Know where every lone worker is.
Detect an incident before it's too late.
Real-time indoor location and automatic man-down detection - using the professional smartphone workers already carry, with NAO® Mobile SDK and BlueSpot beacons. No additional device. No GPS required.
Isolated workers are the highest-risk category. In confined spaces, engine rooms or underground facilities, a fall or medical emergency can go undetected for minutes. Real-time indoor positioning closes that gap - automatically.
GPS stops at the door. The risk does not.
Workers operating alone in confined spaces, underground infrastructure, engine rooms or large industrial facilities are invisible to GPS-based monitoring - and manual check-in procedures cannot detect an immediate incident. When a fall or medical emergency occurs, every minute without a precise indoor location delays the response and worsens the outcome.
No indoor location without the right technology
Satellite signals do not penetrate multi-storey buildings, underground tunnels or metal-clad industrial structures. A worker inside is invisible - even if they carry a GPS-enabled smartphone, it gives no position indoors.
Falls and incidents go undetected too long
A worker who falls in a confined space or loses consciousness in a remote zone may not be found for minutes or hours. Manual radio check-ins rely on the worker being conscious and able to respond - they cannot detect an immediate physical incident automatically.
Adding a dedicated device creates friction
Requiring workers to carry an additional safety device on top of their professional smartphone leads to non-compliance, forgotten equipment and gaps in coverage. The right approach is to embed protection into the tool workers already have.
Lone worker protection built into the smartphone workers already carry.
Rather than adding a dedicated safety device, NAO® Mobile SDK is integrated directly into the existing mobile application used on the worker's professional smartphone. The SDK captures positioning data from NAO® BlueSpot beacons in the environment, transmits the worker's real-time indoor location to the NAO® Positioning Engine, and enables automatic detection of immobility, man-down events and deliberate duress alerts - without any extra hardware on the worker's person.
NAO® Mobile SDK is a software component integrated into an existing mobile application. It retrieves positioning information from the available location infrastructure - BLE beacons, LTE and other signals - and transmits the worker's continuous indoor position to the NAO® platform. This allows the platform to monitor movement patterns, detect anomalies and trigger safety alerts, all from the device already in the worker's pocket.
From smartphone in pocket to precise indoor location - continuously.
Five steps that transform the worker's existing professional smartphone into a full lone worker protection system - with real-time indoor location, automatic incident detection and immediate alert dispatch, all without adding any device to the worker's equipment.
NAO® Mobile SDK integrated in the existing mobile app
NAO® Mobile SDK is embedded directly into the mobile application already installed on the worker's professional smartphone - no second app, no extra device. When the worker opens their usual work application, location monitoring activates automatically in the background.
SDK integration · Existing app · Zero extra hardwareBlueSpot beacons provide indoor positioning signal
NAO® BlueSpot beacons - deployed across the facility, tunnel or building - broadcast BLE signals that the SDK picks up via the smartphone. In demanding environments such as industrial plants or underground infrastructure, NAO® BlueSpot Rugged beacons are used for enhanced durability and signal reliability.
BlueSpot · BlueSpot Rugged · BLE + LTE
Real-time position transmitted to NAO® platform
The SDK continuously transmits the worker's indoor position - derived from BLE beacon proximity, LTE and available infrastructure signals - to the NAO® Positioning Engine. The platform maintains a real-time view of every worker's location, zone and movement status, updated continuously as they move through the building or site.
NAO® Positioning Engine · Real-time zone trackingIncident detected - immobility, man-down or manual duress
The platform monitors three safety scenarios automatically: loss of movement (worker has not moved for a configured time period), man-down (sudden fall or impact detected via smartphone accelerometer), and voluntary duress alert triggered by the worker from the app. Each event raises an immediate alert with the worker's precise last-known indoor location.
Immobility alert · Man-down · Duress buttonSupervisor receives alert with exact indoor location
The safety team receives the alert with the worker's name, zone, floor plan position and alert type - immediately, without any manual escalation. The response team is directed to the exact location rather than searching blindly. Every event is automatically timestamped and logged for incident reporting, audit and compliance purposes.
Instant alert · Precise location · Auto audit trailFaster response. No extra device. Full accountability.
Extra device
NAO® Mobile SDK runs on the smartphone the worker already carries - no badge, no tracker, no second device to forget.
Indoor location
Continuous real-time zone-level position of every lone worker - transmitted automatically through the existing mobile app.
Alert modes
Immobility, man-down and voluntary duress - three independent protection layers, all derived from the smartphone's own sensors and position data.
Incident log
Every alert, response and resolution automatically timestamped and stored - inspection-ready, with no manual documentation required.
Faster response to incidents
Responders receive the worker's precise indoor location the moment an alert fires - no searching a building blind, no radio roll-call before locating the person.
Higher adoption - no extra hardware to manage
Because protection runs on the smartphone workers already use, there is no equipment to forget, charge or lose - leading to higher day-to-day compliance than badge-based systems.
Full indoor coverage - GPS-denied environments
BlueSpot and BlueSpot Rugged beacons extend real-time positioning into tunnels, basements, engine rooms and industrial sites where satellite signals are unavailable.
Regulatory compliance support
Automatic incident logs with timestamps satisfy occupational safety regulatory requirements - confined space entry records, lone worker intervention evidence and safety audit documentation.
BlueSpot beacons + existing smartphones. No new network needed.
NAO® Mobile SDK works with the BLE and LTE signals already available in the environment. NAO® BlueSpot beacons provide the indoor positioning anchor points - deployed quickly on walls, ceilings or columns - while the SDK on the smartphone does the rest. For demanding industrial or outdoor environments, NAO® BlueSpot Rugged beacons deliver enhanced durability.
SDK integration into your existing mobile app. NAO® Mobile SDK is provided as a software component for integration into Android and iOS mobile applications - the worker continues using their familiar work app, with lone worker protection running transparently in the background.
Built for demanding industrial and infrastructure environments.
From underground transit construction sites to nuclear research facilities - NAO® Mobile SDK lone worker protection is designed for the environments where the consequences of a delayed response are most severe.
SDK in existing app - zero friction
Integration into the mobile application workers already use means no behaviour change, no extra device and no adoption barrier - protection is always on.
BlueSpot Rugged - harsh environments
NAO® BlueSpot Rugged beacons withstand industrial conditions - dust, humidity, vibration, extreme temperatures - extending indoor positioning into environments where standard beacons cannot operate.
Scalable across sites and teams
Deploy on a single facility or roll out across multiple sites - same SDK, same platform, same safety standard. New zones are activated by deploying additional BlueSpot beacons without infrastructure reconfiguration.
Audit-ready incident records
Every lone worker event - alert type, timestamp, location, response time and resolution - is stored automatically in the NAO® platform, providing inspection-ready documentation for safety audits and regulatory reviews.
Proven in underground infrastructure and high-security research sites.
From kilometre-scale tunnel construction under Paris to classified research facilities, NAO® Mobile SDK lone worker protection has been deployed in some of the most demanding GPS-denied environments in France.
Grand Paris Express - lone worker protection in active tunnel construction
The Grand Paris Express project involves thousands of workers in underground tunnel environments where GPS is entirely unavailable. NAO® Mobile SDK - deployed on professional smartphones and anchored by NAO® BlueSpot Rugged beacons - provides real-time indoor location and automatic incident detection for isolated workers across the construction sites.
CEA - indoor lone worker tracking across secured research facilities
At CEA facilities, workers operate in technically complex environments - large multi-building sites where specific areas require reinforced lone worker monitoring. NAO® Mobile SDK, integrated in the existing professional mobile application and anchored by NAO® BlueSpot beacons, delivers real-time indoor location and automatic safety alerts for workers in isolated or restricted zones.
Everything you need to know about NAO® lone worker protection.
What is lone worker protection?
Lone worker protection is the set of monitoring, alerting and response systems that ensure workers operating alone or in isolated environments can call for help - and are located quickly when they cannot respond themselves. It covers automatic detection of falls or immobility, manual duress alerts and real-time indoor location provision to a supervisor or security team.
How does NAO® Mobile SDK enable lone worker protection?
NAO® Mobile SDK is integrated directly into the existing mobile application already installed on the worker's professional smartphone. It retrieves positioning information from NAO® BlueSpot beacons in the environment, transmits the worker's continuous indoor position to the NAO® Positioning Engine, and enables detection of immobility, man-down events and voluntary duress alerts - all without any additional device on the worker's person.
Does the worker need to carry an additional device?
No. NAO® Mobile SDK runs on the professional smartphone the worker already carries. The SDK is embedded in the existing mobile application - the worker continues using their usual work app, with lone worker protection running transparently in the background. No badge, tracker or second device is required.
What types of incident does the system detect automatically?
Three types of safety event are covered: loss of movement - when the smartphone has not registered motion for a configured period; man-down - a sudden fall or impact detected via the smartphone accelerometer; and voluntary duress - a deliberate one-tap alert triggered by the worker from the mobile application.
How does indoor positioning work without GPS?
NAO® BlueSpot beacons deployed inside the building, tunnel or facility broadcast BLE signals that NAO® Mobile SDK captures via the smartphone. The SDK combines these signals with available LTE data to determine the worker's indoor position - transmitted to the NAO® Positioning Engine in real time. See also: NAO® BlueSpot infrastructure.
What is the NAO® BlueSpot Rugged beacon?
NAO® BlueSpot Rugged is the ruggedised version of the NAO® BlueSpot beacon, designed for tunnels, engine rooms, construction sites and outdoor industrial facilities. It withstands dust, humidity, vibration and extreme temperatures where standard beacons cannot operate reliably.
Can the system cover underground environments?
Yes. NAO® BlueSpot Rugged beacons can be deployed underground - including active tunnel construction sites. The Grand Paris Express deployment is a real-world example of lone worker protection in a fully GPS-denied underground environment.
What does the supervisor receive when an alert fires?
The supervisor or security team receives an immediate alert with the worker's name, alert type and precise indoor floor plan location - allowing the response team to go directly to the worker rather than searching the facility.
Does SDK integration require rebuilding the mobile application?
No. NAO® Mobile SDK is a software component integrated into the existing Android or iOS application. Workers continue using their familiar app - lone worker protection is added in the background without requiring a full application rebuild.
Is the system available for industrial and offshore environments?
Yes. The combination of NAO® Mobile SDK and BlueSpot Rugged beacons is specifically designed for industrial, offshore and GPS-denied environments. It has been deployed in underground construction and research facilities where conventional tracking cannot function. Contact us for an environment-specific assessment.