Retrieval of positioning assistance data based on persistence information
Embodiments include methods for a user equipment (UE) to obtain positioning assistance data associated with a cell of a wireless network. Such methods include receiving a first part of the positioning assistance data associated with the cell from a positioning node via unicast in the cell, and receiving a second part of the positioning assistance data associated with the cell via system information (SI) broadcast in the cell. Such methods also include, based on the second part, determining a persistence indicator associated with the first part, and based on the persistence indicator, selectively requesting an updated first part associated with the cell from a network node of the wireless network. Other embodiments include complementary methods for a positioning node as well as UEs and positioning nodes configured to perform such methods.
1 . A method for a user equipment (UE) to obtain positioning assistance data associated with a cell of a wireless network, the method comprising:
receiving a first part of the positioning assistance data associated with the cell from a positioning node via unicast in the cell;
receiving a second part of the positioning assistance data associated with the cell via system information (SI) broadcast in the cell;
based on the second part, determining a persistence indicator associated with the first part; and
based on the persistence indicator, selectively requesting an updated first part associated with the cell from a network node of the wireless network.
2 . The method of claim 1 , wherein selectively requesting based on the persistence indicator comprises:
requesting the updated first part from the network node when the persistence indicator indicates that the first part is not persistent; and
refraining from requesting the updated first part from the network node when the persistence indicator indicates that the first part is persistent.
3 . The method of claim 2 , wherein one of the following applies:
the network node is a radio network node (RNN) serving the cell and the updated first part is requested for delivery via on-demand SI broadcast in the cell; or
the network node is the positioning node.
4 . The method of claim 1 , wherein the second part includes an explicit persistence indicator for the first part.
5 . The method of claim 1 , further comprising, before receiving the second part, receiving via SI broadcast in the cell a further second part of the positioning assistance data associated with the cell.
6 . The method of claim 5 , wherein:
the second part includes an associated version number;
the further second part includes an associated further version number; and
determining the persistence indicator comprises:
determining that the first part is persistent when the version number is equal to the further version number; and
determining that the first part is not persistent when the version number is not equal to the further version number.
7 . The method of claim 5 , wherein:
the second part includes a first number of identifiers of transmission sources of positioning signals;
the further second part includes a second number of further identifiers of transmission sources of positioning signals; and
determining the persistence indicator comprises:
determining that the first part is persistent when the first number is equal to the second number and the further identifiers are the same as the identifiers;
otherwise, determining that the first part is not persistent.
8 . The method of claim 1 , wherein:
the second part includes an associated expiration time;
the second part is received before the first part; and
determining the persistence indicator comprises:
determining that the first part is persistent when the current time is before the expiration time associated with the second part; and
determining that the first part is not persistent when the current time is after the expiration time associated with the second part.
9 . The method of claim 1 , wherein:
the second part includes a timestamp indicating when the second part was received, from the network node, by a radio network node (RNN) that broadcasts the SI in the cell;
the first part is received before the second part; and
determining the persistence indicator comprises:
determining that the first part is persistent when the first part was received before the timestamp; and
determining that the first part is not persistent when the first part was received after the timestamp.
10 . The method of claim 1 , wherein:
the first part includes an associated area of validity; and
determining the persistence indicator is further based on whether the cell is within the area of validity.
11 . The method of claim 1 , wherein:
the first part and the second part are positioning assistance data for UE-based observed time difference of arrival (OTDOA) positioning method;
the second part includes relative time difference, RTD, between transmission times of downlink positioning reference signals (DL PRS) from a plurality of sources in the wireless network; and
the first part includes locations of the plurality of sources.
12 . A method for a positioning node to provide positioning assistance data to user equipment (UEs) operating in a cell of the wireless network, the method comprising:
sending, to one or more UEs via unicast in the cell, a first part of positioning assistance data associated with the cell; and
providing a second part of the positioning assistance data associated with the cell to be broadcast in the cell as system information (SI)
wherein the second part includes information that facilitates UE determination of a persistence indicator associated with the first part.
13 . The method of claim 12 , wherein one or more of the following applies:
the first part includes an associated area of validity; and
the second part includes an explicit persistence indicator for the first part.
14 . The method of claim 12 , further comprising, before providing the second part, providing a further second part of the positioning assistance data associated with the cell to be broadcast in the cell via SI.
15 . The method of claim 14 , wherein one or more of the following applies:
the second part includes an associated version number, and the further second part includes an associated further version number; and
the second part includes a first number of identifiers of transmission sources of positioning signals, and the further second part includes a second number of further identifiers of transmission sources of positioning signals.
16 . The method of claim 12 , wherein:
the second part includes an expiration time for the second part; and
the second part is provided for broadcast before sending the first part.
17 . The method of claim 12 , wherein:
the first part and the second part are positioning assistance data for UE-based observed time difference of arrival (OTDOA) positioning method;
the second part includes relative time difference, RTD, between transmission times of downlink positioning reference signals (DL PRS) from a plurality of sources in the wireless network; and
the first part includes locations of the plurality of sources.
18 . The method of claim 12 , further comprising, when the second part indicates that the first part is not persistent, receiving from a UE a request for an updated first part of the positioning assistance data associated with the cell.
19 . A user equipment (UE) configured to obtain positioning assistance data associated with a cell of a wireless network, the UE comprising:
a radio transceiver circuitry configured to communicate with a radio network node (RNN) serving the cell; and
processing circuitry operably coupled to the radio transceiver circuitry, whereby the processing circuitry and the radio transceiver circuitry are configured to:
receive a first part of the positioning assistance data associated with the cell from a positioning node via unicast in the cell;
receive a second part of the positioning assistance data associated with the cell via system information (SI) broadcast in the cell;
based on the second part, determine a persistence indicator associated with the first part; and
based on the persistence indicator, selectively request an updated first part associated with the cell from a network node of the wireless network.
20 . A positioning node configured to provide positioning assistance data to user equipment (UEs) operating in a cell of a wireless network, the positioning node comprising:
communication interface circuitry configured to communicate with the UEs via a radio network node (RNN) serving the cell; and
processing circuitry operably coupled to the communication interface circuitry, whereby the processing circuitry and the network interface circuitry are configured to perform operations corresponding to the method of claim 12 .