I just read, in the latest issue of Voiles et Voiliers dated May 2012, A comparison Inmarsat-Iridium that leaves me unsatisfied. Quite interesting in form, it presents a lot of approximations in substance, and does not allow the reader to form an opinion on precise and quantified elements of comparison. On the other hand, with all due respect to François-Xavier Ricardou, Mac software solutions have been around for a long time and are perfectly proven : just to see the number of participants provided with Mac or iPad at ARC 2011. I will try to contribute complementary, I hope so, enlighten potential buyers.
How it works
With a IsatPhone Pro It takes a minute to set up a connection before you can start downloading the data. Once connected, you can transfer as well as possible 12 KB per minute. A typical GRIB file is 15 KB to 45 KB. This will require at least a little over one minute to download with IsatPhone a file 15 KB.
So 1 Minute to connect + 1 Minute to send the request + 2 Antenna time minutes to download the file (Every minute started being billed whole) = 4 Antenna time minutes, thus 4 Billed units.
The system Iridium is a little faster : 18 Ko per minute is nominal flow (2600bps). A much higher flow could be noted under certain conditions (¹). Needed 20 seconds to establish the connection to the network and invoicing is established by increasing 20 seconds. For the same file of 15 KB, It will therefore take a little less than 1 Minute to download it.
So 20 s. to connect + 20 s. To launch the request + 60 s. to download = 5 billing slices (1mn40s).
How much does it coast (²) ?
- IsatPhone Pro + Carte yes = 579 €
- IsatPhone Pro + SIM card + dock station + Antenna = 1749 €
- Recharge 250 minutes = 245 € (0,98 €/mn). Validity 6 months. Contains 250 Units. The connection time is billed 1 Unit per whole minute.
- Recharge 500 minutes = 489 € (0,98 €/mn). Validity 1 year. Contains 500 Units. The connection time is billed 1 Unit per whole minute
- Iridium 9555 + Carte yes = 1129 €
- Iridium 9555 + SIM card + outer antenna + cable = 1677 €
- Recharge 200 minutes = 449 € (2,25 €/mn). Validity 6 months. Contains 12000 Units, thus 60 Units/MN. The connection time is billed by slices of 20 Units (0,75 €)
- Recharge 500 minutes = 659 € (1,32 €/mn). Validity 1 year. Contains 30000 Units, thus 60 Units/MN. The connection time is billed by slices of 20 Units (0,44 €)
Comparison table of prices including tax in France
It must be taken into account that an external antenna is essential for maritime use, allowing the phone to be kept inside the boat while guaranteeing the best possible connection. Iridium is provided as standard with an antenna connection kit, The Isatphone requires a reception station to connect the external antenna.
How much the request and reception of a Grib file cost and receive ?
On the basis of a communication card of 500 Prepaid antenna time minutes, and a GRIB file request from 15 Ko or 45 KB, We obtain the following costs :
COSTS TTC of communications
The iridium is therefore a little cheaper than the Isatphone to the installation, and much more advantageous for data exchanges.
Professionals point of view
Concerning the speed of data transfers, Opinions are shared :
GMN affirm (³) only, with its box Optimizer associated with the application XGate Email & Web app, data with IsatPhone Pro are now fully functional and simple option for email and weather at sea. It remains to test it.
XGate for iPad/iPhone is an identical application to Iridium Mail & Web app pour Iridium AxcessPoint (¹), also developed by GMN. Unlike the WiFi AxcessPoint router, only dedicated to Iridium 9555 and 9575, The WiFi Optimizer router allows the use of many satellite telephony devices, with all Iridium models. It will therefore bring the same optimization of data transfers to iridium as to the Isatphone Pro.
On his side, MailaSail, British supplier of satellite communications, I realized with few installation for Mac, Gives an unusual opinion regarding the Isatphone :
"I do not know how much to continue the experience anyway because we only see disappointments with Isatphone for the data… It is :
- Less than half the speed of an iridium for download
- Very slow connection times (40-60 seconds against 10 Seconds for Iridium)
- A cost of AirTime about to climb up at prices 3 down to 4 times the iridium price (multiply by 2 To obtain real billing, Downloads being twice as slow with Isatphone Pro)
- The equipment is about to increase price
- Material with external antenna is more expensive than iridium with external antenna
I do not notice any situation where Isatphone is working properly for data. It's slow, inadequate and unsatisfactory, while also being (or more) expansive than Iridium. Last year at ARC 2011, Those who had one were typically people who had come to see us to have a price on an iridium, Then found a cheap Isatphone on the Internet. We then received a large number of calls asking us how to operate effectively and they were totally unsatisfied with the results… ”
This confirms that, Without the help of a data compression service, associated with different optimization systems (firewall, anti-spam, aso.), the use of a satellite phone to receive data is unreliable. On the other hand, In addition to applications such XGate and Iridium Mail, Weather4D PRO In addition, bring to the Iridium system a prediction tool for passing satellites which makes it possible to considerably reduce connection times, So communication costs, by ensuring connections without any interruption (⁴).
This added to price comparisons between the two competitors, That is enough to convince me that the Iridium choice remains more economical and more suitable for the reception of Grib files to this day. The purchase price of the Isatphone alone has certainly deceived a lot of buyers, which must add additional software and service to use their device satisfactorily. Especially since the argument concerning the two years of validity of the Isatphone recharges falls from June 1 2012, date on which these durations will be reduced almost to the equivalent of Iridium recharges.
To conclude : do we beware of appearances ! In such a technical field, it is important to provide an argument based on concrete data, quantified, and the least subjective possible. The ideal being to have been able to test the different devices over a long period. This is what I was able to achieve for the iridium solutions, I hope to have an upcoming opportunity to do the same for the Isatphone.
[Update 26 June 2012] A test board will be made from 20 to late July in the Mediterranean between Port-Leucate and Dubrovnik. Stay connected, a post will be published during August.
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(¹) Navigation with iPad trainings : a complete solution .
(²) Source tarif Nauticom avril 2012
(³) Optimize IsatPhone Pro Satellite Phone Data
(⁴) See Article on use of Weather4D Pro for the prediction of the passage of the iridium satellites.
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In response or complement to the previous comment and your article :
Since your densat on Rafale, 2 Additional deckchairs on 2 Different boats, test supplements therefore with an iridium 9555, The small "capsule" antenna, iPad , Iridium axcesspoint case.
1 – No need to equip yourself with an outdoor antenna.
2 – By cons with Weather4D Pro, satellite prediction allows you to choose the right time and undoubtedly, I tried it, You have to wait for a well -placed satellite and it changes everything. A second point in its latest version, W4D PRO indicates file size, You can choose : 3 days, 5 days to see more, the step, the mesh, etc,. I try not to exceed 12 KO with 2 Types of requests, one at 3 days, step 3 hours steps. and 0.5 ° network, In situations let's say a little hot. If not a forecast at 5 days, in a larger area, step 6 hours steps, 1 ° network, updated all 2 days. On average let's say about 1 Minute to recover the files, But I often do this when I get back or send emails, So difficult to be more precise. But my connections have never reached 2 minutes. This combination of requests seemed sufficient for these last two deckchairs.
To my knowledge, Impossible to do better today. Happy sailing to all.
Thank you Christophe for this feedback.
Hello Francis
Xhosa has been equipped since last year with an Isatphone Pro. Specialists recommended it to me because, according to them, They would offer a better bandwidth than iridium… Like what…
Your article interested me very much but I have a little trouble reconciling the costs you indicate and my real invoices. During my cruise, last summer, I had 16 data connections for a total duration of 33.17 minutes (being under a post-paye plan, billed in USD, I prefer to convert everything to the communication minutes). So 2 minutes 4 seconds on average by connection.
Of course, These are not 16 Connections for GRIB files. These connections are for emails and grib, or combinations of both. I am unfortunately unable to say how many kinds, nor what size were the Grib (that I have erased in the meantime).
Nevertheless, If each connection requires 1 Minute of "negotiation" and at least a minute of "effective work", It becomes almost impossible to reconcile these times with my invoice…
Unless I only asked for hyper-légers gribs, or that I have had connections (billed at only one minute?) or ???
If a life -size test should be organized, I am quite ready to make my device available, Because I really want to understand where the difference comes from! In addition, This would understand which cost supplement to go from a Grib of 3 days at 7 days or an interval between 12 -hour data rather than 6 hours, or from a large geographical area to a smaller (or more 3 at a time).
This analysis also shows that you should not always listen to sellers when they promise wonders…
A positive point to mention nevertheless in favor of the Isatphone is that, When I used it in voice in sea conditions not good at all, The quality of the voice was excellent (as through a fixed line on the ground) and not at all deformed and metallic. But, I only had anecdotal use in this mode…
Thank you for your site and your blog!
Thank you for this interesting feedback. This shows that it is essential to carry out real tests over a long enough period to make a quality judgment, and therefore a reliable opinion.