This invention relates to wireless communication, more particularly, to subscriber radio communication, wherein at least one subscriber is located on board the vehicle, and can be used for providing passenger trains with wireless addressed alarm systems and internal communication.

Hereinafter the technical solution claimed herein will be characterized using the following terms and definitions:

- address alarm is an alarm automatically sent to a subscriber or a group of subscribers in a preset sequence.

- central control system is a PC based device that controls the operation of the base stations incorporated into the system.

- system phone is a device that virtually images the condition of network connections and allows direct connection between subscribers and setup functions.

Known (RU Patent 2058670 H 04 B 7/26, 1996) is a train control communication system comprising a central control point connected with stationary radio stations of the control communication range via the main or backup wire communication lines, wherein each radio station comprises a switching unit, a selectable connection unit and a linear unit connected in series and a transceiver connected with an antenna, wherein other signal inputs of said switching unit are outputs of said main and backup wire communication lines, one of the control inputs of said switching unit is connected via said linear unit with the output of said transceiver, the second output of the first selectable amplifier is connected with the second input of said selectable connection unit,

farther wherein each stationary radio station comprises a second selectable amplifier the output of which is connected with the output of said transceiver, a first and a second control signal generators the outputs of which are connected with the outputs of the first and second selectable amplifiers, respectively, and the inputs of which are connected with the second and third control inputs of said switching unit, further wherein the input of said selectable connection unit is connected via one of the contacts of said switching unit with the output of said main or backup wire communication lines. Said switching unit can be in the form of series connected keys with separate selectable connection control circuits.

Disadvantage of said technical solution is the impossibility of automatic remote control of vehicle status.

Known also (RU Patent 2206177 H 04 B 7/26, 2003) is an onboard train communication network comprising a control and diagnostic terminal (trainmaster's portable console), terminal communication devices (in the form of mobile phones for personnel and passengers, radio detectors and actuators of the car automation system, miniaturized video control terminals and other necessary devices) and a unified switching unit (in the form of a base station) in each car of the train and a digital radio communication line connecting the train onboard network with external communication systems, wherein the connection between said terminal communication devices and said unified switching unit as well as between adjacent unified switching units is performed via a radio channel the frequency range and amplitude of which are chosen in

such a way that said terminal communication devices can only connect to the unified switching unit of the car a terminal communication device is currently in, and said control and diagnostic terminal is mobile and can connect via said radio channel to the unified switching unit of the car the control and diagnostic terminal is currently in.

Said onboard communication system operates as follows. The control and diagnostic terminal (trainmaster's portable console) transmits and receives radio signals in any point of the train via the network of said unified switching units, regardless of whether the trainmaster receives a radio signal from a terminal device or a terminal device receives a radio signal, including one generated by a passenger's mobile phone during communication with an external subscriber.

Disadvantage of said onboard system is the availability of only one control and diagnostic terminal in the form of trainmaster's portable console, a large number of switching points and absence of automatic train status monitoring.

The object of this invention is providing an improved train alarm and communication system to ensure higher passenger train operation safety and higher service level.

Said object is achieved using a passenger train security control and communication system comprising a central control system and DECT base stations (1 to 16), wherein each of these base stations are connected to said central control system via a 5 ^th category screened cable consisting of twisted pair multiwire cords with a length of within 120 m and to each of these DECT base stations two

antennas installed on the car roof are connected through the HF sockets via a high-frequency cable, the length of said antenna cables being within 30 m, and at least one alarm transmitting device for transmitting alarms from the train car alarm systems by generating voice messages for the car conductor or the trainmaster. Said alarm transmitting device comprises a DECT radio socket, a voice automatic informer and a portable button phone set. The alarm transmitting device of each car is connected to at least the outputs of the appropriate car's alarm and fire control systems. Also, said system comprises at least one portable terminal for receiving alarm signals and automatic two-way phone communication (preferable one portable terminal per each car conductor or at least one portable terminal per each car), at least one repeater per each car for amplifying radio signals, at least one phone handset in the conductor's service compartment and at least one alarm button. Moreover, said system may additionally comprise a satellite communication station, a trainmaster portable computer and at least one payphone. Normally, said system comprises at least four antennas at least two of which are circular pattern ones and at least two antennas are directed to provide for maximum transmission power along the train movement direction. Preferably, said alarm signal transmitting device is connected through an HF socket via a 50 Ohm wave impedance cable to an HF signal splitter, the length of said HF cable being within 30 m.

Unlike the counterpart systems known to the author this system provides for:

1. Automatic transmission of voice signals on emergencies in cars to the train crew members located in any point of the moving train or on the platform within 500 m from the car in the direct visibility area.

2. Automatic two-way phone communication between subscribers in the passenger train, either standing or moving.

3. Transmission of emergency messages by the trainmaster from the portable terminal or a system phone.

4. Phone communication between the trainmaster and public telephone system subscribers.

5. Data transmission via the satellite communication channel using the trainmaster's portable computer.

6. Phone communication services for the passengers. Hereinafter the system disclosed herein will be described using the basic embodiment schematic wherein the notations are as follows: 1 is the central control system, 2 is the DECT base station, 3 is the antenna, 4 is the alarm signal transmitting device from the railway car alarm systems, 5 is the portable terminal for receiving emergency signals and providing automatic two-way phone communication, 6 is the repeater, 7 is the phone handset and 8 is the alarm button.

The system disclosed herein comprises the following units and components: a) the central control system combines the functions of switching equipment and a system connection control device. The central control system controls the DECT base stations (1 to 16) to

which external antennas are connected as described above, and one system phone. Each base station is connected to said central control system via a 5 ^th category screened cable consisting of twisted pair multiwire cords with a length of within 120 m. Said DECT base stations are powered (48 VDC) from the central control system via said cables. The power consumption of each DECT base station is within 50 W. To each of these DECT base stations two antennas installed on the car roof are connected through the TNC type HF sockets via a high-frequency cable. A total of six antennas are used two of which are non-directional (circular pattern) ones and four are directed to provide for maximum transmission power along the train movement direction. The length of said antenna cables should be within 30 m. The dimensions of said DECT base stations are within 200 x 120 x 140 mm, and the weight is within 400 g. A system phone is connected to the central control system via a two-way cable. b) The alarm signal transmitting device is used for sending alarm signals from existing alarm and fire control systems via the radio channel to the central control system and further to the portable terminals of the train crew located in any point of the moving train and to the command car, to the trainmaster's workplace. Said alarm signal transmitting device comprises a DECT radio socket, a voice automatic informer, a portable button phone set and a wire handset. Said alarm signal transmitting device is connected through an HF socket via a 50 Ohm wave impedance cable to an HF signal splitter, the length of said HF cable being within 30 m.

Said alarm signal transmitting device is also connected to the existing alarm and fire control systems of the car (through two PC4 sockets) via a two-wire cable of any length. Said alarm signal transmitting device is powered from a 12 V source, its power consumption being within 10 W. c) The HF signal splitter is used for providing simultaneous operation of two devices (the alarm signal transmitting device and the repeater) with one antenna. d) The repeater is used for the amplification (retranslation) of signals transmitted from the central control system to the terminals and back. Said repeater is connected via a 50 Ohm wave impedance cable to said HF signal splitter. Each repeater has an external antenna connection HF socket and a 12 V power source connection socket. e) The portable terminal is a DECT one and used for subscriber connection via the radio channel to the central control system. The charger of said portable terminal has wall mounting openings. Said charger has a clamp for carrying the portable terminal while in motion. Said charger is powered from a 12 V power source. f) Said power source is used for the conversion of the 55 to 110 V input voltage to 12 VDC, 48 VDC and 220 VAC voltages for powering the system devices and the portable computer. g) The Inmarsat M4 satellite communication system station provides communication with the public telephone network through the Inmarsat International Organization's global network. Said network comprises 4 satellites over the equator at a geostationary

orbit distributed between the western Atlantic, eastern Atlantic, Indian Ocean and the Pacific regions thus providing for an optimum worldwide coverage. Said satellite communication station comprises an antenna, an HF amplifier/power source and a terminal.

Said terminal comprises a display, a keyboard and an integral phone handset for placing voice calls. Said terminal con be connected to the central control system for placing voice calls from the portable terminal or a system phone. h) The payphone is connected to the satellite communication station terminal via a two-wire phone cable with a length of within 50 m. Said payphone is powered from the phone line.

For the implementation of the system disclosed herein, the following equipment is installed in the trainmaster's service compartment: the central control system, DECT base stations, a system phone, antenna sockets, a power source, a charger, a portable terminal, the satellite communication station and the trainmaster's portable computer. The central control system is wall- mounted and can be mounted on the compartment side wall. The system phone is installed on the table. The portable terminal charger has wall mounting openings. The portable computer is installed on the table. The DECT base stations are installed in the space between the ceiling and the car roof in a way to minimize the required HF cable length and hence to reduce signal loss.

The following equipment is installed in the car conductor's service compartment: a repeater, an antenna output, an alarm

transmitting device, a charger, a portable terminal and an alarm button.

All the antennas are installed on the car roof, and the repeaters are installed inside the car. The portable terminal charger has wall mounting openings. The power source can be installed on a horizontal or a vertical surface.

The train mechanic's and the militiamen's portable terminal chargers are installed in their respective compartments. These chargers are powered from the 12 V power source installed in the radio communication compartment via 2x0.75 mm ² section two- wire cables of necessary length.

The satellite communication station is installed as follows. The antenna is installed on the command car roof in the non-service car platform area, the terminal is installed in the trainmaster's compartment and the HF amplifier/power source is installed in the trainmaster's compartment.

Two-way radio communication between the DECT system subscribers is established in the 1880-1900 MHz radio frequency range that comprises 10 physical (carrier) channels of 1.728 MHz bandwidth each. For voice communication channels, each carrier frequency is divided into 10 ms time frames each containing 12 pairs of time intervals (i.e. the time-division multiple access (TDMA) method is used). The two-way communication mode is provided due to the time division duplexing method (TDD) wherein the first half of the TDMA frame is used for sequential data transmission via the 12 voice communication channels from the

base station to the portable terminals, and the second half of the TDMA frame is used for data transmission in the reverse direction.

The system operates in uninterrupted dynamic channel redistribution mode, i.e. each base station can automatically select carrier frequencies out of the currently available unoccupied ones and the best (highest quality) communication channel. If no free carrier frequency is available, the system automatically repeats communication establishing requests. Thus, frequencies are repeatedly used in automatic mode, and the repeated use schematic changes between connection sessions.

The operation of the station can be illustrated using the following examples:

1. The brake overheating alarm is activated in the service compartment of a car during train movement. The conductor is currently elsewhere in the car for servicing the passengers. The automatic alarm transmitting device of the car dials the conductor's portable terminal number and sends a five-digit car number message and a brake overheating alarm message, the same voice message being sent to the trainmaster for decision making.

2. Fire alarm is activated in the conductors' service compartment of a car during passenger boarding when the conductor is on the platform. The automatic alarm transmitting device of the car dials the conductor's and the trainmaster's portable terminal numbers and sends a fire alarm message and a five-digit car number message. Upon

the receipt of this message the conductor inspects the car and rinds passengers smoking in an inappropriate place. Then the conductor immediately reports the trainmaster on the elimination of the fire alarm cause.

3. Hooligans initiate a fight in the car in the night. The conductor uses the portable terminal to call militiamen who bring the situation into order.

4. Criminals (terrorists) block the car conductor to avoid him/her calling help. The conductor presses the hidden alarm button, and the automatic alarm transmitting device of the car dials the transport militia patrol and the trainmaster's portable terminal numbers and sends an alarm message and a five-digit car number message.

In this embodiment, the system provides the following functionality:

1. Receipt of car fire alarm, brake overheating, wheel blocking and alarm button alarms;

2. Generation of voice data in accordance with the alarms received and its transmission to the portable terminals of the train crew.

3. Automatic phone communication for the train crew members.

The voice message transmitted in case of emergencies comprises:

- car number (fire digits);

- the words "Fire", "Brake overheat" or "Wheel blocking". The voice message transmitted in case of alarm button pressing to the trainmaster and the transport militia comprises:

- car number (fire digits);

- the word "Emergency".

If an Inmarsat M4 satellite communication system station is used in the command car, the following communication and data transmission possibilities are provided:

- car emergency situation data transmission by the trainmaster to the depot or to the nearest station;

- phone communication between the trainmaster and the public telephone network;

- data transmission via the satellite channel using the trainmaster's portable computer;

- phone communication of the transport militia patrol with their commanders and the possibility of receiving and sending passport affiliations and photos of persons being searched;

- communication services for passengers if a payphone is installed.