areas, the capability to bypass base stations and the backhaul network is a major advantage, because many of these backhaul networks are becoming congested with high-volume data traffic. The importance of femtocells is reflected by the fact that the 3rd Generation Part- nership Project (3GPP) fourth-generation (4G) Long-Term Evolution (LTE) standard includes usage of femtocells for additional coverage. This standard specifies the way gateways and femtocell access points interface with one another as well as security and provisioning. Handheld Devices and Tablet Computers A key enabling technology that makes femtocells feasible is the improved soft- ware algorithms that detect signals from macrocells. Because of the small area COV- ered-about 5,000 square feet-most of the traffic is located at the edge of the cell. Traffic at the edge of the cell has the potential to interfere with frequencies in mac- rocells because signals can "bleed" into surrounding areas. Improved software algo- rithms in femtocells have the capability to sense both the frequencies and the power levels in the microcell, and adjust them as required SO that the femtocell signals don't interfere with the macrocell traffic. According to Dr. Andy Tiller, senior vice president of Product Management and Marketing for Cambridge, England-based femtocell and picocell maker ip.access: ip.access's femtocells and picocells can sense the radio conditions in adjacent cell sites before they start transmitting. This so-called "Network Listen" scan enables the femtocell to, for example, raise its power if the signal from the surrounding macrocell is strong, or conversely, reduce its power if the signal from the macrocell site is weak. This decreases interference and improves voice quality and data speeds for mobile users in the vicinity-both those served by the femtocells as well as those in the surrounding macro network. HANDHELD DEVICES AND TABLET COMPUTERS Handsets and tablet computers are a major expense when upgrading cellular networks, but they are an im