for better battery performance so far i'd try

Setting>phone>sim-pin>off

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Added on November 18, 2011, 8:05 pm
sim pin doens't contribute alot nor at all....

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Before simpin>on my signal is stay one 1 bars even weak no signal.

Have to try simpin>off my signal stay full in the same area.

got my method from apple support communications.

Have u turn cellular network ON?

Try a clean restore without might help.

iphone4s
ios5.0.1
maxis user

new normal sim card cut into mirco sim

Problem: Setting>General>phone>sim application doesn't work.

http://support.apple.com/kb/TS4148


only for iphone4s user, who facing signal and sim card issue.

Try fetch by hour or 15min.