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Mobile Cell Phone Towers For Disaster Relief
cerberus4696 writes "According to today's Denver Post, Verizon recently premiered one of its new Cells On Light Trucks (COLTs), a complete, self-contained CDMA cell that can be moved to wherever it's needed, such as the scene of a natural disaster or a large public event. Since a standard CDMA cell can only handle a theoretical maximum of 62 calls at a time (usually less in practice), the network of permanent fixtures can quickly become overloaded in high-use situations. Verizon already uses a larger version of the system known as a Cell On Wheels (or COW; gotta love these acronyms), but as it takes three trucks and the better part of a day to deploy, nimbleness of response has apparently been an issue."
Which is a good reason that Ham radio ops are still useful, particularly in disaster relief scenarios where much of the local infrastructure may have been destroyed.
But first you have to get us to stop talking about the weather and our rigs.
InfraLynx builds various vehicles now being used by the Homeland Security dept and the military. They have mobile cell towers, satellite uplinks, and all kinds of communications equipment.
i vers/
r alynx&btnG=Google+Search
2600 took some pictures. they are here http://www.2600.com/offthehook/2003/1001files/
another link:
http://iwce-mrt.com/ar/radio_infralynx_hummer_del
and the google page: http://www.google.com/search?hl=en&ie=UTF-8&q=inf
Sectorization refers to the practice, common with all cellular technologies, of dividing up the area around a cell site into regions, or sectors, each served by its own set of directional antennas. Three sector cells are extremely common; that's why so many towers have triangular platforms with a set of antennas on each side. There are usually three antennas on each side: one for transmit and two for receive, with the extra receive antenna providing spatial diversity.
Most CDMA cell sites in built-up areas have three (or six) sectors, operate on more than one 1.25 MHz RF channel, and use the newer CDMA 2000 1x standard. That can easily provide a total cell capacity of considerably more than 61 calls.
CDMA 2000 1x doubles the number of Walsh code channels (to 128) by adding a second set of traffic channels in quadrature to the original 64. Virtually all CDMA phones sold over the past few years do 1x.
Because of CDMA's inherent robustness, the same RF channel can be reused in adjacent cells and even adjacent sectors, greatly increasing the overall capacity of the spectrum in a given area. Because no careful frequency reuse plan is required, CDMA is also very well suited to the rapid deployment of cells in "hot spots" as described in this article.
Disclaimer: I work for Qualcomm.
As past chief of a Fire Department I can tell you that a good, RELIABLE cell phone is critical to emergency management for the following reasons:
-Radio communications that Fire Departments/Ambulances/Police use are usually one or two half duplex channel. If you are lucky, you have four or five channels, but only one or two will get you in touch with you dispatcher (911 center). During a natural disaster, hundreds of units across your county could be trying to reach the 911 center at the same time. The existing communications systems available for emergency response become so overwhelmed during disasters that they become useless for communications (the worst example being NYPD and FDNY on 9-11). When radio systems do get overwhelmed, go to plan B: The cell phone.
-Radio communications are great for units that work together, but what happens when I need to talk to the people at a chemical manufacturing plant to best find out how to deal with a spill of their product? Or talk to the DOT about closing a road. Or even talk to the local Police (not on the same frequency). Or order as many pizzas as I can get my hands on to feed my Firefighter's? Or call the Humane Society to deal with the 57 cats that are homeless now that the crazy cat woman has finally burned her house down? Plan B: The cell phone
-Sensitive information (about a patient or fatality) should be handled discreetly. Many people listen to our transmission (and don't start a debate here, I am glad that people monitor the Fire and Police frequencies). As a medic if I need to talk to a doctor about a 15-year-old girl who has overdosed trying to commit suicide, I don't want that broadcasted to everyone in the county. Plan B: The cell phone.
Once upon a time (1990s) my local cell phone company actually entered our phones in to their systems as priority phones. Assuming that FD communications is more important than civilian communications, the system would kick off a civilian user to let the FD cell phone connect when the tower was full. I could never quite figure out how the tower would know my call was coming in if all of its receiving channels were full, but I never had a problem connecting a call so I never asked. I wish they still had that in place, because there have been many times recently that I haven't been able to connect with my cell phone when I needed to. My town (population of about 1000 year round residence, 5000 winter only residence) hosts a festival that yearly draws about 60,000 people. That is when I most need my cell phone to work, and it usually doesn't.
Where do I order one of these light truck cell towers?
> And now let the EEs shoot down my idea (not literally).
They probably won't