[OT] Reason for delay at GSM cellphone startup ?

Hi,

Anyone doing work on GSM cellphones ? All the GSM cellphones I have used, cannot search for a phone number for something like 10 to 20 seconds after the link has been established at switchon. What is so resource hungry that a simple search through the addressbook cannot be done during this time ? Even the GSM modules I have used behaves the same.

Regards Anton Erasmus

Reply to
Anton Erasmus
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AFAIK, that's not a problem of some procedure hogging the the CPU for that long (if it were, the length of this pause would depend on the age of the phone, as their processors keep getting faster each year). It's simply that the interface between the phone and the SIM card, where at least a part of those numbers are stored, is so slow that it takes a couple of seconds to copy its contents into RAM. And they don't even try to let you use the addressbook before that's completed.

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Hans-Bernhard Broeker (broeker@physik.rwth-aachen.de)
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Reply to
Hans-Bernhard Broeker

Even with a slow 1MHz clock for a SPI EEPROM, it should not take more than 0.5 seconds to read 32K. The delays I have seen are tens of seconds.

Regards Anton Erasmus

Reply to
Anton Erasmus

That might be true, but at what clock rate is the phone reading the card? My phone clearly tells it on the display that it is reading the phonebook from the card.

Meindert

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Meindert Sprang

"Anton Erasmus" skrev i meddelandet news: snipped-for-privacy@4ax.com...

The address book is on the SIM card, and you have the ISO7816 interface which is not very fast. 9600 BAUD typically, maybe up to 115 kBaud.

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Ulf Samuelsson   ulf@a-t-m-e-l.com
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Reply to
Ulf Samuelsson

Thanks, I had a brief look at the standard - The protocol is quite slow. Why nobody at least let you type in the query, and only delay the search at startup is a mistery. Blocking the entry routine because the resource to be searched is not yet available, is not less than optimal.

Regards Anton Erasmus

Reply to
Anton Erasmus

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