http://debianws.lexgopc.com/wiki143/index.php?action=history&feed=atom&title=Communication_during_the_September_11_attacksCommunication during the September 11 attacks - Revision history2026-05-15T16:44:03ZRevision history for this page on the wikiMediaWiki 1.43.1http://debianws.lexgopc.com/wiki143/index.php?title=Communication_during_the_September_11_attacks&diff=4327424&oldid=prev~2025-41091-92: /* Trunked systems, commercial services, and cross-department netting */Removed opinionated comments2025-12-17T03:55:31Z<p><span class="autocomment">Trunked systems, commercial services, and cross-department netting: </span>Removed opinionated comments</p>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=====Trunked systems, commercial services, and cross-department netting=====</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>=====Trunked systems, commercial services, and cross-department netting=====</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>One approach to cross-department netting is the capability of some modern [[Trunked radio system|trunked systems]] to provide a function called ''dynamic regrouping''; a feature that Motorola doesn't support in simplex (e.g. 'fireground') operations. It is therefore necessary for a disaster to be near enough the infrastructure to allow for repeater access/operation. Many agencies with Motorola trunked systems already have this capability <del style="font-weight: bold; text-decoration: none;">but it's hardly ever used; even in a crisis. The difficulty of operating such a system is often too great for poorly educated dispatchers who often have no college – much less any particular training in computers or communications systems – other than the 'cursory' training they receive in a 3 or 5 day class the vendors offer</del>. The feature allows the dispatch center personnel to send units from different agencies who are responding to the same incident to a common talk group or virtual channel. This assumes the agencies all share a capability to operate over the same trunked radio system, which is rare. In an informal survey of three agencies with trunked systems that included this feature, users at two sites reported they did not think their system included the feature. A representative from a third site said he "...thought they had the feature but never used it." Of the three agencies with the feature, no one knew how to use it<del style="font-weight: bold; text-decoration: none;">. This would suggest, (in at least the three agencies contacted,) that ''dynamic regrouping'' was not valuable</del>. Like other disaster readiness processes, users would have to practice using the feature in order for it to be useful during an incident.<ref>Dynamic regrouping is described in ''800 MHz Trunked Radio Request For Proposals'', (Oklahoma City, Oklahoma: Public Safety Projects Office, Oklahoma City Municipal Facilities Authority, October 19, 2000) pp. 99. In systems where this feature is not available, a work-around is to program every fielded radio in the radio fleet with two or three identical fleet-subfleets or talk groups. By doing this, any two radios could meet and communicate.</ref></div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>One approach to cross-department netting is the capability of some modern [[Trunked radio system|trunked systems]] to provide a function called ''dynamic regrouping''; a feature that Motorola doesn't support in simplex (e.g. 'fireground') operations. It is therefore necessary for a disaster to be near enough the infrastructure to allow for repeater access/operation. Many agencies with Motorola trunked systems already have this capability. The feature allows the dispatch center personnel to send units from different agencies who are responding to the same incident to a common talk group or virtual channel. This assumes the agencies all share a capability to operate over the same trunked radio system, which is rare. In an informal survey of three agencies with trunked systems that included this feature, users at two sites reported they did not think their system included the feature. A representative from a third site said he "...thought they had the feature but never used it." Of the three agencies with the feature, no one knew how to use it. Like other disaster readiness processes, users would have to practice using the feature in order for it to be useful during an incident.<ref>Dynamic regrouping is described in ''800 MHz Trunked Radio Request For Proposals'', (Oklahoma City, Oklahoma: Public Safety Projects Office, Oklahoma City Municipal Facilities Authority, October 19, 2000) pp. 99. In systems where this feature is not available, a work-around is to program every fielded radio in the radio fleet with two or three identical fleet-subfleets or talk groups. By doing this, any two radios could meet and communicate.</ref></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Some agencies use commercial two-way radio as an adjunct to their own communications networks. One professional engineering evaluation of public safety radio systems explains that commercial systems such as Nextel's are not built to the same standards of [[Signal strength|coverage]] and [[Traffic|non-blocking]] as public safety trunked systems. Like toy walkie talkies marketed to children, they are usable and helpful for non-urgent communications but should not be considered reliable enough for life safety uses.<ref>''Contra Costa County Public Safety Mobile Radio Master Plan, Final Report, June 18, 2002, '' (Fairfax, Virginia: Federal Engineering, Inc., 2002).</ref> It is also true that most trunked radio system users are likely to hear busy signals, (error tones showing no channels are available,) for the first time during a large disaster<del style="font-weight: bold; text-decoration: none;">. All </del>systems have a finite capacity.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Some agencies use commercial two-way radio as an adjunct to their own communications networks. One professional engineering evaluation of public safety radio systems explains that commercial systems such as Nextel's are not built to the same standards of [[Signal strength|coverage]] and [[Traffic|non-blocking]] as public safety trunked systems. Like toy walkie talkies marketed to children, they are usable and helpful for non-urgent communications but should not be considered reliable enough for life safety uses.<ref>''Contra Costa County Public Safety Mobile Radio Master Plan, Final Report, June 18, 2002, '' (Fairfax, Virginia: Federal Engineering, Inc., 2002).</ref> It is also true that most trunked radio system users are likely to hear busy signals, (error tones showing no channels are available,) for the first time during a large disaster <ins style="font-weight: bold; text-decoration: none;">since all </ins>systems have a finite capacity.</div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>"We don't want or need trunking" is what Chief Charles Dowd (NYPD) was heard to say at an APCO convention in Orlando (2006).{{Citation needed|date=September 2018}} NYPD operates a large, conventional repeater network with many legacy channels in the UHF band; and a technology developed "so a large number of users can share a small number of channels" (e.g. trunking) is clearly unnecessary and a frivolous waste of money.{{Citation needed|date=September 2018}}</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>"We don't want or need trunking" is what Chief Charles Dowd (NYPD) was heard to say at an APCO convention in Orlando (2006).{{Citation needed|date=September 2018}} NYPD operates a large, conventional repeater network with many legacy channels in the UHF band; and a technology developed "so a large number of users can share a small number of channels" (e.g. trunking) is clearly unnecessary and a frivolous waste of money.{{Citation needed|date=September 2018}}</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2" class="diff-side-added"></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;">With sufficient channels, there is no need for trunking. There are no 'busy' tones in a conventional repeater system. In the event an individual needs to chime in, he simply waits his turn – just as he would do in a trunked system.</del></div></td><td colspan="2" class="diff-side-added"></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Mobile data terminals===</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Mobile data terminals===</div></td></tr>
</table>~2025-41091-92http://debianws.lexgopc.com/wiki143/index.php?title=Communication_during_the_September_11_attacks&diff=3140248&oldid=previmported>Plasticwonder: Reverted edits by 2601:283:4D83:1520:2F36:57FD:A435:21C3 (talk) (AV)2025-10-23T02:11:52Z<p>Reverted edits by <a href="/wiki143/index.php?title=Special:Contributions/2601:283:4D83:1520:2F36:57FD:A435:21C3" title="Special:Contributions/2601:283:4D83:1520:2F36:57FD:A435:21C3">2601:283:4D83:1520:2F36:57FD:A435:21C3</a> (<a href="/wiki143/index.php?title=User_talk:2601:283:4D83:1520:2F36:57FD:A435:21C3&action=edit&redlink=1" class="new" title="User talk:2601:283:4D83:1520:2F36:57FD:A435:21C3 (page does not exist)">talk</a>) (<a href="/wiki143/index.php?title=WP:AntiVandal&action=edit&redlink=1" class="new" title="WP:AntiVandal (page does not exist)">AV</a>)</p>
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<td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 02:11, 23 October 2025</td>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><br></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Communication]] problems and successes played an important role during the [[September 11 attacks]] in 2001 and their aftermath. Systems were variously destroyed or overwhelmed by loads greater than they were designed to carry, or failed to operate as intended or desired.</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Communication]] problems and successes played an important role during the [[September 11 attacks]] in 2001 and their <ins style="font-weight: bold; text-decoration: none;">[[Aftermath of the September 11 attacks|</ins>aftermath<ins style="font-weight: bold; text-decoration: none;">]]</ins>. Systems were variously destroyed or overwhelmed by loads greater than they were designed to carry, or failed to operate as intended or desired.</div></td></tr>
<tr><td class="diff-marker" data-marker="−"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:President George W. Bush <del style="font-weight: bold; text-decoration: none;">watches Television Coverage of </del>Terrorist Attacks.jpg|thumb|<del style="font-weight: bold; text-decoration: none;">350px</del>|U.S. President [[George W. Bush]] talks on a [[STU-III]] secure telephone <del style="font-weight: bold; text-decoration: none;">as he watches television coverage of </del>the [[<del style="font-weight: bold; text-decoration: none;">September 11 attacks</del>]] <del style="font-weight: bold; text-decoration: none;">from a school classroom in Florida</del>.]]</div></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:President George W. Bush <ins style="font-weight: bold; text-decoration: none;">Receives Information Regarding </ins>Terrorist Attacks.jpg|thumb|<ins style="font-weight: bold; text-decoration: none;">350x350px</ins>|U.S. President [[George W. Bush]] talks on a [[STU-III]] secure telephone <ins style="font-weight: bold; text-decoration: none;">while in </ins>the [[<ins style="font-weight: bold; text-decoration: none;">Emma E. Booker Elementary School</ins>]].]]</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Attackers==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Attackers==</div></td></tr>
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<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Federal government==</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Federal government==</div></td></tr>
<tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">{{See also|Air traffic control during the September 11 attacks}}</ins></div></td></tr>
<tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>According to [[9/11 Commission]] staff statement No. 17<ref name="Improvising a Homeland Defense"/> there were several communications failures at the federal government level during and after the 9/11 attacks. Perhaps the most serious occurred in an "Air Threat Conference Call" initiated by the [[National Military Command Center]] (NMCC) after two planes had crashed into the [[World Trade Center (1973-2001)|World Trade Center]], but shortly before [[The Pentagon]] was hit. The participants were unable to include the [[Federal Aviation Administration]] (FAA) [[air traffic control]] command center, which had the most information about the hijackings, in the call.</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>According to [[9/11 Commission]] staff statement No. 17<ref name="Improvising a Homeland Defense"/> there were several communications failures at the federal government level during and after the 9/11 attacks. Perhaps the most serious occurred in an "Air Threat Conference Call" initiated by the [[National Military Command Center]] (NMCC) after two planes had crashed into the [[World Trade Center (1973-2001)|World Trade Center]], but shortly before [[The Pentagon]] was hit. The participants were unable to include the [[Federal Aviation Administration]] (FAA) [[air traffic control]] command center, which had the most information about the hijackings, in the call.</div></td></tr>
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</table>imported>Plasticwonderhttp://debianws.lexgopc.com/wiki143/index.php?title=Communication_during_the_September_11_attacks&diff=18457&oldid=previmported>KingEuronIIIGreyjoy: /* Mobile data terminals */2025-05-12T13:19:09Z<p><span class="autocomment">Mobile data terminals</span></p>
<a href="http://debianws.lexgopc.com/wiki143/index.php?title=Communication_during_the_September_11_attacks&diff=18457">Show changes</a>imported>KingEuronIIIGreyjoy