GPS Insight | GPS Fleet Tracking Blog

Dec 26 2011

Be sure you pick the right cellular coverage for GPS tracking!

Category: Ad Hoc Reports,Arizona,Availability,Cellular Coverage,Google Earth,Reports — rdonat @ 4:40 pm

Not all companies who track their vehicles need to worry about which cellular provider they use. Most don’t even know they may have a choice.

But if you do work in remote areas, you should pay attention and work with your GPS provider to ensure you get the right network.

I went to see ‘Mission Impossible’ today with my son and drove into town (Flagstaff) from our house which is in EXTREMELY bad AT&T coverage.

On the way home, I drove a couple miles around in our neighborhood to try to compare the reliability between AT&T and Verizon coverage.

My vehicle has both a Verizon-based device (labeled Rubicon) and an AT&T device (labeled Rubicon PNP).

We have a couple of internal mechanisms for determining how good the coverage ACTUALLY by:

Viewing purported AT&T or Verizon coverage
Showing ACTUAL cellular “lag” on a map
Generating a report of ACTUAL cellular “lag” with a graph

Below is an actual AT&T coverage map showing the area where I typically lose coverage in “light blue” which is not ideal coverage. In the “dark blue” area, you can see there are very few places where the time for the device to report through the cellular network is more than a few seconds. In my area, you can see some “tall” pins which visually represent how long it took the device to report (which is really a measure of how far the vehicle had to move before forwarding that data once it recovers cellular coverage):

AT&T coverage vs. time it took for a device to report

Note that the Verizon device (Rubicon) has a “pink” line and the AT&T device (Rubicon PNP) is in white. Verizon shows perfect coverage throughout (not pictured).

Here is how I pulled up the “lag report” version of the 3D map within GPS Insight:

Choosing both Rubicon devices once at a time

Choose the "Lag Report" option for a 3D History Map

[note this functionality is internal to GPS Insight support staff and is only available to end-customers upon special request]

Here is the display of my drive WITHOUT the coverage map. Notice that there are very few “tall” pins meaning very few “lagged” points:

Slight lag (24 seconds to 3 minutes) for remote AT&T device

Next I will run a quantitative analysis of today’s data, for just the 2 devices in this vehicle, after quickly creating a “Rubicons” vehicle group containing them both:

Create a "Rubicons" Vehicle Group containing both devices

I can then run this (internal use) “Lag Report” on the “Rubicons” for today:

Cellular "Lag Report" between AT&T and Verizon

Note there is a “landmark” option where we could restrict the report to ONLY data within a certain area we define, such as a mine, or wherever a customer may be concerned about coverage. Also note above, that GPS Insight still thinks I am driving, since when I pull into my bad coverage and put the car in the garage, sometimes the final ignition off event doesn’t get transmitted until I drive back into coverage the next time I leave. This is normal behavior for poor coverage areas, and is unavoidable (unless you know enough to choose Verizon when purchasing in these cases, which is the point of this article).

Here is the output, showing 100% coverage for Verizon and 95.8% coverage for AT&T for today’s drive:

Verizon 100%, AT&T 95.8%

The AVERAGE time to report for Verizon is 2 seconds, whereas AT&T averages 7 seconds. The max for Verizon is 4 seconds, and for AT&T, the max times are 51 seconds and 3 minutes, for when the report reports within 1 minute or 10 minutes (we break it out into 1, 10, 30, 30+ minute “bands”).

Here is the past week, since I drove up to Flagstaff for vacation from Scottsdale, driving through notoriously bad AT&T coverage in the mountains (I know this because my iPhone is AT&T & worthless for that drive) — note that the percentage of < 1 minute reports is 100% for Verizon and only 83.7% for AT&T:

Poor AT&T Performance in mountains between Scottsdale and Flagstaff

However, the week PRIOR to me leaving for vacation, driving around the more populated Scottsdale/Phoenix area, shows a much better 95.1% performance for AT&T vs. a 99.9% availability percentage for Verizon:

AT&T vs. Verizon coverage in Phoenix/Scottsdale

The moral of the story here is threefold:

BEFORE you purchase GPS Tracking devices for your fleet, make sure to determine A) if you have coverage issues in the areas your vehicles travel and B) whether or not you can afford to wait the minutes, hours, or sometimes overnight before the device reports in these areas.

If you may be affected, and aren’t sure, then make sure your GPS Tracking provider can provide not just multiple coverage options, but ALSO the tools to determine if there is a need for one coverage or another, as shown above.

As a point of reference, Verizon devices cost roughly $50 more than AT&T devices (due to additional modem and CDMA licensing costs). But that’s a onetime cost and will probably amount to less than 5% over the life of the device and service.

If that $50 keeps you from experiencing occasional cellular delays due to poor (typically) AT&T coverage, then it, and finding a company which provides the right coverage (e.g GPS Insight…), is certainly worth considering.

Thanks,

Rob.

Tags: AT&T, cellular coverage, Fleet Tracking, gps fleet tracking, GPS Tracking, gps tracking devices, Vehicle Tracking, Verizon

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Oct 14 2008

AT&T coverage and GPS Insight hardware

Category: Cellular Coverage,Google Earth,GPS Tracking,Mapping,Overlays — rdonat @ 8:59 pm

While testing some new units today (mentioned in the previous article), we saw a couple of 1-2 minute “lags” from the time a GPS location/speed/direction measurement was taken and what time it made it to our servers over the AT&T network.

We are able to pull in exact coverage maps and “overlay” them on top of the troublesome points (1-2 minutes is still VERY GOOD, but typically points take only 2-5 seconds from the time they’re reported to the time we have them in our database for our customers’ real-time-mapping and alerts):

You can see the highlighted times from report to receipt on the left, and the one 2 minute “lagged” point takes place right where AT&T claims only “Good” coverage — not “Best” coverage. You can tell by the lighter shade of orange.

Here is another Salesperson — David, and he had mostly 2-6 second updates, but had a couple of 1-2 minute reports. Again, the 2 minute report is right where AT&T drops from “Best” to “Good” coverage:

You can see that the vast majority of the 1-minute-by-1-minute reports take just a few seconds to become available — the only exceptions are typically 1-2 minutes where we need to retry because the AT&T signal isn’t strong enough or we temporarily lose a connection.

This happens without our customers even noticing typically. No data is ever lost — we “Store and Forward” so that could drive to a foreign county where we don’t have coverage (Mexico for us Scottsdale-dwellers), and all that data will be forwarded up once you hit the border again.

Since we are constantly testing and building tools like this to help us test our GPS Insight tracking devices and software, I thought I would share a glimpse of how we visualize the quality of our service.

Here are a couple coverage/Store-and-Forward related articles which talk about this as well:

Finding lost vehicles using GPS Insight

GPS Insight and the US Border

Tags: gps fleet tracking, GPS Tracking, gps vehicle tracking

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Oct 14 2008

GPS Antennas don’t work so well inside the office

Category: Cellular Coverage,GPS Insight Employees — rdonat @ 8:15 pm

So we’ve been a little busy lately & I haven’t had much time to write for the blog.

We’ve been in our new office for a month now, and new or not, GPS antennas generally need to see the sky to work well.

However, this picture shows that they are still reasonably accurate, even inside a building, as this unit spent the night last night after we programmed it for one of our salespeople to put into her vehicle for testing purposes: (the arrow points to where the unit physically was inside our office):

It reported every minute with quite a few “bouncy” points which are due to inaccuracies from receiving bounced signals from the satellite through the halls of our office (this unit spent the night in an interior, no-windows office). Here is a picture of all the various reports (green indicating slight movement, blue indicating no movement):

Once it was installed in Alissa’s car (in the parking garage) and drove away at the end of her day, however, it tracked perfectly, once per minute, within about 5 feet of accuracy or so:

We have been testing our newest hardware offering, and are happy to see it track perfectly.

We put GPS tracking devices of various types on all of our employees’ vehicles for testing and training purposes. Thankfully, we do what our customers do, so our employees don’t mind: We use vehicle groups and permissions to only let a couple employees (the ones doing the development and testing) see all the vehicles. Everyone can see their own vehicle, which is useful when we go to customers and show our car parked in its exact parking space on a web browser or even a Blackberry, using satellite imagery.

Plus we get a discount.

Rob.

Tags: gps fleet tracking, GPS Tracking, gps vehicle tracking

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Apr 08 2008

New California Cell Phone Laws — stop calling your drivers & use GPSI to see where they are

Category: California,cell phone capabilities,Cellular Coverage,GPS Tracking — rdonat @ 2:46 pm

The new California cell phone law goes into effect 7/1/08. Now drivers can be cited for using their cell phones while driving, unless they use a hands free device.

See the CA Cell Phone Law document here.

While GPS Insight users DO use cell phone communication to send and receive group-wide or individual text messages, and to annotate their stops (e.g. they’re stopped when sending them…), overall, the amount of communication while they are driving is lessened significnatly.

A dispatch person may just choose a single group (or all vehicles) and instantly map them with a couple clicks:

Now if I want to see where a particular vehicle is (or which vehicle is closest to a particular area) I can just double click on that vehicle:

Additionally, we now have given our customers the ability to use cell phone text messages to find the closest 10 vehicles to another vehicle or location (within 10 miles, which is configurable). For instance, if you want to know the 10 closest vehicles to “TC1-CREW” (above), this customer can send a text message of “gps tc1-crew close” and receive a text message of the closest vehicles, how far they are, which direction, and if they are moving (and how fast or for how long have they been stopped).

Additionally the customer can just send “gps TC1-CREW” and get a text message of where that vehicle is. This is even useful if you don’t feel like walking to a computer to find out. A quick SMS text message is returned within seconds (almost instantly on AT&T, maybe 10 seconds on Verizon, our two carriers of choice). It tells you the address (or landmark), and vehicle status (stopped 10 minutes, idle stop 20 minutes, 72 mph NW, etc.). You can even abbreviate the truck name, or give a partial truck name which will return all vehicles matching (e.g. TC will return both TC1 and TC2). Here is the “console” record of some sample activity. Bear in mind the “Message” is coming from, and being sent back to the driver’s/supervisor’s cell phone:

(We break it up into multiple text messages for easy reading when necessary)

Also bear in mind if you have a higher end phone, we can help you easily display all your vehicles on a map on your cell phone.

Zooming down:

This is very useful to keep track of your fleet, but has a nice side benefit of helping your drivers to avoid breaking the new California (and other states’) cell phone laws while driving.

Rob.

Tags: gps fleet tracking, GPS Tracking, gps vehicle tracking

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Sep 10 2007

Using GPS Data to find cell phone dead zones

Category: Arizona,Cellular Coverage,GPS Tracking,Truck Tracking,Vehicle Tracking — rdonat @ 4:41 pm

In this article I will detail how I use GPS Data to answer questions about cell phone signal inadequacy in Arizona using all of our data collected in August.

We have a large municipal customer who commands some respect from AT&T and is able to actually ask them to put up new cell phone towers in certain areas which are lacking.

They track a large number of vehicles using our GPS Tracking product, and asked us if we could help them determine the worst cell coverage areas in Arizona, based on our customers’ data.

Since we track several thousand vehicles in Arizona, we were able to do this.

Above is shown a real-time location of all several thousand vehicles we track in the Arizona and San Diego area.

I took the data from August so far and compared the track time with the time we received the data, where the “lag” is due to cell signal being unavailable.

We pulled 2500 points ranked by longest to shortest lag, where the shortest lag was 6 minutes — bear in mind our updates occur in 2 minute intervals and typically take 5 seconds to make it from the tracking device and another 10 seconds to be processed and pushed down to your map.

I plotted these lagged position updates and color and height coded them based on how long they took to ultimately get forwarded.

This shows all places where there was some level of poor cell coverage in Arizona for August:

Thankfully, when comparing where the vehicles we track are, relative to where the “dead spots” are, they are not very troublesome, and do not cover where most of our drivers tend to be:

Then we can place it in a 3-D view where the height of the lagged positions indicates how bad that coverage is (e.g. how long the vehicle was out of range after it collected that point):

Then I can pull both a Cingular/AT&T Coverage image I prepared (from their website) and overlay it with Arizona. This map is not 100% accurate, and there are a lot of T-Mobile and partner network areas where our product works which are NOT depicted, but it gives a good idea of where our coverage is (it follows the roads and major metro areas typically. Note the edges are not exactly aligned since our mapping knows about curvature of the earth but the Cingular map does not:

Zooming down we see that the worst area of coverage is not “orange” (which indicates areas AT&T claims to work in):

Zooming down on this area, we see it’s a desolate road leading to a mine:

Looking at the data points relative to the aerial photo, we see how accurate our GPS Track is. Then we can zoom WAY down and see the exact areas of the mine which are being driven in.

So if I was Cingular, I wouldn’t worry about covering this remote mine, but I would worry about coverage where I pointed out with 2 arrows below, and perhaps place or adjust the cell tower there.

Knowing there are around 800 square miles in all of Arizona where our typical vehicles (e.g. forgetting about the mining vehicles) go out of range for more than 5 minutes is great to know, since there are 111,500 square miles in Arizona.

This means we are out of range less than 1% of the time. Since most GPS tracking products (ours included) store this data until the vehicles return to coverage, there is never any data lost. We store roughly 45 days of typical driving, so if a vehicle goes down into Mexico (where we do not currently have service) and back, we still will be able to show the exact locations they were at, if they were speeding, etc, once they return.

One of our customers drives back & forth to Mexico and is currently using our service to include our polygon geofences in order to ensure compliance with Federal law, and to check their times spent at the border (which helps them in their business due to certain reporting requirements). I will cover this company and their unique usage of the GPS Insight product in the future.

Tags: gps fleet tracking, GPS Tracking, gps vehicle tracking

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