Sunday, 19 April 2015

Iridium Go! - Game Changing Satellite Transceiver

For many years we've used our Icom HF / SSB radio for email and weather updates when at sea. Planning our crossing of the Indian Ocean this year, we knew that HF radio propagation was at best fitful and often impossible. So once again we looked at the satellite telephone market place for a backup communication system for Crystal Blues.

In the past we had been put off by the inflexible and costly satellite useage plans.  However the game has changed with the availability of the Iridium Go! satellite terminal.

There are several important new features. Firstly, the availability of an unlimited data plan for US$125.00 per month. This allows us to use the system extensively, without incurring additional data costs, and includes a generous monthly allowance of 150 minutes for voice calls.

Secondly, the "plan" can be suspended at the end of any month, and re-started when required for a fee of US$50.00.

So when we arrive in an area with consistent cell phone coverage we can turn off the Iridium system and reactivate it when we need it, without losing our unique phone number.

Finally, this isn't so much a telephone as it is a transceiver. It doesn't even come with a handset. Instead, it creates a local wifi hotspot that can be accessed by smart personal telephones, iPads and personal computers. Free Iridium software apps provide voice call, messaging and email services.

After hearing good reports from other sailors we ordered a system and started to plan the installation...

IRIDIUM NETWORK BASICS   This device works with the Iridium LEO (low earth orbit) satellite system, essentially a unique cell network that is floating in low earth orbit.

"Floating" is probably a misleading descriptor - they travel at an altitude of around 476 miles, zipping along at 17,000 miles per hour !

Uniquely, in this system call traffic is passed from satellite to satellite before being downlinked at one of several earth stations.  As the satellites are in low orbits, constantly moving, they can "hand off" calls from one satellite to another during the progress of a call - the same as land based cell networks "hand off" to an adjacent tower as we move across the land.

Each satellite can handle over 1000 concurrent voice calls at 2400bps.  For those of us old enough to remember what a telephone modem looks like, that speed was considered sluggish on telephone lines 20 years ago.  So it is not fast, but is is everywhere as Iridium are keen to remind us.  The network covers the entire earth's surface.  Uniquely, due to the polar orbits, maximum satellite density is achieved near the poles, where it really isn't needed !  Conversely, the lowest density is near the equator, right where we are now ....

PURCHASING   We purchased a packaged system online, from Predict Wind, who have also developed a custom weather software application (download it here) to work with the Iridium Go!

The equipment was delivered to us in Malaysia in less 10 days, complete with all the parts needed for a cruising boat installation.  The Predict Wind kit includes a passive external antenna, 10 meter coaxial cable and all the necessary adapters, power supplies, brackets etc.

The SIM card for the unit was included, and we were able to activate it online once the gear was installed.

INSTALLATION   Assembling the system is quite straight forward, though the antenna cable install took us some considerable time.  The system runs at 1600Mhz, and at those frequencies the antenna cable must be installed perfectly.  The co-ax cable is quite stiff, so care is needed - it must not be bent sharply.

The transceiver unit includes a GPS receiver, so the unit is position aware at all times.  This allows it post accurate position updates and to broadcast emergency messages if required.

Our Patented Iridium Go! Sun Shield
However the GPS receiver is mounted in the main unit, not in the remote antenna.  Therefore the installation location must be chosen to give the transceiver a view of the sky.  On a metal boat like ours that means above deck, so we installed it under the hard dodger, close to the windscreen glass.

Caution :  The Iridium Go! does not like to be too hot.  It is shipped with a grey plastic cover to be used when exposed to the sun ..... however being dark grey I figure that cover absorbs quite a lot of solar energy.  It sure doesn't work.  The system has internal monitoring of processor temperature and will shut down if safe levels are exceeded.

We had problems with temperature until we developed a custom sun shield for the system - quite innovative as you can see in the photo at right.

COMMISSIONING   After activating the SIM card account the system came up working straight away.  We had loaded the Iridium Go! application into our iPhone and were able to place a voice call immediately.  The instructions are clear enough and the process is simple.

By default, the administrator role is assigned to the guest account, without password protection.  Not a very safe way to run a system. I recommend that once you have the system up and running, you should register yourself as a user on the system, with password protection, and assign administrator rights to that new account.  If you have multiple users you can also restrict access to telephony if required.  There are multiple options for providing crew services via the unit.

Phone & Messaging App
If you already use a router on board your vessel to connect to other devices, you may need to re-jig the IP address plan.  The Go! uses as it's default address, so your other router may need to be configured as (say) to avoid clashing (our router was already configured this way for other reasons).  Doing this means our PC at the nav station can remain connected to both services at all times.

VOICE CALLS   Making a telephone call is a simple matter.  You connect to the Iridium wifi hotspot with your smart phone, then load the Iridium Go! application.  Select a number from the directory and dial.  That is it.  Quality is at the "low end" but acceptable and the link appears solid.

MESSAGING   Iridium provides a messaging service that is run from their own system servers, interfacing with the GSM mobile text message system..  Outgoing messages are free to Iridium Go! users, sized up to about 1000 characters.   Iridium users are not charged for the received messages, though these are limited to only 160 characters, including the address header.

Messaging is one option within the Iridium Go! application on the smart phone or iPad app.

Note :  Cell phone users who respond directly to your message may not be aware of the 160 character limit, and there is nothing in the response system that shows when that limit is reached.  Consequently we receive a lot of truncated messages with lost data.  It is better for responders to logon and use the Iridium messaging server on the web, as it will actually show when the 160 character limit has been reached.  Alternately they can originate messages to the Iridium Go! from their email account, but will have to carefully watch the character count.  It is not a perfect world.

Mail & Web App
EMAIL   Iridium provide a free email service using a separate application called Iridium Mail & Web, that must also be downloaded (its free). You can select your own email address prefix within the system setup, though the suffix will always be

The mail application is kind of clunky, partly because the data rate on the network is so slow, and partly because the application is .... well its just clunky !

You can attach a photograph to an email, but by default the application will automatically resize the image to shorten the transmission time.  The result (300 pixels wide) is acceptable for web posting and simple photo sharing, but you'll need to adjust the configurations if you want to send higher resolution (it will be very slow).  Remember all of these services are being delivered on your connected mobile device - iPhone or iPad etc.

We have used the email app to post short blog updates, with an attached image, and it works fine.

A note to Iridium LLC :  Why do we have to deal with two separate apps ?  It does create pointless complexity for the users.

Opera Mini Browser & Facebook
WEB BROWSING   By using the special Opera Mini browser app, you can browse the web.  Once again it is very slow, and the app must be configured to ignore images and graphics, so its basically text only most of the time.  Ley has managed to post to Facebook, and occasionally we can read our favourite newspaper.  It works, but you have to be patient.

POSITION REPORTING   The system offers a range of position reporting options, including automatic reporting at configurable intervals.  You can create a list of email addresses that these reports are sent to.   You can initiate a position report at any time. We use an automatic hourly update, that generates the report seen at the top of this page.

EMERGENCY NOTIFICATION   The Iridium Go! will send a distress message using it's dedicated distress button.  During commissioning you are able to decide where the distress messages are sent and to provide relevant contact details.  Iridium offer an optional (no charge) service to route those messages to a third party control center for action.

3RD PARTY APPLICATIONS   Iridium is working with third party developers to broaden the base of applications available for the system.   We are using two of those - Sailmail and Predict Wind, that both run on our notebook PC.  After some extensive testing there is a lot to say, so I'll cover our experiences with these in a future posting.

Complete Control Via The Web Applet
SYSTEM CONFIGURATION   Most configuration issues can be handled in the Iridium Go! application on the iPad or iPhone.

However the unit includes a HTML browser interface, called "Iridium Go! Advanced Features".  Type in the IP address of the unit (usually from a connected notebook PC or portable device web browser and the Go! will serve up a quite sophisticated set of control and configuration pages.  You can even monitor internal temperatures if you are experimenting with installation locations.

Warning :  Do not remove administration privileges from the guest account until you have assigned admin privileges to a another new account on the unit - apparently it is possible to "lock yourself out" !

PURCHASE & OPERATING COSTS   Compact satellite systems have been affordable for some time, however the monthly operating costs could be daunting.  While you can buy a plan with limited data capacity, Iridium have been clever in offering an unlimited data package at a price that is affordable.   For that US$125.00 per month we're getting free messaging, unlimited data / email / weather forecasting via Iridium apps or third party software,  position reporting and emergency reporting.  Not to forget those 5 free minutes of telephone voice calls per month !  The per-minute rate for additional voice calls seems reasonable.

PERFORMANCE & RELIABILITY    After two months of use I must say that I am pleased with the system.  For me the value is in the third party applications - we've only made two or three phone calls in two months, and the Iridium apps are dedicated to portable devices, so I find them a little limiting.  However with Predict Wind and Sailmail applications working I see good value.  

We are now very close to the equator - Latitude 00degrees 49.54 north.  Reliability with the Iridium iPad apps has dropped off quite a bit - Ley has been trying now for 30 minutes to pull one 100k email attachment down on the Iridium mail application.  However the Sailmail and Predict Wind software still work fine, as they appear to handle the data transfer more efficiently, with Sailmail's performance being by far the best of all.

So we are impressed, but must emphasize that everything you do requires a generous lashing of patience - it is not fast, but it does work everywhere !


  1. How is support for the Go by Predict Wind?
    We rented an Iriduim phone from Global Marine Networks last year and were not pleased with service although we worked out how to get the phone to work well for data

  2. Fingers crossed, so far we have not required any in-depth support. The vendor has been quite pro-active, and the few questions we had were cleared up very fast. I think it helps that this device was planned from the start as a connective tool - rather than being planned as a telephone that also can do data. That mindset, plus the ease of wifi connections, makes it a simple setup.


Have something to say ? Let us know your thoughts ....