Methods and systems for positioning of a mobile device using broadcast of assistance data

A user equipment (UE) for using broadcast location assistance data in a network, comprising:

• a wireless transceiver;
• and
• one or more processors configured to:
• send a request via the wireless transceiver for ciphering key parameters in response to expiration of a time of applicability of ciphering key information or the UE leaving a geographic area of applicability of the ciphering key information or receipt, by the UE, of ciphered positioning assistance data for which the UE lacks corresponding ciphering key information;
• obtain first ciphering key parameters received at the wireless transceiver from a network node in the network during a mobility management procedure;
• obtain a System Information Block (SIB) periodically broadcast from a base station within at least one cell for the base station received at the wireless transceiver, the SIB comprising ciphered and encoded first positioning assistance data for the at least one cell for the base station, and an indication of ciphering;
• decipher the encoded first positioning assistance data based, at least in part, on the first ciphering key parameters and the indication of ciphering;
• decode the deciphered and encoded first positioning assistance data;
• and
• determine location information for the UE based, at least in part, on the deciphered and decoded first positioning assistance data.

A non-transitory storage medium comprising computer readable instructions stored thereon which are executable by one or more processors at a user equipment (UE) to:

• request ciphering key parameters in response to expiration of a time of applicability of ciphering key information or the UE leaving a geographic area of applicability of the ciphering key information or receipt, by the UE, of ciphered positioning assistance data for which the UE lacks corresponding ciphering key information;
• receive, at the UE, ciphering key parameters from a network node in a network during a mobility management procedure;
• receive, at the UE, a System Information Block (SIB) periodically broadcast from a base station within at least one cell for the base station, the SIB comprising ciphered and encoded positioning assistance data for the at least one cell for the base station, and an indication of ciphering;
• decipher, at the UE, the encoded positioning assistance data based, at least in part, on the ciphering key parameters and the indication of ciphering;
• decode, at the UE, the deciphered and encoded positioning assistance data;
• and
• determining, at the UE, location information for the UE based, at least in part, on the deciphered and decoded positioning assistance data.

A user equipment (UE) for using broadcast location assistance data in a network, comprising:

• means for requesting ciphering key parameters in response to expiration of a time of applicability of ciphering key information or the UE leaving a geographic area of applicability of the ciphering key information or receipt, by the UE, of ciphered positioning assistance data for which the UE lacks corresponding ciphering key information;
• means for receiving, at the UE, first ciphering key parameters from a network node in the network during a mobility management procedure;
• means for receiving, at the UE, a System Information Block (SIB) periodically broadcast from a base station within at least one cell for the base station, the SIB comprising ciphered and encoded first positioning assistance data for the at least one cell for the base station, and an indication of ciphering;
• means for deciphering, at the UE, the encoded first positioning assistance data based, at least in part, on the first ciphering key parameters and the indication of ciphering;
• means for decoding, at the UE, the deciphered and encoded first positioning assistance data;
• and
• means for determining, at the UE, location information for the UE based, at least in part, on the deciphered and decoded first positioning assistance data.