Different cell phone models get different reviews on their overall quality and reception. Many factors contribute to cellular phone reception, including make and model of the cell phone. Each phone is a small, low-power transmitter, and each phone also has one or more antennas that pick up the signals from nearby cell towers.
Cell Phone Antennas
Deep in the circuit boards of your cellular phone is a set of fractal antennas which, if the phone is engineered properly, are designed to be electromagnetically shielded from the other electronics of the phone, and positioned so that metal components within the case of the phone at the very least don't interfere with reception. In a few cases, some of the metal components inside the phone are carefully arranged to act as a reflector to redirect energy to the antenna itself. Digital signal processor chips tease out the most information possible on a weak signal. Sometimes, the antenna is placed in a less-than-optimal in the cell phone chassis, so that reception is affected by the way you hold the phone, or by conductivity changes from oil and sweat from your hand. The most well-publicized such case was that of the iPhone 4; Apple eventually responded to consumer complaints by issuing free nonconductive "bumper cases" for the device. This design flaw does -- albeit rarely -- crop up in lower profile devices.
Cell Phone Towers
When cell phones were new, and about the size of a brick, cell phone broadcast frequencies were around 900 MHz, requiring antennas that extended beyond the length of the phone itself. As cell tower broadcast frequencies have gotten higher, the wavelengths have shrunk and the antenna sizes have been reduced proportionately. Laying out antennas as fractals has also shrunk antenna sizes, and, additionally, reduced the amount of power needed to use the radio in the phone. Likewise, as the distance between towers has diminished, so has the amount of power needed to use the transceiver on the phone (the part that hands your cell phone signal to the next nearest tower when you move), and phone batteries can last longer as a result.
Carrier Network Standards
While there are those who hold that one of the underlying standards (CDMA or GSM or UMTS) provides better reception, the reality is that this isn't the case. The carrier standards used impacts the digital signal processors on the phone, but those interpret the signals rather than the receive them. Where carrier choice makes a difference is in cell phone tower locations and coverage maps.
An over-the-air software update can impact cell phone reception. Your cell phone broadcasts a weak signal that queries the cellular tower, identifies your phone and is used to hand the signal off to another tower as you move. Software updates that boost or weaken this signal can improve reception, while software updates that weaken the signal can improve battery life, but result in more dropped calls.
- Harris Communications: Cellular Phone Reception
- Yale-New Haven Teacher's Institute: The Physics of Cell Phones
- Bloomberg: Apple Engineer Told Jobs IPhone Antenna Might Cut Calls
- Gizmodo: Giz Explains: What’s the Difference Between GSM and CDMA?
- MIT Engineering: Why Don't Cell Phones Have Retractable Antennas Anymore?
- Radio World: Fractal Antennas Offer Benefits, Tom Vernon
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