What to do when No GSM signal


#1

I am putting data on a ftp every 3 minutes (with gprs) , everythig works fine, i can’t figure out what happens when the GSM signal is lost.
Right now i do netInit after that i create the bearer, when the bearer is ok i create ftp , then wip_putFile, and wip_write. I have a variable that is set true if data was sent ok and false if not. If data was not sent ok (like when the GSM signal is lost) i retry sending until send is ok .
I stumbled upon a problem i get that data was not sent ok(no gsm signal) , i retry to send it , o couple of times , then GSM signal is ok ,retry again, but i get WIP_CEV_ERROR (event->content.error.errnum =0) in ftp channel event handler.
Is the bearer stopped after some time and i need to restart it or what is the problem?


#2

Ok so far no answer, maybe i’ not clear enough :frowning:
I whant to know what happens when the gsm signal is lost,i am using GPRS to put data on a ftp, everything is ok when i have signal but when the signal is lost during the tests i run, i get different behaviours at each test, so could some one enlighten me with what happens when there is no GSM signal?


#3

You seem to be thinking of “signal lost” as a single, well-defined event - which, of course, it’s not!

Precisely what happens will depend on precisely how the signal failed, and precisely what was happening in the transfer at the exact time.

Think about what would happen if you were just using a wired network, and cut the cable - that’s a much more well-defined event, but you’d still get some variation depending on what exactly happened.

Some FTP implementations support “restart” - where they can detect a failure and resume from where they left off once the connection recovers.
I don’t know if the WIP implementation does this - you’ll have to check for yourself…


#4

I was told the FTP implementation supports the resume session and Wavecom claims it on its web site… so it should be somewhere in the documentation…


#5

What version of WIP are you using?

WIP_OFFSET is documented in the WIPLib v3.00 guide for wip_putFileOpts() and wip_getFileOpts() on an FTP Channel


#6

Has anybody already used this WIP_OFFSET option with success ?

I tried to use it, but WIP_OFFSET isnt define in the wip headers files so it gives me an error… (at least for version 2.00.12 and 3.00.07)


#7

You could try with WIP_COPT_RESTART instead of WIP_OFFSET…
It’s listed among the file-handling related options in the headers and could be what is supposed to be used. It’s not the first time Wavecom documentation have been flawed :smiling_imp: