EP2297998A1

EP2297998A1 - Redundant connection of radio network elements to a central station

Info

Publication number: EP2297998A1
Application number: EP08774778A
Authority: EP
Inventors: Philipp Honegger; Urs Kästli; Philipp Blum
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2008-07-04
Filing date: 2008-07-04
Publication date: 2011-03-23
Also published as: WO2010000334A1; US20110261795A1; CN102144416A

Abstract

The invention relates to a radio communication system (100) comprising a central station (130), at least one slave radio station (a, b, c, d, e, f), a first gateway (g1) and a second gateway (g2). The slave radio station (a, b, c, d, e, f) is coupled to the central station (130) by means of a first transfer path using the first gateway (g1) and by means of a second transfer path using the second gateway (g2). The invention further relates to a method for transferring data between a slave radio station (a, b, c, d, e, f) and a central station (130, 230, 330, 430) of a radio communication system (100) of the type described above.

Description

description

Redundant connection of radio network elements to a control center

The present invention relates to the technical field of radio communication systems. In the context of this application, a radio communication system is understood to be a communication network having a plurality of subscribers, with at least some subscribers communicating with each other wirelessly via a radio interface. In particular, the present invention relates to a radio communication system having a central office and at least one radio secondary station, which are interconnected via a gateway. Moreover, the present invention relates to a method for transmitting data between a radio slave station and a center of a radio communication system of the type described above.

In the field of building technology, radio communication systems designed as fire alarm systems are known, in which the radio secondary stations are connected to a control center via a gateway. The gateway typically provides for the conversion of "radio messages" into "wire messages" and vice versa. "Radio messages" are in this context

Data transmitted via a radio interface. "Wire Messages" are data transmitted over a wired connection.

It is also known to connect a plurality of radio substations by means of a meshed network, which is also referred to as a mesh network with each other. In this case, data transmission can also take place via other radio secondary stations which act as an intermediate station or as a repeater. Such a data transmission is usually referred to as a multi-hop transmission. Furthermore, it is known that several radio transmission paths can exist within a meshed multi-hop network between a selected transmitting station and a selected receiving station. As a result, data transmission between the selected transmitting station and the selected receiving station can continue to be ensured even after a failure of an intermediate station.

It is an object of the present invention to further increase the transmission reliability within a radio communication system.

This object is achieved by the subject matter of the independent patent claims. Advantageous embodiments of the present invention are described in the dependent claims.

According to a first aspect of the invention, a radio communication system is described. This comprises (a) a central office, (b) at least one radio secondary station, (c) a first gateway and (d) a second gateway. According to the invention, the radio secondary station is coupled to the central office via a first transmission path involving the first gateway and via a second transmission path involving the second gateway.

The radio communication system described is based on the knowledge that the use of at least two gateways can improve the security in the transmission of data between the radio secondary station and the control center. A reliable data transmission is namely ensured even if one of the two gateways fails due to an error.

The term gateway is understood in particular to mean a network element which implements a protocol conversion. In this case, the gateway can independently make a suitable conversion of the data to be transmitted between the radio secondary station and the center. Even omitting information may be possible if it can not be transported in the respective destination network. For example, all log information appended to a data packet may be removed and replaced with other protocol information. In particular, a gateway can implement a conversion between "radio messages" and "wire messages" and vice versa.

The two gateways can also be referred to as network transceiver devices between different network types or between two different subareas of a network.

It is expressly pointed out at this point that the present invention can also be implemented with two or more gateways. In this way, the number of transmission paths between a radio slave station and the center and thus ultimately the transmission or the communication security can be further increased.

The control center can have an evaluation unit which receives the communication signals of the radio secondary stations and optionally evaluates them in combination with one or more communication signals from other radio secondary stations. In the case of a radio building management system and / or a radio danger detection system, for example, a plurality of communication signals can be evaluated by different radio substations designed as measuring instruments and / or as danger detectors in combination. Possibly. For example, a danger message can be initiated which forces people inside a building, for example inside a building, to monitor an area monitored by the danger detector and to leave the danger zone. - A -

The radio slave stations may also have output elements such as actuators. These include audible and / or visual display devices such as alarm sirens or flashing lights. Output elements may also be electrical switching contacts, for example

Press the smoke flaps or activate a sprinkler system. To activate the actuators, the same transmission paths between the control center and the respective radio substation can be used.

The first and / or the second gateway may be directly or indirectly connected to the center. For example, a fieldbus can be used to connect the gateways to the control center.

According to a further exemplary embodiment of the invention, the first transmission path and the second transmission path are independent of each other.

By using at least two gateways, which are each assigned to a separate transmission path between the at least one radio secondary station and the central office, the radio secondary station is thus connected to the central office via at least two completely independent transmission paths. In this context, the term "independent" can be understood to mean that there is no partial path between the relevant radio secondary station and the central station, which is shared by both transmission paths. This applies both to wired sections and to radio links. By providing independent transmission paths, the connection of the radio substation to the control center is completely error-proof. This means that within a larger system, which may in particular also have several radio secondary stations, even in the event of failure of any component of the system, such as a radio link, a gateway or a wire connection, the functionality of the entire system is maintained.

The described redundant connection between the central and the radio secondary station via at least two mutually independent transmission paths has the advantage that an increased reliability of the overall system can be achieved. On the one hand this is a direct advantage for the operator of the radio communication system, on the other hand it will in the future also make possible larger systems, i. Allow systems with a greater number of radio substations than conventional communication systems, while ensuring, for example, the relevant regulations for radio alarm systems legal requirements for reliable operation.

It should be noted that the first gateway and / or the second gateway can optionally also be arranged together with the center in a common housing. Furthermore, the first gateway and / or the second gateway can also be realized within the central office.

According to a further exemplary embodiment of the invention, the two gateways are coupled to the central office via a ring line. Under the term Ringleitung can in this

Connection a connection line are understood, which extends from a first terminal of the center to a second terminal of the center. This means that the gateways are at least coupled via a wired connection to the central office.

In this context, a loop may enable efficient wired connection of the two gateways to the control center with regard to the required connection cable. Of course, the ring line may also include one or more optical fibers, so that the two gateways are connected via an optical connection to the center. The central office can be designed such that in the case of a simple interruption of the loop continue both gateways are connected to the center. The communication between a radio substation and the control center can thus continue to take place via the same gateway. A change to the use of the other gateway is thus not required for only a simple interruption of the loop.

The communication between the two gateways on the one hand and the control center on the other hand can also take place via a bus connection. This means that the devices connected to the loop are electrically connected in parallel to the bus. In the described error case of a simple interruption of the loop, the communication between the control center and one of the two gateways via the non-disturbed part of the loop takes place. The communication is thus still possible with both gateways over the undisturbed part of the loop.

According to a further exemplary embodiment of the invention, at least one of the two gateways is coupled to the control center via a separate branch line. In the case of using multiple stubs this means that to one

Stub line only a single gateway is connected. In this way, a fault in a spur line can only lead to the failure of a single gateway.

According to a further exemplary embodiment of the invention, the control center has a first evaluation unit and a second evaluation unit. The two evaluation units are coupled together. Furthermore, the first evaluation unit is connected to the first gateway and the second evaluation unit is connected to the second gateway. The connection of the two gateways to the two different evaluation units can thereby optionally via a loop and / or via a stub.

The use of two separate evaluation units has the advantage that a redundancy with respect to the failure of one of the two evaluation units can also be achieved with respect to at least some tasks of the center. This is true in any case if, in the event of failure of the first evaluation unit, at least one indirect communication between the second evaluation unit and the first gateway via the failed first evaluation unit is possible. The indirect communication can take place, for example, via the second gateway. This is especially true when the first gateway and the second gateway are connected via a common loop to the center. In the event of a failure of the first evaluation unit, all evaluation procedures with respect to the signals which are provided via the two different gateways can then be carried out by means of the second evaluation unit.

According to a further embodiment of the invention, the radio communication system has a plurality of radio substations which form a meshed radio network.

A meshed radio network may, for example, be understood to mean a subnetwork of the radio communication system described consisting of a plurality of radio secondary stations. In this case, the individual radio secondary stations can be connected to one another via a multiplicity of radio interfaces. In particular, some radio substations can also indirectly communicate with each other via other radio substations.

The meshed radio network can be, for example, a so-called ad-hoc network, which is able to independently set up and configure itself. The meshed radio network can also be a so-called multi-hop network in which data from wireless Slave station to radio slave station to be passed on until they have reached their receiver.

When forming a meshed radio network with a plurality of radio secondary stations, the advantage can advantageously arise that the data load is distributed more advantageously than in networks with a central access point. Scarce resources such as computation time, power and bandwidth require effective collaboration between the radio substations, each of which acts as a network node. Special routing procedures can be used to ensure that the ad-hoc network adapts itself automatically when network nodes move, join or fail.

In particular, when using a plurality of radio substations, the use of a meshed network has the advantage that most radio substations can send messages to a gateway and receive messages from it via a plurality of connection paths. The message transmission then takes place frequently via so-called multi-hop connections, in which the transmitted data are transmitted indirectly via a plurality of radio secondary stations. As a result of the inventive use of at least two gateways, data transmission from and to the center via redundant connection paths is thus possible for most radio substations, so that a particularly high level of fail-safety of the entire radio communication network can be achieved.

It should be noted, however, that within the scope of the invention described in this application, even if they are incorporated in

Connection with a meshed radio network from several radio substations in terms of the first error security offers the greatest advantage, several radio substations can of course be connected to each other by means of other radio network technologies. Even with the use of other wireless network technologies is by providing achieved by two gateways due to the appropriate redundancy improved reliability.

According to a further exemplary embodiment of the invention, at least some of the radio secondary stations are assigned to one of two groups, wherein the radio secondary stations (a) assigned to a group normally each use one of the two gateways for data transmission from and / or to the central station and ( b) use only in case of failure of a gateway, the other gateway for data transmission from and / or to the control center.

The individual radio secondary stations can preferably be assigned to the two groups in such a way that the best reliability and / or the highest speed is ensured for the normal data transmission path. As a rule, the gateway that can be reached via the least intermediate stations is used for each radio slave station.

It should be noted that the radio secondary stations can also be designed such that they automatically select that gateway for the normal transmission path which allows the best reliability and / or the best speed.

According to a further exemplary embodiment of the invention, the radio communication system is locally limited to a building or a building complex.

The limited in terms of its spatial extent wireless communication system thus differs significantly from known cellular mobile networks, which usually cover a spatial area depending on the number of individual cells, which goes well beyond the size of a building or a larger building complex. The described near-field radio communication network may for example have a spatial extent along a direction of 20m, 50m, 100m, 200m or 500m. It should be noted that a building complex can also have a plurality of preferably adjacent buildings. In particular, these may be interconnected through the use of a meshed multi-hop technology based network described above.

According to a further exemplary embodiment of the invention, the radio communication system is a radio building management system.

The building management system can be used for a variety of different tasks that are required and / or useful within a modern equipped building. For example, the radio building management system described can be used for climate control, door operation and / or window opening or room monitoring. The radio communication system can have a sensor network and / or an actuator network, which records measured values in different rooms and forwards them to the central office and receives switching or positioning commands from them. Thus, with the described building management system, a comprehensive building management can be achieved.

According to a further exemplary embodiment of the invention, the radio communication system is a radio hazard detection system.

The intended use of the radio hazard alarm system described is typically determined by the functionality of the individual radio secondary stations. All radio substations can provide the same functionality or different functionality. In the case of the provision of various functionalities, a comprehensive building monitoring can be carried out, for example, with regard to (a) burglary (intrusion protection), (b) flooding, (c) the emergence and / or intrusion of, if necessary human health dangerous gases and / or (d) the emergence of smoke. In addition to monitoring functions, radio substations in a hazard detection system can also have evacuation and control functionality, for example for closing fire doors or smoke flaps, which can be controlled by the control center in dangerous situations. The radio communication system may in particular be a fire alarm system. Since for all these dangerous situations the person skilled in the field of danger alarm technology suitable peripherals are known, which can be used as a radio substation, will not be discussed in the context of this application to possible specific embodiments such devices.

It should be noted that in particular the formation of a meshed network by a plurality of radio substations in the field of danger detection technology is particularly advantageous. By providing fully redundant Ubertragungswegen between the control center and the individual radio stations can namely a particularly high reliability can be achieved. In the case of a radio communication system designed as a radio danger detection system, this can be of great advantage, since even high human lives can be saved by a high reliability in some dramatic cases, such as a dangerous fire situation.

As a precaution, it should be noted at this point that the radio communication system can also be a combination of a building management system and a hazard detection system.

In accordance with another aspect of the invention, a method of transmitting data between a radio substation and a center of a radio communication system of the type described above is described. The data transmission method described is based on the knowledge that the reliability of the data transmission can be improved by providing at least two different possible transmission paths between the radio secondary station and the central station. According to the invention, the two different transmission paths run via two different gateways. Thus, a proper data transmission is ensured even if one of the two gateways fails due to an error.

According to an exemplary embodiment of the invention, the data is normally transmitted redundantly both via the first transmission path and via the second transmission path. In this case, the term normal case is understood to mean a state of the radio communication system described, in which both the first and the second gateways are ready for operation.

The normally redundant data transmission has the consequence that the same data arrive via two preferably independent transmission paths at the respective destination network element, the radio secondary station or the central office. In order to avoid an unnecessary accumulation of data in the destination network element, duplicate identical data can be filtered and possibly deleted. This can ensure that data processing operations performed on the target network element do not need to unnecessarily work with redundant data. The described filtering of multiply received data can be carried out in the center, in particular by an evaluation unit.

The continuous redundant transmission over more than one Ubertragungsweg allows a simple check of the integrity of all transmission paths and thus the certainty that even if a single component or communication link all network elements remain connected. It should be noted that if more than two transmission paths exist between a radio secondary station and the control center, the data can normally be transmitted redundantly over any number of existing transmission paths. Of course, a redundant data transmission is only possible if the number of selected transmission paths is greater than one.

According to a further exemplary embodiment of the invention, the data (a) are normally transmitted only via the first transmission path and (b) in the event of a fault via the second transmission path from a first network element to a second network element. In this case, the first network element may be the central station and the second network element may be the radio secondary station. Alternatively, the second network element may be the central office and the first network element may be the radio secondary station.

Of course, if possibly the second transmission path is disturbed, a possibly existing further transmission path can likewise be activated.

The described division of the data transmission between the normal case and the fault case may mean that, in the event of an interruption of a transmission path, the communication is diverted to a further transmission path. The diversion can be activated by the radio substation and / or the control center. The activation of the diversion can be done by a failure confirmation message, which confirmation message is returned in the normal case of the relevant gateway when the radio station and / or the center sends a message to the relevant gateway.

It should be noted that the same messages or the same data can be transmitted via the diversion as over the normal transmission path. This has the advantage that even if one gateway fails, all data can be transmitted via the other gateway, which would normally be transmitted by the failed gateway.

The communication between the central office and the respective radio secondary station can be bidirectional as well as unidirectional. Bidirectional communication means that data is transmitted both from the respective radio secondary station to the central station and from the central station to the respective radio secondary station. This type of communication is the norm for most radio communication systems used in the field of building technology. However, unidirectional communication is also possible. If the respective radio secondary station is equipped only with an input element, such as a sensor for detecting a measured variable, then the unidirectional communication takes place from the radio secondary station to the central station. If the respective radio slave station is equipped only with an output element such as an actuator, then the unidirectional communication takes place from the central office to the radio slave station.

It should be noted that the transmission reliability can of course only be improved if the second or the further transmission path is still present after a failure of the first transmission path and can actually be used for data transmission.

In order to reliably monitor the availability of the second or the redundant and possibly further redundant transmission paths, the following measures are suitable, inter alia, which can be used individually or in any combination with one another: - As part of a regular data transfer is a periodic change between all available transmission paths. In this way, a failure of a Ubertragungsweges can be detected quickly and reliably.

- Also the second or the redundant gateway and possibly further redundant gateways are monitored as network component (s) of the described radio communication system in the context of an integrity check. This integrity check can be carried out at periodic intervals.

- Between the different gateways telegrams are transmitted in temporally preferred periodic distances, with which the sender reports to the other gateway or to the other gateways a fault-free operating state. The telegrams can be transmitted directly or indirectly via the control center and / or individual radio substations.

According to a further exemplary embodiment of the invention, the current use of the second gateway is detected in the event of a fault by the first network element on the basis of a message received via the second transmission path. Furthermore, for future data to be transmitted to the second network element an addressing is used in which the use of the second transmission path is described.

The described correct addressing used by the transmitting network element after a failure of a gateway has the advantage that in the event of a fault the correct path to the receiver is already given when sending messages. In this way, the security and also the speed of the data transmission between the first and the second network element or between the radio slave station and the control center can be considerably improved. According to a further exemplary embodiment of the invention, in the event of a fault, the first network element does not recognize that the data is being transmitted via the second transmission path and messages to the second network element continue to be addressed in the same way as in the normal case. This means that the first network element does not recognize an activated diversion of the data flow from the defective first gateway to the operational second gateway. Despite a resulting addressing with a possibly incorrectly specified Ubertragungsweg an error-free data transmission to the correct destination network element can be done by the operational gateway pulls the appropriate data and thus ultimately for the realization of the diversion from the first transmission path provides the second Übertragungsweg.

According to a further exemplary embodiment of the invention, a radio communication system with a plurality of radio substations is used, and in the event of a fault, data from at least one particular radio substation is transmitted to the center such that it remains hidden from the identity of the at least one particular radio substation , This can be realized, for example, by transmitting the corresponding messages of the radio secondary stations as a whole via the activated diversion via the second transmission path. In the case of a radio danger detection system, the control center thus has no possibility of identifying the individual radio substation which has issued a danger message.

Even if important data are not transmitted in the described deliberate concealment of the identity of the sender of a message, if necessary, for the assessment of a dangerous situation by the central office, this concealment has at least the advantage that the volume of all data that in the described case of disruption all over the second gateway must run, can be reduced. in case of a Radio-hazard detection system with a plurality of radio substations can then be reduced in a so-called. Emergency, which only a reduced operation of the system, the amount of data to be transmitted via the second gateway or the remaining gateways by omitting corresponding sender information.

Further advantages and features of the present invention will become apparent from the following exemplary description of presently preferred embodiments. The individual figures of the drawing of this application are merely to be regarded as schematic and not to scale.

Figure 1 shows a radio-hazard detection system with three gateways, wherein a first gateway is connected via a loop and a second gateway via a spur line to a central office and wherein a third gateway is integrated in the center.

Figures 2a, 2b and 2c show three different radio hazard detection systems, each with a different connection of two external gateways to a central office.

FIGS. 3a and 3b show the transition from a fundamentally redundant data transmission in the normal case (FIG. 3a) and a redundant data transmission activated only in the event of a fault (FIG. 3b).

Figures 4a and 4b show a radio-hazard detection system with two adjacent wireless networks, each associated with a gateway, in case of failure of a gateway data transmission over the other gateway can be maintained.

It should be noted at this point that in the drawing the reference numbers of the same or of each other differ only in their first digit speaking components. Letters used as reference numerals for network elements are uniformly used in the drawing for corresponding network elements.

FIG. 1 shows a radio communication system 100 embodied as a radio danger detection system. The radio hazard detection system 100 has a meshed radio network 110 which comprises a plurality of radio secondary stations a, b, c, d, e, f. The radio secondary stations a, b, c, d, e, f are coupled to one another at least via single hop (single-hop) or via multiple hop (multi-hop) communication links.

The radio communication system 100 also has two external gateways gl and g2 and a central station 130. The gateway gl is connected via a ring line 122 to the central 130. The ring line 122 also extends over further network elements h, i, j. The network elements h, i, j can have the same functionalities within the radio danger detection system 100 as the radio auxiliary stations a, b, c, d, e, f. In the case of the fire alarm system, the network elements h, i, j can thus fire detectors, input / output modules, alarm devices, display and control devices, etc. have. This also applies to building management systems.

The decisive difference between the network elements h, i, j and the radio substations a, b, c, d, e, f results from the type of communication with the center and the resulting respective of the power supply. The network elements h, i, j can communicate with the control center 130 by way of a wired connection, whereas the radio substations a, b, c, d, e, f are at least partially dependent on wireless radio communication. Since the radio secondary stations a, b, c, d, e, f typically have additional restrictions with respect to the power requirement, the supply voltage, the size, the electrical For example, functionalities that have a particularly high power consumption are preferably offered in connection with wired network elements to be connected to the center. This applies, for example, to so-called linear fire detectors, which detect smoke on the basis of an extinction caused by smoke aerosols. This also applies, for example, flame detectors, xenon flashing lights and / or display and Bediengerate.

The use of a ring line for connecting the gateway gl to the central unit 130 has the advantage that in the case of the interruption of only one branch of the ring line 122, the gateway can continue to communicate with the center 130 via the other branch of the ring line 122. The ring line 122, which extends from the central office 130 via the gateway gl back to the center 130, thus provides for the communication between gateway gl and central 130 two independent transmission paths available.

The gateway g2 is connected via a branch line 124 to the control center 130. The stub 124 further extends over other network elements k, 1, m. The network elements k, 1, m can take over the same tasks within the radio danger detection system 100 as the network elements h, i, j arranged within the ring line 122.

It should be noted at this point that it is irrelevant for many aspects of the invention, of which gateways are connected to the control center via a loop or via a spur line. In this sense, the type of line over which the gateways are connected to the headquarters, irrelevant. This also applies to the radio hazard detection systems shown below with reference to the further figures 2a, 2b, 2c, 3a, 3b, 4a and 4b, even if only the connection via a respective loop is shown there. The two gateways g1 and g2 ensure, in a known manner, a conversion between "radio messages" from and for at least one radio secondary station of the muted radio network 110 and "wire messages" from and for the central station 130. In particular, the gateways gl and g2 can perform a protocol conversion.

According to the exemplary embodiment illustrated here, the control center 130 has an evaluation unit p, which receives the messages provided by the individual radio secondary stations a, b, c, d, e, f and optionally evaluates them in combination with one another. For example, in the case of a message from a radio secondary station, which is designed as a fire detector, a corresponding fire alarm message can be initiated by the evaluation unit. By means of such an alarm message, for example, persons who are located within a building monitored by the relevant radio danger detector can be made to leave the danger area.

The radio communication system 100 also has another gateway g3. According to the exemplary embodiment illustrated here, the further gateway g3 is integrated in the control center 130. The gateway g3 can also be used to connect radio secondary stations a, b, c, d, e, f to the central station 130. Of course, could be used to increase the security of communication between the center 130 and the radio stations a, b, c, d, e, f also other gateways.

Figures 2a, 2b and 2c show three different radio hazard detection systems 200a, 200b and 200c, each comprising a meshed radio network 210 with a plurality of substations a, b, c, d, e and f, two gateways gl and g2 and have a central 230. In the case of the danger detection system 200a shown in FIG. 2a, the two gateways gl and g2 are coupled to the control center 230 via the same ring line 222.

In the case of the danger detection system 200b illustrated in FIG. 2b, the gateway is coupled to the control center 230 via a ring line 222. The gateway g2 is coupled to the control center 230 via a spur line 224. It is relevant here that the gateways gl and g2 are connected to the control center 230 via different lines 222, 224. Whether these lines as

Ring or stub lines are formed is irrelevant here.

In the danger detection system 200c shown in FIG. 2c, the control center has two units 230a and 230b which are spatially separated from one another. The unit 230a is a first evaluation unit pl and the unit 230b is assigned a second evaluation unit p2. The two units 230a, 230b are coupled to each other via a communication link 231. The communication link 231 may be a wireless connection (for example, over the air) and / or a wired connection (for example, via an optical fiber or a metallic line). The connection 231 can be designed not only as a single but also as a multiple connection, for example by means of a ring line.

FIGS. 3a and 3b show the transition from a normally redundant data transmission to a data transmission which is not redundant in the event of a fault for a radio hazard detection system 300. According to the exemplary embodiment illustrated here, the radio hazard detection system 300 has a network radio 310 with a plurality of secondary stations a, b, c, d, e and f, two gateways gl and g2 and a control center 330. The two gateways gl and g2 are each connected via a separate ring line 322 to the control center 330. For the purpose of processing the received input signal nale or input messages from different radio substations, the control center 330 has an evaluation unit p.

Normally, d. H. When all the network elements of the radio hazard alarm system 300 and in particular the two gateways gl and g2 are ready for operation, for example, the radio substation e with the center 330 via two completely independent transmission paths, a first transmission path 341 and a second transmission path 342 connected. The first transmission path 341 runs via the gateway gl, the second transmission path runs via the gateway g2. This state, which is characterized by a completely redundant data transmission between the central station 330 and the radio secondary station, is shown in FIG. 3a.

In this case, all data between the radio secondary station e and the central 330 are transmitted redundantly. This means that all data are transmitted twice to the control center 330 or to the evaluation unit p. In order to avoid an unnecessary accumulation of data in the control center 330 or in the evaluation unit p, suitable data filtering can be carried out there in which redundant data is deleted.

If, for example, the first transmission path 341 is interrupted by a fault 341a, then only a data transmission via the second transmission path 342 is possible. This fault condition, which occurs in particular in case of a failure of the gateway gl, is illustrated in FIG. 3b. If the second transmission path 342 has a sufficient bandwidth, all data that pass through the first transmission path 341 in the case of interference can be forwarded to the second transmission path 342.

Of course, it is also possible that in the normal case the data is not redundant but only transmitted via the gateway gl from the radio secondary station e to the central station 330 become. In the event of a fault in the gateway gl or a communication connection linked to the gateway g2, the redundancy with regard to possible transmission paths can then be activated so that the future communication between the radio secondary station and the e and the center 330 takes place via the second gateway g2.

The detection of the failure of the first gateway gl can be performed by the evaluation unit p, for example, by a "failure" message received directly or indirectly from the gateway via a radio secondary station and / or by the absence of positive "operating" messages (so-called keepalive Messages). Both "outage" messages and positive "operation" messages can be communicated to the other users of the radio communication system in all possible ways and detours. These paths and / or detours may comprise, for example, wired fieldbus as branch or ring line, radio links and / or additional connections, for example via wire, radio, optical fibers.

Figures 4a and 4b show two operating states of a radio hazard detection system 400. The hazard detection system 400 has two adjacent radio networks 410a and 410b. For example, the radio networks 410a or 410b may be a meshed network having a plurality of radio substations a, b, c, and d, e, f, respectively. For communication of the relevant substations with a center 430, the first radio network 410a is assigned a gateway gl. Accordingly, the second radio network 410b is assigned a gateway g2.

In a trouble-free operating state shown in FIG. 4a, in which in particular the two gateways g1 and g2 are ready for operation, the communication between the radio secondary station e and the center 430 takes place via the gateway g1, which defines a first transmission path 441. The communication between the radio substation a and the central office 430 takes place via the gateway g2, which defines a second transmission path 442.

In case of a failure of the gateway gl or a failure of the communication link between the gateway gl and the

Substation e or between the gateway gl and the center 430, the data traffic between the substation e, which normally runs over the first Ubertragungsweg 441, is redirected to the second Ubertragungsweg 442. This operating state is shown in FIG. 4b. Thus, even in the event of a fault or interruption of the first transmission path 441, frictionless data traffic between the secondary station e and the center 430 can be ensured.

It should be noted that the embodiments described herein represent only a limited selection of possible embodiments of the invention. Thus, it is possible to combine the features of individual embodiments in a suitable manner with one another, so that a multiplicity of different embodiments are to be regarded as obviously disclosed to the person skilled in the art with the embodiments explicitly illustrated here.

Claims

Patent claims

1. Radio communication system comprising

A central station (130, 230, 330, 430), at least one radio secondary station (a, b, c, d, e, f),

• a first gateway (gl) and

A second gateway (g2), the radio substation (a, b, c, d, e, f)

- Via a first Ubertragungsweg (341, 441) with the inclusion of the first gateway (gl) and

- Is coupled via a second Ubertragungsweg (342, 442) including the second gateway (g2) with the center (130, 230, 330, 430).

2. A radio communication system according to claim 1, wherein the first Ubertragungsweg (341, 441) and the second Ubertragungsweg (342, 442) are independent of each other.

3. Radio communication system according to one of the preceding claims, wherein the two gateways (gl, g2) via a ring line (122, 222, 322, 422) to the central office (130, 230, 330, 430) are coupled.

4. Radio communication system according to one of the preceding claims, wherein at least one of the two gateways (g2) via a separate spur line (124, 224) is coupled to the central office (130, 230).

5. Radio communication system according to one of the preceding claims, wherein the control center (130, 230, 330, 430) has a first evaluation unit (pl) and a second evaluation unit (p2), which are coupled to one another, wherein the first evaluation unit (pl) to the first gateway (gl) and the second evaluation unit (p2) to the second gateway (g2) is connected.

6. A radio communication system according to one of the preceding claims, wherein the radio communication system comprises a plurality of radio substations (a, b, c, d, e, f) comprising a meshed radio network (110, 210, 310, 410) form .

A radio communication system according to any one of the preceding claims, wherein at least some of the radio substations (d, e, f; a, b, c) are associated with one of two groups (410a; 410b), one of said groups (410a; 410b) associated radio substations (d, e, f; a, b, c)

In the normal case, in each case one of the two gateways (gl; g2) for a data transmission from and / or to the control center

Use (430) and

- Use only in case of failure of one gateway (gl) the other gateway (g2) for a data transfer from and / or to the center (430).

A radio communication system according to any one of the preceding claims, wherein the radio communication system (100, 200a-c, 300, 400) is localized to a building or a building complex.

A radio communication system according to any one of the preceding claims, wherein the radio communication system is a radio building management system (100, 200a-c, 300, 400).

10. The radio communication system according to claim 7 or 8, wherein the radio communication system is a radio hazard detection system (100, 200a-c, 300, 400).

11. A method for transmitting data between a radio substation (a, b, c, d, e, f) and a control center (130, 230, 330, 430) of a radio communication system (100, 200a-c, 300, 400) according to any one of the preceding claims.

12. The method of claim 11, wherein the data is normally redundant both over the first

Transmission path (341, 441) and via the second transmission path (342, 442) are transmitted.

13. The method of claim 11, wherein the data

- Normally only via the first Ubertragungsweg (341, 441) and

- In the event of a fault, they are transmitted via the second transmission path (342, 442) from a first network element to a second network element, and wherein

the first network element the central station (130, 230, 330, 430) and the second network element the radio secondary station (a, b, c, d, e, f) or the second network element the central station (130, 230, 330, 430) and the first network element is the radio sub station (a, b, c, d, e, f).

14. The method of claim 13, wherein in case of failure of the first network element

the current use of the second gateway (g2) is detected by means of a message received via the second transmission path (342, 442) and

- For future data to be transmitted to the second network element addressing is used, in which the use of the second Ubertragungsweges (342, 442) is described.

15. The method of claim 12, wherein in the event of a failure of the first network element is not recognized that the data over the second Ubertragungsweg (342, 442) are transmitted and messages to the second Network element continues to be addressed in the same way as normally.

16. The method according to any one of claims 12 to 15, wherein a radio communication system with a plurality of radio substations (a, b, c, d, e, f) is used and in case of failure, data from at least one particular radio substation ( e) are transmitted to the central office (130, 230, 330, 430) in such a way that it remains hidden from the identity of the at least one particular radio secondary station (s).