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# Location Verification without GPS?

Need location data when GPS fails? Discover how to leverage telecom network APIs and Kotlin Multiplatform for secure, offline-capable device tracking.

- **Speakers:** [Mario Bodemann](https://www.wearedevelopers.com/@mario-bodemann)
- **Event:** 
- **Published:** August 22, 2024
- **Duration:** 23:51
- **URL:** https://www.wearedevelopers.com/videos/1184-location-verification-without-gps

## Summary

Capturing location data without GPS relies on telecom network APIs, offering a critical solution for offline tracking, non-GPS IoT devices, and location-based fraud prevention. By querying the telecommunications network directly, developers can verify if a device, identified by its MSISDN or User Equipment Identifier (UEID), is within a specific geographic radius. This approach leverages cellular infrastructure to maintain location state even when devices briefly lose internet connectivity, returning a simple boolean validation down to a legally mandated accuracy limit of two kilometers. Building a location-aware application requires orchestrating these telecom location APIs alongside downstream UI or mapping services. A robust architecture can be structured using Kotlin Multiplatform (KMP), enabling a unified codebase across Android, iOS, and Web clients. Utilizing Ktor for the backend and Jetpack Compose for the frontend, developers can parse shared data models with Kotlinx Serialization to efficiently process complex geolocation logic without duplicating platform-specific code. Standardizing these network capabilities are global initiatives like the CAMARA consortium and GSMA Open Gateway, which provide open API specifications for the telecommunications industry. Successfully integrating these network-level APIs necessitates stringent privacy measures, requiring explicit user consent through OAuth 2.0 flows before exposing any geographic data. While current implementations are bound to domestic networks with cross-border API roaming still under development, standardizing Telco APIs unlocks powerful, secure verification patterns for modern mobile and IoT architectures.

**Keywords:** location verification, telco network APIs, GPS alternative tracking, CAMARA API consortium, GSMA Open Gateway, Kotlin Multiplatform architecture, Jetpack Compose UI, Ktor server framework, cellular network positioning, IoT device geolocation, location-based fraud prevention, MSISDN phone identification, user equipment identifier, geospatial radius validation, OAuth consent flow

## Chapters

1. **Location verification concepts and practical network device tracking** (00:02) — Network-based geolocation systems track offline equipment and mobile sensors efficiently without relying on battery-intensive GPS hardware integrations.
1. **Building a location-aware city sightseeing mobile application** (02:10) — A demo application cross-references network phone numbers with registered city coordinates to suggest relevant nearby travel destinations.
1. **Calling telecom network APIs to query geographic location data** (04:31) — Developers can construct HTTP requests utilizing OAuth access tokens and specialized equipment identifiers to authorize perimeter validations.
1. **Integrating Google Places API to map nearby tourist attractions** (08:22) — External data providers map relevant points of interest using telecom coordinates and efficiently constrained HTTP field masks.
1. **Developing front-end client applications using Kotlin Multiplatform libraries** (11:34) — Kotlin Multiplatform deploys identically structured material design interfaces across disparate operating environments utilizing a centralized code hub.
1. **Architecting shared modules for seamless frontend and backend integrations** (13:50) — Shared architectures leverage tools like Ktor and native Kotlin serialization to completely align frontend and backend interactions.
1. **Standardizing telecom network API access with CAMARA and Open Gateway** (17:28) — Standardization projects like CAMARA and Open Gateway provide software engineers simplified entry into varied global telecom systems.
1. **Potential security applications and future multiplatform performance enhancements** (20:34) — Future API applications enable secure location-based transaction validations while backend translation mechanisms facilitate broader cross-browser component compiling.
1. **Addressing operational constraints involving international roaming and explicit permissions** (22:29) — Current ecosystem limitations impact robust international tracking tasks and necessitate explicit authorization measures directly from human operators.

## Related Moments

- [Tracking devices without GPS using telco location data](https://www.wearedevelopers.com/videos/1567-unleash-the-power-of-5g-in-your-code-transform-your-apps) (from "Unleash the power of 5G in your code: transform your apps")
- [Mitigating telecom fraud and sim swap attacks](https://www.wearedevelopers.com/videos/1686-code-meets-connectivity-developers-as-the-powerhouse-of-network-api-innovation) (from "Code meets connectivity - Developers as the powerhouse of Network API innovation")
- [Exposing location tracking vulnerabilities in mobile application software kits](https://www.wearedevelopers.com/videos/1288-wearedevelopers-live-scammer-payback-with-python-grok-goes-unhinged-the-future-of-chromium-and-mo) (from "WeAreDevelopers LIVE: Scammer Payback with Python, Grok Goes Unhinged, The Future of Chromium and mo")
- [Demonstrating on-device indoor navigation in real time](https://www.wearedevelopers.com/videos/100225-edge-ai-on-ios-beyond-the-cloud-designing-the-next-generation-of-intelligent-on-device-apps) (from "Edge AI on iOS: Beyond the Cloud, Designing the Next Generation of Intelligent On-Device Apps")
- [Live demo of telecommunication identity verification checks](https://www.wearedevelopers.com/videos/1686-code-meets-connectivity-developers-as-the-powerhouse-of-network-api-innovation) (from "Code meets connectivity - Developers as the powerhouse of Network API innovation")
- [Confirming user presence utilizing device location APIs](https://www.wearedevelopers.com/videos/1043-no-more-post-its-boost-your-login-security-with-apis) (from "No More Post-its: Boost your login security with APIs")

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