A SYSTEM OF TELECOMMUNICATION

Abstract: The present invention relates to a telecommunications system (1) that includes a general telecommunications network (2) to which a number of telephone sets (21, 22, 23) are connected and in which a calling telephone set is able to initiate and establish via network switching means (2a) a connection with a called telephone set, and which further includes a private branch exchange function (3) related to the telecommunications network, said function being capable of being connected via an outward extension telephone port or line (3b) to an inward port or line (4a) for equipment that includes switching functions among other things. A peripheral extension telephone set (21) belonging to the branch exchange function is connected (21a) to the telecommunications network (2) as a network-adapted telephone set. An equipment-related outward port or line (4) is connected to the telecommunications network (2) so that branch exchange services can be offered to the peripheral extension telephone set (21).

Description: A SYSTEM OF TELECOMMUNICATION Field of Invention The present invention relates to a telecommunications system and then more particularly to a telecommunications system that is included in or that itself includes a general or public telecommunications net, among other things. A general telecommunications network includes, among other things, a plurality of telephone sets, wherein a calling telephone is able to initiate and thereby establish a connection with a called telephone belonging to the telecommunications network, through the medium of a switching means. By telephone set or telephone set belonging to the telecommunications network shall be understood primarily as meaning a subscriber-connected telephone set, which may include tone dialling functions. The term telephone set may also include telephone exchanges and switching means. According to the invention, the telecommunications system also utilises a private branch exchange function that is either related to or integrated with the telecommunications network. This private branch exchange function may be implemented beneficially as a private branch exchange that is connected to the telecommunications network through the medium of inward lines. By private branch exchanges is meant primarily in the present context a large, operator-manned exchange that incorporates service-adapted functions or services. The exchange is assumed to have a plurality of outward ports or lines re- lated to extension telephone sets, where said ports or lines can be connected to inward ports or lines for equipment that includes call switching functions, among other things. The expressions outward and inward ports or lines shall be seen symbolically and include every means whereby information exchange is appropriate and that the call direction given has merely been chosen with a view to clarification. Description of the Background Art Several different types of telecommunications systems of the aforesaid nature are known to the art. Telecommunications systems that include large operator-manned private branch exchanges connected to the public telecommunications network are also known. The reason why private branch exchanges are connected to the general or public telecommunications network is because the public branch exchange is able to provide greater service to an extension telephone set of the branch exchange than the telecommunications network, including services that are adapted more di- rectly to the needs of these collective extension telephone sets. Moreover, the number of lines that can be used between the private branch exchange and the telecommunications system are greatly reduced. In addition to connecting a private branch exchange to the public telecommunications network via telephone lines, it is also known to incorporate a private branch exchange function in the public telecommunications network and to allow network-connected telephone sets to serve as extension telephone sets belonging to the private branch exchange. In the case of the aforesaid two private branch exchange applications, it is also known to connect to the private branch exchange equipment that provides an audio response system and also other services, with the intention of increasing the number of service options that can be provided for the branch exchange extension telephone set. Although such items of equipment can well be incorporated physically in a private branch exchange, it is nevertheless usual for such items of equipment to form separate line-interconnected units. Private branch exchanges of this kind, i.e. large private branch exchanges, normally include inward ports and outward ports that are adapted for digital and/or analog signals, where information concerning extension telephone set is received on outward ports. For instance, it is known to structure the outward port signals in accordance with a CAS protocol, wherewith each extension telephone set is allocated an outward port in the form of a time slot. The exemplifying embodiment illustrating the present invention shows that a number of exchange outward ports, one port for each extension telephone set, is coupled to a corresponding number of equipment inward ports, via a coaxial cable. Such equipment that provides an audio response system and also switching functions among other things is known to the art by virtue of equipment marketed by Trio AB, Taby, Sweden, under the trade name -Televoice-. Several different types of large private branch exchanges that can be con- nected to a general telecommunications network are known to the art. A private branch exchange suitable with respect to the present invention is retailed under the designation M 110 by Ericsson, Stockholm, Sweden. Earlier known, equipment and private branch exchanges of the kind intended here are complex in themselves, and consequently the following description has been restricted solely to exchange features required by the invention. It is known to allow the equipment to include a number of services, or to in- elude a number of services in coaction with functions in the private branch exchange, either with or without the assistance of a telephone operator. For the sake of simplicity, only a few services will be discussed in the following description, for instance services such as temporary transfers, follow-me diversions, and interception services for instance, although the person skilled in this art will be aware that other services may be exploited in a similar way. One example of such a further service is the ACD service (Automatic Call Distribution), where calls to and intended for one and the same group, such as telephone operators, are controlled for distribution equally to all telephone operators within the group. With respect to significant features of the present invention, it can also be mentioned that it is known to transfer temporarily or divert calls that are intended for an extension telephone set connected directly to the private branch exchange to a peripheral subscriber-connected telephone set belong to the public telecommunications network by means of a transfer or diversion service provided by said branch exchange, wherein said peripheral telephone set is able to function as a peripheral extension line to the private branch exchange for the duration of the call transfer service. Such a peripheral extension telephone set is adapted to solely receive transfer calls from the private branch exchange and has a very limited function with respect to further use as an extension telephone set belonging to the telephone exchange. However, it is necessary to distinguish a temporary transfer connection from the connection of a peripheral extension telephone set to the telecommunications network, as applicable in accordance with the invention. It is also known to provide a service (Centrex) in the public telecommunications network with which selected telephone sets affiliated with said telecommunications network are also allocated extension telephone set functions within the Centrex service. In the case of very high traffic loads, it is also known to connect a fixed leased line between two subscribers. A leased line is quite expensive and is therefore only justified economically in the case of very high traffic loads. Summary of the Invention Technical Problems When taking into consideration the technical deliberations that a person skilled in this particular art must undertake in order to provide a solution to one or more technical problems that he/she encounters, it will be seen that on the one hand it is necessary initially to realise the measures and/or the sequence of measures that must be implemented to this end, and on the other hand to realise which means is/are required to solve one or more of these problems. On this basis, it will be evident that the technical problems listed below are highly relevant to the development of the present invention. When considering the present state of the art, as described above, it will be evident that a technical problem resides in creating with the aid of simple means conditions which enable an extension telephone set associated with a public branch exchange function to be placed peripherally in relation to other direct dialling ex- change extension telephone sets, and therewith be separated connection-wise from direct access to said exchange, but where said peripheral extension telephone set can still be afforded access to all services provided by the exchange, or at least substantially all such services. Another technical problem is one of providing with the aid of simple means and measures conditions which will enable such a peripheral extension telephone set belonging to said exchange to be connected through the general telecommunications network and therewith allow each peripheral person served by the extension telephone set to be located physically anywhere within the total range of the network without the person concerned needing to refrain from accessing the significant service functions afforded by the public branch exchange. Another technical problem is one of creating conditions which will enable ready access to interception functions to be provided in the private branch exchange and/or provided with the aid of said equipment without needing to lease lines or some other fixed connection. Still another technical problem is one of providing with the aid of simple means conditions that will enable a peripherally connected extension telephone set to be readily connected to the public telecommunications network in addition to being readily connectable to the branch exchange receiver means for the extension concerned. Despite the positioning of a peripheral extension telephone set and its connection to the telecommunications network, a technical problem nevertheless exists in creating conditions that will ensure that the private branch exchange has, and will be able to obtain within the storage areas of the branch exchange, at least substan- tially all information relating to the status of the peripheral extension telephone set, and to enable the peripheral extension telephone set to transfer or divert to the private branch exchange and/or its telephone operator/operators each requested service function of said exchange in a simple manner and on equal terms with a di- rect dialling extension telephone set. Another technical problem resides in realising the simplifications that can be obtained by allowing such a peripheral extension telephone set to be easily connected to the telecommunications network, such as a subscriber telephone set adapted to said network, and still provide with the aid of a connection set-up through or within the telecommunications network all options to the selection of different services that can be offered through an operator-manned private branch exchange. With respect to an application of this nature, a technical problem resides in the significance of choosing for this particular application a private branch exchange that has ports and interfaces suitable for said application and to adapt outward ports or lines for said equipment for direct connection to the telecommunications network or indirect connection via the branch exchange. Another technical problem is one of creating with the aid of simple means and through the medium of the telecommunications network conditions which will enable the peripheral extension telephone set to be connected with its own inward circuit for the branch exchange via a call, and to listen to or monitor a branch exchange dialling tone via a communication path connected through the network, and to transfer to said branch exchange via said communications path such extension telephone set control signals as e.g. the telephone number of the extension con- cerned, the telephone number of the telephone set associated with the telecommunications network, signals requesting or cancelling one or more interception services, call forwarding services and/or other branch exchange services, and to adapt the private branch exchange to establish a desired connection with, or to implement, a requested service, either directly or via said equipment, in a known manner. In the case of a renewed connection with the branch exchange inward circuit from an intercepted or forwarded peripheral extension telephone set via a communications path set up in the network, another technical problem is one of being able to monitor or listen to a branch exchange dialling tone and also to a chopper tone to call attention to the fact that a connected service is on hand and has been activated. If the telecommunications network requires a B-response in respect of a control signal exchange via such a connection, the private branch exchange shall be adapted to be able to receive extension telephone set signals subsequent to the B-response being delivered to circuits within the telecommunications network: In respect of the use of a private branch exchange that includes inward ports and outward ports, it will be seen that a technical problem resides in the ability to realise those advantages that are afforded when said outward ports, on which there is applied a signal structure where each extension telephone set is allocated information significant to said telephone set within an own time slot, are connected to equipment inward ports and thereby create conditions which enable information significant to said extension telephone set to be transferred or diverted readily to said equipment. It will also be seen that a technical problem resides in realising the significance of enabling an inward call to be connected via said equipment to a sound (audio) channel belonging to the telecommunications network, such as to deliver to the calling telephone set tone or speech messages that can be generated within the telecommunications network. In the case of a telecommunications network with which a control-signal adapted connection can be set up between the equipment and the peripheral extension telephone set without generating a B-response, another technical problem resides in the realisation that said equipment shall be adapted to receive control signals belonging to the extension telephone set without generating a B-response to circuits in the telecommunications network. If the telecommunications network requires a B-response for such control signals, the equipment shall be adapted to be able to receive signals belonging to said extension telephone set subsequent to the requisite B-response to the tele- communications network. When a requested service is stored in the exchange memory area for the peripheral extension telephone set concerned, such as a call forwarding service or an interception service, a technical problem resides in realising the significance of and the advantages afforded by enabling means belonging to the private branch exchange to implement the measures required in respect of said requested service in the event of a call to the peripheral extension telephone set being received by the branch exchange, wherewith a requested service directed solely to the branch exchange is performed by said exchange, for instance a request for the call to be forwarded to a direct dialling extension telephone set. It will also be seen that a technical problem resides in realising the significance of enabling a connection to be established through the telecommunications network via said equipment and therewith connect a call from the private branch exchange intended for the peripheral extension telephone set to a sound channel be- longing to the telecommunications network, therewith enabling tone or speech messages that can be generated within the telecommunications network to be switched to the calling telephone set. This can also be effected either with or without a B-response. It will also be seen that a technical problem resides in the significance of and the advantages that are afforded by allowing the peripheral extension telephone set belonging to the private branch exchange and connected to the telecommunications network to utilise a network function, namely a function that will automatically and immediately establish a connection through the telecommunica- tions network with a pre-programmed number belonging to said branch exchange and/or forward said call to said equipment, in response to lifting the telephone receiver or the like. Another technical problem is one of ensuring, with the aid of simple means, that the pre-programmed number in the private branch exchange will establish a connection between the peripheral extension telephone set and its inward circuits associated with the branch exchange, so as to enable a branch exchange dialling tone to be transmitted to the peripheral extension telephone set. A technical advantage is gained by electing to establish the switching path to the equipment via the branch exchange, so that a switching path established between a peripheral extension telephone set and the equipment can be exploited to transmit control-signal related information. Another technical problem is one of realising the significance of allowing the equipment to ascertain which extension telephone set or which calling telephone set is the calling telephone set, for instance by evaluating a direct dialling number or by evaluating a relevant A-number. The present invention also enables each peripheral extension telephone set that calls the branch exchange via an established connection and through the medium of a telephone keyset, to activate one or more codes that represent a temporary transfer or follow-me diversion, an interception, or some other desired ex- change function or service, and to enable these services to be stored in the exchange storage area. Moreover, the peripheral extension telephone set can be offered the function in the telecommunications network that corresponds to depression of an R-button, by activating and sending over a connection a code combination corresponding to the R-button and discernible solely in the branch exchange and/or said equipment. Another technical problem is one of realising the significance of and the advantages that are afforded by inhibiting said function of automatically activating a connection to a pre-programmed branch exchange number when lifting the receiver of the handset concerned, by dialling a code such as to connect the extension telephone set directly to the telecommunications network and therewith enable the telephone set to immediately activate functions relating to said network. A further technical problem is one of creating conditions which, when a pe- ripheral extension telephone set is busy or engaged with an own connection solely within the telecommunications network, will activate an equipment-associated callback function and be able to co-ordinate each subsequent inward call to the engaged peripheral extension telephone set within the branch exchange. Solution The present invention thus takes as its starting point a telecommunications system that includes: a general telecommunications network to which a plurality of telephone sets are connected and where a connection can be initiated and set up by a calling party to a called telephone set via switching means belonging to said telecommunications network, a public branch exchange function which is related to the telecommunications network and which is connected to inward ports or lines for equipment that includes switching functions, among other things, via outward ports or lines of the extension telephone set. With the intention of solving one or more of the aforesaid technical prob- lems, it is proposed in accordance with the present invention that an extension telephone set peripheral to a private branch exchange and associated with the exchange function shall be connected to the telecommunications network as a telephone set adapted to said network, and that outward ports or iines for said equipment are also connected directly or indirectly to the telecommunications network, wherewith said peripheral extension telephone can be directly allocated services belonging to said branch exchange. In accordance with embodiments that lie within the scope of the inventive concept, it is also proposed that the peripheral extension telephone set can be connected to a private branch exchange via a switching path related to a teiecommuni- cations network, and that said peripheral extension telephone set is able to communicate as an extension telephone connected directly to said branch exchange via said switching path. According to the invention, a signal transmission path can be set up via the telecommunications network without needing to generate a B-response related to the branch exchange. The signal transmission effected from the peripheral extension telephone over said switching path with respect to a desired service can be stored in the private branch exchange so as to be readily available for a call from a direct dialling Q extension telephone or from a telephone belong to a telecommunications network, via said private branch exchange According to the invention, information relating to desired services or services desired for each extension telephone set can be structured in a co-ordinated manner, such as within respective storage areas In the absence of information associated with the branch exchange in relation to requested services, it is proposed in accordance with the invention that a call to a peripheral extension telephone set arriving at the branch exchange is forwarded to said equipment, which in turn sets up a switching path through the tele- communications network When information relating to one or more requested services is stored in the branch exchange, a call arriving at the branch exchange for a peripheral extension telephone can be switched within the exchange or forwarded to said equipment It is also proposed that a telephone set belonging to a telecommunications network or an extension telephone belonging to a private branch exchange with which a call is initiated to a peripheral extension telephone connected to the telecommunications network will activate means within said branch exchange that, in turn, activates a port, line or time slot or the like appertaining to the extension telephone, said port, line, time slot or the like being sensed by said equipment and causing said equipment to carry out a function in accordance with said information It is also proposed that upon the occurrence of a time slot concerning a peripheral extension telephone or the like, the equipment will establish a connection to a subscriber number allocated to said peripheral extension telephone, via a switching path through the telecommunications network The equipment initiates the connection via said switching network without needing to generate a B-response relating to the extension telephone set When the equipment has established a connection of an inward call to a peripheral extension telephone set, a tone or speech message, that can be generated within the telecommunications network, is delivered to the calling telephone, via a sound channel belonging to the telecommunications network When a connection is established with the private branch exchange through the telecommunications network, one or more service significant codes, such as temporary transfer, interception or some other chosen function of the branch exchange, are activated through the keypad of the extension telephone According to the invention, in the case of a call to a peripheral extension telephone number that has been diverted in the branch exchange the storage area appertaining to this telephone set will include information relating to the diversion, or temporary transfer of the extension telephone number When this information dis- closes a diversion to an extension telephone connected directly in the branch exchange, the call is switched within the exchange. On the other hand, if the information discloses a diversion to another peripheral telephone or the like, the information can be sensed by said equipment in the time slot of the second peripheral exten- sion telephone, wherewith the equipment causes a connection to be established with the subscriber number of said other peripheral extension telephone through the telecommunications network. The connection of an inward call to a called telephone number can also be controlled via said equipment so as to enable the use of a sound channel belonging to the telecommunications network to deliver tone or speech messages that can be generated within the telecommunications network. In certain cases, a switching path established via the telecommunications network can be used without generating a B-response related to the telecommunications network. Such desired call diversions or interceptions can be transmitted to and stored within the storage area in the branch exchange through the medium of branch exchange personnel, such as telephone operators, or by dialling a code, for instance via the own peripheral extension telephone. It is particularly proposed in accordance with the invention that a peripheral extension telephone which belongs to the private branch exchange and which is connected directly to the telecommunications network is able, conveniently, to utilise a function or service provided by the telecommunications network, for instance the function of initiating a connection to a pre-programmed number belonging to the branch exchange and/or said equipment automatically as the receiver or the like of a telephone is lifted. Suitably, such a switching path will be selected via the branch exchange to said equipment. It is also proposed in accordance with the invention that said equipment is able to ascertain which extension telephone is the calling telephone, such as a di- rect number within the branch exchange or by establishing the A-number within peripheral extension telephone sets connected to the telecommunications network, and thereafter initiating a connection to the called telephone. In the case of this application, it is proposed that the calling telephone will receive a tone or speech message generated via the branch exchange. A switching path established via the branch exchange is set up without generating an exchange-related B-response. When a call is made from a direct dial-in extension telephone set to another extension telephone set, the connection is set up internally through the branch ex- change or there is initiated via said equipment a connection to a telephone set belonging to a telephone communications network or to a peripheral extension telephone set belonging to a telecommunications network According to the invention, in the case of such an application the telephone user is able to inhibit the function of an automatic connection to a pre-programmed number, by dialling a code when lifting the telephone receiver The peripheral extension telephone will then be connected directly to the telecommunications network so as to be able to activate directly network-related functions According to the invention, the peripheral extension telephone set may be a mobile telephone connected to a mobile telephone network which, in turn, is connected to said telecommunications network and/or said equipment When a peripheral extension telephone is busy, or engaged, the equipment causes activation of call-back functions and/or queuing functions in the branch exchange via a path connected directly through the telecommunications network Advantages Advantages primarily characteristic of an inventive telecommunications system reside in the provision of conditions which will enable a peripheral extension telephone belonging to a private branch exchange to be connected as an inward line in the general telecommunications network and as a network subscriber in the absence of a leased fixed line connection, and wherein measures have been taken so that said peripheral extension telephone can be provided by the branch exchange with the same services and the same options as those afforded to an extension telephone adjacent to the branch exchange and connected directly to in- ward lines to the branch exchange, or at least essentially the same services and the same options, despite the proposed connection with the telecommunications network This enables telephone operations distanced from the branch exchange to be carried out without foregoing a desired service level to any appreciable extent. The primary characteristic features of an inventive telecommunications system are set forth in the characterising clause of the accompanying Claim 1 Brief Description of the Drawings A telecommunications system that has features characteristic of the present invention will now be described in more detail with reference to the accompanying schematic drawings, in which Figure 1 illustrates a telecommunications system constructed in accordance with the invention, and shows a calling telephone belonging to the telecommunications network connected to a peripheral extension telephone via a private branch exchange and an equipment, said peripheral extension telephone also being connected to the telecommunications network; Figure 2 illustrates a switching sequence in which the peripheral extension telephone connected to the telecommunications network is switched to the private branch exchange, so as to be able to deliver service requests to said exchange, among other things; Figure 3 illustrates a switching option where the peripheral extension telephone connected to the telecommunications network utilises network functions solely for a direct connection to a telephone set connected to said telecommunications network; Figure 4 is a greatly simplified illustration of equipment belonging to the telecommunications system and connected to the private branch ex- change; Figure 5 illustrates an embodiment in which the peripheral extension telephone may be a mobile telephone; and Figure 6 illustrates a switching option via a telecommunications network function when a peripheral extension telephone is busy, and where a call- back function and a call queuing function provided by said equipment is available. Description of Embodiments at present Preferred Figure 1 is thus a greatly simplified illustration of a telecommunications system 1 constructed in accordance with the invention. The illustrated telecommunications system 1 includes a general or public telecommunications network 2. The telecommunications network 2 has a plurality of telephone sets, such as telephone sets 22, 23, connected thereto in a known manner, said telephone sets being subscriber telephones which have been allocated a telephone number appertaining to said network, so that the users of respective telephones are able to avail themselves of network services and functions through the medium of their respective keypads adapted for tone transmission. These telephone sets 22, 23 can be considered to be connected directly to the telecommunications network 2, since a call initiated from the telephone set 22 produces, among other things, a call signal and dialling tone from a network- associated tone generator 2c, and since when the subscriber number of the telephone set 23 is dialled network-associated switching means 2a are activated to establish a communications path (not shown). This connection thus differs from a fixed connection established via a leased line. Thus, in respect of a switching function, which will be described in more detail hereinafter, a telephone set 21 can be considered to be a direct dialling tele- phone set belonging to the telecommunications network. In other respects, however, the telephone set 21 operates as a peripheral extension telephone to a private branch exchange function 3, which will also be described in more detail hereinafter. One or more smaller telephone exchanges having subordinate extension telephones, such as those referenced 24 and 25, may also be connected to the network 2. The telecommunications network 2 is constructed so that a calling telephone connected to said network, such as the telephone set 23, is able to initiate and set up a connection with a chosen, called telephone, such as a telephone set 22 or the private branch exchange 3, through the medium of switching means 2a belonging to the telecommunications network. This connection procedure is well known and will not therefore be described in detail here. The invention is based on the exploitation of a private branch exchange function 3 with a number of direct dialling extension telephones, such as the tele- phone set 31. By a direct dialling extension telephone is meant that the telephone is connected directly to the private branch exchange 3 so that an initiated call will result, among other things, in a call signal and a dialling tone from a tone generator (not shown) in the branch exchange, via the extension line. Although the present invention is illustrated in the following with the aid of a private branch exchange 3 which is connected to the public telecommunications network via lines 3a and 3c, it will be obvious to the person skilled in this art that the exchange function 3 can be integrated within the control equipment and the network functions. In the embodiment of the invention illustrated in Figure 1 there is exploited a private branch exchange 3 which is connected to the communications network via inward lines 3a and which is connected via outward ports or lines 3b on the branch exchange to inward ports or lines for equipment 4a which includes switching functions among other things and the outward ports or lines 4b of which are connected to the telecommunications network 2 via the branch exchange 3 and its lines 3c. The function of the invention could very well be implemented via lines 4b' connected directly between the equipment 4 and the network 2. More particularly, the outward ports 3b are related to extension telephones so that the signal on a port implemented by a time slot represents one extension telephone and signals on another port implemented by another time slot represents another extension telephone, and so on. The private branch exchange 3 also includes internal storage devices where a first storage area can be considered to represent prevailing conditions for a first extension telephone, a second storage area can be considered to represent prevailing conditions for another extension telephone, and so on. The storage area for an extension telephone set also contains activated in- terception services for said extension telephone, together with other information significant to the extension telephone concerned. The branch exchange control system is adapted to perform certain necessary functions in accordance with information stored in the storage area. Thus, in the illustrated case, the lines comprise branch exchange outward ports 3b, one for each extension telephone, connected to corresponding inward ports 4b on the equipment 4 via signal transmission means, such as pairs of conductors or coaxial cables. The invention is based on the connection of one or more peripheral extension telephones belonging to the branch exchange 3 to the telecommunications network 2. In Figure 1 , only one peripheral extension telephone 21 belonging to the branch exchange 3 is shown connected to the telecommunications network 2 as a typical direct dialling subscriber telephone (such as 22 and 23) adapted to the telecommunications network (this means that this extension telephone 21 cannot be considered to be connected directly to the branch exchange). The line 21 a belong- ing to the peripheral extension telephone 21 is connected to the network 2 as a subscriber in a known way, and has therefore been allocated its own network subscriber number. The invention will now be described and explained initially with reference to a few chosen switching examples. A call from a network-connected telephone 23 to a peripheral extension telephone 21 belonging to the private branch exchange In the case of the embodiment illustrated in Figure 1 , the user of the telephone 23 lifts the handset and obtains a dialling tone from a circuit 2c belonging to the telecommunications network. The user then either dials a group number applicable to the branch exchange 3 or a branch exchange extension number for direct connection to the extension telephone. In the former case, the call is connected to a telephone operator in the branch exchange, who answers the call and sets up a connection to the extension telephone 21 as requested. If the storage area for the called extension telephone 21 indicates an inter- ception service, the telephone operator will pass this information on to the calling party. In the latter of the two above-mentioned cases, the call is connected in the branch exchange to the dialled extension number 21 without the assistance of a telephone operator. If it is assumed initially that the dialled extension number is the number of the peripheral extension telephone 21 and the storage area in the branch exchange contains no information concerning a diversion, temporary transfer or any other service, the call is connected to a telephone operator in the case of a group number who, after receiving a message over the connection line 23a, 3a, forwards the call to the number of the extension telephone 21 in the branch exchange. Relevant information in the storage area concerning the extension telephone 21 is transformed via its time slot to the equipment 4, which transposes the transmitted extension number 21 to a subscriber number belonging to the telecommunications network, namely the number applicable to the extension telephone 21 , whereafter the equipment 4 is able to initiate a call to the subscriber number concerned. Because the called extension telephone 21 is, in this case, a peripheral extension telephone connected to the public telecommunications network via its subscriber number, the equipment 4 transforms the extension number to a network subscriber number in a block 47. The equipment 4 now initiates, in a known manner, a call to the telecommunications network 2, which connects the lines 3c and 21a via switching means 2a belonging to the network. The equipment 4 is now able to connect the line 3a with the line 3c via the branch exchange 3, and therewith also connects the sound channels for tone and speech message transmission. When the called extension telephone 21 answers the call, the equipment 4 is able to activate a signal structure corresponding to a B-response. The earlier known private branch exchange MD 110 includes an interface that has a number of ports 3b where signal exchange is structured in accordance with a CAS protocol and is therewith adapted for digital signals and has a port- associated time slot for each extension telephone set. It will be evident to the person skilled in this art that other considerations and solutions will be required for other types of private branch exchanges 3, although these considerations and solutions will not be described here for the sake of simplicity When a time slot on a port for the extension telephone 21 arrives at the equipment 4, the equipment 4 sets up a connection to the subscriber number allocated to the peripheral extension telephone 21 through the telecommunications network 2, via a computer unit 41 and a switching block 42 in accordance with Figure 4, without needing to first send a B-response to an inward call from the tele- phone 23 Since certain telecommunications networks permit a connection for signal exchange to be made through the network without a B-response, it is proposed that this option is utilised primarily If the network requires a B-response in respect of such a connection, rele- vant steps are taken to enable such a B-response to be generated When speech messages or the like are transmitted over an established connection, a B-response to the network 2 will, of course, be required As shown in Figure 4, an inward call, on a port with its time slot, is connected to a sound channel belonging to the telecommunications network via said equipment 4, wherewith a tone or speech message generated in the telecommunications network 2 is delivered to the calling party 23 When the call on the peripheral extension telephone 21 is answered, the equipment 4 generates a B-response instead of the extension telephone 21 , via a block 43 Upon termination of the call the connection set-up via the branch exchange 3 can be released either from the extension telephone 21 or the telephone 23 or from both, this latter option being effected by a double clearing function A call from a peripheral extension telephone 21 to the private branch exchange 3 When the user of the peripheral extension telephone 21 (Figure 2) wishes to make a call to the branch exchange 3, he/she lifts the telephone handset and therewith activates automatically a network-related function with which a switching path 21a-3d is established in the network to a dialled subscriber number belonging to said network and applicable to the branch exchange 3 This subscriber number shall be a direct dial-in number, so that the call can be connected directly to the branch exchange inward circuits appertaining to the extension telephone 21. When the call arrives at this direct dial-in number, the call is switched in the branch exchange so that the dialling tone from said branch exchange can be sent to the peripheral extension telephone 21 via the connection 3d-21a established through the network 2. It will be clearly apparent from this that the peripheral extension telephone 21 is connected directly to the branch exchange 3 via a network-related switching path 21a-3d, and that said peripheral extension telephone 21 is able to communicate with devices and its own storage area in the branch exchange 3 via said switching path as a direct dial-in extension telephone. If the user of the extension telephone 21 wishes to establish a telephone connection with some other extension telephone or with a telephone belonging to the telecommunications network, this is effected in a known manner by dialling a desired number on the telephone keypad 21 b. Messages sent from the peripheral extension telephone 21 over the switching path 21a-3d with respect to desired services can be stored in the branch exchange 3 in the storage area belonging to the subscriber telephone and are therewith readily accessible to another call arriving at the branch exchange from a direct dial-in extension telephone 31 or from a telephone 23 belonging to the telecommunications network. More specifically, and as shown in Figure 2, such a connection is established from the peripheral extension telephone 21 via the conductor or line 21a and through the telecommunications network 2, the line 3d to the branch exchange 3, via a port 3e, a port 4b, the equipment 4, a port 4a, a port 3b and to the branch exchange 3 and so that messages concerning selected services, such as a temporary transfer service, an interception service, ACD and the like can be entered into and stored in the branch exchange 3 (and in the equipment 4). One or more service significant codes, such as temporary transfer code, an interception code or some other chosen function associated with the branch exchange is/are activated through the keypad 21 b of the peripheral extension telephone 21. Call to a peripheral extension telephone 21 that has requested one or more services A call arriving at the branch exchange 3 and directed to a peripheral extension telephone 21 in respect of which information concerning one or more re- quested services is stored in said exchange, is expedited by reading the information stored in the storage area of said telephone. Branch exchange functions are now actuated so as to effect the switching processes necessary to activate requested services. For instance, there can be activated within the branch exchange a relevant connection through said exchange 3 or through the telecommunications network 2 via the equipment 4, or the equipment can be activated to deliver a preprogrammed response itself. A telephone 23 belonging to the telecommunications network or an exten- sion telephone 31 belonging to a private branch exchange used to initiate a call to a peripheral extension telephone 21 connected to the network also activates means within the branch exchange 3. The storage area for the extension telephone 21 now contains all information relating to requested services. A call to a peripheral extension telephone 21 is forwarded It is assumed here that the storage area of the peripheral extension telephone 21 includes a call forwarding request in the branch exchange 3, this request having been entered either by dialling a code on the own telephone 21 or through the medium of a telephone operator 3e. In the event of an inward call to the extension telephone 21 , the branch exchange establishes that the call forwarding service is activated, together with information relating to an extension number or an extension number to the telephone to which the call shall be forwarded. When this telephone is a direct dial-in extension telephone 31 , the call is switched internally within the branch exchange 3. If the telephone is a peripheral extension telephone (similar to telephone 21), the branch exchange 3 sends information to the equipment 4 on the time slot applicable to this peripheral telephone and the equipment 4 is activated as earlier described. In both cases call-information appears on one of the ports 3b and can be sensed or read in a block 44 in the equipment 4, wherewith the equipment 4 establishes through the telecommunications network 2 a connection (via block 42) to a subscriber number to which the call shall be forwarded as requested by telephone 22, without giving a B-response to the inward call. A call to a peripheral extension telephone 21 is intercepted It is assumed in this case that the peripheral extension telephone 21 has requested an interception service in the branch exchange 3 in a known manner, either by dialling a code on the own telephone 21 or through the medium of a tele- phone operator 3e. When a call directed to the extension telephone 21 arrives, the branch exchange establishes that the intercept service has been activated and also information concerning the measures to be taken. The branch exchange 3 evaluates and initiates activation of a requested procedure, which may be to connect the call to an answering system within the equipment 4, or to a telephone operator 3e, via the port 3b. By virtue of the switching facility according to Figure 2, the extension telephone 21 is now able to enter or inhibit a desired service function, such as an inter- ception function, temporary transfer function or some other exchange service function, either via a branch exchange telephone operator 3e or by dialling a code on the own telephone 21 , this information being entered into or deleted from the information content on the storage area for the extension telephone 21 , as applicable. Processing corresponding to a chosen function can be effected in a block 45 in the equipment 4. In accordance with one particular embodiment of the invention, the peripheral extension telephone 21 belonging to the branch exchange 3 may be so connected to the telecommunications network 2 and so utilise the network function 2b that when the telephone receiver is lifted or the telephone activated in some other way, a connection is automatically and immediately set up through the telecommunications network 2 to a pre-programmed subscriber number, which is a direct dial- in number and belongs to the branch exchange 3 and/or the equipment 4. In this particular application of the invention, it may be beneficial to select the switching path to the equipment 4 via the branch exchange 3 as illustrated in Figure 2 and described in more detail above. Because of this arrangement the peripheral extension telephone 21 will be perceived by the calling party as being constantly in direct connection with the branch exchange 3 immediately a call is desired, and measures of the nature described below are necessary in order to release this automatic connection. The equipment 4 may also be designed to ascertain in a block 46 which extension telephone 31 or telephone 23 is the calling telephone, such as via a direct dial-in number (or by evaluating an A-number), and initiate setting up of a connection to the called telephone, deliver a B-response and connect-up sound channels. The calling party therewith receives a tone message, which may be generated in the branch exchange 3. In the case of a calling extension telephone 31 , a connection is established to a called extension telephone through the branch exchange 3, or to a network telephone via the equipment 4, or to a peripheral extension telephone belonging to said network. In order to enable the extension telephone 21 connected in a known manner to the telecommunications network 2 to exploit network functions directly, it is proposed that said function of automatically instigating a connection to a pre- programmed number is inhibited when the telephone handset is lifted and a code 21 ' is dialled, and that the extension telephone 21 then remains connected directly to the network 2 as a telephone through which network-related functions can be activated. A network-adapted switching path between the peripheral extension tele- phone 21 and a telephone 23 in accordance Figures 3 and 6 cannot be detected by the branch exchange 3 until a connection initiated by said equipment 4 through the network 2 indicates via network-associated equipment that the line is busy and produces a line busy indication. This line busy indication was thus not indicated in the branch exchange 3. In view of this, there is provided in accordance with the invention (Figure 6) whereby when a peripheral extension telephone 21 is busy, a call-back and/or a coordinating function is activated in block 48 of said equipment 4, via a network- connected switching path and in response to a call from said equipment 4. The co-ordinating function may conveniently be included in the branch ex- change 3. Figure 5 illustrates schematically how a mobile telephone 26 can be allocated the function of a peripheral extension telephone (21 ). The mobile telephone 26 is in radio connection with a mobile telecommunications network 2' whose base stations or other equipment are connected to said equipment 4 either directly or indirectly via a connection 4c and/or to said telecommunications network 2 via a connection 4c', such radio connections being known to the art. It is preferably preferred that each switching path can be set up via the network 2 without needing to generate a network-related B-response. It can be mentioned that the functions included in the branch exchange 3 can very well be assigned to and included in network-related functions, such as the services offered by the designation-Centrex-. Those persons conversant with this system will realise that given codes from the peripheral extension telephone 21 over a line connected through the telecommunications network 2 will be able to activate desired network functions, such as when pressing an R-button. However, it is possible to enable such actuation to be prevented, by activating a unique combination of further codes instead of actuating the R-button (which activates the function within the telecommunications network) thereby being able to communicate with and actuate the branch exchange 3 without affecting the network-adapted functions in a harmful way. Another significant feature of the present invention is that when the memory area of the extension telephone 21 includes intercept information to an extension telephone 24, the branch exchange 3 activates the storage area for the extension telephone 24 and activates the time slot applicable to said extension telephone. The equipment 4 now establishes through the network 3 a connection de- termined by the time slot, which means that insignificant intelligence is required with regard to the equipment 4 and that the predominantly intelligent connection is effected within the branch exchange 3. It will be understood that the invention is not restricted to the afore- described and illustrated exemplifying embodiments thereof and that modifications can be made within the scope of the following claims.

Claims: CLAIMS 1. A telecommunications system that includes: a general telecommunications network to which a number of telephone sets are connected and in which a calling telephone set is able to initiate and establish via network switching means a connection with a called telephone set, a private branch exchange function related to the telecommunications network, said function capable of being connected via an outward extension telephone port or line to an inward port or line for equipment that includes switching functions among other things, characterized in that a peripheral extension telephone set belonging to the branch exchange function is connected to the telecommunications network as a network adapted telephone set; and in that an equipment-related outward port or line is connected to the telecommunications network so that branch exchange services can be offered to the peripheral extension telephone set. 2. A system according to claim 1 , characterized in that the peripheral extension telephone set can be connected to a private branch exchange via a switching path related to the telecommunications network and is able to communicate with said private branch exchange as a direct dial-in extension telephone set, via said switching path. 3. A system according to claims 1 and 2, characterized in that a switching path for signal transmission is established via the telecommunications network without the need of generating a branch exchange related B-response. 4. A system according to claim 1 , 2 or 3, characterized in that a signal transmitted from the peripheral extension telephone set over said switching path with respect to a desired service can be stored in the branch exchange in a storage area specific to said extension telephone set and therewith readily accessible in the event of a call to said extension telephone set via the branch exchange from a direct dial-in extension telephone set or from a telephone set belonging to the telecommunications network. 5. A system according to claims 1 , 2, 3 or 4, characterized in that information relating to a selected service or selected services for each extension telephone set are co-ordinated in the branch exchange and structured within each respective storage area. 6. A system according to any one of the preceding claims, characterized in that in the absence of information in the branch exchange relating to a requested service, an inward call to the branch exchange directed to a peripheral extension telephone set is forwarded to said equipment and through the telecommunications network via a switching path. 7. A system according to any one of the preceding claims 1-5, characterized in that an inward call to the branch exchange directed to a peripheral extension telephone set where information relating to one or more requested services is stored in the storage area in said branch exchange is forwarded to said equipment, which activates either a relevant connection or itself delivers a response, depending on the service requested. 8. A system according to claim 7, characterized in that call information re- sides in the occurrence of a time slot belonging to an extension telephone set. 9. A system according to claim 1 , characterized in that a telephone set belonging to the telecommunications network or an extension telephone set belonging to the private branch exchange and initiating a call to a peripheral extension tele- phone set connected to the telecommunications network activates within said branch exchange means that, in turn, activate a port, line or time slot or some corresponding element significant to the calling extension telephone set, this activation being detected by said equipment. 10. A system according to claim 1 or 2, characterized in that when a time slot for a peripheral extension telephone set is delivered to the equipment or the like, the equipment sets up a connection to a subscriber number allocated to said peripheral extension telephone set via a switching path through the telecommunications network. 11. A system according to claim 10, characterized in that said equipment sets up the connection via said switching path without needing to use an extension- related B-response. 12. A system according to claim 1 or 3, characterized in that when said equipment has established an inward call connection to a peripheral extension telephone set, a tone or speech message that can be generated within the telecommunications network is forwarded to the calling telephone. 13. A system according to claim 1 or 4, characterized in that one or more service-significant codes, such as a temporary call transfer code, an interception code or some other selected function belonging to the branch exchange is/are acti- vated via the keypad of said peripheral extension telephone set. 14. A system according to any one of the preceding claims, characterized in that when a called peripheral extension telephone has initiated a response, the equipment generates a B-response for said extension telephone set. 15. A system according to claim 1 or 2, characterized in the event of a call to a peripheral extension telephone number that has been diverted or temporarily transferred in the branch exchange, the storage area for this telephone set includes diversion information pertaining to said extension telephone set, wherein said infor- mation can be detected and the equipment initiated and activated in accordance with said information such as either to set up through the telecommunications network a connection to a subscriber number allocated to another peripheral extension telephone set or to a telephone set belonging to the telecommunications network. 16. A system according to claim 15, characterized in that when said equipment has controlled a connection of an inward call to a called telephone set, a calling tone or speech message that can be generated within the telecommunications network is sent to the calling telephone set via a sound channel belonging to the telecommunications network. 17. A system according to claim 16, characterized in that a switching path is established via the telecommunications network without generating a B-response related to said network. 18. A system according to claim 1 , characterized in that a temporary transfer or diversion request can be transferred to and stored in the branch exchange through the medium of exchange personnel, such as a telephone operator, or by dialling a code via the own telephone set. 19. A system according to claim 1 , characterized in that the peripheral extension telephone set connected to the telecommunications network and belonging to the branch exchange is adapted to utilise a function belonging to the telecommunications network, such as when the telephone handset is lifted or the telephone is likewise activated there is set up a connection to a pre-programmed number belonging to said branch exchange and/or to said equipment. 20. A system according to claim 19, characterized in that the switching path to the equipment is here selected via the branch exchange. 21. A system according to claim 19, characterized in that the equipment establishes which extension telephone set is the calling telephone set, such as a direct number in the branch exchange or an A-number in the peripheral extension tele- phone set or sets connected to the telecommunications network, and thereafter initiates a connection set-up to the calling telephone set. 22. A system according to claim 21 , characterized in that the calling telephone set receives a tone or speech message generated in the branch exchange. 23. A system according to claim 22, characterized in that a switching path is set up by the branch exchange and the equipment without generating a B-response related to the branch exchange. 24. A system according to claim 1 , characterized in that in the event of a call made from a direct dial-in extension telephone set a connection is established internally through the branch exchange to a called extension telephone set, or a connection is initiated via the equipment to a telephone set belonging to the telecommunications network or to a peripheral extension telephone set belonging to said network. 25. A system according to claim 1 or claim 19, characterized in that the function of automatically setting up a connection to a pre-programmed number is inhibited by dialling a code when the telephone handset is lifted, wherewith the periph- eral extension telephone set is connected directly to the telecommunications network as a telephone set that is able to activate network-related functions. 26. A system according to claim 1 , characterized in that the peripheral extension telephone set is a mobile telephone connected to a mobile telephone network, which, in turn, is connected to said telecommunications network and/or to said equipment. 27. A system according to claim 25, characterized in that when a peripheral extension telephone is busy, a call-back and/or queuing function belonging to said equipment and/or to said branch exchange is/are activated via a switching path connected to the telecommunications network and in response to a call from said equipment.

Inventors: KJELLQUIST STAFFAN LARS ALLAN, KJELLQUIST, STAFFAN, LARS, ALLAN
Applicants: KJELLQUIST STAFFAN LARS ALLAN, TRIO AB, KJELLQUIST, STAFFAN, LARS, ALLAN
Application year: 1999
Main classification: H04Q3
IPC codes: H04M3, H04M7, H04Q3