Question: In E-UTRAN, what is the primary purpose of providing a Reference Location to a GNSS receiver in a User Equipment (UE), and what geodetic reference frame is mandated for this location estimate?
Option 1: To initialize the GNSS search process with an estimated location (using methods like Cell-ID) and its uncertainty, using the WGS-84 geodetic reference frame.
Option 2: To enhance cellular network coverage by utilizing the GNSS receiver's precise location, referenced against the European Terrestrial Reference System 1989 (ETRS89).
Option 3: Solely to provide an alternative positioning method when GNSS signals are weak, without specifying a standard geodetic reference frame.
Option 4: For billing purposes, associating the UE's location with its cellular usage, using the North American Datum 1983 (NAD83) as the reference.
Explanation: The correct answer is Option 1 because providing a Reference Location to a GNSS receiver in a UE serves to expedite the acquisition of satellite signals by offering an initial location estimate (which could be derived from Cell-ID, downlink positioning, etc.) along with its uncertainty. This process is crucial for efficient positioning. Moreover, as per specifications, WGS-84 is mandated for such location estimates in E-UTRAN, ensuring global consistency and accuracy in geographical coordinates.