ISP Information:
This is normally read-only memory that retains its information until it is exposed to ultraviolet light. You can often tell a chip is an EPROM by the small window on it that lets ultraviolet light though to program the EPROM.
ISP Glossary:
Erasable Programmable Read Only Memory - Why's that? I'm not a network-side guy, but it seems to me that thelocal system just needs to talk to its own VLR to find out what itneeds to know about you. All the phone is doing is sending up a databurst (encapsulated in one of several ways, depending on the systemand the length of the message and the phase of the moon), whichwouldn't seem to be a process requiring any special contact with thehome network.I am not a very technical person, but you program a Service Center tothe phone. The service center phone number includes the country codein order to be reachable from other networks. So, I believe whathappens is that you are actually calling this number (at least itappears this way last time I roamed in Switzerland). Also when SMSfirst started you could use any Service Center in the past few years,it seems that all the networks allow only their subscribers to usetheir center. This means that you are forced to call home to send themessage. Certain networks will not charge for this minimal call. Others will charge you the minimum international call. You mean it not only phones home, but it generates a *CDR* for the process? I don't get it -- what's the other end of the call supposed to be? In the phone bills I have received from 3 different carriers, SMS appear intermixed with normal calls. I believe the CDR comes from the Service center. At the other end of the call, you see the number you sent the message to. In the case I described above, I remember seeing both the call to the Service Center from the Swiss network in the roaming section of the bill, and the actual SMS in the local part of the bill.Spyros
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