This document provides the Stage One description of Location Services (LCS). A Stage One description provides an overall service description, primarily from the service subscriber's and user's points of view, but not dealing with the details of the Man Machine Interface (MMI). This TS includes information applicable to network operators, service providers and terminal, base station system, switch, and data base manufacturers.
This document provides core requirements to an extent sufficient to derive a complete definition of location services at the service level. However, the present document also provides additional requirements which may suggest in a non-normative manner certain ways the system may be implemented to support location services.
LCS can be offered without subscription to basic telecommunication services. LCS is available to the following categories of LCS clients:
Value Added Services LCS Clients - use LCS to support various value-added services. These clients can include UE subscribers as well as non-subscribers to other services.
PLMN Operator LCS Clients - use LCS to enhance or support certain O&M related tasks, supplementary services, IN related services and bearer services and teleservices.
Emergency Services LCS Clients - use LCS to enhance support for emergency calls from subscribers.
Lawful Intercept LCS Clients - use LCS to support various legally required or sanctioned services.
LCS is applicable to any target UE whether or not the UE supports LCS, but with restrictions on choice of positioning method or notification of a location request to the UE user when LCS or individual positioning methods, respectively, are not supported by the UE.
LCS is being developed in phases with enhancements added in 3GPP releases.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
For the purposes of the present document the following definitions apply:
Change of Area:
is one event supported for deferred Location Requests. Change of Area means that the network is required to report the location or the occurrence of the event of the requested subscriber in triggered fashion immediately after the network (MSC/SGSN) processes the mobility event for the new location of the subscriber. Usually new location is noticed after the Location Update, Tracking Area Update, Handover, RAU, Registration or RANAP Location Report, e.g. when the SAI changes.
access code, which is used by a Requestor or LCS Client in order to gain acceptance of a location request for a Target UE. The codeword is part of the privacy information that may be registered by a Target UE user.
after a location attempt has successfully delivered a location estimate or Dispatchable Location and its associated time stamp, the location estimate or Dispatchable Location and time stamp are referred to as the 'current location' at that point in time.
Deferred location request:
a location request where the location response (responses) is (are) required after specific event has occurred. Event may or may not occur immediately. In addition, event may occur many times.
The civic location of a UE and/or a valid Mobile Equipment (ME), expressed as civic data (e.g. floor, street number, city.) The Dispatchable Location shall be represented in a well-defined universal format. Regional regulations may specify the mandatory and optional elements in this universal format to be included in a Dispatchable Location.
Immediate location request:
a location request where a single location response only is required immediately.
in the context of an originating emergency call the location estimate or Dispatchable Location and the associated time stamp at the commencement of the call set-up is referred to as 'initial location'.
Last Known Location:
The current location estimate or Dispatchable Location and the associated time stamp for Target UE stored in the LCS Server is referred to as the 'last known location' and until replaced by a later location estimate or Dispatchable Location and a new time stamp is referred to as the 'last known location'.
a software and/or hardware entity that interacts with an LCS Server for the purpose of obtaining location information for one or more Mobile Stations. LCS Clients subscribe to LCS in order to obtain location information. LCS Clients may or may not interact with human users. The LCS Client is responsible for formatting and presenting data and managing the user interface (dialogue). The LCS Client is identified by a unique international identification, e.g. E.164.
LCS Client Access barring list:
an optional list of MSISDNs per LCS Client where the LCS Client is not allowed to locate any MSISDN therein.
LCS Client Subscription Profile:
a collection of subscription attributes of LCS related parameters that have been agreed for a contractual period of time between the LCS client and the service provider.
the capability of a PLMN to support LCS Client/server interactions for locating Target UEs.
a software and/or hardware entity offering LCS capabilities. The LCS Server accepts requests, services requests, and sends back responses to the received requests. The LCS server consists of LCS components which are distributed to one or more PLMN and/or service provider.
the geographic location of a UE and/or a valid Mobile Equipment (ME), expressed in latitude and longitude data. The Location Estimate shall be represented in a well-defined universal format. Translation from this universal format to another geographic location system may be supported, although the details are considered outside the scope of the primitive services.
a radio access network connecting to the 5G core network which uses NR, E-UTRA, or both.
North American Emergency Services Routing Digits (NA-ESRD):
a telephone number in the North American Numbering Plan (NANP) that can be used to identify a North American emergency services provider and its associated LCS client. The ESRD also identifies the base station, cell site or sector from which a North American emergency call originates.
North American Emergency Services Routing Key (NA-ESRK):
a telephone number in the North American Numbering Plan (NANP) assigned to an emergency services call by a North American VPLMN for the duration of the call. The NA-ESRK is used to identify (e.g. route to) both the emergency services provider and the switch in the VPLMN currently serving the emergency caller. During the lifetime of an emergency services call, the NA-ESRK also identifies the calling mobile subscriber.
PLMN Access barring list:
an optional list of MSISDN per PLMN where any LCS Client is not allowed to locate any MSISDN therein except for certain exceptional cases.
list of LCS Clients defined within a privacy exception class to which permission may be granted to locate the target UE. The permission shall be granted either on activation by the target UE or permanently for a contractual period of time agreed between the target UE and the service provider.
A service provided by an LCS Client is identified by a Service Identifier. One LCS client may have one or more services. The combination of the LCS client Identifier and the Service Identifier constitutes a unique identification of a service.
Privacy Exception List:
a list consisting of various types of privacy classes (i.e. operator related, personal etc.). Certain types of classes may require agreement between the service provider and the target UE.
an originating entity, which has requested the location of the target UE from the LCS client.
The UE being positioned.
Target UE Subscription Profile:
the profile detailing the subscription to various types of privacy classes.
deferred Location Request event in which the MSC/SGSN has established a contact with the UE. Note, this event is considered to be applicable when the UE is temporarily unavailable due to inaction by the UE user, temporarily loss of radio connectivity or IMSI detach and so on. Note that IMSI detach is only applicable in the case UE has previously been registered and information is still kept in the node.