Briartek Cerberlink experience

[Rex Sanders]

My experience with the Briartek Cerberlink

I rented a Briartek Cerberlink two-way satellite texting device for a five day backpacking trip in Henry Coe State Park, California in April 2013. I wanted to keep in touch with my wife, and communicate in an emergency.

Bottom line: I will not rent the Briartek Cerberlink again. I had serious problems with both the device and the iPhone app.

How I used it

The rented Cerberlink arrived several days earlier than I requested, in a sturdy waterproof box, with a nylon pouch, charger, folding card cheat-sheet, return instructions, and a UPS return label.

I setup a Cerbercenter web account, downloaded the Cerbertouch app to my iPhone 4, paired the iPhone with the Cerberlink via Bluetooth, and tried the device in my backyard, and on a short day hike.

For the backpack trip, I set the Cerberlink for one hour tracking – one fix every hour, sent every hour. I set up the Cerbercenter web account to deliver check-in messages to both my email account and cell phone, and to my wife's email account and cell phone. Each recipient and method must respond to a verification message in order to receive check-in messages, which caused some confusion. I also created a custom map link, so my wife could follow my progress. The folding card cheat sheet omits tracking instructions, so I downloaded and read the manual and created my own cheat sheet.

At the trailhead, I turned on the fully-charged Cerberlink, and pressed 1-1-1 to send a check-in message. A Cerberlink check-in message includes GPS latitude and longitude with a link to Google Maps. I put the Cerberlink at the top of my tent's stuff sack (which sat vertically in a side pocket), with the Cerberlink sitting vertically as instructed. Every afternoon, when I reached camp, I sent a check-in message by pressing 1-1-1; waited for the LEDs to to indicate success; then turned the device off. In the morning, just before leaving camp, I turned on the Cerberlink, which would automatically resume 1 hour tracking. Twice in the evening while sitting in my tent, I turned on the Cerberlink and my iPhone for a while to send and receive messages. One afternoon during a break I sat on an open ridge top with the Cerberlink and iPhone to send and receive messages.

Results

The Cerbertouch app went crazy on first connection to Cerberlink, repeatedly cycling through several messages almost faster than I could read them, and self-dismissing. After watching this for about a minute, I took a stab at an "OK" button, and the cycling stopped.

I send the first satellite message to my phone number. I got a message back a few minutes later that the address wasn't recognized. Cerberlink can send and receive emails only. Check-in and SOS messages can be sent to pre-determined phone numbers setup through the web site, but recipients can't reply directly – they must reply via email. Yes, you can send and receive SMS messages by email (with some effort, unreliably), but the Cerberlink documentation doesn't cover that.

I ran more tests from my back yard. I did not succeed in sending a message via satellite. When I turned on Airplane mode, then turned on Bluetooth, as suggested in the pop-up help messages, the app complained about not being paired with the Cerberlink, even after I reconfirmed that the phone was paired with the Cerberlink. Later I turned off Airplane mode, turned on Bluetooth, and things started working.

The LED blinks were so short, especially when multiple LEDs blinked simultaneously, that I had a hard time figuring out which LEDs were on and what color, especially in the dark.

I successfully sent one check-in from the back yard. All check-ins are tagged with GMT instead of local time, which confused my wife and even me sometimes. I took the Cerberlink on a day hike and sent a check-in, then tracked the hike with 20 minute tracking. Everything seemed to work OK.

I sent the first three check-ins a few minutes after turning on the device, but after the LEDs indicated all was well. I sent the last four check-ins at the end of the day, several hours after turning on the device. I measured distances between my actual location and the Cerberlink check-in latitude/longitude using the Google Earth ruler. All check-ins were delivered within a few minutes of pressing 1-1-1.

• 330 feet off – Back yard, deep in a forested canyon
• 25 feet off – Day hike trailhead parking lot, flat open area
• 1.9 miles off – Coe Park HQ, on top of an open ridge

• 73 miles off – Kelly Lake dam, in an open canyon
• 2 miles off – 0.5 miles south of Rodeo Pond on Wagon Road, near the top of an open ridge
• 21 feet off – Pacheco Camp, in a forested canyon
• 813 feet off – Los Cruzeros Camp, in an open canyon

Yes, you read that correctly – the position reported in one check-in was 73 miles off, after the device had been running for over six hours. I was never closer than 70 miles to that location since delivery of the device.

I attempted to send four custom messages to my wife using the Cerbertouch app; one was delivered over 24 hours later; two were delivered within minutes; one was never delivered despite repeated attempts to push it through.

My wife replied to three check-ins, in spite of this statement in the Cerberlink manual: "Contacts cannot respond to check-in messages either by e-mail or SMS." All her replies were short, but because the replies included my original message, each resulted in 3-4 separate messages and message charges.

Tracking was reasonably close to my path, with one or two exceptions out of about 50 points. I forgot to turn off the Cerberlink for the drive home, so I have a few track points along the drive, even with the device laying in the back of my truck under a fiberglass shell.

I never used the Alert, Breadcrumb, or SOS functions.

On the last night of the trip (four days in), the app reported 90% of battery life left.

Total cost was $107.95 – $77.95 rental & shipping, plus $30.00 for 40 messages over the 20 included.

User experience

I was confused by the Briartek jargon; I had to learn the difference between Check-Ins, Breadcrumbs, Tracking, Alerts, and Messages; and Syncing versus Mailbox Checks.

The Cerberlink device has several red/green LEDs paired with icons. Even after seven days of use, I was mystified by some of the blinking LED patterns.

I found the Cerbercenter web site reasonably easy to use, though I was glad I set up everything several days before I left, and didn't leave setup until the last minute.

I found the Cerbertouch iPhone app confusing. It didn't provide good feedback, and used standard icons and techniques in some places but non-standard icons and techniques in others. The app provided lots of options that I didn't want.

According to the manual, you must press four app buttons to save and send a message immediately via satellite; in my experience, that never worked. I carefully pushed all the proper buttons in the right sequence. I got a satellite dish icon next to the message – and then nothing happened. No feedback in the app, and no new blinking lights on the device (the power light was blinking as normal). So I kept pushing buttons in the app and on the device hoping something would happen. Usually, I stopped in frustration after many minutes of flailing. Once, a message got a green check mark indicating "sent" after only a few minutes of flailing, despite no new blinking lights on the device. The other messages that got through, must have been sent when I wasn't looking.

I was confused by the many variations on "Cerber" in different product categories: Cerberlink (device), Cerbertouch (app), Cerbercenter (web site and email address), Cerberus (generic trademark?).

Concept of satellite texting devices

One reason I rented the Cerberlink was to try a satellite texting device.

I'm not sold, yet. Simplicity is a major virtue in lightweight backpacking. I usually don't take a smart phone or GPS while backpacking. I don't like managing the setup, operation, and health of two complex battery powered devices – a smart phone and a texting device. In an emergency, that complexity could be a serious problem.

Standalone two-way satellite texting devices, like the Yellowbrick 3 or the new DeLorme InReach SE, might work out well. I might try one.

After this experience, I have more appreciation for the simplicity and immediate feedback of satellite phones.

Conclusion

I really wanted the Cerberlink to work well – I was depending on it to keep my wife happy and to communicate in an emergency. Luckily, I had cell coverage on a few high ridge tops, so I could stay in touch with my wife, and I didn't need rescue.

Based on my experience, I'm not comfortable relying on the accuracy of Cerberlink positions, or my ability to send and receive messages under stressful emergency conditions. I'm not willing to manage two complex electronic devices in the back country. I will not rent the Briartek Cerberus again.

— Rex

[Roger Caffin]

Hi Rex

Thanks for the report.
We had similar problems with Spot I, including the seriously wrong positions bit.

Cheers

[Bob Gross]

It is interesting to read about the apparent problems with one product such as this.

Let me comment about the apparent GPS position errors. In virtually every civilian GPS receiver, there is a problem called a GPS Blunder. It is not a performance problem within the receiver as much as it is an inherent situation with GPS as an overall system. It doesn't happen very often, but when it does happen, a huge position error shows.

Here is the typical scenario. You power up the unit, and it gets a position fix within one minute. However, the position is either off by many miles, or else it reports your speed as something fairly irrational.

At the last time that I saw one of these blunders (next to my home), my receiver had a position fix that was about forty miles away from my home, and it showed my speed as about 350 miles per hour! Obviously that was wrong, so I shut it down, counted to ten, then powered it back up again. This time it got new readings that were perfectly accurate. What does this mean?

As you know, a receiver could get an accurate position fix on fewer satellites if its internal clock were perfectly accurate. But, it isn't. So it must acquire one extra satellite signal to be able to "buck out" the clock errors. Still, in most cases, there are two possible 3-D positions (somewhere around the Earth) that will satisfy the math. Typically, one of those two possibilities is totally impractical, like a thousand miles up and going at Mach 1. The receiver knows this and invalidates one of the solutions. It validates the one that is typically within 300 miles of where you last used it. Basically, it tries to use some common sense.

Once in a great while, this machine version of common sense is wrong. It picked the wrong solution, and the weird data result shows up. Once in a while, the receiver will quickly figure out that it picked the wrong one, and it will issue a screen order for the user to restart or reinitialize it. Sometimes you have to wait for a while for it to figure that out, and then you have to restart, so it is easier to restart it when you (the human) first start seeing the bogus information.

Now, I used to see a GPS Blunder about once or twice a year. That was back when there were fewer usable satellites. Now that the constellation is complete, I haven't seen very many. If you suspect that this might be happening, it is neat to fire up a second receiver ten feet away and see if it gets the right answer. I've done this many times. In this situation, I usually had two receivers working side-by-side with fixed antennas.

Additionally, besides the GPS Blunder problem, there is the possibility of multipath interference. That means when a signal is coming down from space, it should hit your receiver antenna directly and with no confusion. Instead, if it hits some reflective surface and then bounces over to hit the antenna, it starts making error problems. Many good receivers have good enough software to detect when multipath errors are happening, and it will invalidate that one satellite signal temporarily until it can find itself. If multipath gets bad enough (like when you are in the bottom of an urban canyon of concrete and glass), you may not get a position fix at all, or you may get one with errors. Of course, this doesn't happen much in a wilderness environment except for a box canyon.

And then, let's suppose that the GPS receiver actually got a perfect position fix, and then it sent that out via satellite and then via Internet to some destination address. You never know when some server along the way might have a software hiccup and some data gets corrupted by a few digits. Granted, it doesn't happen very often. It is more an indictment of the _service_ and not the actual device. Obviously the consumer expects to have all of these working perfectly or else it isn't worth much.

So, if you really want to _wring_out_ a GPS receiver, you need to collect more data.

I agree, this Briartek thing sounds a little too suspicious.

–B.G.–

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