To help adhere to Federal Communications Commission rules, cell phone companies have to be able to provide authorities with handset latitude and longitude to an precision of 50 to 300 meters. Cell Tower Triangulation will not always meet this requirement. For comparison, commercially available GPS modules can certainly achieve accuracy down to less than 10 meters. This is dependent on a lot of factors, as GPS signals are often really weak and are affected by numerous environmental factors. With Mobile Location Services (MLS), the GSM cellular network provider utilizes triangulation algorithms to determine the location of the cell phone, its accuracy is proven to be much worse than that of GPS. MLS is further impacted by factors similar to GPS in the sense of the barriers impeding signal quality and the density of GSM towers to assist in the triangulation effort. In rural areas position accuracy may be off as much as a mile. GPS receivers, no matter whether within a smart phone, or perhaps a specific Portable gps tracking system, compute location through accurately timing the signals passed on by GPS satellites. This information provides the moment the message was sent, precise orbital information (formally called the ephemeris), plus the basic system health and determined orbits of all GPS satellites (technically referred to as the almanac). GPS receivers often take a long time to become ready to use after being turned on because it must acquire some basic information in addition to finding GPS satellite signals. This delay is sometimes caused when the GPS smartphone has been unused for days or weeks, or has been transported a far distance while turned off. The GPS must update its almanac and ephemeris data and store it in memory. The GPS almanac is a set of data that every GPS satellite transmits. When a GPS receiver has current almanac data in memory, it can capture signals and compute initial position faster.