoistway, and the unit carries a <strong>battery</strong>
because it no longer gets power from the phone company. Many are sold as
&ldquo;dual path,&rdquo; with a second connection for backup.</li>
<li><strong>VoIP / IP systems.</strong> The elevator phone rides the building network. That
works, but now the phone depends on the building&rsquo;s power, switches, and
internet, so battery backup and network design matter a lot more.</li>
<li><strong>Car displays.</strong> To meet the newer text and video rules, the car gets a
small screen, and the monitoring center can type or show video back.</li>
</ul>
<div class="el-callout"><b>Why ErrorZap cares</b><p>This is the kind of thing that breaks quietly. An analog adapter that doesn't pass the elevator phone's signaling cleanly, a cellular unit mounted where there's no signal, or a battery nobody has tested all look fine until someone actually presses the button. If you manage a building's phone lines, find out where the elevator lines are, what they're really connected to, and when someone last made a test call.</p></div>
<h2 id="sources">Sources</h2>
<ol class="ez-sources">
<li><a href="https://nationalelevatorindustry.org/elevator-emergency-communications/">NEII: elevator emergency communications and A17.1-2019 requirement 2.27.1</a></li>
<li><a href="https://up.codes/s/emergency-operation-and-signaling-devices">UpCodes: ASME A17.1 Section 2.27</a></li>
<li><a href="https://www.kingsiii.com/elevator-code/">Kings III: what the latest elevator code says about emergency phones</a></li>
<li><a href="https://www.usatoday.com/story/money/2024/12/04/att-eliminate-traditional-landline-copper-phone-service-2029/76765766007/">USA Today: AT&amp;T to eliminate most traditional landline service by 2029</a></li>
<li><a href="https://www.kingsiii.com/pots-emergency-phone-replacement/">Kings III: POTS emergency phone replacement</a></li>
<li><a href="https://dataremote.com/solutions/elevator-emergency-communication">DataRemote: elevator emergency communication</a></li>
<li><a href="https://www.access-board.gov/ada/">U.S. Access Board: ADA Accessibility Standards (section 407, elevators)</a></li>
</ol>
]]></content:encoded></item><item><title>Grand Canyon Communications Map: Radio, Cell, Microwave, Phone</title><link>https://errorzap.com/grand-canyon/communications-map/</link><pubDate>Wed, 23 Sep 2026 03:00:00 -0600</pubDate><guid>https://errorzap.com/grand-canyon/communications-map/</guid><description>Overview map linking Grand Canyon&amp;#39;s radio, cellular, microwave, telephone, fiber, dispatch, and aviation-comms dossiers into one picture.</description><content:encoded><![CDATA[<div class="ez-dossier-lede"><span>GRAND CANYON · BIG PICTURE · TOPIC 86</span><p>Ten separate dossiers on this site cover how Grand Canyon actually talks to itself: repeaters bolted onto a 1909 fire tower, a satellite dish in a shed at the bottom of the canyon, a five-tower cell-permitting framework that's been "approved" since 2020 without a confirmed tower built. This page is the map — what each layer does, when it showed up, and where the full story lives.</p></div>
<h2 id="the-short-version">The short version</h2>
<ul>
<li>Grand Canyon runs at least seven distinct communications layers at once: two-way radio, cellular, microwave backhaul, historic copper telephone, fiber, satellite hazard alerts, and dedicated aviation airspace rules.</li>
<li>The oldest layer (a 1909 tree-platform fire lookout) and the newest (satellite text alerts, live since June 2025) are 116 years apart, and both got tested for real within the same week during the August 29, 2026 Bright Angel Canyon flash flood.</li>
<li>Cellular coverage is still effectively rim-only and, as of the park&rsquo;s own 2019-2020 planning documents, dependent on a single carrier; a 2020 federal framework approved up to five new towers, but no public record confirms any have actually gone up since.</li>
<li>Nearly every layer crosses jurisdictional lines on purpose — shared towers with the U.S. Forest Service, a site inside neighboring Glen Canyon National Recreation Area, and co-located gear for Arizona DPS, the county sheriff, and the Navajo Nation.</li>
<li>None of it is secret infrastructure in the conspiratorial sense: NPS publishes exactly which sites are closed and why, and the reasons are consistently mundane — protecting equipment, not hiding it.</li>
</ul>
<h2 id="the-ten-layers-at-a-glance">The ten layers, at a glance</h2>
<table>
	<thead>
			<tr>
					<th>System</th>
					<th>Era / status</th>
					<th>One fact worth knowing</th>
					<th>Full dossier</th>
			</tr>
	</thead>
	<tbody>
			<tr>
					<td>Radio communications system</td>
					<td>1909 lookouts → digital P25 (reported complete ~2010)</td>
					<td>A 2007 federal study found &ldquo;large portions of remote, backcountry and inner-canyon areas do not have radio coverage&rdquo;</td>
					<td><a href="/grand-canyon/radio-communications-system/">/grand-canyon/radio-communications-system/</a></td>
			</tr>
			<tr>
					<td>Hopi Point repeater site</td>
					<td>Fire tower since 1909/1927, repeater since ~2010</td>
					<td>Closed site and access road, &ldquo;for public safety and protection of the integrity of operational communications equipment&rdquo;</td>
					<td><a href="/grand-canyon/hopi-point-repeater-site/">/grand-canyon/hopi-point-repeater-site/</a></td>
			</tr>
			<tr>
					<td>NPS public-safety radio</td>
					<td>Four channels + tactical net</td>
					<td>Backs roughly 265-310 search-and-rescue incidents a year and a five-function Emergency Services program</td>
					<td><a href="/grand-canyon/nps-public-safety-radio/">/grand-canyon/nps-public-safety-radio/</a></td>
			</tr>
			<tr>
					<td>Interagency communications</td>
					<td>1993 federal narrowband mandate onward</td>
					<td>Two of the park&rsquo;s own repeater sites sit on Forest Service land outside the park entirely</td>
					<td><a href="/grand-canyon/interagency-communications/">/grand-canyon/interagency-communications/</a></td>
			</tr>
			<tr>
					<td>Cellular coverage</td>
					<td>One-carrier era → 2020 five-tower framework</td>
					<td>No commercial tower is permitted below the canyon rim, full stop</td>
					<td><a href="/grand-canyon/cellular-coverage/">/grand-canyon/cellular-coverage/</a></td>
			</tr>
			<tr>
					<td>Microwave links</td>
					<td>Backbone technology since at least the 2007 radio rebuild</td>
					<td>A microwave dish in a shed at Phantom Ranch has quietly carried the settlement&rsquo;s phone service for decades</td>
					<td><a href="/grand-canyon/microwave-links/">/grand-canyon/microwave-links/</a></td>
			</tr>
			<tr>
					<td>Telephone &amp; historic telecom</td>
					<td>1922 line → CCC rebuild 1934-35 → National Register, 1986</td>
					<td>592 metal poles carried 25 miles of open copper wire from rim to river to rim</td>
					<td><a href="/grand-canyon/telephone-and-historic-telecom/">/grand-canyon/telephone-and-historic-telecom/</a></td>
			</tr>
			<tr>
					<td>Fiber &amp; data connectivity</td>
					<td>2019-2020 Telecommunications Plan, still permit-by-permit</td>
					<td>No evidence found this research that any of the plan&rsquo;s five approved towers have actually been built</td>
					<td><a href="/grand-canyon/fiber-and-data-connectivity/">/grand-canyon/fiber-and-data-connectivity/</a></td>
			</tr>
			<tr>
					<td>Emergency communications &amp; dispatch</td>
					<td>GCRCC dispatch center, PSAR since 1997</td>
					<td>Eight dispatchers cover Grand Canyon plus five to six other NPS units region-wide, around the clock</td>
					<td><a href="/grand-canyon/emergency-communications-and-dispatch/">/grand-canyon/emergency-communications-and-dispatch/</a></td>
			</tr>
			<tr>
					<td>Aviation communications</td>
					<td>Federal rule since 1987-2000 (14 CFR Part 93 Subpart U)</td>
					<td>Grand Canyon runs its own airspace statute, separate from every other national park, after two fatal mid-air collisions</td>
					<td><a href="/grand-canyon/aviation-communications/">/grand-canyon/aviation-communications/</a></td>
			</tr>
	</tbody>
</table>
<h2 id="why-there-are-seven-layers-instead-of-one">Why there are seven layers instead of one</h2>
<p>Most places solve &ldquo;communications&rdquo; with a cell network and call it done. Grand Canyon can&rsquo;t, because the terrain that makes the park famous is also what breaks radio line-of-sight, blocks satellite view, and makes trenching fiber either absurdly expensive or physically impossible below the rim. Every layer on this page exists because an earlier layer hit a wall the canyon itself put up.</p>
<p>Radio came first, growing out of fire-lookout towers built starting in 1909 — the same <a href="/grand-canyon/hopi-point-repeater-site/">Hopi Point</a> site went from tree platform to steel tower to digital repeater without ever stopping being useful. Telephone came next, literally strung by hand: the <a href="/grand-canyon/telephone-and-historic-telecom/">1922 line and its 1934-35 Civilian Conservation Corps rebuild</a> connected the rims decades before radio or microwave could. Microwave arrived to solve the problem fiber couldn&rsquo;t: <a href="/grand-canyon/microwave-links/">rim towers &ldquo;backhaul&rdquo; over line-of-sight dishes</a> because burying cable across a mile of vertical relief is, in NPS&rsquo;s own words, mostly not worth attempting. Cellular arrived last and thinnest — a <a href="/grand-canyon/cellular-coverage/">single-carrier, 850-megabit park-wide system</a> as recently as 2019, with a fix that&rsquo;s still mostly paperwork five years after federal approval.</p>
<figure class="gc-cartoon">
  <img src="cartoon-dispatch-backup.webp" alt="Comic panel of a cluttered dispatch room where screens for a streamgauge sensor and a satellite alert system go dark while an old rotary-style radio dispatcher keeps working" loading="lazy">
  <figcaption>When the fancy sensors went dark during the 2026 flood, the oldest system in the room — a dispatcher answering the phone — carried the load.</figcaption>
</figure>
<h2 id="one-event-every-layer-at-once">One event, every layer at once</h2>
<p>Federal environmental assessments and press releases are abstractions until something actually happens. On August 29, 2026, a flash flood tore through Bright Angel Canyon and Phantom Ranch, and inside about 48 hours nearly every system on this page got used for real. The purpose-built streamgauge network installed after the 2025 Dragon Bravo Fire sent an early alert on rising water, then failed. With it down, the <a href="/grand-canyon/emergency-communications-and-dispatch/">Grand Canyon Regional Communications Center</a> — the same eight-dispatcher room that answers for six National Park Service units across two states — became the park&rsquo;s primary real-time flood intelligence source, fielding 911 calls as reports came in. The <a href="/grand-canyon/fiber-and-data-connectivity/">Grand Canyon River Alert System</a>, a satellite-text network barely a year old, pushed hazard warnings to hikers and boaters whose phones had never had a signal. NPS&rsquo;s <a href="/grand-canyon/nps-public-safety-radio/">public-safety radio network</a> coordinated a joint rescue with Arizona Department of Public Safety helicopters, documented in the <a href="/grand-canyon/interagency-communications/">interagency communications dossier</a>, that extracted 61 people in the flood&rsquo;s first 36 hours. It&rsquo;s the clearest evidence available that these aren&rsquo;t ten unrelated infrastructure footnotes — they&rsquo;re one system, built in layers over more than a century, that gets tested together whenever the canyon decides to.</p>
<figure class="gc-cartoon">
  <img src="cartoon-fenced-repeater.webp" alt="Comic panel of the HOST leaning on a chain-link fence around a small radio repeater shed at a scenic overlook, next to a simple sign, looking unimpressed" loading="lazy">
  <figcaption>Every comms site behind a fence has the same boring, honest reason on the sign.</figcaption>
</figure>
<h2 id="whats-actually-off-limits-and-why">What&rsquo;s actually off-limits (and why)</h2>
<p>None of the active equipment sites behind these ten dossiers are open to the public, and the reasoning is consistent across every one of them: protecting equipment and the people who maintain it, not concealing anything. The <a href="/grand-canyon/hopi-point-repeater-site/">Hopi Point Repeater Site</a> and its access road are closed under the current Superintendent&rsquo;s Compendium &ldquo;for public safety and protection of the integrity of operational communications equipment&rdquo; — language that, in substance, repeats across every other fenced radio, microwave, or telephone site described in these dossiers. The one closure that isn&rsquo;t about a fence at all is airspace: Grand Canyon&rsquo;s aviation communications rules restrict what pilots can legally do overhead, not where a visitor standing on the rim can walk.</p>
<h2 id="sources">Sources</h2>
<ol class="ez-sources"><li><a href="/grand-canyon/radio-communications-system/">Grand Canyon radio communications system</a></li><li><a href="/grand-canyon/hopi-point-repeater-site/">Hopi Point repeater site</a></li><li><a href="/grand-canyon/nps-public-safety-radio/">NPS public-safety radio network</a></li><li><a href="/grand-canyon/interagency-communications/">Federal/interagency communications</a></li><li><a href="/grand-canyon/cellular-coverage/">Cellular infrastructure and coverage</a></li><li><a href="/grand-canyon/microwave-links/">Microwave links and remote communications sites</a></li><li><a href="/grand-canyon/telephone-and-historic-telecom/">Telephone and historical telecom infrastructure</a></li><li><a href="/grand-canyon/fiber-and-data-connectivity/">Fiber/backhaul and modern data connectivity</a></li><li><a href="/grand-canyon/emergency-communications-and-dispatch/">Emergency communications, ranger dispatch and rescue communications</a></li><li><a href="/grand-canyon/aviation-communications/">Aviation communications and Grand Canyon air operations</a></li></ol>
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