My point on “days for rescue” was that ONCE you have alerted authorities (regardless of how that was done) it can still take time for them to get to you especially when you are remote, not that authorities would magically start looking for you (unless you had an intentions form or person); and I wanted to make the point that if you did have two way communications, then authorities can tell you how long they think it will take and they know what to prepare.

I don’t want to take away from a SPOT or PLB’s benefit, it is simply an extra tick for phone (if you have coverage) or sat phone use. Sat phones can be very expensive to buy and run compared to a PLB, so that’s a negative for sat phones.

For example, if I set off the SPOT in the middle of the nowhere, the authorities have no way of knowing whether I have a critical vehicle breakdown or a snake bite to deal with, so they follow their protocols. If I make a sat phone call and talk to them, then they can decide to send a mechanic rather than a doctor.

My apologies here, but I do feel a bit defensive about the benefits of two way communications because I’ve been in a situation in the remote Kimberleys where a member of the party became sick in the late afternoon. It was 4 or 5 days drive to the nearest town with a doctor. I had an EPIRB (a few years back) and the sat phone. If I had I set off the EPIRB, authorities would have probably contacted the local Ranger, who would probably have taken a few hours to reach us that evening, or more likely would have come in the morning. He may have used his sat phone or RFDS radio (VHF) to arrange an evacuation, which would take more time - perhaps later that day or the following day …. That’s a long time for the casualty and a lot of stress for the rest of the party; and if I’d only had one way communications it would have been a very anxious wait never knowing when someone would arrive or what was happening. Many people have un-realistic expectations about how long it might take to be rescued which is compounded in a high stress situation.

As it turned out I used my sat phone and spoke to an RFDS doctor immediately who was able to give reassurances and advise me to administer some high dose antibiotics. Fortunately the matter was dealt with straight away (I have a remote area first aid kit, and of course a Ranger would have access to one too). When we did eventually reach “civilization” we called in for a check up and made a hefty donation to the RFDS.

Why be defensive about thinking two sat communication is better than no cell coverage or punching a one way PLB. Of course two way conversation is best. But in my opinion between a person buying a PLB and sat Phone, PLB is taking market share in that department.

Be aware that text messages often get through when a voice call won't. They make best use of whatever coverage is available.

Instead of carrying two phones, if your phone is unlocked you should just need a second SIM.

I am seriously not trying to be contincious here, but can can anyone speak to actually sending a text message in a no service cell area and it getting through. To me this is a urban myth. I am on AT&T and have tried this over 50 times in the last year and it has never worked. Several of these attempts have been while my friends with Sprint & Verizon in the car or onThe trail w/ me have service so I know signal is there for someone but not AT&T.

Interesting. I've never had a problem with Iridium. From what I know Globalstar had reliability issues in the past and am not sure if they still do as they are starting to launch new satellites.

Hi Comms, you cannot send an SMS on someone else's network. I think there may be some confusion about emergency calls to 911 (in the US). If "any" carrier has network coverage (that is compatible with your phone), then you can make a 911 call ONLY.

The point about SMSs is that it only takes a "millisecond" to transmit, so if your network is congested, or your coverage is marginal, then the SMS may get through where a voice conversation (which lasts much longer) may have difficulty staying established. This is particularly true when we had analogue networks, but can still occur now.

I make the point is saying "compatible with your phone" because there are a few different phone technologies about. In my part of the world we have 3G and GSM. Generally older handsets are GSM only and newer ones are both, but occasionally one is 3G only, so if you gave a GSM only handset and there is 3G coverage, it isn’t going to work !

Thanks Aussie, that makes sense.

I think people often mix up the situations of "no service" with "can't get through" when repeating this often used mantra about SMS. If your handset is not getting any signal at all, then obviously, even SMS won't work. It's possible that you may get brief, intermittent reception, in which case, you might have some success. Recall that in the James Kim family tragedy, their phone did briefly hit some cell towers intermittently.

In contrast, I have gotten SMS to go through in a couple cases where I couldn't make a voice call due to network congestion. SMS started in places like Europe, which use GSM. GSM has a separate radio channel for actual calls versus another channel for administrative tasks, like sending a signal to your phone that you have a voicemail message waiting. SMS utilizes that second channel, so even if all the voice channels are overloaded with users, SMS usually gets through on that second channel.

I don't believe other protocols, like CDMA, CDMA2000, etc., operate the same way regarding sending SMS on a separate channel, although they may have other reasons for being fairly reliable when sending SMS on a congested network. If anyone knows how other protocols handle SMS, I'd be interested to know.

Why not do what we did for years and just be self reliant. I know were are in the age of instant commnication, but to many people abuse the system.
cheers

I suspect that everyone who reads this post is as self reliant as possible. Unfortunately there are some things which just can't be dealt with by yourself, depending on your circumstances and skills.

Having said that, for people starting out and learning, I think it would be nice to think that they have a safety net if their plans go wrong.

Having a safety net is part of good planning.