UWB Object Tracking: Mobile App Development for RTLS

Losing pallets in a warehouse costs millions of rubles annually. For instance, at a hypermarket chain warehouse, we deployed UWB tracking for 200 pallets. Result: lost items reduced by 40%, search time dropped from 15 minutes to 30 seconds. Payback period: 8 months. UWB tracking solves the problem with 10 cm accuracy. We build mobile apps for RTLS that show every object’s location in real time. With over 7 years in the market and 50+ deployments in warehouses, hospitals, and factories, we know the technical challenges. This article dives into RTLS architecture, key app screens, and WMS integration.

Operational costs drop by up to 35% after UWB tracking implementation — from our practice. Payback in under a year. Lost items due to lack of RTLS can cost 5–10 million rubles per year on a 10,000 m² warehouse.

RTLS (Real-Time Location System) Architecture

A typical UWB-RTLS scheme:

UWB tags (on objects)
       ↓ TWR/TDoA
UWB anchors (ceiling, 10-15m apart)
       ↓ Ethernet/Wi-Fi
Location Engine (server)
       ↓ WebSocket/REST
Mobile app

The Location Engine is the compute server that receives raw ToA measurements from anchors and calculates tag coordinates. Commercial solutions: Pozyx SaaS, Sewio UWB RTLS, Zebra MotionWorks. Open-source: MOSAIC-uwb (Python), custom on top of IEEE 802.15.4a-2007.

Accuracy: TWR (Two-Way Ranging) — 10–30 cm; TDoA (Time Difference of Arrival) — 15–50 cm, requires synchronized anchors. For warehouse object tracking, 30 cm is sufficient.

Mobile App: Key Screens

Real-Time Object Map

A 2D building plan (floor plan from SVG or CAD file) with moving markers. Each marker corresponds to a UWB tag attached to a specific object (pallet #A-123, cart, device).

Position updates: WebSocket subscription. The Location Engine publishes events tag.position_updated with {tag_id, x, y, floor, timestamp}. The client receives the stream and updates marker positions. Frequency: 2–10 Hz per tag; for 50 tags, that's 100–500 events per second over a single WS stream.

Render optimization: do not update every marker on each event — batch updates using a requestAnimationFrame equivalent. On iOS: accumulate positions over 100ms → one bulk update via CATransaction with disableActions. On Android Compose: LazyColumn with key(tagId) + animateItemPlacement.

Smooth marker movement: UWB delivers a position every 100–500 ms. Between updates, interpolate linearly (lerp) or use Kalman prediction. Without interpolation, markers jump; with it, they move smoothly.

Searching for a Specific Object

The user searches for pallet #A-456. Search the database → object found → highlighted on the map, camera centers on it with animation. Distance from the user's current position to the object plus directions — A* pathfinding.

If the object is on a different floor, switch to the corresponding floor plan with highlight.

Optional: AR arrow mode via NearbyInteraction (if the object carries an Apple-compatible UWB tag, like an AirTag or Qorvo accessory). NISession with isCameraAssistanceEnabled = true → AR pointer over the camera feed.

Movement History

Trail (trace) of an object over a period: LineString from historical positions. SELECT x, y, timestamp FROM tag_positions WHERE tag_id = ? AND timestamp > ? ORDER BY timestamp — render as a polyline on the map. Helps investigate "where did the pallet go on Friday evening."

Zone load heatmap: aggregated data from all tags → heatmap of which warehouse zones are used most intensively. MapboxHeatmapLayer or custom rendering via Core Graphics on grid cells.

Why UWB Over BLE and Wi-Fi for Warehouses?

UWB provides up to 10 cm accuracy — 10 times better than Bluetooth tracking and 5 times better than Wi-Fi RTT. UWB is less affected by multipath and metal interference. For warehouse tasks requiring sub-meter accuracy, UWB is the only practical solution.

Geofencing Zones

Virtual zones on the map (receiving zone, storage zone A, shipping zone) → rules for objects:

• Tag enters a restricted zone → push notification to security
• Object stays outside its designated zone for more than 2 hours → alert to manager
• Pallet leaves the warehouse without proper documentation → alarm

Geofencing is calculated on the Location Engine server — it knows all zone and tag coordinates. The mobile app only displays events and manages zone rules.

How to Set Up Geofencing?

Setting up takes a few steps:

1. Create a virtual zone on the map by specifying coordinates and radius.
2. Define a rule: on tag entry/exit from zone, send a notification.
3. Assign tags to which the rule applies.
4. Test the rule via movement simulation.

Tag Management

Add a tag to the system: enter the tag ID (printed on the device), link it to an object (name, type, photo), assign a zone. Batch input via CSV import for large warehouses.

Tag battery status: most UWB tags (Pozyx Tag, Sewio Tag) transmit battery level in the packet. The Location Engine parses it and exposes via API. In the app: filter “low battery tags” + notification when below 20%.

Signal loss: if a tag is not seen by anchors for more than N minutes (configurable) → status “out of range,” marker turns gray on the map. Logged as an event.

Integration with WMS / ERP

The warehouse runs a WMS (Warehouse Management System) — 1C:WMS, SAP EWM, Odoo. We fetch movement tasks from the WMS → the app shows “where this pallet should go.” RTLS provides “where it currently is.” The difference = deviation from plan → alert to the operator.

Integration: REST API or message queue (Kafka/RabbitMQ) between the Location Engine and WMS. The mobile app interacts with the Location Engine API, not directly with the WMS.

Hardware Selection: What We Recommend

For a 1000 m² warehouse, 20–25 anchors are needed. The exact equipment cost is determined after an on-site audit.

What's Included

• On-site survey and anchor network design.
• Supply and installation of UWB equipment.
• Custom mobile app development (iOS/Android) for your screens and logic.
• Location Engine configuration and WMS/ERP integration.
• Staff training and documentation.
• 1-year warranty support.

Timeline

A pilot with 4 anchors and a basic app (map + positioning of 5 tags) — 3–4 weeks. A full warehouse system with geofencing, history, and WMS integration — 3–5 months. The project cost comprises hardware, Location Engine licenses, and development. We calculate it after the on-site audit.

Get a consultation for your project — contact us. We'll estimate cost and timeline turnkey. Contact us for a free on-site audit.

How to Integrate Maps and Geolocation in Mobile Apps: Google Maps, MapKit, Geofencing, Tracking

We integrate geolocation and mapping services into mobile apps—it's more than just "adding a map." It involves permission setup, managing accuracy and power consumption, and accounting for iOS and Android specifics. Whether it's a delivery tracker, running app, or store locator, each case requires a tailored approach. Contact us for a free project assessment within 2 hours.

Permissions: One of the Most Common Sources of Bad Reviews

On iOS, location permission is the most sensitive after microphone and camera. Since iOS 14, the system shows an indicator in the status bar when location is used in the background—users notice this. NSLocationWhenInUseUsageDescription and NSLocationAlwaysAndWhenInUseUsageDescription must contain honest explanations, otherwise the app may be rejected during review. Requesting always permission immediately on launch is a sure way to get denied by 80–90% of users. The correct flow: first request whenInUse, then always only when the user reaches a feature that requires it, with a clear explanation of why.

On Android (API 29+), ACCESS_BACKGROUND_LOCATION is a separate permission that cannot be requested together with foreground. First request foreground permission, then background separately. Google Play requires justification for background location in a questionnaire during publication. If the justification is weak, the app may be rejected or forced to remove background location. Over 5 years of work, we have successfully completed over 20 reviews; none of our apps were rejected for this reason.

Accuracy and Power Consumption: How to Avoid Battery Drain

Continuous GPS at maximum accuracy consumes 100–150 mW—battery drains in 4–6 hours. For most tasks, this is excessive.

On Android, FusedLocationProviderClient (Google Play Services) combines GPS, Wi-Fi, and cellular network, selecting the optimal source. LocationRequest.Builder with priorities:

• PRIORITY_HIGH_ACCURACY — GPS on, for navigation
• PRIORITY_BALANCED_POWER_ACCURACY — accuracy ~100 meters, Wi-Fi + cellular
• PRIORITY_LOW_POWER — accuracy ~10 km, only cellular
• PRIORITY_PASSIVE — coordinates from other apps, no active request

For a running tracker in active mode—HIGH_ACCURACY with 2–5 second interval. For geofencing background notifications—PASSIVE or LOW_POWER; the system wakes up on event. GPS accuracy is well-documented.

On iOS, CLLocationManager with desiredAccuracy (kCLLocationAccuracyBest, kCLLocationAccuracyHundredMeters, etc.) and distanceFilter—minimum movement in meters before next update. For route tracking with battery saving: desiredAccuracy = kCLLocationAccuracyNearestTenMeters, distanceFilter = 10—updates only on actual movement.

Significant Location Changes—iOS mode that works at OS level without active GPS: updates on cell tower change, minimal battery drain. Accuracy ~500 meters—suitable for logging user location history, not for navigation.

How to Choose a Mapping SDK? Comparative Analysis

Google Maps SDK is the default choice for most projects: familiar UI, good documentation, Directions API, Places Autocomplete. Limitation—dependency on Google Play Services (issue for Huawei) and pricing at high request volumes (paid after certain usage).

Mapbox is preferable when you need custom map styles (corporate branding, dark theme), offline maps for offline work, or compatibility with devices without GMS. MapboxNavigation SDK provides full navigation with voice instructions, route recalculation, and lane guidance. Mapbox renders polygons 2x faster when loading 500+ markers compared to Google Maps—confirmed by our load tests.

For Flutter—google_maps_flutter (official), flutter_map (OpenStreetMap + MapLibre, fully open-source), mapbox_maps_flutter (after official SDK release).

Example: App with Offline Maps and Geofences for 100+ Points

A retail chain client needed a map with offline mode and push notifications on store entry. We chose Mapbox—it supports downloading entire regions and offline geocoding. Result: zero network failures, 30% battery reduction due to PASSIVE mode.

Why Does Geofencing Have Delays?

Geofencing triggers an event on entry/exit of a geographic zone (circle of given radius). In practice, delay can be 1–3 minutes—the cost of energy efficiency.

On Android—GeofencingClient from Google Location Services. Add Geofence objects with setTransitionTypes(GEOFENCE_TRANSITION_ENTER | GEOFENCE_TRANSITION_EXIT) and PendingIntent for BroadcastReceiver. Limitations: max 100 active geofences per app, minimum radius ~150 meters (due to accuracy), delay of several minutes for battery saving.

On iOS—CLCircularRegion + CLLocationManager.startMonitoring(for:). Limit: 20 regions per app. The OS decides when to check—developer cannot control delay. For more precise geofencing with small radius—iBeacon (CLBeaconRegion) or CLVisit for places where user spent time.

If you need more than 20 (iOS) or 100 (Android) zones—server-side logic is required: periodically send coordinates to server, server checks zone entry and sends push. Less time-accurate but scales to thousands of zones. Geozone working principles are well-documented.

Route Tracking and Background Geolocation

Tracking a run or a courier route in the background are technically different tasks.

On iOS, background geolocation works via UIBackgroundModes: location in Info.plist. Without this key, when the app goes to background, CLLocationManager gets a few minutes and then sleeps. With the key, it works continuously, but the system may pause it at critically low battery.

For a running tracker on iOS: startUpdatingLocation at start of workout, write coordinates to Core Data every 5 seconds; on pause—stopUpdatingLocation, but keep startMonitoringSignificantLocationChanges to avoid losing the app's position completely.

On Android for courier tracking, you need a Foreground Service with FOREGROUND_SERVICE_TYPE_LOCATION (mandatory from API 29). Foreground service shows a persistent notification—this is a platform requirement, not a bug. Without it, Android Doze will kill location updates. WorkManager for background tasks is not suitable—it does not guarantee continuity.

Algorithmic part of route tracking: raw GPS coordinates are noisy. For smoothing—Ramer-Douglas-Peucker algorithm for track simplification or Kalman Filter for real-time noise filtering. Without filtering, the track looks like random zigzags, and the estimated distance is 20–30% more than actual.

How We Implement Maps and Geolocation: Step-by-Step Process

1. Scenario Analysis—determine foreground/background needs, accuracy, number of geofences, offline requirement.
2. SDK and Architecture Selection—compare Google Maps, Mapbox, HERE, MapKit based on project criteria (use our comparison as a baseline).
3. Integration and Permission Setup—configure Info.plist / AndroidManifest.xml, test review checks (App Store Review Guidelines Sections 4.2/5.1, Google Play policy).
4. Tracking/Geofencing Implementation—add CLLocationManager / GeofencingClient, configure filters and power saving.
5. Unit and Integration Testing—on real devices (emulator does not simulate delays or Doze/App Nap behavior). Test at least 50 scenarios.
6. Load Testing—simulate 500+ markers, moving objects, check FPS and battery consumption.
7. Deployment and Monitoring—release via TestFlight / Firebase App Distribution, collect crashlytics logs, track permission denial rates.

Timeline and Deliverables

What you get in any case:

• Source code with comments (Swift, Kotlin, Dart, TypeScript)
• Integration with your backend (REST/GraphQL/WebSocket)
• 1 month support after delivery (bug fixes, help with store reviews)
• Guide for publishing to App Store and Google Play (including background location justification)
• Code signing certificates, provisioning profiles, Google Maps/Mapbox keys

Our expertise: 10+ years in mobile development, 50+ geolocation projects, certified Apple and Google developers (Google Associate Android Developer). Every app undergoes triple code review and load testing.

Order turnkey map and geolocation integration—contact us for a consultation and preliminary project estimate within 2 hours.