Claims:1. Altitude determining circuitry for use in a User Equipment of a wireless communication network, the altitude determining circuitry comprising:
a receiver to receive at least one pressure parameter representative of a plurality of indoors pressure measurements from a respective plurality of indoors pressure measurement units located inside a building at corresponding measurement-unit altitudes; and
processing circuitry to receive from a pressure sensor in the User Equipment a local pressure measurement at the User Equipment and to determine an indoors altitude of the User Equipment using the at least one pressure parameter and the local pressure, wherein the plurality of indoors pressure measurements comprise at least two indoors pressure measurements corresponding respectively to at least two different measurement-unit altitudes.
, Description:Technical Field
Embodiments relate to determining an indoors altitude of a user equipment in a wireless communications network.

Background
Determining an outdoors location (geographical position) of a User Equipment (UE) in a wireless communications system can be performed using signal measurements made by the UE or an associated eNode B and also by using position and/or velocity calculations based on the signal measurements. One example of a wireless communications network is a network implementing third generation partnership project (3GPP) Long Term Evolution (LTE) or LTE-Advanced (LTE-A) technology. Positioning methods that are used in wireless networks include network assisted Global Navigation Satellites Systems (GNSS) methods, downlink positioning and enhanced cell-identification methods. GNSS methods can be ineffective when a UE is located indoors due to attenuation of the signals by roofs, walls and other objects. Even where an indoors location can be performed using GNSS, the level of accuracy is likely to be too low for the derived indoors position to be useful for potential applications such as indoors navigation in buildings such as museums, airports and hospitals and mobile object-tracking for objects such as mobile robots or specialist equipment (e.g. hospital equipment).

Brief Description of the Drawings
Embodiments described herein are illustrated, without limitation, by way of example, in the accompanying drawings in which:
Figure 1 schematically illustrate illustrates a User Equipment (UE) incorporating a Global Navigation Satellite System (GNSS) chip according to one embodiment;
Figure 2 schematically illustrates an indoors pressure measurement unit according to one embodiment;
Figure 3 schematically illustrates a first embodiment of an indoors pressure-altitude determining system in which a plurality of indoors pressure measurement values are transmitted to a UE;
Figure 4 is a signal diagram showing communication of signals in the indoors location system of the Figure 3 embodiment;
Figure 5 is a flowchart that schematically illustrates an indoors altitude determination for a UE, performed by the system of the embodiment of Figure 3;
Figure 6 schematically illustrates a second embodiment of an indoors pressure-altitude determining system, in which a master indoors pressure measurement unit and one or more slave indoors pressure measurement units are provided;
Figure 7 is a flowchart that schematically illustrates method performed by an indoors altitude determining system for a UE according to the second embodiment of Figure 6;
Figure 8 is a signal diagram showing signals communicated between a plurality of indoors pressure measurement units and a UE according to the second embodiment of Figure 6; and
Figure 9 illustrates, for ?one ?embodiment, example components of a UE device.

Description of Embodiments
The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of the claimed invention. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the invention claimed may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.