case of CP/mobile-phone device linked to a cellular network provider data service). A mobile device with just an L1 front-end radio receiver and no GPS acquisition, tracking, and positioning engine only works when it has an internet connection to an ISP/CNP, where the position fix is calculated offboard the device itself. It doesn't work in areas with no coverage or internet link (or nearby base transceiver station (BTS) towers, in the case on CNP service coverage area). Without any of those resources, it can't connect to the A-GPS servers usually provided by CNPs. On the other hand, a mobile device with a GPS chipset requires no data connection to capture and process GPS data into a position solution, since it receives data directly from the GPS satellites and is able to calculate a position fix itself. However, the availability of a data connection can provide assistance to improve the performance of the GPS chip on the mobile device. Modes of operation Assistance falls into two categories: Mobile Station Based (MSB) Information used to acquire satellites more quickly. It can supply orbital data or almanac for the GPS satellites to the GPS receiver, enabling the GPS receiver to lock to the satellites more rapidly in some cases. The network can provide precise time. Mobile Station Assisted (MSA) Calculation of position by the server using information from the GPS receiver. The device captures a snapshot of the GPS signal, with approximate time, for the server to later process into a position. The assistance server has a good satellite signal and plentiful computation power, so it can compare fragmentary signals relayed to it. Accurate, surveyed coordinates for the cell site towers allow better knowledge of local ionospheric conditions and other conditions affecting the GPS signal than the GPS receiver alone, enabling more precise calculation of position. Not every A-GNSS server provides MSA mode operation due to the computational cost and the declining number of mobile terminals incapable of performing their own calculations. Google's SUPL server is one that doesn't. A typical A-GPS-enabled receiver uses a data connection (Internet or other) to contact the assistance server for aGPS information. If it also has functioning autonomous GPS, it may use standalone GPS, which is sometimes slower on time to first fix, but does not depend on the network, and therefore can work beyond network range and without incurring data-usage fees. Some A-GPS devices do not