Search results
Results from the WOW.Com Content Network
In the GSM cellular mobile phone standard, timing advance (TA) value corresponds to the length of time a signal takes to reach the base station from a mobile phone.GSM uses TDMA technology in the radio interface to share a single frequency between several users, assigning sequential timeslots to the individual users sharing a frequency.
Many GSM phones support three bands (900/1,800/1,900 MHz or 850/1,800/1,900 MHz) or four bands (850/900/1,800/1,900 MHz), and are usually referred to as tri-band and quad-band phones, or world phones; with such a phone one can travel internationally and use the same handset. This portability is not as extensive with IS-95 phones, however, as IS ...
Since cell phones rely on radio waves, which travel through the air and are easily attenuated (particularly at higher frequencies), mobile phones may be unreliable at times. Like other radio transmissions, mobile phone calls can be interrupted by large buildings , terrain, trees, or other objects between the phone and the nearest base.
GSM uses TDMA and FDMA for user and cell separation. UMTS, IS-95 and CDMA-2000 use CDMA. WiMAX and LTE use OFDM. Time-division multiple access (TDMA) provides multiuser access by chopping up the channel into sequential time slices. Each user of the channel takes turns to transmit and receive signals.
The phone also offers a call screening option which, when activated only allows the numbers that are in the phone's memory to call that phone. The standard features of the phone are up to 8.5 days standby time and up to 6 hours talk time. Texting and download capability are unavailable, which allows parents to manage phone costs. [citation needed]
The most common example of a cellular network is a mobile phone (cell phone) network. A mobile phone is a portable telephone which receives or makes calls through a cell site (base station) or transmitting tower. Radio waves are used to transfer signals to and from the cell phone.
Quick Charge is a proprietary technology that can charge battery-powered devices, primarily mobile phones, at power levels exceeding the 7.5 watts (5 volts at 1.5 amps) supported by the USB BC 1.2 standard, using existing USB cables. The higher voltage available allows more power (watts) to be supplied through wires without excessive heating.
The Lumia 920 has a 2000 mAh non-user-replaceable battery, providing a maximum standby time of up to 19 days and maximum talk time of up to 7.5 (2G) or 10 hours (3G). In addition to USB charging, the Lumia 920 can be recharged inductively using the Qi standard . [ 28 ]