A DEVICE, METHOD AND SYSTEM FOR IMPROVING THE TRANSMISSION RELIABILITY OF AN ALARM IN AN ALARM SYSTEM

FIELD OF THE INVENTION The present invention relates to a data communications technology. The present invention relates to a method, device and system for improving the usability as well as the transmission reliability of an alarm in an alarm system.

BACKGROUND OF THE INVENTION

Different types of targets, such as real estate properties, can be monitored in many ways, for example, in case of burglary or fire. One means of monitoring is so-called remote surveillance, in which the target, for example, a real estate property, has an automatic surveillance system that will, for example, in the event of a burglary or fire, relay alarm information forward. Traditionally, alarms are trans- mitted in a message transfer system (MTS) , which is based on the landline network (subscriber cable) . Many Finnish service providers offer service that works in the manner described above.

Changes in operator activities as well as re- arrangements in the internal activities of the operators have created a situation, in which a cable connection may no longer be economically sensible. Within the same company there may be many fare collectors, such as the terminal, cable, central facilities, con- nections between centres, etc.

In the monitoring of alarms, relating in particular alarms to the authorities (fire, theft) , it is particularly important that the alarm is transmitted through to the receiving party. For this reason, the alarm transmission systems are verified. In one solution, the primary communications means in the alarm

transmission device is a mobile communications module, for example, a GSM module (GSM, Global System for Mobile Communications) as well as an analog connection as a verifying connection. In other words, the alarm transmission device requires both a GSM module and an analog modem. The reason for this verification method is that the adequately assured verification cannot be achieved using the subscriber identity module (SIM) of one mobile communications operator, instead a landline connection is also required in order to assure that the alarm has reached its destination. Additionally, in a mobile communications system, there is always the possibility that all time slots (TS) are in use at that moment . The usability of the alarm transmission system is specified, for example, in the document Cenelec TC79EN50136-1-1, draft 7, reliability specifications: Class A4, Annex B, table 4:

- Annual overall usability 99.8% (17.3 hours per year, 3 min per day) .

- Monthly usability 98.5%, (10 hours per month, 22 min per day) .

Transfer time maximums are as follows:

- Alarm 15 s - Line fault 100 s.

The transfer times presented above are in accordance with the CEA 4039:2002-08 standard, "Aim Oriented Requirements for Message Transmission Systems".

One disadvantage of current solutions is that in them the (overall) usability and reliability of alarm transmission are not of an adequately high level. In an alarm transmission system, there are many independent circumstances that can, due to a functional failure, endanger the transfer (transmission) of an alarm to the recipient. Below is a list of possible problems collected as an example:

a program fault in the alarm transmission device; a connection fault between the alarm transmission device and the alarm recipi- ent (in the mobile communications network/ general telephone network) ; a device fault in the alarm transmission device; congestion in the mobile communications network in an alarm situation.

OBJECT OF THE INVENTION

The object of the invention is to obviate the aforementioned disadvantages or to at least signifi- cantly alleviate them. In particular, the object of the invention is to provide a method, device and system for improving the transmission reliability of an alarm in an alarm system.

SUMMARY OF THE INVENTION

The solution according to the invention is made up of three factors, which together maximize the overall usability of the alarm system and the transmission reliability of an alarm. In the solution, within the alarm transmission device, which monitors a given surveillance target, is placed a subscriber identity module from a mobile communications operator, which is not limited to work in only one mobile communications network in the country in question. The term "country in question" refers to the country, in which the alarm monitoring device monitors its target. If the subscriber identity module is, for example, the module of a foreign operator, which functions in many mobile communications networks "in the country in question", the alarm transmission device should in principle be constantly in contact with the mobile communications network, because it always selects a

functional roaming operator. The function of the alarm transmission device and the functionality of the connection to the alarm transmission device are monitored by formation of a test connection. The alarm transmis- sion device and the connection to the alarm transmission device are verified as functional, if the alarm transmission device actively rejects the forming of the test connection. Actively rejecting means that the "ringing" telephone call is disconnected actively by an action of the alarm transmission device (B- subscriber) . In one embodiment of the invention, the function of one or more of the applications contained within the alarm transmission device is separately verified prior to actively rejecting formation of the test connection. A test connection to the alarm transmission device can be formed at given intervals, for example, every 50 or 100 seconds.

Further, an alarm to the authorities according to the invention is given by making an emergency telephone call from the alarm transmission device to an alarm centre, if an alarm to the authorities cannot be transmitted through the primary alarm transmission connection of the alarm transmission device within a predetermined time period. The primary alarm transmis- sion connection is, for example, a mobile communications network data connection, for example, a GSM data connection. This is of course just one example of a possible transmission connection. The transmission connection can also be based on other means of data transfer. The connection may be of either a circuit switchedor packet switched connection, as long as the service it uses functions in the networks of all operators in the target country.

In the alarm centre is preferably formed an alarm card, which contains the telephone number (A- subscriber identifier) of the subscriber identity module placed within the alarm transmission device and

other information about the surveillance target of the alarm transmission device. The location and type of an alarm to the authorities coming from the alarm transmission device can be automatically recognized based on information contained in the alarm card.

The invention also relates to an alarm transmission device for transmitting an alarm to the alarm centre. The device comprises at least one interface for receiving alarm information from the surveillance target, a subscriber identity module for linking the alarm transmission device to a mobile communications network, a receiver for receiving the formation of a connection from the mobile communications network, and a transmitter for transmitting alarm information to the alarm centre through the mobile communications network. The alarm transmission device is characterized in that within it is placed a subscriber identity module from a mobile communications operator, which is not limited to function in only one mobile communica- tions network in the country in question. The alarm transmission device further comprises a module, which is arranged to actively disconnect formation of a test connection. Further, the transmitter is arranged to form an emergency telephone call to the alarm centre in the situation of an alarm to the authorities, if an alarm to the authorities cannot be transmitted using the primary alarm transmission connection of the alarm transmission device within a predetermined time period. The invention also relates to a system for improving the transmission reliability of an alarm in an alarm system. The system comprises a mobile communications network, a surveillance target, an alarm transmission device, in which is placed a subscriber identity module and which is connected to the mobile communications network and which is arranged to monitor the surveillance target, and which alarm transmis-

sion device comprises a receiver for receiving a mobile communications connection from the mobile communications network, a transmitter for transmitting alarm information through the mobile communications network and at least one interface for receiving alarm information from the surveillance target. The system further comprises an alarm centre and a reception centre, which are connected to the mobile communications network. The system is characterized in that the subscriber identity module placed within the alarm transmission device is from a mobile communications operator, which is not limited to function in only one mobile communications network in the country in ques- tion. Further, the reception centre is arranged to form at given intervals a test connection to the alarm transmission device, and the alarm transmission device comprises a module, which is arranged to actively disconnect formation of the test connection. The trans- mitter is arranged to form an emergency telephone call to the alarm centre in the case of an alarm to the authorities, if an alarm to the authorities cannot be transmitted through the primary alarm transmission connection of the alarm transmission device within a predetermined time period. The primary alarm transmission connection is, for example, a mobile communications network data connection.

In one embodiment of the invention, the module of the alarm transmission device is further ar- ranged, when receiving formation of the test connection, to verify the function of one or more applications prior to actively rejecting formation of the test connection.

In the alarm centre is preferably arranged an alarm card, which contains the telephone number of the subscriber identity module placed within the alarm transmission device and other information about the

surveillance target and that the alarm centre is arranged to automatically recognize the location and type of the alarm to the authorities coming from the alarm transmission device on the basis of information contained in the alarm card.

Due to the present invention, the overall usability as well as the overall transmission time of the alarm transmission system can be brought to required levels. Further, the connection to the alarm transmission device and the function of the alarm transmission device itself can be monitored in a manner that does not produce additional expenses for the surveillant .

LIST OF FIGURES

In the following, the invention is described in detail by means of embodiment examples, in which

Figure 1 shows an embodiment of a system, in which the present invention is used, Figure 2a shows a block diagram, in which the function according to the invention is described in greater detail,

Figure 2b shows another block diagram, in which the function according to the invention is de- scribed in greater detail, and

Figure 3 shows an example of an alarm transmission device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows an embodiment of a system, in which the present invention can be used. The system comprises a surveillance target 100, which is, for example, a real estate property owned by a private person or a company. For transmission of an alarm and other state information an alarm transmission device 102 is used, which contains a mobile communications module for connecting the alarm transmission device

102 to the mobile communications network 104. The mobile communications module is, for example, a GSM module and the mobile communications network respectively a GSM network. Under normal circumstances, for example, GSM network data characteristics are used for changes in the state of the target or alarm transmission device. The information is sent through the GSM network 104 and/or landline network 106 to the reception centre 108, which then sends them to the alarm centre 112. Although it is shown in Figure 1 that the reception centre 108 and the alarm centre 112 are connected to the MTS network 110 (MTS, Message Transfer System) , they usually are in practice a part of the MTS network 110. The reception centre 108 is, for example, a surveillance company providing surveillance services. It can, however, be any sort of entity that has the right to connect to and use the MTS network 110.

In the embodiment according to the invention, an alarm to the authorities can be transmitted from the alarm transmission device 102 directly to the alarm centre 112 without going through the reception centre 108 and the MTS network 110. Further, in one embodiment of Figure 1, the alarm centre 112 is a pub- lie or national alarm centre, maintained by the authorities, or some entity empowered by the authorities. In this type of situation, an alarm from the alarm transmission device is transmitted to the alarm centre by forming an emergency telephone call to the public emergency number, for example, 112 in Finland and 911 in the United States. In another embodiment of Figure 1, the alarm centre 112 is not a public alarm centre and respectively an emergency telephone call is not made to the public emergency number. The alarm centre can be, for example, maintained by a company empowered by the authorities and providing security services.

Further, as is shown in Figure 1, the connection from the alarm centre 112 and/or reception centre 108 in the direction of the alarm transmission device 102 can be bidirectional. In other words, the alarm centre 112 and/or the reception centre 108 can additionally function as the party controlling the alarm transmission device 102.

Figure 2a shows a block diagram, in which the function according to the invention is described in greater detail. In the embodiment of Figure 2a, the functionality of the alarm transmission device and the connection to the alarm transmission device are verified by one or more "test calls". For example, the reception centre 108 in Figure 1 forms a test connection to the alarm transmission device (step 200) . The formation of the connection is made, for example, from an ISDN connection (ISDN, Integrated Services Digital Network) , in which case the coupling of the connection formation is fast. The alarm transmission device re- ceives the connection formation request (step 202) and the reception centre waits for an Alerting message (a telephone network marking message according to standards) . The Alerting message notifies the reception centre that a telephone call is ringing in the alarm transmission device and that the telephone call is waiting to be answered. The alarm transmission device determines on the basis of the signalling of the telephone network that the call is coming from a predetermined number (the number of the reception centre) . The alarm transmission device is arranged to verify its own function and, for example, the function of the software installed on the alarm transmission device, when it receives a connection formation request from the reception centre (step 204) . The alarm transmis- sion device actively rejects the call, if the verification completes successfully (steps 206 and 210) . The rejection of the call causes the sending of a Discon-

nect message in the telephone network. As a result of the message the partially formed (allocated) connection is cancelled. The reception centre receives a Release message from the telephone network, which indi- cates to it that the alarm device is functional (step 212) .

In the manner described above, both the existence of a connection from the reception centre to the alarm transmission device and the function of the alarm transmission device and/or its applications can be verified. The method presented does not create additional charges to either of the parties involved, because the call between the reception centre and the alarm transmission device is at no point completely formed. The mobile communications network and telephone network signalling used in the method presented is standardized signalling.

The presented formation of a test connection can be done at given intervals, for example, at 100 second intervals, as a result of which the reception centre is in effect constantly knowledgeable of the functional state of the alarm transmission device (step 214) . If the verification produced faults in the function of the alarm transmission device in step 206, information regarding this can be sent to the alarm centre using an MTS connection (step 208) that is also normally in use.

The function presented in Figure 2a can be further simplified, for example, by leaving out the separate verification of the software. In this type of embodiment, with reference to Figure 2a, the separate steps 204, 206 and 208 are left out. In other words, when the alarm transmission device receives the test connection formation, it is arranged to automatically actively reject formation of the test connection. If the rejection does not occur within a predetermined time period, the reception centre knows that there is

some fault in the function of the alarm transmission device. However, if the GSM data connection (or other corresponding connection, for example, a GPRS connection (GPRS, General Packet Radio Services)) from the alarm transmission device is still in functional condition, the alarm transmission device can transmit information regarding a possible fault to the reception centre through this connection.

Figure 2b shows another block diagram, in which the function according to the invention is described in greater detail . The block diagram shown relates to a situation, in which the alarm transmission device receives from the target an alarm to the authorities (a fire alarm, burglary) (step 220) . First, an attempt is made to send information regarding the alarm using normal known art (step 222), in other words, by forming, for example, a GSM data connection to the reception centre, which then sends information regarding the alarm to the alarm centre. If the mobile communications network is not congested, the alarm centre receives information regarding the alarm in a conventional manner (step 230) .

An arrival of an alarm is defined for purposes of usability and alarm transmission reliability by limit values. Reliability specifications can, for example, define that information regarding a fire or burglary alarm must be successfully transmitted forward within 15 seconds. However, the transmitting forward of an alarm from the alarm transmission device is hindered, for example, in the case that all usable time slots in the mobile communications network are busy.

For this reason, the alarm transmission device is arranged to form a connection directly to the alarm centre, if information regarding an alarm cannot be transmitted through the conventional route, for example, within said 15 seconds (step 226) . Even if the

mobile communications network should happen to be congested, an emergency call always connects through within the range of the mobile communications network. For example, in the GSM specifications the term "Emer- gency Setup" is defined. In practise, "Emergency Setup" functions such that when the radio network is full, one or more time slots are automatically freed in order that the emergency call can get a free time slot to use. In the alarm centre, a so-called alarm card for the surveillance target is created in advance that contains essential information about the target. In addition to normal information, the alarm card also defines the telephone number of the subscriber iden- tity module (SIM) of the alarm transmission device in the alarming target, based on which the alarm card can be connected to the correct target (step 228) . In the alarm card is then defined, for example, that a call arriving from a given telephone number is an automatic fire alarm.

Using the procedure described above, an alarm is transmitted through to the alarm centre, even if all time slots of the mobile communications network (of the base station) should happen to be in use. A device fault alarm and returns to rest (return from the alarm as well as from the device fault) are not time-critical alarms among alarms to the authorities. For this reason, the alarm centre connection is not in any way used for the transmission of these. A line fault (connection fault) is time-critical, but information regarding one is transmitted through the reception unit in the case that the terminal has not answered test calls within a given time limit. Let it be noted, that in the solution according to the inven- tion, alarm information is transmitted utilizing the emergency number selection only when a GSM data con-

nection (or other corresponding connection) cannot be formed.

The probability that the selection of a direct alarm connection will in practise be needed is relatively small. A network congestion situation is, however, a real possibility, nor for this reason could a method based solely on the use of GSM data have any chance of being approved by the authorities.

Figure 3 shows an example of an alarm trans- mission device according to the invention. Let it be noted, that in Figure 3 are shown only those portions of an alarm transmission device 102, which are essential for the invention. Thus, an alarm transmission device in use may also contain other components and/or softwares .

To maximize usability and transmission reliability, such a subscriber identity module SIM of a mobile communications operator is placed within the alarm transmission device 102, which is not limited to function in only one mobile communications network in the country in question. For this reason, this type of subscriber identity module SIM randomly selects a network of an operator for use. In Finland, at this time, there are three mobile communications operators that have their own networks: TeliaSonera, Elisa and DNA. If the network connection services of the operator in use are interrupted, for example, due to a network fault, the alarm transmission device seeks a new functional operator. In this manner, manifold function verification of signalling is achieved. Under normal circumstances, if the terminal is in place, the base station updates the visitor in its register (VLR, Visitor Location Register) at two-hour intervals on the average. In an embodiment of the present inven- tion, the alarm transmission device forms a test connection at regular intervals, for example, at 100 second intervals, and for this reason, the alarm system

is constantly knowledgeable of the function of the network. The interval for the formation of test connections can of course be freely defined.

The alarm transmission device contains a processing unit CPU that is in connection with other functional parts of the device. In the memory MEM can be stored one or more applications, and with the defining of the functions by an action of these applications the device is functional. The alarm transmission device 102 also contains a transmitter TX and a receiver RX that are arranged to send information to and receive information from the mobile communications network .

The alarm transmission device 102 further comprises a module CHK that is arranged to actively disconnect formation of a test connection, if the alarm transmission device 102 is functioning properly. In one embodiment, the module CHK is further arranged, when receiving formation of a test connection, to ver- ify the function of one or more of the applications prior to actively rejecting formation of the test connection. In this case, verification of even greater scope is achieved that the alarm transmission device is functional. The module CHK is in practise imple- mented, for example, using a suitable software application stored in the memory.

For the receiving of surveillance information, the alarm transmission device comprises at least one interface IF for the receiving of alarm informa- tion from the surveillance target. The interface is implemented, for example, by hardware and/or software.

The invention is not limited to only the embodiment examples presented above, rather many variations are possible within the scope of inventive idea defined by the claims.