For Dropped Calls on AT&T's 3G wi-fi and cell phone network due to weak tower signal try these products for 5 bar signal strength:
Dropped calls are especially an issue when switching over to the high-speed 3g wi-fi network using all models of the apple iPhone, including 3G, 3GS, 4Gs etc Many apps from apple's iTunes store that you can download for your iPhone are made as stand alone applications, but some require a network connection and to do that you must have a decent cellular signal.
Do you need to know signal strength? Most important, do you need to know what frequency (800 MHz or 1900 MHz) your iPhone works on? Follow the directions below for answers:
1. Access the iPhone’s Field Test mode by typing *3001#12345#* in the phone’s keypad and press dial. This will bring up the Field Test menu.
2. Select the “Cell Information” menu option to display a summary of all nearby towers. The “RX” code displays the signal strength of each tower. These RX values are dBm signal strength readings, where lower values means strong signal (so -60 signifies stronger signal than -80). The towers are listed by signal strength, and the top tower is usually the tower your phone is connecting to.
3. Selecting the first tower will take you to a further menu that displays more specific information. The “Freq” value shows the frequency block that the network is using. If the Freq number is between 128 and 251, the tower is using the 850 MHz Cellular band. If the Freq number is between 512 and 810, the tower is using the 1900MHz PCS band.
This has been known to help in the following areas:
Better cell phone signal in Canada
Stronger cellular signal in California
Five bar signal strength in Kansas
To improve signal strength, we recommend the following products:
(841263) Kit. Awesome! Test (point) the outside antenna for best signal boost. Can add-on additional inside antenna's for more coverage. Dual Band 800/1900 MHz.
(841262) kit. Easy if you have no time to point outside antenna. Omni-directional Antenna makes setup a breeze. Dual Band 800/1900 MHz.
(841245) Great booster kit for small office/basement area. Better than than the desktop unit but limited inside coverage...
(841365) kit 1900 MHz. Direct 65db gain. Best in class, but depends on location. Works on 1900 MHz only. Check frequency value. Between 512-810 is 1900MHz and this kit is the best single band. If frequency value is between 128 and 251 use the (841165) kit or (801165) Amplifier to build your own kit. Update 12/02/2012. ONLY buy if you need 1900 MHz on Sprint.....
Desktop Kit: (801247) dual band. Works good but limited to desktop area only...
Mobile Kits: (801212) (801213) (801240) (801242) (801243)