Is anyone able to give me some details about the GSM network search algorithm? I know that a terminal will oscillate between +CREG state 0 and 2 (not searching / searching) when attempting to register with the network. If the terminal is in an area of poor coverage, the duration of the "not searching" phase (+CREG 0) increases indicating a search backoff. Can someone tell me what the timings are for this back-off procedure?
Also, would the terminal ever stop searching after a period of x mins? For example, if the terminal is searching but out-of-range for a number of hours/days, then brought in to an area of good coverage, would the terminal register automatically? Is it a better idea to initiate a search (+COPS 0) every hour perhaps?
All thoughts/theories gratefully received!
the GSM network search algorithm is not so trivial. Basically you could have automatic or manual PLMN selection mode
PLMN Selection State diagram (automatic mode)
Figure 2b: PLMN Selection State diagram
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