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SMS Messaging Unreliable
Lovejoy writes "From a Reuters story: Keynote announced today that in its two-week, 26,000 message test-period 7.5% of its text messages never reached their destinations Ouch. I don't have SMS - Is this report consistent with your experience?"
Works here (in Finland) well enough. I'd say 99% of my messages reach their destination.
SMS messages can be set to "expire" if the are not delivered in a certain amount of time. All the phones I've owned had this set to "now or never", so if the message couldn't be delivered at the moment it got trashed. Mos users, of course, have no idea this setting exists.
AT&T got me started on SMS with a "free for now ..." package, then switched to one where incoming is free, and outgoing costs 10 cents each. So I adapted and basically never send a text message from my phone. However, it is handy that you can e-mail messages to an AT&T cell phone at 5055551234@mobile.att.net (i.e. insert appropriate phone number) for no cost. So I regularly e-mail my wife's cell phone from my desktop.
Crispin
----
Crispin Cowan, Ph.D.
Chief Scientist, WireX Communications, Inc.
Immunix: Security Hardened Linux Distribution
Available for purchase
How is $0.10 a message (with Cingular) a free service? My carrier charges for both sent and received messages, although it's possible to buy your messages in bulk for a discount, i.e. 100 messages a month for $3.99, 200 for $5.99, etc.
"It's Dot Com!"
The handset gets a received receipt via the network when a) the message is waiting to be received by the other handset and b) the message is delivered successfully. If your handset doesn't get the first receipt back immediately, the network received receipt, it gives you an error. You can frob a bit on most Nokias to show you all this, it's really handy.
Feel that power? That's mah MOUSING FINGER
Is this report consistent with your experience?
:)
Well for what it's worth,
1. International (roaming) messaging is a disaster. You're lucky if anything arrives, and if it does, it can easily be delayed a few days. Once it gets through, you're likely to get the message several times - people reported up to seven times. Can you say ACK ?
2. During peak loads, it looks like the (Belgian) operators give priority to packets originating from subscribers -- ie people who are not using a GSM-version of a calling card containing n minutes / m messages. This was especially obvious at new years' eve -- everyone I know with a subscription got through with every single SMS; people with a card got exactly zero messages through the stampede. If delivery fails, you get a notice though, and afaik you're not billed.
I have a t68 world and a t28 world. the t68 is for my cingular wireless here in the states. Every third sms croaks with this service, while my Slovenia phone co, Mobitel, can get every sms to me when I cut on my t28 in the States, or anywhere for that matter. I think it really has to do with the provider and the importance that they put on sms. Cingular charges 3 bucks for 100 sms's a month, while Mobitel charges nothing and only 1 tolar a minute for phone calls within SLO and 55 tolars a minute for international roaming for my Cingular phone. Cingular charges 400 tolars a minute (2 bucks, roughly) for a minute to my Mobitel phone. US GSM and mobile phone plans in general are a ripoff. How can Slovenia, while pretty prosperous for a former Yugoslav republic, keep rates so cheap? It can just be 90 percent market penetration alone!
Comparing it to Windows will be a moot point, since El Dorado is going to have a 40% larger code base than XP.
SMS is never intended to be reliable. There are many places that the SMS can be lost. So, lets go through a description. :) Before we begin, let me prefix this by saying it's all GSM, and probably wrong (going from memory), but probably close enough.
Acronyms:
Your handset is connected to a base station. The base station talks to the SMSC and gives the SMS to it to deliver. The SMSC then attempts to forward it on to the destination SMSC, who will send it to the destination BS and finally to the destination phone.
Now, add in the fact that a destination phone may not always be available to receive the SMS. It may be outside of signal range, have a dead battery, or simply be turned off. So the destination SMSC has to store the SMS. The SMS is usually lost because the SMSC has to flush it, like a congested router.
The next place that it can be lost is in the originating SMSC. Consider, it takes a _lot_ of negotiation between carriers to get links set up, and add more. Cost/SMS, payments, etc have to be agreed. Now, imagine you've saturated that link and need to send another message. Yep, it queues up on the sending SMSC too, only he doesn't care as much because you're not his customer. :)
Let's look at some math:
- SMS/subscriber/day: 10 (billed+others)
- Number of subs/SMSC: 2m
- Size of SMS: 256bytes
- Percentage lost: 3%
- Number of lost messages: 600k
- Space needed to store all lost messages until delivery: 600,000 *
.25kbytes = 150megs
So, assuming that all messages can be delivered in 24 hours, you would have to find 150megs of free space on the system to get it to work (good luck). Of course, the messages would be late and confusing, but who cares!An SMS is an unreliable, time limited message. It doesn't carry long term value, and is usually used for "ping" type messages. Top it off with TV shows receiving votes by SMS which result in rates going from 100SMS/second to 500SMS/second, and you get an idea into how hard the problem can be.
Jason Pollock
I'm seeing a lot of "Why the hell would someone use a cell phone to message when they can just talk?!?"
Well, besides the giggle factor that comes into play the first time you message a friend who's staring at you from right across the room, my answer would be because IT QUIET!!!
In the movie theater and your mom/boss/significant other wants to know where you are, or why the hell you aren't someplace you're supposed to be? Your phone on vibrate can show you who's calling you, and you can quickly type in a message and reply back with information without disturbing those around you.
On New Years Eve, I was at a Rave at the LA Sports Arena. Do you think I'll really be able to hear or talk to anybody next to a wall of subs blowing out my ear drums? Considering there were quite a few people there, I also get separated from my friends. Where's my buddies? When do I know when it's time to go? How far is Kenny getting with that Bree chick (seriously!)? There would be no way we could talk on our phones, but we were still able to communicate with our SMS text messages.
Now granted, SMS isn't nessecary, but then again, this is Slashdot. How often do we do things that are truely nessecary?
-Kefabi
In europe the phone tells you the moment you send your message if the network has accepted it or not.
If the network has accepted your message for delivery, it will try to deliver it for a certain amount of time (this is configurable on the sender's phone), I have set mine to 72 hours.
You get a delivery report the moment the network has accepted your message, and another one the moment the intended recipient has gotten it.
If after the delay the message couldn't be delivered (read: recipient cellphone was offline during all this time) you get a delivery report for failure, so at least you know it's failed.
This works in almost ALL european countries, the few exceptions are certain operators (like Bouyges Telecom) which filter SMS coming from foreign numbers.
I'd say the service is great, reliable, informative and cheap. As a result, SMS has mostly replaced pagers in Europe.