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The call flows and information exchange required to enable MBS positioning in a handset have been developed in 3GPP and Open Mobile Alliance (OMA) standardization bodies. In the context of location, the 3GPP standards group is involved in developing the Control plane protocols and call flows, whereas the OMA has been involved in enabling the User Plane protocols. Note that Control Plane is the channel in Mobile Systems that is used to send Signaling Information, and User Plane is the channel in Mobile Systems that is used to send User Data.

The concept of TBS was introduced in Release 13 of the 3GPP standards, and MBS was included as a special case of TBS. Release 13 included support for UE‐assisted measurements, pressure sensor measurement (for altitude estimation), and stand‐alone positioning for MBS. Both protocols (e.g. Location Positioning Protocol LPP document 36.355 [14]) and performance/conformance specifications (e.g. documents 37.171 [15] and 37.571 [16]) were updated to enable MBS support in Release 13. 3GPP Release 14 expanded MBS support in 36.355 [17], 37.171 [18] and 37.571 [19] to include UE‐based positioning modes as well as beacon assistance. With Release 14, the MBS system call flows and protocols have a similar level of maturity to those of A‐GNSS.

A sample LPP call flow between the server (eSMLC) and device (UE) for 3D positioning using MBS along with assistance is shown in Figure 39.20.

Figure 39.20 LPP call flow for MBS positioning using assistance.

Corresponding standards work has been done in OMA for MBS positioning in the data plane. Mobile Location Protocol MLP version 3.5 [20] includes support for indicating the use of the MBS positioning solution, the barometric pressure sensor solution, as well as hybrids thereof from the Location Server to the Mobile Location System MLS client (e.g. UE), while SUPL version 2.0.3 [21] includes support for the signaling of MBS capability.