Posted by Lakshmanan Lakshmanan, firstname.lastname@example.org
on April 16, 2002 at 11:09
Satisfactory window of delivery would be < 2 mins
-- The limitation is not in the delivery from the service provider (in anycase all of the receipients are connected to the MSP), but in sending the message - sequence is send - wait - check inbox and send (we need to do this there may be requests coming in as well), the quickest a message therefore could be sent is 8 seconds because of the capability of the instrument ....
Posted by gabor salai, email@example.com
on April 16, 2002 at 12:58
: Satisfactory window of delivery would be
: < 2 mins
: -- The limitation is
: not in the delivery from the service provider
: (in anycase all of the receipients are
: connected to the MSP), but in sending
: the message - sequence is send - wait
: - check inbox and send (we need to do
: this there may be requests coming in as
: well), the quickest a message therefore
: could be sent is 8 seconds because of the
: capability of the instrument
i use my own sms managing software based on at-command interface between gsm/pc; i use nokia 6210 and serial dlr-3p cable.
what exactly are you referring with "inbox": inbox inside gsm instrument, or inbox on your communicating software?
i am going to describe you timings as i found them looking on at-command level.
from attempting to make a sms (issuing at+cmgs command) to finishing the text of message it needs about 1 second (transferring the message more quickly from pc to nokia, sometimes rise error on my nokia, so this 1 second delay is for safety purposes; maybe i have some problems in handshaking)
after completition of message, it needs about 4-5 seconds to receive a confirmation from gsm that message is transferred to operator;
so total (active) time is time1+time2=cca 6 second, after which gsm seems to be ready to process next sms.
after a total of about 10 seconds my colegeau, sitting next to my desk, receives that sms.
i found difficulties when trying to initiate new sms before gsm returns confirmation in time2.
according to nokia's at specificatons, there is some kind of "block mode", which allows you to send few messages in one session, reducing allover time. normaly, each message has its own session, having to establish connection (time slot) with gsm operater, resulting in time overhead. personaly, i didn't succed to obtain this block mode yet.
this possibility also depends on local gsm operator.
i don't make so often the inbox checking, because i leave new messages to be buffered in nokia's inbox (nokia 6210 has 20 inbox places)
i found 15 seconds inbox checking interval sufficient.
gsm instrument is a peace of hardware, with its own software release. so, there is, also, allways a possibility of not resolved bugs in your exemplar of instrument. also, there must be some kind of built-in cpu, which, obviously has its own data processing limits, depending of model.
i am writing this to you, because i am still trying to improve my software solution, also trying to test some newer nokia models.
I tested sending SMS messages by using AT commands as well by using the Nokia SDK and a Visual Basic application. The solution with the SDK is about twice faster by transmitting. There is not necessary including any waiting loops. Probably they are already implemented in methods used in the SDK. I think that the implementation is much efficient as can be done by using AT commands.