WO2004070962A1

WO2004070962A1 - Microphone/speaker unit for use with a wireless transceiver

Info

Publication number: WO2004070962A1
Application number: PCT/PL2003/000068
Authority: WO
Inventors: Jacek Birtus
Original assignee: Vhf Group As
Priority date: 2003-02-07
Filing date: 2003-07-14
Publication date: 2004-08-19
Also published as: AU2003256187A1

Abstract

GPS signals received by the GPS antenna (5) are transferred to the low-noise amplifier (6) and the GPS- receiver (1), which is coupled to the extra battery power supply (7), then to the microprocessor (11). The microprocessor (11) selects, processes and stores location information. A request signal for the location information from the wireless transceiver (10) is received in a voice channel via the communicating means and transmitted to the microprocessor (11) which activates the audio path cut-off unit (13) while the last valid location information is transmitted by the microprocessor (11) back to the transceiver (10) and from the transceiver (10) to a monitoring station.

Description

Microphone/speaker unit for use with a wireless transceiver

The object of the invention is to provide a microphone/speaker unit for use with a wireless transceiver, for employing in location devices and mobile communications systems, capable of receiving and processing GPS (Global Positioning System) signals and reporting position locating information via said radio transceiver to a base station.

Wireless communications networks are commonly used by companies or public institutions and services for enabling communication of workers or servicemen with their headquarters. The additional feature, that in some cases is essential, is tracking and monitoring the position of users by a central monitoring station. It can be useful either in large construction fields or for armed forces and security services.

Many local- and global-area location methods are known and used. One of them, proved to be very universal, is based on the Global Positioning System (GPS) that enables to derive the position of a user by receiving and processing satellite radio signals.

There are prior art devices, which enable location reporting and voice communication via the same radio transceiver. Most of them use separate GPS units connected to a transceiver in the same or separate housing. However, separate GPS units increase the complexity and the costs of portable user's equipment. On the other hand modification of radio transmission equipment in order to comprise a location unit may be even more expensive as a result of required radio regulatory type approval testing.

US patent No. 5,884,199 describes a portable wireless transceiver provided with a speaker/microphone unit or a headset unit, which include a GPS antenna and a GPS signal receiver. The drawback of the device is that it includes its own wireless transceiver so it cannot be used with any existing wireless communication systems. There are no means for activating the location unit by a central controller. Moreover a patch antenna, which is described in the document, needs to be equipped with a flat metal surface as a ground plane and as a result of its narrow directional pattern it is very sensitive to changes in its horizontal position, GPS radio waves fading and reflections and proximity of a human body.

Patent No. WO9921149 discloses a locating device for use with any existing radio transceiver. The locating device comprises a microphone, a speaker, a sensor for sensing a signal containing position locating information, a memory for storing said information, a communications device for communicating with the radio transceiver, a control device for controlling the radio transceiver and an activating means for activating the location device. The sensor may be adapted to different types of signals containing location information, including GPS signals. The activating means for transmitting the location information can either comprise a switch on the device, a movement or removal sensor or an activating signal transmitted from a remote transmitter. The drawback of the device is that being not • constructed especially for GPS-assisted location, it doesn't profit all the features of GPS. Once the microprocessor is programmed, it doesn't show any flexibility in reprogramming the way of processing the data acquired from a GPS receiver. There's no means (like additional battery supply) for. storing the satellite configuration data after the device is turned off, prolonging significantly the acquisition time of new data (a "cold start"). The patent document also doesn't present the embodiment of the device that would enable transmitting an activating signal from the radio transceiver by audio wires nor a means for selecting the GPS data in order to use a radio channel efficiently, especially when many mobile objects are monitored. On the other hand, the described embodiment includes other units that increase the complexity and energy consumption of the device.

The object of the present invention is to provide a microphone/speaker unit for use with a portable wireless transceiver in conventional, trunking or TET A systems, transmitting the GPS location signal in response to a request signal received in a voice channel from a remote transmitter.

A microphone/speaker unit, especially for use with a wireless transceiver, comprising within single hand held housing a microphone, a speaker, a press-to-talk switch, a GPS antenna, a GPS receiver^ a microprocessor and a communicating means to communicate with a wireless transceiver, according to the present invention is characterised in that GPS signals received by the GPS antenna are transferred to the low-noise amplifier and the GPS receiver, which is coupled to the extra battery power supply, then to the microprocessor. The microprocessor selects, processes and stores location information. A request signal for the location information from the wireless transceiver is received in a voice channel via the communicating means and transmitted to the microprocessor which activates the audio path cut-off unit. The last valid location information is transmitted back to the transceiver and from the transceiver to a monitoring station.

An embodiment of the invention can include the communication means which comprises an analog-to-digital converter and a cable connection to the wireless transceiver.

A variant embodiment of the invention includes the communication means which comprises a modem and a cable connection to the wireless transceiver.

An embodiment of the invention can include a power supply unit which comprises a highly efficient impulse voltage stabiliser and a miniature power source for supporting the GPS receiver's memory.

An embodiment of the invention can include the GPS antenna which is a helix antenna with a large beam width and highly resistant to the influence of a human body on the received GPS signal.

In another embodiment of the invention the housing contains a built-in camera and a means to take and transmit pictures from the camera to the wireless transceiver.

The ^■ invention provides means to comprise a location unit within a microphone/speaker unit, which is often mounted in a hand held housing, connected with a cable to a radio transceiver that can be placed at the waist or in a car. The microphone unit is small enough to allow its comfortable use.

The advantage of the invention is a capability to operate with any known radio transceiver, to transmit and receive data through a voice channel and to filter the structures of the GPS information blocks so as to obtain only the information required currently by a user. The other features are simple structure and low energy consumption.

The invention is described in detail in an embodiment presented in drawings. Fig. 1 presents a block diagram of the microphone/speaker unit. Fig. 2 presents a configuration of elements within the housing of the microphone/speaker unit. Fig. 3 presents a wireless transceiver connected to the microphone/speaker unit containing the GPS location unit.

The device comprises a GPS antenna 5, a low-noise amplifier 6, a GPS receiver 1 with an extra battery power supply 7, a microprocessor 11 equipped with a memory 18, a speaker 3, a microphone 2 and a press-to-talk switch 4, an impulse voltage stabilising feeder within a single hand held housing 9 connected with a cable 8 to a wireless transceiver 10.

The GPS antenna is a helix antenna 5 in the form of a small cylinder mounted on the top part of the device. The application of the helix antenna with an omnidirectional pattern and a large beam width enables GPS reception in different environments and accessibility to many satellites.

After GPS radio waves are received by the conventional GPS antenna 5, the GPS signal is amplified in a low-noise amplifier 6 and transferred to a multichannel receiver unit I. The GPS receiver unit 1 is capable of receiving automatically GPS signals and transmitting position information in the form of the international standardised frame structure containing current or previous latitude and longitude, time, altitude and the number of satellites in the antenna's field of vision.

The device is equipped with the extra power supply source 7 which supports the GPS receiver's memory 1, which stores recent data, and enables the receiver to restore quickly the current position information after the device and an usual source of power is turned off and then turned on again after some period of time. Normally the receiver would need a few minutes time to restore the satellites' configuration data each time it would be turned on. The additional battery 7 reduces this time to a few seconds.

The received GPS data are transmitted to the microprocessor ϋ. The microprocessor 11 corrects and processes data in order to establish the user's current or recent location. If the current location information is unavailable the microprocessor 11 transmits to a transceiver 10 the last valid position which has been established and stored in a memory unit 18. This feature is very useful in case of users getting often inside and outside buildings or any other radio shadowed area where GPS radio waves from satellites is unavailable.

The data transmission is activated on the request received from a remote base station. Because the standardised GPS frame contains a lot of information that is not useful for the user, the microprocessor JJ. can filter this information and leave only some of the data according to a current microprocessor's program. In case of monitoring a large number of users by the central control station it is an important issue because it allows the efficient channel utilisation. To ensure enough flexibility, the microprocessor U can be reprogrammed via an appropriate connector disposed in the housing 9.

The usual two-way voice communication with a remote base station uses an audio path, which includes a microphone 2, a speaker 3 and a press-to-talk switch 4. When the push-to-talk switch is activated, this is detected by the microprocessor U which, according to programmed priority, blocks it or transfers it to the transceiver 10. The audio signal is connected to the transceiver 10 by a cable 8. The data transmission uses the same voice channel. The signal received from the transceiver 10 is monitored by a modem V2. When the base station transmits a request for location data, the received request signal is detected by the modem 12. The request is immediately transmitted to the microprocessor \l which turns on an audio path cut-off unit 13 in order to avoid transferring the digital request signal to the speaker 3. The last valid location data that are stored in the microprocessor's memory 18 ate transmitted directly or by the modem 12 to the wireless transceiver 10 and then back to the base station, where it is processed automatically or according to the request of a monitoring station. This ensures that the base station or any other control stations are able to supervise the user.

The microphone/speaker unit includes a small camera for taking and transmitting pictures to the base station, automatically or on activation by the user. The unit for taking and transmitting pictures comprises a button 14, a picture buffer equipped with a RAM memory 15 and a CCD camera 16. When the button M is pressed or a "take a picture" command is received from the remote transmitter via the radio transceiver, the microprocessor 11 activates the picture buffer's memory 15 and the CCD camera 16. The picture is stored in the, picture buffer 15. The microprocessor JJ. transfers the data from the picture buffer.15 to the modem 12, which transmits th«m back to the base station via the wireless transceiver. After the transmission is complete and confirmed correct, the microprocessor - 11 empties the memory in the picture buffer J_5 and the device is ready to take another picture.

The impulse voltage stabilising feeder 17 installed iri the microphone/speaker unit decreases the power consumption of tihe device.

Claims

1. A microphone/speaker unit, especially for use with a wireless transceiver, comprising within single hand held housing a microphone, a speaker, a press-to-talk switch, a . GPS antenna, a GPS receiver, a microprocessor and a communicating means to communicate with a wireless transceiver, characterised in that, GPS signals received by the GPS antenna (5) are transferred to the low-noise amplifier (6) and the GPS receiver (1), which is coupled to the extra battery power supply (7), then to the microprocessor (U) where location information is selected, processed and stored, while a request signal for the location information from the wireless transceiver (10) received in a voice channel via the communicating means is transmitted to the microprocessor (U) which activates the audio path cut-off unit (13) and transmits the last valid location information back to the transceiver (10) and from the transceiver (10) to a monitoring station.

2. A microphone/speaker unit according to claim 1, characterised in that the communication means comprises an analog-to-digital converter and a cable connection to the wireless transceiver (10).

3. A microphone/speaker unit according to claim 1, characterised in that the communication means comprises a modem (12) and a cable connection (8) to the wireless transceiver (10).

4. A microphone/speaker unit according to claim 2 or 3, characterised in that it includes a power supply unit which comprises a highly efficient impulse voltage stabiliser (17) and a miniature power source for supporting the GPS receiver's (1) memory.

5. A microphone/speaker unit according to claim 4 characterised in that the GPS antenna (5) is a helix antenna with a large beam width and highly resistant to the influence of a human body on the received GPS signal.

6. A microphone/speaker unit according to claim 5, characterised in that the housing (9) contains a built-in camera (16) and a means to take and transmit pictures (15) from the camera (16) to the wireless transceiver (10).