# US 10,771,948 B2 · System and method for monitoring a spatial position of a mobile transmitter, man-over-board detection system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,771,948 B2
- Document ID: US10771948B2
- Status: Granted
- Kind: B2
- Application number: 16/207,880
- Filed: 2018-12-03
- Published: 2020-06-04
- Granted: 2020-09-08
- Earliest claimed: 2018-12-03
- Assignees: Rohde & Schwarz GmbH & Co. KG
- Applicants: Rohde & Schwarz GmbH & Co. KG
- Inventors: Matthias Haubs
- Web page: https://patentgrep.com/patent/US10771948B2

## CPC

- H04W 4/90: Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
- H04W 24/10: Scheduling measurement reports {; Arrangements for measurement reports}
- B63C 9/0005: {by means of alarm devices for persons falling into the water, e.g. by signalling, by controlling the propulsion or manoeuvring means of the boat (alarms responsive to presence of persons in a body of water in general G08B21/08)}
- G01S 5/0036: {of measured values, i.e. measurement on mobile and position calculation on base station}
- G01S 5/019: {Energy consumption}
- G01S 5/0231: {Emergency, distress or locator beacons}
- G01S 5/14: Determining absolute distances from a plurality of spaced points of known location
- G08B 21/086: {by monitoring a perimeter outside the body of the water}
- G08B 25/009: {Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range}
- H04B 17/23: Indication means, e.g. displays, alarms, audible means
- H04W 4/021: Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
- H04W 4/027: {using movement velocity, acceleration information}
- H04W 24/08: Testing, {supervising or monitoring} using real traffic
- B63C 2009/0017: {characterised by making use of satellite radio beacon positioning systems, e.g. the Global Positioning System [GPS]}
- G01S 2205/06: Emergency
- G08B 21/0261: {System arrangements wherein the object is to detect trespassing over a fixed physical boundary, e.g. the end of a garden}
- H04W 4/42: for mass transport vehicles, e.g. buses, trains or aircraft
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- B63C: LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS (floating nets, floating slipways, or the like for recovering aircraft from the water B63B35/52)
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G08B: SIGNALLING SYSTEMS, e.g. PERSONAL CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- H04B: TRANSMISSION

## Abstract

A system and method for monitoring a spatial position of a mobile transmitter is provided. In particular, the mobile transmitter may be attached to or included in an object of interest. By analyzing the signal strengths of radio frequency signals emitted by the transmitter, a spatial position of the mobile transmitter can be determined, and it is possible to detect whether or not the spatial position of the mobile transmitter is outside an allowable area. By applying the monitoring of the spatial position to a radio frequency system on a vessel, a reliable man-over-board detection can be achieved.

## Claims

### Claim 1

A system for monitoring a spatial position of a mobile transmitter, the system comprising:
a number of at least two base stations for receiving at each base station a radio frequency signal emitted by the mobile transmitter,
wherein at least one of the number of the at least two base stations is configured to establish a wireless data communication with the mobile transmitter and the at least one base station is connected to a further device of a communication network, and
wherein the mobile transmitter is configured to establish a wireless communication link to the further device of the communication network via the at least one base station; and
a processing unit for obtaining signal strength of the radio frequency signal received by the number of the at least two base stations, computing a spatial position of the mobile transmitter based on the signal strengths of the received radio frequency signals, determining whether or not the computed spatial position of the mobile transmitter is outside a predetermined spatial area, and generating an alert indication if the computed spatial position of the mobile transmitter is outside the predetermined spatial area,
wherein the signal strength of the radio frequency signals obtained by the processing unit comprise a signal strength of the at least one base station which is connected to a further device of a communication network.

### Claim 2 (depends on 1)

The system of claim 1, wherein the predetermined spatial area is a predetermined two-dimensional or three-dimensional area.

### Claim 3 (depends on 1)

The system of claim 1, wherein the number of at least two base stations are located on a vessel, and the predetermined spatial area corresponds to a surface of the vessel.

### Claim 4 (depends on 1)

The system of claim 1, comprising an alert indication unit for receiving the alert indication from the processing unit and generating an alert signal upon receiving the alert indication from the processing unit.

### Claim 5 (depends on 1)

The system of claim 1, wherein the processing unit is configured to compute a speed or an acceleration of the mobile transmitter, and wherein the processing unit is further configured to generate the alarm indication, if the computed speed or the acceleration of the mobile transmitter exceeds a predetermined threshold value.

### Claim 6 (depends on 5)

The system of claim 5, wherein the processing unit is configured to compute the speed or the acceleration of the mobile transmitter in a vertical direction.

### Claim 7 (depends on 1)

The system of claim 1, wherein the processing unit is configured to compute a direction of movement of the mobile transmitter after determining that the mobile transmitter is outside the predetermined spatial area.

### Claim 8 (depends on 1)

The system of claim 1, wherein the wireless data communication is performed according to a wireless local area network standard, in particular IEEE 802.11.

### Claim 9 (depends on 1)

The system of claim 1, wherein the processing unit is configured to determine a battery status of the mobile transmitter.

### Claim 10 (depends on 9)

The system of claim 9, wherein the processing unit is configured to generate an alert message, if the determined battery status is a predetermined value and no radio frequency signal is received from the mobile transmitter by the number of at least two base stations.

### Claim 11 (depends on 1)

The system of claim 1, including the mobile transmitter for emitting a wireless signal, the mobile transmitter is configured to be attached to or included in a target of interest.

### Claim 12 (depends on 11)

The system of claim 11, wherein the mobile transmitter comprises an emergency transmitter, in particular a global maritime distress and safety system transmitter, and the mobile transmitter is configured to activate the emergency transmitter, if signal levels of the number of the at least two base stations fall below a predetermined signal level.

### Claim 13 (depends on 11)

The system of claim 11, wherein the mobile transmitter is configured to determine signal levels of base stations, and to indicate the determined signal levels to at least one of the number of at least two base stations.

### Claim 14

A man-over-board detection system, the system comprising:
a mobile transmitter for emitting a wireless signal, the mobile transmitter is configured to be attached to or included in a target of interest;
a number of at least two base stations arranged on a vessel, each base station is configured to receive a radio frequency signal emitted by the mobile transmitter,
wherein at least one of the number of the at least two base stations is configured to establish a wireless data communication with the mobile transmitter and the at least one base station is connected to a further device of a communication network, and
wherein the mobile transmitter is configured to establish a wireless communication link to the further device of the communication network via the at least one base station; and
a processing unit for obtaining signal strengths of the radio frequency signal received by the number of the at least two base stations, computing a spatial position of the mobile transmitter based on the signal strengths of the received radio frequency signals, determining whether or not the computed spatial position of the mobile transmitter is outside a predetermined spatial area of the vessel, and generating an alert indication if the computed spatial position of the mobile transmitter is outside the predetermined spatial area,
wherein the signal strength of the radio frequency signals obtained by the processing unit comprise a signal strength of the at least one base station which is connected to a further device of a communication network.

### Claim 15

A method for monitoring a spatial position of a mobile transmitter, the method comprising:
receiving, by each of a number of at least two base stations, a radio frequency signal emitted by the mobile transmitter,
wherein at least one of the number of the at least two base stations is configured to establish a wireless data communication with the mobile transmitter and the at least one base station is connected to a further device of a communication network, and
wherein the mobile transmitter is configured to establish a wireless communication link to the further device of the communication network via the at least one base station;
obtaining, by a processing unit, signal strengths of each radio frequency signal received by the number of at least two base stations, wherein the obtained signal strengths comprise a signal strength of the at least one base station which is connected to a further device of a communication network,
computing, by the processing unit, a spatial position of the mobile transmitter based on the signal strengths of the received radio frequency signal,
determining, by the processing unit, whether or not the computed spatial position of the mobile transmitter is outside a predetermined spatial area, and
generating, by the processing unit, an alert indication if the computed spatial position of the mobile transmitter is outside the predetermined spatial area.

### Claim 16 (depends on 15)

The method of claim 15, wherein the predetermined spatial area is a predetermined two-dimensional or three-dimensional area.

### Claim 17 (depends on 15)

The method of claim 15, wherein the number of at least two base stations are located on a vessel, and the predetermined spatial area corresponds to a surface of the vessel.

### Claim 18 (depends on 15)

The method of claim 15, comprising receiving the alert indication and generating an alert signal upon receiving the alert indication from the processing unit.

### Claim 19 (depends on 15)

The method of claim 15, comprising computing a speed or an acceleration of the mobile transmitter, and generating the alarm indication, if the computed speed or the acceleration of the mobile transmitter exceeds a predetermined threshold value.

### Claim 20 (depends on 19)

The method of claim 19, the speed or the acceleration of the mobile transmitter is computed in a vertical direction.

### Claim 21 (depends on 15)

The method of claim 15, comprising computing a direction of movement of the mobile transmitter after determining that the mobile transmitter is outside the predetermined spatial area.

### Claim 22 (depends on 15)

The method of claim 15, wherein the wireless data communication is performed according to a wireless local area network standard, in particular IEEE 802.11.

### Claim 23 (depends on 15)

The method of claim 15, comprising determining a battery status of the mobile transmitter.

### Claim 24 (depends on 23)

The method of claim 23, wherein an alert message is generated, if the determined battery status is a predetermined value and no radio frequency signal is received from the mobile transmitter by the number of at least two base stations.

### Claim 25 (depends on 15)

The method of claim 15, comprising emitting a wireless signal by the mobile transmitter attached to or included in a target of interest.

### Claim 26 (depends on 25)

The method of claim 25, comprising activating an emergency transmitter, in particular a global maritime distress and safety system transmitter, if signal levels of the number of the at least two base stations, fall below a predetermined signal level.

### Claim 27 (depends on 25)

The method of claim 25, comprising determining signal levels of base stations, and indicating the determined signal levels to at least one of the number of at least two base stations.