Been a while since I posted, but I just went through this myself so hopefully this will help.
Last trip away to keep in touch with work we would use the iPhone as a hotspot, but in some area's there's not enough signal for that to be a viable option ... so we added a 4G WiFi modem with an external 7db antenna mounted ontop of a 7m telescopic fibreglass mast (packs down to just under 2m) ... in fringe area's where there's little or no signal for the handset we get 1-3 bars of 3G service on the wifi modem ... the phone is on a 10gig monthly plan ($60/month) and the 4G Wifi Modem is on a 24month expiry pre-paid $140/16GB. In many places we stopped where others around us had no service we did with the mast setup.
For this years trip the coverage maps show no service, so I looked into the sat' phone route ... minefield !!
Long story short ... Went with the Thuraya system (XT-Lite handset - calls and sms only - Purchased phone through Epirbhire. You can google them. $50 more than I could find elsewhere but I'm dealing with a specialist, not a box retailer, who are contactable 24/7. I would reccomend them highly!!). The calls are 0.99c/min, no flagfall, the sms are 0.50c each, and the plan is $15/month with no minimum term. The plan is post paid with Pivotel. You don't run out of credit when you MAY need it the most, no swapping SIM cards between devices (iphone in an otterbox defender case) AND at this monthly rate and call costs, we CAN use the phone freely without incurring the national debt. Callers to the service only pay whatever their plan charges them for a call to a std Australian mobile phone number, or to send an SMS (so for most your included calls/sms mean you incur no additional charge to ring my sat' phone) ... Immarsat system by comparison cost people who call YOU around $15-18 per minute !! Irridium is too expensive. I pay $180/year for a sat' service + calls and at that price I consider it cheap ... and work pays for the plan, and work purchased the phone outright. If I dont use the service I'm paying $15/month. Big deal. The number for my sat' service is a std Australian mobile phone number. Pivotel have a nice customer log-in that lets you look at all your unbilled calls, sms, and all in/out traffic with itemized call costs and numbers shown. Appears to update every 24hrs, and my monthly bill is emailed to me with 14 days or so to pay.
This Pivotel plan provides data capability, BUT, data is $5.00/MB ... yes ... $5000/GB ... Optus had the phone for $700 (no minimum term) on a very similar, slightly cheaper call rate/$15month plan and data was $2.50/MB ... yep, $2500/GB ... question is, HOW BAD do you need data
... for me, not that bad. I passed on Optus as even their satellite specialists couldn't tell me how much incoming calls were likley to cost the caller .... BUT you could buy the phone for $700, take the $15 plan for a month THEN cancell and you've scored a cheap Thuraya XT-Lite ...
So IF work needs me that bad, they call the sat' phone, leaving a voice message (costs me $0.99c/min to retrieve the voice mail) OR they send an SMS to the sat' phone (which costs me nothing to recieve ... calls or sms inbound cost me nothing) ... We intend to check the sat' phone every morning and every evening when we are out of normal mobile coverage area's ... IF the need to call back or log-in to work is urgent, I can ring, or SMS, or if it has to be a data connection it just has to wait until we have enough mobile coverage to run up the 7m mast and fire up the 4G wifi modem (which runs 3G in outback area's) and do what's gotta be done ... sometimes, even when your on holidays, you can't just walk away from your business for 3-4 weeks and not be contactable. An unfortunate fact of being in business these days.
All the other (3x) sat' systems available are too expensive for a casual month by month plan, have call costs that are 2-3 times (or more) than Thuraya, have handsets that cost far more, and data on any of them is prohibitively expensive ... and the data speeds are way slow ... I think Thuraya's data speeds are faster than the other 3x .... If you want data, Thuraya do an XT (full spec, not Lite) data capable phone ... best I found was around $1300 outright + your plan.
The sat' phone, chargers, leads, 12v chargers, 4G Wifi etc all are packed into a Pelican 1200 case, packed away in the rear drawers. If we had a rollover, this protects these items and makes them still workable for emergency comm's. The 4G wifi modem has the ability to compose and send an SMS message stand alone without a phone or laptop connected.
There are Sat' Sleeve, Sat' Hotspot products from Thuraya that allow you to use your Android or iPhone as the Sat' handset connected via WiFi to these devices, but if your Mobile device is damaged (they tend to ride loose in the cabin, not packed in a case) the sleeve/Hotspot devices can only send a pre-configured message to a preset (by you) number ... They will do data just like you'd use your iPhone for example when connected to the cellular mobile network, but the cost of the data makes it prohibitive. I prefered the idea of a completely separate stand alone phone ... which I can afford to use when stationary each morning/night ... $15plan + 10x 2min calls + 10x SMS messages gets me a $40 bill for the month ... I think Telstra starts at $35/month Irridium plan with no calls with calls at $3.40/minute
The XT-Lite handset works like my old Nokia 5110 ... calls, sms, basic mobile phone handset. It's a tad larger than an iPhone 4S and a bit thicker. From here (Newcastle area) the sat' is 22deg above the horizon, in a stationary orbit above Singapore ... point the phone WNW at 22deg up, wait for a GPS fix, wait for service to acquire, then dial ... takes a couple of minutes. The further north, or north west you travel, the higher above the horizon you point ... Once the phone has a fix and has acquired the service, I can actually take it inside and sit it on the coffee table ... it alerts you to incoming calls or sms and asks you to take the phone outside to where you have a clear view of the sky ... in practice, tree's are a no no but I've found that you can maintain enough service under tree cover to get an sms in or out ... if your in a big ass valley with a giant mountain between you and the satellite you will have to change your location.
Hope this helps !
Cheers
Kevin