Method and apparatus for handling a cell change

#Example embodiments presented herein are directed towards a user equipment, and corresponding method therein, for handling a cell change. Example embodiments presented herein are also directed towards a network node, and corresponding method therein, for handling a cell change of a user equipment.

#In a typical cellular system, also referred to as a wireless communications network, wireless terminals, also known as mobile stations or user equipments, communicate via a Radio Access Network (RAN) to one or more core networks. The wireless terminals can be mobile stations or user equipment units such as mobile telephones also known as “cellular” telephones, and laptops with wireless capability, e.g., mobile termination, and thus can be, for example, portable, pocket, hand-held, computer-comprised, or car-mounted mobile devices which communicate voice and/or data with radio access network.

#The radio access network covers a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g., a Radio Base Station (RBS), which in some networks is also called “eNodeB” or “NodeB” and which in this document also is referred to as a base station. A cell is a geographical area where radio coverage is provided by the radio base station equipment installed at a base station site. Each cell is identified by an identity within the local radio area, which is broadcast in the cell. The base stations communicate over the air interface operating on radio frequencies with the user equipment units within range of the base stations.

#The foregoing will be apparent from the following more particular description of the example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the example embodiments.

#FIG. 1 is a schematic of positioning architecture in LTE;

#FIG. 2 is an illustrative example of user equipment performing a positioning measurement;

#In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular components, elements, techniques, etc. in order to provide a thorough understanding of the example embodiments. However, the example embodiments may be practiced in other manners that depart from these specific details. In other instances, detailed descriptions of well-known methods and elements are omitted so as not to obscure the description of the example embodiments.

#Overview of Positioning Measurements

#For the purposes of explanation, an overview of positioning methods will be provided. Thereafter, limitations of such methods will be identified and discussed. FIG. 1 illustrates positioning architecture in an LTE system. The positioning architecture may comprise a user equipment 101 which may be configured to perform positioning measurements. The user equipment 101 may be in communication with a base station 103. The base station 103 may be in communication with a core network comprising a Serving Gateway (SGW) 109, a Packet Data Network Gateway (PGW) 111 and a Mobility Management Entity (MME) 107. The core network may also comprise one or more nodes with positioning functionality, for example, a Gateway Mobile Location Centre (GMLC) 105, an Enhanced Serving Mobile Location Centre (E-SMLC) 115 and/or a Secure User Plane Location Platform (SLP) 113.