Ohio district deploys SchoolSAFE solution invented by Motorola dealer

2 way radio range extenderWithout giving too much about this two way radio intercom piece of writing, but I found it exciting and relevant to what I’m now doing.

Chardon Local Schools personnel in northeast Ohio can use their MOTOTRBO radios to speak directly to first responders on a P25 network, thanks to the recent installation of the SchoolSAFE bridge link that was created by a Motorola Solutions dealer in Colorado.

While Motorola Solutions’ ASTRO 25 P25 networks are designed to meet the stringent requirements of public-safety communications, school districts are more inclined to use more-affordable MOTOTRBO radios for daily use, said Patrick Gray, Motorola Solutions’ director of North America channel operations and development.

However, during an emergency, school personnel wanted to be able to communicate directly with first responders that were being dispatched to the scene, instead of having information passed through multiple people—a common occurrence, according to Michael Hanlon, superintendent of Chardon Local Schools.

“Typically, on site, we had a limited number of lower-grade walkie-talkies that were just talking to each other,” Hanlon said during an interview with IWCE’s Urgent Communications. “That information would somehow get to someone—in the school office, presumably—who would make a 911 call. Then, first responders would be reporting to the school or to the scene, and all of that information would flow through whoever might be on the phone with them at the time … but not someone who had firsthand knowledge of the incident.”

Colorado-based QDS Communication—a 13-employee dealer for Motorola Solutions—developed the SchoolSAFE solution that lets a 911 dispatcher activate a bridge between the MOTOTRBO system at a school and the P25 public-safety network, Gray said. The QDS solution has two major components: (1) a “technology tower” that houses a MOTOTRBO and an ASTRO 25 radio (http://assimumabrastemp.com/) that are linked together to create the potential for a communications bridge, and (2) software housed at the 911 center that enables a dispatcher to activate the bridge, if warranted.

“The software that does the bridging technology actually resides at the 911 dispatch center, so the 911 dispatchers are in complete control of turning the bridge on or off,” Gray said during an interview with IWCE’s Urgent Communications.

Hanlon said school-district personnel have embraced the SchoolSAFE concept, which the district plans to incorporate in emergency-incident drills in the future. In addition, the school district is gaining practical experience with the system in situations that tend to happen in a school environment, with Hanlon providing a hypothetical scenario of a student suffering a broken arm in gym class.

“Now, that [school-district] first responder on the scene can be relating exactly what’s happening with the student [in discussions with public-safety personnel],” Hanlon said. “Is this a compound fracture that we’re dealing with? Is the child unconscious? We can be controlling the flow of information much more accurately than having a secretary in the office say, ‘All I know is that somebody’s hurt in the gym.’”

QDS Communications has deployed the solution in about 200 facilities near its Colorado locations, but officials for Motorola Solutions wanted to learn what it would take to install the system in another part of the country. The 10-school Chardon Local Schools was selected, and SchoolSAFE was deployed at no cost to the district.

“It’s a pilot, not in terms of the technology but in terms of Motorola understanding what needs to be wrapped around this solution to implement it—the training and so on—so that we could help QDS package this up, so that we could provide it to our dealer channel,” Gray said. “That was the entire intent here.”

While the current SchoolSAFE solution provides a communication bridge between P25 and MOTOTRBO networks, Motorola Solutions’ recent acquisition of Twisted Pair could allow an expanded method of interoperability in the future, Gray said.

“Now, with the acquisition of Twisted Pair—and we’ve talked about this with Chardon—you can actually take an Android or an Apple cell phone and put it in this same environment,” he said.

Gray said the SchoolSAFE solution will be featured at the Motorola Solutions Channel Partner Expo that will be conducted in Las Vegas on the eve of the IWCE 2014 exhibit hall opening.

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How To Use Distant Measuring Equipment Within A Flight Planner

I don’t know if you came here because you read it on social media, twitter, facebook, google +, stumble upon or somewhere else. But thank you for coming and I trust you enjoy reading this as much as I did.

walkie talkie overWhat is distance measuring equipment that is used within a flight planner?

Distance measuring equipment is a transponder based DP2400 two way radio navigation technology that measures slant range distance by timing the propagation delay or VHF or UHF radio signals. Developed in Australia, it was invented by Edward George Bowen while employed as Chief of the Division of Radio physics of the Commonwealth Scientific and Industrial Research Organisation (CSIRO).

Another engineered version of the system was deployed in the early 1950s operating in the 200 MHz VHF band. The Australian domestic version was referred to by the Federal Department of Civil Aviation as DME (D) and the later international version adopted by ICAO as DME.
DME is similar to secondary radar, except in reverse. This system was a post war development of the IFF systems of World War II. To maintain compatibility, DME is functionally identical to the distance measuring component of TACAN used within a flight planner.

Operation
Aircraft use DME to determine their distance from a land based transponder by sending and receiving pulse pairs. These are two pulses of fixed duration and separation. The ground stations are typically located with VORs. A typical DME ground transponder system for en-route or terminal navigation will have a 1 kW peak pulse output on the assigned UHF channel.

A low power DME can also be co-located with an ILS glide slope antenna installation where it provides an accurate distance to touchdown function, similar to that otherwise provided by ILS Marker Beacons.
Distance calculation and accuracy used within a flight planner
When using a flight planner, a radio pulse takes around 12.36 microseconds to travel 1 nautical mile to and from and it is also referred to as a radar mile. The time difference between interrogation and reply 1 nautical mile minus the 50 microsecond ground transponder delay is measured by the interrogator’s timing circuitry and translated into a distance measurement (slant range) which is stated in nautical miles and then displayed on the cockpit DME display.

The accuracy of DME ground stations is 185m. Its important to know that DME provides the physical distance from the aircraft to the DME transponder. This distance is often referred to as ‘slant range’ and depends trigonometrically upon both the altitude above the transponder and ground distance from it in a flight planner.