Device for intercom network

Abstract

The invention relates to, among others, a network device (10, 11, 12) for an intercom network (13) for permitting an audio communication, in particular a duplex audio communication with other users (14a, 14b, 14c, 14d, 14e, 14f) of the intercom network, comprising a housing (33) and a communication module (20a, 20b) arranged therein or thereon, with which a radio link can be established for the transmission of audio signals to another user, wherein the radio link is subject to the DECT protocol. The speciality, among others, consists in that the network device (10, 11, 12) comprises a means (21) for preventing or reducing multipath interferences.

Claims

1. A network device for an intercom network for duplex audio communication between users of the intercom network, the device comprising: a housing; a communication module in or at the housing and that can establish a radio link for transmitting audio signals to and receiving audio signals from another user, the radio link being subject to the DECT protocol or another protocol, the audio signals to the communication module being broken by reflection into a plurality of radio paths; and means for preventing or for reducing multipath interference by: detecting that a received signal is transmitted via the different radio paths, separating the radio paths and selecting from the separated radio paths the path with the best signal quality, and suppressing signal information from all the radio paths except the selected path with the best signal quality.

Description

(1) Further advantages of the invention are revealed in the sub-claims not cited as well as in the description below of the embodiments depicted in the figures, in which

(2) FIG. 1, in a view of a schematic block diagram, shows an embodiment of an intercom network according to the invention wherein two mobile network devices according to the invention are shown,

(3) FIG. 2, in a partially cut schematic and partially perspective view, shows an embodiment of a network device according to the invention designed as a belt pack, and connected thereto a headset, wherein two different radio paths between the belt pack and a transmitter of the intercom network are depicted, and

(4) FIG. 3, in a schematic view, shows an operator carrying a network device designed as a belt pack according to the invention and a headset connected thereto.

(5) Embodiments of the invention are described by way of example in the figure description hereunder, also with reference to the drawings. For clarity's sake and insofar as different exemplary embodiments are concerned, identical or comparable parts or elements or areas are marked with identical reference symbols, partially with the addition of lower-case letters.

(6) Features that are described only with respect to one embodiment, may be provided also in any other embodiment in terms of the invention. Embodiments altered in this way are also covered by the invention, even if they are not shown in the drawings.

(7) All disclosed features are essential, on their own, to the invention. Fully included in the disclosure of the application is the disclosure content of the associated priority documents (copy of the preliminary application) as well as of the cited publications and the described devices of the state of the art, also for the purpose of including individual or several features of these documents in one or in several of the claims of the present application.

(8) A network device according to the invention is depicted by way of the embodiment in the figures and in its entirety is denoted with 10.

(9) FIG. 2 shows such a network device 10 according to the invention that is designed as a belt pack 11. According to FIG. 2 a headset 22 is connected to the belt pack 11 via a connecting line 25. The headset 22 comprises a microphone 23 and a loudspeaker 24.

(10) The belt pack 11, as schematically shown in FIG. 3, may be attached to a belt 32 of an operator 30 by means of a fastening means not shown and be worn by the operator 30.

(11) The belt pack 11 is part of an intercom network 13, the structure and architecture of which is illustrated in the block diagram of FIG. 1.

(12) The intercom network 13, in the embodiment of FIG. 1, comprises six stationary users in total that are marked by reference symbols 14a, 14b, 14c, 14d, 14e, 14f. These stationary users 14 are so-called intercom stations.

(13) Each of the intercom stations 14a, 14b, 14c, 14d, 14e, 14f is connected via its own connecting line 16a, 16b, 16c, 16d, 16e, 16f with one of the two switching centers 15a, 15b. The switching centers 15a, 15b may be connected to each other via a connecting line 16.

(14) Each intercom station comprises a microphone-loudspeaker combination. FIG. 1 shows that each intercom station 14a, 14b, 14c, 14d, 14e, 14f has its own fixedly installed microphone 17a, 17b, 17c, 17d, 17e, 17f. What is not shown in FIG. 1 is that each intercom station 14a, 14b, 14c, 14d, 14e, 14f also has its own loudspeaker.

(15) Further, it is not shown in FIG. 1 that each of the intercom stations 14a, 14b, 14c, 14d, 14e, 14f comprises a plurality of configurable or programmable keys that an operator of an intercom station 14 can actuate in order to establish a direct point-to-point connection with another user at another intercom station 14a, 14b, 14c, 14d, 14e, 14f.

(16) These connection paths are managed by the switching centers 15a, 15b. To this end each switching center 15a, 15b comprises at least one control 18a, 18b that handles the respective switching work.

(17) The stationary users 14a, 14b, 14c, 14d, 14e, 14f are, as the name indicates, arranged in a fixed place and not designed to be moved. The intercom network 13 as per FIG. 1 comprises also however a random number of mobile users, that is mobile network devices.

(18) This includes the initially described belt pack 11 shown in FIG. 1 but also a mobile microphone 12 as shown in FIG. 1. Mobile network devices 11, 12 can be worn by operators 30 and moved by the operators. Whilst in particular the switching centers 15a, 15b are stationary, i.e. arranged in a fixed place, the operators can be moved at random during an event within range of the intercom network 13.

(19) A mobile network device 11, 12 is able to enter into a radio link with different switching centers 15a, 15b or other users of the intercom network 13 at different points in time.

(20) In order to be able to establish such a radio link between a mobile network device 11, 12 and another user, e.g. 15a, 15b of the intercom network 13, a communication module 19a, 19b is arranged at each of the two switching centers 15a, 15b. A corresponding communication module 20a, 20b is also arranged in each mobile network device 11, 12.

(21) The mobile network device 10 in form of the belt pack 11 may for example establish a radio link to the switching center 15b. To this end the communication module 20a of the belt pack 11 enters into a radio link with the communication module 19b of the switching center 15b. The radio link is subject to the DECT protocol. Audio signals can be bi-directionally transmitted via the radio path.

(22) When the belt pack 11 is moved by the operator 30, the belt pack 11 can, at a later point in time, also enter into a corresponding radio link with the communication module 19a of the second switching center 15a via the communication module 20a.

(23) FIG. 2 illustrates that the radio link between a belt pack 11 and an antenna 31 is affected by a multipath problem.

(24) The antenna 31 of FIG. 2 may for example be provided by one of the two switching centers 15a, 15b of the intercom network 13 of FIG. 1. Alternatively the antenna 31 may be a further additional element in the intercom network 13 of FIG. 1 that is connected to one of the switching centers 15a, 15b and that participates in the bidirectional audio data exchange. Finally the antenna 31 of FIG. 2 may be provided by another mobile network device 10, in case there is a need for a direct transmission of radio signals between mobile network devices among each other.

(25) FIG. 2 illustrates that a radio link is achieved by the antenna 31 with a first radio path Pa being provided. The first radio path is the direct shortest connection (line of sight) between the antenna 31/the communication module of the antenna 31 not shown in FIG. 2 and the communication module 20a of the belt pack 11.

(26) FIG. 2 in addition shows that a second radio path is generated that comprises a radio path Pb and a further partial path marked with Pc that is generated after reflection from the building surface 29.

(27) The first radio path is in total also marked with the reference symbol 27, the second radio path with the reference symbol 28.

(28) Both radio paths 27, 28 each connect the antenna 31 with the communication module 20a.

(29) It will be clear to the expert that because of the two different radio paths 27, 28 an interference of the electromagnetic waves may occur in the area of the communication module 20a of the belt pack 11. The interference may be constructive or destructive, in particular. Due to this superimposition signals may be weakened or deleted altogether.

(30) In order to deal with this phenomenon the belt pack 11 according to the invention comprises a means 21 that is assigned to the communication module 20a. This assignment may be effected for example in that the meansas indicated in FIG. 2is directly connected to the communication module 20a via a connecting line 35. The means 21 may also be part of the communication module 20a. Alternatively the means 21 may be arranged upstream of the communication module 20a in the reception path of the radio signals.

(31) Due to electronic processing of the audio radio signals arriving via the different paths 27, 28, the means 21 can for example, prevent a destructive interference, and/or correct a respective received signal and thereby prevent or reduce the multipath phenomenon.

(32) For example the means 21 of the belt pack 11 according to the invention may be able, to detect different radio paths in the first place, to separate them and e.g. select the radio path 27 with the best signal quality, whilst suppressing the other radio signals arriving via other paths 28.

(33) The network device 10 according to the invention in form of the belt pack 11 in FIG. 2 may, similarly to the mobile microphone 12, include a plurality of programmable or configurable actuating elements 26a, 26b, 26c, 26d, 26e. These may be configured, for example, as keys, switches, a graphic user interface or the like. The network device 10 according to the invention, in particular in form of the belt pack 11, may also comprise a display not shown in FIG. 2.

(34) It will be clear to the expert when looking at FIG. 2 that in addition to the two radio paths 27, 28 shown a plurality of further parallel radio paths may develop of course, causing unwanted interference. Equally the expert will realize that the problem of multipath propagation will increase in line with how many mobile network devices 10 are present in the intercom network 13.

(35) According to the embodiment shown in FIG. 2 the means 21 is arranged inside the housing 33 of the belt pack 11. It is also covered by the invention if the means 21 is arranged on the housing 33 of the network device 10, 11.

(36) FIG. 2 depicts a DECT radio path from the antenna 31 to the belt pack 11. But the expert will recognize that transmission of the radio signal is bidirectional. Consequently the antenna 31 or the alternatively schematically shown switching center 15a in FIG. 2 as well as further advantageously any other user of the intercom network 13 that can establish a DECT radio link for the transmission of audio signals, comprises an appropriate means 21 for reducing or avoiding multipath interferences.

(37) The network device 10 according to the invention in form of a belt pack 11 in FIG. 2 comprises a port 34 for connection to the headset 22. The invention also covers network devices that have a loudspeaker or a microphone arranged directly in or on the housing or assigned to the housing.

(38) According to the depiction in FIG. 1 a communication module 20b is provided on the mobile microphone 12 that corresponds or essentially corresponds to the communication module 20a of the belt pack 11. In addition the mobile microphone 12 may also comprise programmable or configurable keys 26e, 26f, with which certain preliminary settings or configurations can be performed.

(39) The microphone 12, above all, serves to transmit audio information from the microphone to another user, e.g. to a switching center 15b. Microphones 12 are, however, also to be regarded as network devices in terms of the present patent application that additionally comprise a loudspeaker not shown in FIG. 1 or a port for a loudspeaker not shown.

(40) To this extent the invention covers network devices for intercom networks that permit a unidirectional communication with other users of the intercom network, but in particular cover network devices that allow a bidirectional communication with other users of the intercom network.