Just finished the steps seems to work great! Follow these steps : http://www.itweakios.com/apps/blog/...t-carrier-update-for-iphone-and-ipad-ios-6-7- ---------- Change Log This hack fixes the reported issue of unstable HSPA+ speeds/signal and iPad users having trouble updating and losing all signal. This hack enables, along with the previous enabled features, HD Voice for all iPhone models running on AT&T so users can now use the UMTS/HSPA/HSPA+ network for HD qaulity calling on their 4S and 5. This hack also enables Release 7 HSDPA speeds for the iPhone 4S, giving it a new maximum theoretical downlink of 21Mbps, which AT&T does indeed support. Signal improvements from the previous release have not changed and are still present in this release along with unthrottled LTE and HSPA+. The previous band preferences have been altered this time around but not to prefer bands. It has been reprogrammed to do the following: - "Optimize WCDMA" which will deliver the fastest available speeds without hindering the towers and other users on it. - "Set LTE near threshold" which will also deliver the fastest available speeds that the LTE towers support.