Tech Tips and Tid Bits...

WHERE IS YOUR EQUIPMENT?
Submitted by AVL/GPS Specialist William "Bill" Wetzel

Commercial operators are facing losses and insurance premiums so staggering that many of them are being driven out of business. Do you really know where your truck or trailer is tonight? Can you afford not to know? Let’s look at some ways you can protect your rolling assets.

For auto theft, LoJack is by far the most well known system sold as an accessory or aftermarket product. It works (after activation) by a terrestrial method of tracking known as the Doppler system. Police cruisers equipped with LoJack systems have spike antennas on their roof arranged in a circular pattern. The Doppler system is a very effective method of vehicle recovery, which has been well documented. Its uses, however, are very limited beyond this single purpose. There is no way to monitor the vehicle’s daily activities.

We now come to AVL systems (Automatic Vehicle Location), which includes terrestrial and/or satellite technology. Early methods of AVL incorporated cellular technology. A vehicle would be located through a cell site that it was within range of when polled. This method was not very accurate, by GPS standards, but it did work and provided a fair report of vehicle daily activities. As a method of vehicle recovery, it left much to be desired. Between vehicle recovery and asset management, fleet operators were forced to choose which one had top priority.

When GPS was added to AVL, good vehicle recovery and good asset management became possible with the same system. Two excellent providers of this technology are Trimble and S3. The GPS subsystem of AVL assumed the locating role from the cell sites. The GPS receiver determines a vehicle’s location and then the AVL system would report the data to a host platform through a cellular network. One box is typically used to house the GPS subsystem and the AVL data processor system. Two antennas hook into this box. The GPS antenna is low profile. The data antenna is similar to the old analog cellular antennas that were common before PCS. Trimble likes to use gain antennas for data.

Because different technologies exist for transmitting data for AVL, terms like GPRS, GSM, CDPD and others exist. In Amateur Radio, GPRS has long been favored. As an Amateur Radio operator myself, it is the technology that I currently prefer. GSM is a technology native to Europe. CDPD will no longer be available since the major carriers plan to drop it in the near future. Current users of CDPD technology will have to have their AVL system boxes replaced or, at least, their modems contained inside. For fleet operators, this will be somewhat costly and inconvenient. Users already on GPRS will see no interruption in their service. The major carriers of CDPD are AT&T and Verizon Wireless. Many AVL system providers now face going to their subscribers and notifying them of this change. Since I always preferred GPRS, this is one drama that I am (thankfully) only going to be a spectator of.

The AVL system technology should be the heart of any fleet operator’s concern. A GPS subsystem is only as good as the AVL system that it is a part of. A revolutionary system that I am a fan of is S3’s utilization of Motorola’s ReFLEX satellite system. This data technology is based, in part, on satellites. A system of sites, with a voting receiver type of architecture, receives data from the S3 AVL system processor units. They then transmit their data up to the ReFLEX satellite system. If, for some reason, any of the voting receivers cannot adequately pick up a signal from any AVL system processor unit, then the ReFLEX satellite will pick up the link.

It’s not a departure from the cellular concept, unless there is no other choice. A cellular concept is always preferred over a wide area concept, so as to keep congestion down to a minimum. S3 units, as a result, have far superior performance in maintaining contact with their host platform. An experiment, which I had personally seen myself, had such a unit down in a sewer - and it worked! I have no plans to go exploring sewers, but it is comforting to know that even when I am in a parking structure below a building, my panic button is still available.

Three major concerns for monitoring include, but is not limited to, mapping, messaging and reporting. Most providers of GPS enabled AVL systems can do all of these. S3, on the other hand, offers remote control! On their website, they have documented experiments of an engine cut-off of a semi truck, on a test track, for a scenario such as a hi-jack or theft. When considering an AVL system, hazmat material operators should be attentive of this. Losing one’s asset and load is one thing; a public threat is another. Since 9-11, private operators have to be as diligent of Homeland Defense as the military has to be. What S3 had accomplished here is nothing less than a major contribution to this end.

Mapping is accomplished by integration of third party software, like Microsoft’s MapPoint or by software developed by the GPS enabled AVL provider. This allows a fleet operator to see the location of their assets continuously in a command room style dispatch center. With an optional text messaging module attached to a GPS enabled AVL unit, computer aided dispatching becomes practical. This can be extremely good for profits, as well as driver and public safety. An owner operator can usually install their monitoring software on as many computers as they want, even on their wireless laptops.

No matter what profession you are in, reports have become a part of life. Reports are becoming more sophisticated and a burden on operators and drivers alike. Due to the efforts of most providers of GPS enabled AVL units, a new term in the field has evolved as GPS fleet management. Tracking and dispatching no loner suffice to describe the AVL systems of today. Additionally, voice is also possible. Optional phone capabilities are being integrated into the modem systems. I can even see a printer someday too.

Specialized applications can include units for trailers as well. An AVL box, a rechargeable battery and a solar panel is all that is needed to protect your trailer. My last visit to S3 had such a prototype being tested which was working well. The same components can be used to monitor and control expensive vending machines and other fixed assets. A fixed asset can be (and many times is) re-locatable. Knowing their location and status can be as vital as knowing the status of a mobile fleet. Another specialized fixed application is monitoring and controlling industrial equipment and processes. The sky is the limit!

There is so much more of what is being done today with GPS enabled AVL systems that I cannot begin to address them all here. Perhaps the term AVL no longer applies with all these possibilities. Perhaps a new term, such as CDU, Central Data Unit, would be better to describe the boxes. Trimble, for example, calls theirs the “CrossCheck” unit. No matter what the generic term is or will be, this new area of technology will grow to integrate, protect and assist both mobile and fixed resources better than ever before.

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