Location (Based) Application

Description

A Location (Based) Application, as defined in 3GPP TS 23.171 and TS 23.271, is an application software that processes location information or utilizes it in some way. The location information can be input by a user or detected by the network or the User Equipment (UE). Navigation is a classic example of a location application. This definition is part of the Location Services (LCS) framework, which specifies how location information is obtained and delivered to applications.

Location applications can be categorized into two main types: pull and push. Pull applications are those where the user or application actively requests location information, such as a navigation app that asks for the current position to calculate a route. Push applications are those where location information is delivered to the application without an explicit request, often triggered by events like entering a specific area. The LCS architecture supports both types by providing standardized interfaces for location requests and reports.

The LCS architecture includes several key components: the UE, which may support positioning capabilities; the Radio Access Network (RAN), which provides measurements for network-based positioning; the Core Network (CN), which hosts the Location Services (LCS) entities such as the Gateway Mobile Location Centre (GMLC) and the Location Retrieval Function (LRF); and the external LCS client, which is the application that consumes location information. The LCS client can be internal to the network (e.g., for emergency services) or external (e.g., a third-party navigation app). The interfaces between these components are standardized to ensure interoperability.

Location applications rely on the underlying positioning methods to obtain location information. These methods include UE-based (e.g., GPS), UE-assisted (e.g., Assisted GPS), and network-based (e.g., Cell ID, OTDOA). The choice of method depends on factors such as accuracy requirements, availability, and cost. The location information is typically represented as a set of coordinates (latitude, longitude, altitude) along with a timestamp and accuracy estimate. The application may also receive additional information such as velocity, direction, and geographic area labels.

The evolution of the Location (Based) Application definition has been minimal, reflecting its stable role in the LCS framework. The initial definition in R99 referred to "MS" (Mobile Station), which was later changed to "UE" (User Equipment) in Rel-4, aligning with the terminology shift in 3GPP. Subsequent releases maintained the same wording, with only minor punctuation changes. This stability indicates that the fundamental concept of a location application has not changed significantly, even as the underlying technologies have advanced. The definition remains broad to accommodate a wide range of applications, from simple navigation to complex location-based services.

Purpose & Motivation

The Location (Based) Application concept exists to provide a clear definition of what constitutes an application that uses location information within the 3GPP Location Services (LCS) framework. It serves as a foundational term for specifying the interfaces, protocols, and procedures that enable location-based services. By defining location applications, 3GPP ensures that different stakeholders—network operators, service providers, and application developers—have a common understanding of the entities involved and their interactions.

Historically, location-based services emerged as a key value-added service for mobile networks, driven by regulatory requirements (e.g., emergency call location) and commercial opportunities (e.g., navigation, advertising). The LCS framework was developed to standardize how location information is requested, computed, and delivered, regardless of the underlying positioning technology. The term "Location (Based) Application" was introduced to distinguish the end-user application from the network functions that provide location information. This separation allows applications to be developed independently of the network infrastructure, fostering innovation and competition.

The definition has remained largely unchanged because the fundamental concept of an application processing location information is timeless. However, the types of applications and the technologies they use have evolved dramatically, from simple cell-ID-based services to sophisticated augmented reality applications. The 3GPP definition provides a stable anchor, while other specifications detail the technical mechanisms for location determination and delivery. This approach ensures backward compatibility and interoperability across generations of mobile networks.