WO2003028352A1

WO2003028352A1 - Monitoring terminals in telecommunication system

Info

Publication number: WO2003028352A1
Application number: PCT/FI2002/000756
Authority: WO
Inventors: Pauli Hietasalo
Original assignee: Yit Primatel Oy
Priority date: 2001-09-24
Filing date: 2002-09-23
Publication date: 2003-04-03
Also published as: FI20011873A; FI112838B; FI20011873A0

Abstract

A method and an arrangement for monitoring terminals and connections between them in a telecommunication system comprising at least one terminal group including at least two terminals (MS1 to MS8), in the arrangement the terminals of a terminal group being arranged to check each other's state in a predetermined order in such a manner that the last checked terminal in an accepted state checks the state of at least one next terminal.

Description

MONITORING TERMINALS IN TELECOMMUNICATION SYSTEM

BACKGROUND OF THE INVENTION

[0001] The invention relates to monitoring terminals in a telecommunication system. [0002] Monitoring the operation of terminals is important in various systems. For example in fire or burglar alarm systems, where the alarm is given by means of a terminal of for instance of a public telephone network, connected to actual alarm equipment, it is essential to monitor, not only the operation of the alarm equipment but also the operation of said terminal and the connection to the terminal; if the terminal or the connection thereto is damaged, the alarm system is unable to give an alarm. It is thus as essential to detect such failures, as it is to detect for instance an actual fire or a burglary attempt. Furthermore, monitoring terminals is usable in improving the safety of the user of a terminal, such as a mobile station, particularly in dangerous con- ditions of usage, when an abnormal state of the terminal or losing the connection thereto can be interpreted as a potential risk situation for the user, and the necessary measures can be taken.

[0003] A prior art solution for monitoring terminals particularly as regards terminals using a wired connection is for the terminal to continuously transmit a suitable signal to a connection line, whereby monitoring this signal allows the state of the terminal to be found out; if the signal is lost, there is something wrong with the terminal or the connection thereto. However, this prior art solution is not well suited to monitoring terminals using a radio path, such as mobile stations or the like, since a dedicated radio channel would have to be reserved for the transmission of the monitoring signal for each terminal to be monitored, which often is not wise or even possible due to the limited radio frequency resources.

[0004] Another prior art solution is based on polling the terminals to be monitored such that polling inquiries are transmitted to the terminals from a special server or the like continuously or at given intervals, and the terminals respond to the inquiries. Consequently, this solution is subject to the existence of some kind of centralized server that attends to making the inquiries. Herein, the problem is possible congestion of such a server if there are several terminals to be monitored and they also happen to reply to the polling inquiry substantially simultaneously. A further problem in using a centralized server is possible failure of the server, which leads to an interruption in the monitoring of the terminals unless there is another server in reserve that could .continue to monitor the terminals. It is also possible that the communication lines of the inquiry server to the rest of the system fail, which leads to an interruption in the monitoring of the terminals even though the connections of the terminals to the rest of the system were operational.

BRIEF DESCRIPTION OF THE INVENTION

[0005] The object of the invention is thus to provide a method and an apparatus for implementing the method so as to solve or at least alleviate the above problems. The object of the invention is achieved by a method, arrangement and terminal, which are characterized by what is stated in the independent claims 1 , 14 and 19. The preferred embodiments of the invention are described in the dependent claims.

[0006] The invention is based on monitoring terminals from other terminals, there being no need for a centralized inquiry server for monitoring the state of the terminals, since any terminal is able to check the state of another terminal.

[0007] An advantage of the method and system of the invention is improved reliability of monitoring terminals, since the operability of the monitor- ing does not depend on the operation of any centralized system element. A further advantage compared with centralized monitoring is a more even distribution of the traffic caused by the monitoring in the telecommunication network, since terminals are usually evenly distributed in the network area, and therefore the monitoring traffic is unlikely to cause load to any given local con- nection.

BRIEF DESCRIPTION OF THE FIGURES

[0008] In the following, the invention will be described in greater detail in connection with preferred embodiments with reference to the accompanying drawings, in which Figure 1 shows the structure of a telecommunication system in accordance with an embodiment of the invention,

Figure 2 is a diagram of monitoring the state of terminals in accordance with an embodiment of the invention,

Figure 3 is a diagram of monitoring the state of terminals in accor- dance with an embodiment of the invention, Figure 4 is a diagram of an arrangement including several terminal groups; and

Figures 5A, 5B and 5C are diagrams of arrangements wherein one or more terminals belong to two or more terminal groups.

DETAILED DESCRIPTION OF THE INVENTION

[0009] Figure 1 shows an architectural diagram of a telecommunication system where the invention can be utilized. The telecommunication system shown in the figure comprises a mobile system PLMN (Public Land based Mobile Network), which is for example a GSM (Global System for Mobile Communication) system, without restricting the invention thereto, however. The mobile system can also be e.g. a third generation system, such as the UMTS (Universal Mobile Communications System), or there may be no mobile system at all. The GSM system can also comprise services supporting more advanced protocols, such as GPRS (General Packet Radio Service) and WAP (Wireless Application Protocol). The BSS (Base Station Subsystem) is a base station system, which provides an air interface via which terminals MS1 , MS2, MS3, MS4, MS5, MS6, MS7 and MS8 are linked to the system. The terminal MS1 to MS8 may be any terminal capable of communication in a mobile system, such as a mobile station, or a combination of several devices. The mobile system PLMN is further linked for example to the Internet (not shown) and to the public switched telephone network PSTN. The figure also shows two monitoring stations, of which monitoring station 1 is linked to terminal MS1 and monitoring station 2 is linked to the system via the public switched telephone network PSTN. The details of the systems presented are a technology well known to a person skilled in the art, and they need not be described in any more detail herein. It is to be noted that although in this example the invention is described in connection with a mobile system, the invention is also applicable to another wireless or wired telecommunication system or a combination thereof. Similarly, the terminals used may be any terminals of such systems, for example terminals in a public telephone network or Internet terminals, and the application of the invention is thus not in any way restricted only to terminals of a mobile system, for example.

[0010] The basic idea in monitoring terminals according to the invention is to monitor terminals from other terminals by alternately checking the state of each terminal in a given group of terminals from another terminal in the group of terminals in such a manner that the terminal that was checked last and was in a normal state checks the state of the next terminal. Herein, a normal state of a terminal means that both the terminal and the connection between the telecommunication system and the terminal operate normally, i.e. the terminal is able to carry out its routine tasks; e.g. a terminal coupled to alarm equipment has to be able to forward an alarm forward. An abnormal state, in turn, means that there is sufficient malfunction in the terminal and/or the connection to the terminal to prevent normal operation of the terminal. Figure 2 illustrates how the invention is applied in accordance with an embodiment. The figure shows eight terminals MS1 to MS8, which are assumed to be- long to the same terminal group. In this context, a terminal group refers to a logical entity of terminals MS1 to MS8, within which the terminals monitor each other. If needed, the composition of the group may be altered. A telecommunication system may comprise one or more such terminal groups, and a given terminal may also belong to more than one group. In the example shown in Figure 2, the state of the terminals is checked as a checking cycle, during which the state of each terminal is checked once. The outer periphery of the circle in the figure shows polling inquiries 1 , 3, 5, 7, 9, 11 , 13 and 15. Correspondingly, the inner periphery of the circle shows polling acknowledgements 2, 4, 6, 8, 10, 12, 14 and 16 to these inquiries. In a normal state, the checking cycle of terminals MS1 to MS8 proceeds by terminal MS1 first checking the state of terminal MS2, which is preferably carried out by contacting terminal MS2, i.e. making polling inquiry 1. The telephone number or corresponding address information of terminal MS2 is preferably in the memory of terminal MS1 , based on which said contact 1 is made. Depending on the telecommuni- cation system PLMN used, the contact may be made for instance by making a call from terminal MS1 to terminal MS2 or by sending a message from terminal MS1 to terminal MS2. Such a message may be for instance an SMS (Short Message Service) message or a GPRS message or the like, depending on the telecommunication system. Having received acknowledgement 2, terminal MS1 concludes that terminal MS2 and the connection thereto are operational, i.e. the state of terminal MS2 is normal, wherefore no further measures are required. Acknowledgement 2 may be a contact made by terminal MS2, which again may be for instance a call from terminal MS2 to terminal MS1 or a message from terminal MS2 to terminal MS1. Acknowledgement 2 may also be other information stating that terminal MS2 and the connection thereto are operational, such as a notification from the mobile system PLMN stating that in- quiry 1 is delivered all the way to terminal MS2. As to the basic idea of the invention, it is only essential that terminal MS1 that made inquiry 1 get some information 2 about the state of terminal MS2 being normal.

[0011] Having received polling inquiry 1 and having possibly sent acknowledgement 2, and if its state is accepted, such as a normal operational state is, terminal MS2 becomes the checking terminal, whereby it, in its turn, checks the state of the next terminal by sending polling inquiry 3 to terminal MS3, whose number or other address is preferably stored in the memory of terminal MS2. The terminal checking cycle continues as Figure 2 shows, so that the last checked terminal in a normal state always checks the state of the next terminal. Finally, terminal MS8 checks the state of terminal MS1 , whose number or other address is preferably stored in the memory of terminal MS8, and the checking turn passes again on to terminal MS1 , which completes the checking cycle. In accordance with a preferred embodiment of the invention, a new checking cycle is then always started, whereby terminals MS1 to MS8 are continuously checked at regular intervals.

[0012] If the above polling inquiry and acknowledgement are carried out as telephone calls, this may be implemented in telephone systems transferring the caller's number for instance as follows: the checking terminal first calls the number of the terminal to be checked (polling inquiry). The terminal to be checked preferably does not answer the call but registers the caller's number, i.e. what is known a subscriber A number. The terminal to be checked then calls the number of the checking terminal (acknowledgement), and the checking terminal also preferably does not answer the call but identifies the caller's number and therefore knows that an acknowledgement to a polling inquiry is concerned. As calls are not answered, charging for calls can also be avoided in systems where charging does not begin until a call is answered. This manner is suitable for use particularly in terminals reserved only for instance for the use of a fire alarm system or the like, and which are not usually used for other telephone traffic. The checking and acknowledgement can also be implemented by the check being made as a call and the acknowledgement by means of a short message or the like. It is apparent to a person skilled in the art that this can also be implemented the other way round or by any other combination. [0013] As distinct from Figure 2, terminals MS1 to MS8 in a terminal group may also be checked in some other order than is described and the state of some terminal(s) may be checked more than once during a checking cycle. The checking order may also be changed between checking cycles or in the middle of a cycle by providing terminals MS1 to MS8 with new information about which terminal(s) they should check in their checking turns. Said infor- mation also specifies the current composition of the terminal group, since terminals MS1 to MS8 in the terminal group do not necessarily have anything else in common than that they belong to the same checking cycle.

[0014] Terminal MS1 to MS10 of the telecommunication system of the invention preferably comprises telecommunication means for contacting the terminal to be checked. An example is a radio apparatus for setting up the connection. The terminal also preferably comprises identification means for identifying the checking terminal. This could operate simply by a memory being arranged in the terminal, and the subscriber number of the checking terminal being stored in the memory. By comparing the number in the connection re- quest with the number in the memory, the checking terminal can be identified. The terminal preferably also comprises acknowledgement means for indicating to the checking device that the operation of the device being checked and the connections thereto are operational. The terminals are preferably also provided with memory means for storing contact information about other terminals belonging to the terminal group and/or information on a possible monitoring station or monitoring stations. The presented functionalities of a terminal are preferably implemented by software utilizing the terminal's processor capacity.

[0015] Figure 3 shows an example of a situation where the state of one terminal to be checked is abnormal. In the same way as Figure 2 does, Figure 3 shows eight mobile stations MS1 to MS8. Polling inquiries 31 , 33, 34, 36, 38, 40, 42 and 44, and acknowledgements 32, 35, 37, 39, 41 , 43 and 45 are also shown. The difference as compared with the situation in Figure 2 is thus that as terminal MS2 checks the state of terminal MS3 using polling inquiry 33, terminal MS2 receives no acknowledgement to the inquiry, and there- fore the state of terminal MS3 is found abnormal. Terminals MS1 to MS8 are preferably arranged to wait for an acknowledgement according to predetermined rules. A rule may be for instance that the acknowledgement is to arrive within a given predetermined time. If this is not the case, the state of the terminal to be checked is found abnormal. An alternative is a situation where the mobile system PLMN or another system transferring the polling inquiry indicates in some way to the checking terminal MS2 that the inquiry could not for example be delivered to the destination, allowing the state of terminal MS3 to be checked to be immediately found abnormal. Such an unacknowledged polling inquiry 33 may also be repeated once or several times. Once the state of the terminal MS3 to be checked is finally found abnormal, a predetermined no- tification is preferably made. Such a notification may be made locally in the checking terminal MS2. However, the notification is preferably made to some predetermined address, such as a telephone number or, if the system is linked to the Internet, for instance to a given IP address (Internet Protocol). The notification may be for instance in the form of a message or any other suitable contact. The notification is preferably made to a special monitoring station, of which Figure 1 shows two. Such a monitoring station may be linked for instance in the manner presented to some terminal of the mobile system PLMN (monitoring station 1) or be linked for instance via a telephone network PSTN (monitoring station 2) or the Internet to the telecommunication system used. There is usually continuous on-call duty at a monitoring station, allowing the necessary measures to be taken once such a malfunction notification arrives. The notification can also be made to more than one address. The address to which the notification about the abnormal state is made is preferably stored in a memory in terminal MS1 to MS8. A terminal may also comprise two or more alternative addresses in case the notification cannot for some reason be delivered to the primary address.

[0016] Once a notification is made about an abnormal state of terminal MS3, terminal MS2 preferably checks the next terminal MS4 by sending polling inquiry 34, whereupon the checking cycle proceeds forward from termi- nal MS4 as shown in Figure 2. The memories of terminals MS1 to MS8 preferably include contact information about at least one other terminal that they are to check during their checking turn and instructions about making a notification about an abnormal state. These data are preferably stored in a manner allowing them to be altered for instance by sending new information from the monitoring station to the terminal. In addition to this, terminals MS1 to MS8 may include contact information about one or more alternative other terminals in case the state of the primary (and possibly one or more following) terminals to be checked is found abnormal, and the checking turn cannot thus be transferred to it, but the same terminal has to check at least one alternative terminal as was described above. It is obvious that if the reliability of the system is to be ensured, each terminal MS1 to MS8 is provided with the contact information of all terminals in the same terminal group, and said terminal goes through said information sequentially until a terminal is found from which an acknowledgement is received. If this is not the case, the terminal group only includes one operational terminal or only one whose connections are operational, which preferably informs the monitoring station of the malfunction. In accordance with the invention, an arrangement may also be preferably implemented wherein the terminal group is to deliver an acknowledgement signal to the monitoring system, such as a monitoring station, at predetermined intervals. This brings about the advantage that since no acknowledgement signal arrives if all termi- nals and/or the connections between them are damaged, the monitoring station detects that the entire terminal group is damaged.

[0017] An arrangement can also be implemented to improve system reliability, wherein several connections are arranged from a single terminal to the next terminal to be monitored. This may be implemented for instance by implementing the primary connection via a mobile network. If this connection does not operate, an attempt to set up a connection to the terminal to be monitored can be made via a secondary telecommunication network, such as a fixed telephone network. If a connection is established on a fixed connection, the detection is that the connections of the mobile network are faulty, but the terminal to be monitored is operational. Such an arrangement allows malfunction to be informed to the monitoring station more exactly, if desired. An alternative to accomplish this is to provide the terminal with a radio link that is able to use the networks of all operators in said area. In this case, if the first mobile network is not operational, an attempt can be made to use some other network connection operating in the same area. Such a safety arrangement is excellent in cases where the terminals to be monitored operate in a highly significant operational environment.

[0018] Alternatively, such contact information of an alternative terminal to be checked can be received for instance from a network element or other party, to whom a notification was made about the abnormal state of the terminal to be checked, in response to the notification made. For example, if the notification is made to a monitoring station, the monitoring station may send instructions to the terminal that made the notification regarding how to continue the checking cycle in each particular case. [0019] Figure 4 illustrates a case involving three terminal groups

G1 , G2 and G3, each including eight terminals, denoted by blacks balls. The telecommunication system may comprise several terminal groups as shown in the figure. When required, the checking cycle time of a given terminal group G1 , G2, G3 can be shortened by removing one or more terminals from it, which may be transferred for instance to another terminal group, or an entirely new terminal group may be set up if no more terminals can be placed in the existing groups. Two or more separate terminal groups G1 , G2, G3 may also use one or more common monitoring stations for notifying abnormal terminal states detected in the checks. The composition of a terminal group is thus determined according to the checking order of the checking cycle, and thus the composition of a group can be altered by altering the other terminals' contact information preferably included in the terminals, the information specifying the checking order in a checking cycle. Figure 4 also illustrates by broken lines the process of the checking cycle, whereby the group-specific checking cycle proceeds in rounds in each terminal group G1 , G2, G3. Furthermore, besides each intra-group checking, terminal groups G1 , G2 and G3 can also monitor each other as the figure illustrates by broken lines between the terminal groups. Such multilevel monitoring results in increasingly reliable monitoring.

[0020] The solution of the invention can also be implemented by a single terminal belonging to two or more terminal groups simultaneously, sepa- rate monitoring being implemented in each group. For example, Figure 5A shows an arrangement where terminal MS5 belongs to two terminal groups MS1-MS2-MS3-MS4-MS5 and MS5-MS6-MS7-MS8-MS9, each group performing separate monitoring.

[0021] Figure 5B shows an arrangement where terminals MS1 and MS5 belong to two terminal groups MS1-MS2-MS3-MS4-MS5 and MS1-MS5- MS6-MS7-MS8, each group performing separate monitoring. Figure 5C shows an arrangement where still another terminal group MS5-MS9-MS10 is added to terminal MS5, which belongs to the terminal groups shown in Figure 5B. Each group performs separate monitoring. [0022] It is apparent to a person skilled in the art that Figures 5A to

5C show different alternatives by way of example, which can be implemented using the solution of the invention. There are several different combinations, and they are not restricted to the ones presented herein.

[0023] In cases where a terminal to be checked belongs to two or more terminal groups, the terminal to be checked identifies the checking terminal by means of subscriber A identifier and/or some other identifier identifying the checking terminal. The terminal knows, based on the identifier, the terminal group whose checking inquiry is concerned and is also able to conclude, based on said identifier, to which terminal to send the following inquiry.

[0024] The above describes monitoring mainly in a mobile system. As was stated previously, it is obvious that a corresponding solution is also applicable to other devices that can be interconnected via some other than a mobile network. Such include for instance terminals interconnected via the Internet. The solution of the invention is also applicable in cases when a special telecommunication network is arranged for the terminals and the terminals operate within the network and are able to communicate with each other.

[0025] It is obvious that although the above mainly describes monitoring the state of terminals, the solution presented can also be used for checking the operation of telecommunication connections between terminals and for reporting it. [0026] It is obvious to a person skilled in the art that as technology advances, the basic idea of the invention can be implemented in a variety of ways. The invention and its embodiments are thus not limited to the above examples, but may vary within the claims.

Claims

1. A method of monitoring terminals and connections between them in a telecommunication system comprising at least one terminal group including at least two terminals, characterized by checking the state of the terminals in the terminal group in a predetermined order from another terminal in the terminal group in such a manner that the last checked terminal in an accepted state checks the state of at least one next terminal.

2. A method as claimed in claim 1, characterized by ac- knowledging the check from at least one terminal to be checked to at least one checking terminal when the terminal to be checked is in an accepted state.

3. A method as claimed in claim 1 and 2, characterized by making the contacts between the checking terminal and the terminal to be checked by means of telephone calls.

4. A method as claimed in claim 1 and 2, characterized by making the contacts between the checking terminal and the terminal to be checked by means of message traffic.

5. A method as claimed in claim 1 and 2, characterized by making the contacts between the checking terminal and the terminal to be checked by means of a combination of a telephone call and message traffic.

6. A method as claimed in any one of claims 1 to 5, characterize d by using subscriber A number and/or another terminal identifier in identifying the checking terminal and the terminal to be checked.

7. A method as claimed in claim 1 and 2, characterized by giving a predetermined notification from the checking terminal to at least one predetermined party when the checking terminal detects a lack of acknowledgement from the terminal to be checked within predetermined rules.

8. A method as claimed in claim 7, characterized by performing an alternative check of a second terminal to be checked from the same checking terminal in case of a lack of acknowledgment within the predetermined rules from the first terminal to be checked.

9. A method as claimed in claim 8, characterized by selecting the alternative second terminal to be checked from a list known to the checking terminal.

10. A method as claimed in claim 8, characterized by notifying the alternative second terminal to be checked to the checking terminal in response to the notification given by the checking terminal regarding the lack of acknowledgement from the first terminal to be checked within the predetermined rules.

11. A method as claimed in claim 1, characterized by dis- tributing the terminals to be checked into at least two separate terminal groups including at least two terminals.

12. A method as claimed in claim 1, characterized by distributing the terminals to be checked into at least two terminal groups including at least two terminals, the terminal groups including at least one common ter- minal.

13. A method as claimed in claim 1, characterized by arranging at least two separate telecommunication connections in at least one checking terminal in a terminal group to a terminal to be checked.

14. An arrangement for monitoring terminals and connections be- tween them in a telecommunication system comprising at least one terminal group including at least two terminals (MS1 to MS10), characterized in that in the arrangement the terminals in a terminal group are arranged to check each other's state in a predetermined order in such a manner that the last checked terminal in an accepted state checks the state of at least one next terminal.

15. An arrangement as claimed in claim 14, characterized in that at least one terminal (MS1 to MS10) to be checked is arranged to acknowledge the check to at least one checking terminal when the terminal to be checked is in an accepted state.

16. An arrangement as claimed in claim 14, characterized in that the terminals (MS1 to MS10) are arranged in at least two separate terminal groups including at least two terminals.

17. An arrangement as claimed in claim 14, characterized in that the terminals (MS1 to MS10) are arranged in at least two terminal groups including at least two terminals, the terminal groups including at least one common terminal.

18. An arrangement as claimed in claim 14, characterized in that in at least one checking terminal belonging a terminal group is arranged at least one alternative telecommunication connection to a terminal to be checked.

19. A terminal in a telecommunication system, the terminal belong- ing to a terminal group to be monitored, characterized in that the terminal (MS1 to MS10) comprises: telecommunication means for setting up a connection to a terminal to be checked, identification means for identifying a checking terminal, and acknowledgement means for giving an acknowledgement to the checking terminal.

20. A terminal as claimed in claim 19, characterized in that the terminal (MS1 to MS10) comprises memory means for storing the contact information of the terminals belonging to the terminal group.

21. A terminal as claimed in claim 19, characterized in that the terminal (MS1 to MS10) comprises memory means for storing the contact information of a monitoring station assigned to the terminal group.

22. A terminal as claimed in claim 19, characterized in that the terminal (MS1 to MS10) comprises notification means for notifying a lack of acknowledgement to a monitoring station.