Since the operational commissioning of the constellation Iridium NEXT (¹), the Iridium company has started offering its new range of services called “ Certus® ". These services rely on the significantly increased technological capabilities of new satellites, which allowed, among other things, for Iridium to be approved as a second satellite communications provider for the GMDSS maritime security service (²), of which the competitor Inmarsat had held the monopoly since 1979.
Certus®, besides showing that American businessmen are also literate (³), is a range available in six bandwiths levels starting from 22 Kb/s up to 704 Kb/s, and up to 1408 Kb/s in the near future.
Iridium first started providing broadband services for professionals (aviation, maritime, railway, etc.) and public institutions (Military, Civil Protection, etc), as the industrial partners, Thales, Intellian, Sailor, and others, put their compatible communication devices on the market. The first certified devices Certus® 700 et 200 were marketed from mid-2020. We saw them on the boats of the last Vendée Globe, and more recently the Transat Jacques Vabre. This November 2021, Iridium has just announced the availability of several new devices that are compatible with the service Certus® 100
Certus® 100, adapted to the (great) yachting
Two devices are currently available for maritime use. The most affordable is the SkyLink 6100 by Blue Sky Network LLC. With a nominal bandwith about 88 Kb/s., or a maximum of 650 KB/minute, it is 40 times faster than an Iridium GO!®. This allows for a relatively comfortable internet connection. 
In addition, The device doubles as a cellular router : a cellular SIM card can be inserted in addition to the Iridium SIM card. This allows, Once set up, Prioritize cellular connection, as long as it is accessible, and thus save on satellite communication costs. So, once connected to the SkyLink device's Wi-Fi, with cell phone enabled, One can browse any website and use all the apps.
The device supports messaging apps, IoT data transfer and mobile-optimized web browsing. It is not, however, intended for general web browsing or high-bandwidth applications. With a smartphone or tablet, in example, the "Network Connection Measured" mode can be set on the WiFi configuration screen of the SkyLink network.
For the voice, SkyLink enables Iridium calling with a SIP app on a smartphone. Currently, two applications are documented, with a setup guide : Linphone et Wave Lite (⁴). It is likely that other SIP applications can be used, compatible with the SIP server built-in the device. This remains to be verified.
Comparison of available products
A column has been inserted for a possible future device according to the service Certus® 20 not yet available, in order to compare the bandwiths.
Communications costs
Communication services are billed by the volume of data, with airtimes per tranche corresponding to a maximum volume, to which may be added an overage cost. Voice is charged at a single price per minute.
Airtime 25 MB and 50 MB (⁵) correspond to monthly usage, as commonly practiced with an Iridium GO!®with a flat rate Unlimited data + 150 mn voice, for downloading GRIB files and messaging. Like what, the airtime 50 Mo will cost about 350 € incl. VAT/month for data, to which we will add about 70 € incl. VAT/month for 150 Voice call minutes. The service will therefore cost 2,5 times that of an Iridium GO! with a device approximately 3 times more expensive. Still, This is still quite reasonable for a very superior service.
But we can also be satisfied with 25 MB/month for approximately 210 € incl. VAT/month, and limit voice calls. In this case, the price is only slightly higher than that of unlimited plans for Iridium GO!®.
Certus® 100 associated with SkyLink 6100 could therefore satisfy long-distance boaters, practising of expeditions or polar navigations (not covered by Inmarsat), Professional conveyors, or individuals who remain in professional activity while browsing, there are more and more of them !
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(¹) The new Iridium NEXT constellation is completed
(²) GMDSS : Global Maritime Distress and Safety Service. See GMDSS in the Glossary.
(³) Certus, Latin word meaning : decided, resolute, and also : precise, sure.
(⁴) All SkyLink Guides 6100 are accessible On this page in PDF format.
(⁵) 50 MB = 50 Mega-Bytes = 50 Megabytes (not Mbps = Mega-bits/second)
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