DE19721127C2 - Method for expanding a unidirectional paging network to a quasi bidirectional paging network and device and terminal for carrying out the method - Google Patents

Description

The invention relates to a method for expanding a unidirectional paging network to a quasi bidirectional Paging network, as well as a device and a terminal for Execution of the procedure.

Calls are usually made using a classic paging network (Paging network), e.g. B. Cityruf, Scall performed. Also a GSM cellular network offers via the Short Message Service (SMS) limited the functions of paging. A full fledged Paging service as it is paged in terms of functionality, Number of participants and call throughput etc. is possible through the SMS infrastructure from technical - and above all Cost reasons - not to be replicated and realized. In principle, the following can be used in this context Features between paging and the GSM SMS highlighted become:

paging

Benefits:

• - Almost nationwide supply
• - Good supply inside buildings
• - Very small receivers
• - High standby time (battery time)
• - Cost

Disadvantage:

• - No acknowledgment function for the paging
• - High airtime consumption when transmitting Text, especially nationwide Reachability.

SMS

Benefits:

• - Almost nationwide supply
• - Acknowledge
• - Caching of messages
• - Location of the receiver possible (GSM Mobility Management

Disadvantage:

• - Poorer care within buildings
• - Low standby time, high power consumption of the terminal

The paging is consistently one-way Communication, d. H. the participant has no way to send a message yourself. When paging the caller does not know whether the called party receives the message received or read. Here would be one Acknowledgment function is advantageous, through which the called party can Receipt of the message confirmed. To such a Acknowledgment function in conventional paging networks realize, two-way communication is required with the associated infrastructure of broadcasting and Receiving devices. Into the pager would also have to a sufficiently powerful transmitter unit integrated become.

Bidirectional paging networks have already been developed (e.g. in the USA, called TANGO).

However, for the reasons mentioned, these are only very difficult high investments in the infrastructure of the paging network realizable.

WO 94/13093 A1 discloses a method and a Facility for expanding a unidirectional Paging network to a quasi bidirectional paging network, the sending of radio calls to a terminal via the Paging network is carried out and the transmission of Acknowledgment signals via a cellular network. In doing so however, those received via the cellular network  Acknowledgment signals via another telecommunications network forwarded to the paging network.

A similar system is disclosed in WO 96/38996 A1, but here the transmission of the acknowledgment signals between pager and another Telecommunications network via infrared signals. The Return signal is so through an infrared receiver public telephone network to the paging system transferred back. However, an infrastructure is required here be built for infrared transmission, d. H. to have to area-wide infrared receivers are installed, which the acknowledgment signals sent by the pager received and via a telephone network to the paging system can transfer back.

EP 697 781 A1 relates to a paging system in which the Subscriber control signals via a conventional telephone network can send to the operator of the paging system, e.g. B. the Settings of its pager or its participant parameters to change. The control signals are transmitted using DTMF tone signals. It is not known to Retransmission of the acknowledgment signals to a cellular network to use and especially SMS function Use signal transmission.

It is an object of the invention to propose a method to existing one-way radio paging networks for a quasi two-way To make paging ready, using the method low technical and financial expenditure can be realized should be.  

The object is achieved by the features of patent claim 1 solved. A device and a terminal for implementation The method is the subject of claims 17 and 22, respectively.

According to the invention, a paging network (paging network) and a Telecommunications network, preferably a GSM mobile radio network, via a common access (gateway) with each other connected. This makes it possible to take advantage of the previous advantages of paging the missing Acknowledgment function of radio calls, which normally only possible in two-way paging networks. The Paging will continue to be sent in the paging network. The Acknowledgment takes place in the GSM network. Major advantage of Invention is that only existing infrastructures be exploited and no additional, costly Facilities are necessary.

Another advantage is that through the mobility management Function in the GSM network to determine the location of the receiver becomes possible. This can lead to the paging zone assignment of the Receiver and thus to save airtime in the paging network be used. The required airtime of a radio call is a measure of the transmission capacity and utilization of a radio network. The necessary modifications are in principle independent of the standard of the paging network. The procedure is therefore can be used for any paging network.

Some paging systems (e.g. ERMES) transmit paging Area code to the pager, which enables the terminal to change the To recognize the paging area. When changing to one new paging area can be via GSM Short Message Service Mobile originated in the paging network a so-called paging area Update will be carried out.

The following advantages are achieved by the method according to the invention:

• - Direct acknowledgment of radio calls possible;
• - Extended acknowledgment parameters possible (e.g. yes,  No, I'm calling back. , .);
• - Through mobility management in GSM is done by targeted transmission of the paging one Airtime savings in the paging area, nationwide Accessibility (possibly international accessibility when using roaming connections);
• - By transferring the paging area to the network and management of the paging area is done by targeted transmission of the paging one Airtime savings in the paging area, nationwide Accessibility (possibly international accessibility when using roaming connections);
• - New service offerings with new applications possible;
• - Existing services in the GSM and paging network not affected;
• - Participants in the GSM or paging service have the Possibility to use the services of the other network as well to use;
• - independence from the paging network standard used - thus also usable for future networks;
• - No new network structure necessary;
• - No new network standard necessary;
• - Subsequent implementation in existing Network infrastructure is possible at any time;
• - minimal investment;

The coupling of a GSM network with a paging network can technically according to the invention through various concepts will be realized. The implemented in GSM Mobile Originated Short Message Service (for acknowledgment) and the mobility management function (for location determination) be usable.

The first concept sees the connection of the GSM network to the Paging network through a gateway with a short Message Service Center (SMSC) can be realized. A Integration of functionality into an existing SMSC possible. A modification of an SMSC according to the requirements  and use as an independent network node is exclusively for the application purpose according to the invention also possible. The Short Message Service Center e.g. B. the D1- Cellular network is already set up for the necessary gateway functions prepared.

A second concept sees the use of a special one Gateway computer through which the two networks without Modifications can be linked together.

Two essential functions of the GSM standard are used in all concepts:

• - Mobility management for the localization of the end device and thus to determine the corresponding paging zone.
• - Mobile Originated Short Message Service to acknowledge the Radio call.

The proposed concepts have the following special properties:

• - There will be an acknowledgment of radio calls and a Location determination of the recipient enables, for this Functions no user channel (i.e. channel for the transmission of Language, data etc.) of the GSM network. The whole necessary exchange of information between terminal and short Message Service Center (SMSC) happens through Signaling channels of the GSM network.
• - The SS # 7 interface becomes the GSM network standard GSM protocols used without modification. The corresponding Connection to the SS # 7 network is via a gateway. The required MAP signaling procedures are in every GSM Network implemented.
• - The acknowledgment function primarily becomes this used to indicate to the system that a paging successfully transmitted and received by the participant is, and therefore no new paging is necessary.

In a development of the invention it is provided that the Participants also payload (predefined and freely defined answers to the call) with the acknowledgment can send in a short message.

•  ä If the ERMES paging system is used, it transmits the paging area code, which makes it the Terminal is possible, a change of ERMES paging area to recognize. When changing to a new ERMES Paging area can be done using the GSM function Short Message Service Mobile Originated a so-called ERMES paging area Update will be carried out.
• - The existing through the GSM mobility management As an alternative to determining the location information Location area of the terminal can be used.
• - To implement the acknowledgment is on the mobile radio side the GSM Short Message Service is required. There will be none Transfer voice information.
• - The normal operating state of the terminal is switched off Energy saving reasons a constantly on Pager and one (automatic) only for the GSM Location updates or ERMES paging area updates and Acknowledgment must be switched on mobile part. The advantage is a very high standby time for the end device due to low Energy consumption of the cellphone part.

The location update procedure in the GSM network (for storing the Location of the GSM terminal in GSM databases) can - for energy saving reasons - via a timer controlled cyclically (automatic Switch on the mobile phone component and carry out a Location updates).

If the cell phone part is switched off for a long time or there is no radio contact, no location update can be carried out. The end device may already be in a different area than the last paging zone determined. If a radio call is now sent and is not acknowledged within a predefined period, the following options are available:

• - In principle, every unacknowledged call is repeated sent out.
• - The calls are in one by a time factor certain, constantly increasing radius around the most recently determined paging zone up to nationwide sent out.
• - The paging is made a second time e.g. B. nationwide which automatically sends a location when it is received Triggers update procedure for paging zone assignment.
• - The call is placed in the default call zone of the paging service

To the functionality resulting from coupling the networks to be able to fully utilize the resulting possibilities appropriate end devices necessary. There are different ones Device configurations conceivable.

The "Economy" configuration is for existing ones Mobile subscribers suitable, or for those without the Use of new terminals the advantages of the invention Want to use the procedure. There is a separate one GSM terminal and a pager terminal are used. Will be from Pager receive a message, so this can be done directly via the GSM device can be acknowledged. To transfer the Acknowledgment signals can also be the multi-frequency dialing method (DTMF) can be used. It is also possible that Acknowledgment via any DTMF-compatible phone. In the GSM network it is Mobile Originated Short Message capable GSM terminals, manually via the short Message Service to acknowledge the call.

"Expert" -Endgerät

This system represents an independent terminal. This Terminal includes a pager (preferably a text pager) as well as a cell phone part, which only an SMS Has functionality. Both components are internal coupled via an interface (e.g. RS232). For operation the device becomes a normal SIM card with SMS authorization needed. It is sensible to use one designed only for this purpose SIM card. When a message is received via the pager a direct acknowledgment of the message with this terminal possible. The individual possibilities of acknowledgment and Location determination of the participant will be explained in more detail later. So that the mobility management of the GSM network in full Scope should be used, the cellular component do not send an IMSI Detach Message. An execution as PCMCIA variant for laptops / palmtops is also conceivable. Transitional normal text pagers with interfaces can be used be used. These can e.g. B. in a special Adapter in which the mobile radio part is implemented, be coupled.

"Vision" -Endgerät

This system represents an independent device and includes a pager, taking advantage of the paging Infrastructure, as well as a fully "speaking" Mobile phone. A normal SIM card required. The pager can be integrated Paging receiver (e.g. city call or in the future via ERMES) via the paging infrastructure are called and via the GSM Acknowledge infrastructure.

Both devices are internal via a common interface coupled. A direct acknowledgment of the message is with possible on this device. The individual possibilities of Acknowledgment and location of the participant have already been explained. So that the mobility management of the GSM network in can be used in full, can be provided that the mobile radio component does not have an IMSI Detach Message sent.

In the following the invention based on several Drawings illustrating execution paths explained in more detail. Here go from the drawings and their description further features and advantages of the invention Innovation. It shows:

Fig. 1 The principle of coupling a paging and GSM network;

Fig. 2 Simplified representation of the required network architecture;

FIG. 3 shows the coupling of networks in a first embodiment;

FIG. 4 shows the coupling of the networks in a second embodiment;

FIG. 5 Coupling of the networks in a third embodiment;

Fig. 6 Schematic structure of a suitable terminal;

Fig. 7 operating principle of the call acknowledgment with the "economy" terminal configuration.

Fig. 1 shows the general concept of the invention. In a known paging network 1 (e.g. city call, ERMES), a call signal 2 is sent to a terminal 3 , which is set up to receive paging calls. In addition, the terminal 3 is GSM compatible or at least can be coupled to a GSM mobile radio device. This makes it possible to use the terminal to send an acknowledgment signal 4 associated with the paging via the GSM mobile radio network 5 , which is received by a corresponding GSM switching center. Between the paging network 1 and the cellular network 5 there is an interface 6 through which a direct connection between the two networks is established. The acknowledgment signal 4 is transferred from the GSM mobile radio network 5 to the paging network 1 and registered or processed there. In addition, there is the possibility of locating the location area of the terminal 3 by means of the functions implemented in the GSM mobile radio network and making this location information available to the paging network. With this location information, the paging network is able to send out the paging in a targeted manner in the determined location area of the subscriber.

In FIG. 2, in simplified form, the network architecture required is shown. The paging switch 7 of the paging network 1 , here an ERMES paging network in the example, has access to a switching center MSC of the GSM network 5 via a direct interface 6 and a gateway 20 . The agency responsible for the management of subscriber data in the paging network 22 is connected to the post-processing point 21 of the GSM network so that common subscriber data can be accessed and exchanged between the two networks.

The customer interface 23 of the paging system enables third parties to initiate a paging and the acknowledgment of the paging z. B. to answer on his phone.

Three concepts are provided for realizing the connection between the GSM network and the paging network:
Referring to FIG. 3, the connection of the two networks, the GSM network 5 and radio transmission network 1 is made by a gateway (access), which can be realized with a Short Message Service Center 10 (SMSC) of the GSM network. An SMSC already has gateway functions in GSM networks (in particular the D1 network), ie it is prepared for a connection to external systems.

The SMSC 10 essentially consists of two components:

Interworking Entity 11 (IW Entity)

The IW Entity 11 represents the interface to the signaling standard of the GSM network and has a MAP interface (MAP: Mobile Application Part). Existing MAP signaling procedures enable the location of the subscriber and thus the paging zone to be determined, as well as the SMS procedures that are necessary to acknowledge a paging.

Service Center 12 (SC)

This is the actual service center. The service center 12 has, inter alia, a direct interface 12 to the switching center 7 (PNC: Paging Network Controller) of the paging network, which, for. B. can be a standardized X.25 interface (packet-oriented transmission). An X.25 interface must also be provided in the paging network controller 7 . The databases required for assigning subscriber and device identifications, for determining the location information and for storing the status information of radio calls (which are to be acknowledged) are implemented in the service center 12 . The databases in Service Center 12 have e.g. B. the following entries:

• - Participant identity IMSI / MSISDN
• - MSC identifier
• - Storage and evaluation of status information for each call:
  Radio call sent, await acknowledgment
  Acknowledgment has taken place
  acknowledgment parameters
  further parameters for assigning the acknowledgment to a radio call that has already been sent (e.g. consecutive numbering of a radio call, date of receipt ..)
• - Date / time of the last database action

Paging Network Controller (PNC)

The databases required for assigning subscribers (MSISDN / IMSI) and device identification (PagerID), for determining location information and for storing additional status information from the respective radio calls should be implemented in PNC 7 . Relevant subscriber data therefore only has to be administered and maintained at one point in the system. The PNC 7 needs the subscriber data in order to determine whether a radio call is to be sent to a subscriber and the procedures according to the invention are to be carried out.

At this point, the connection between paging and GSM subscriber data are produced.

The PNC databases have e.g. B. the following functions:

• - Assignment of the pager ID to the MSISDN / IMSI (and vice versa)
• - Assignment of the MSC identifier to the paging zone (s)
• - Storage and evaluation of status information for each radio call, e.g. B .:
  subscriber data
  specific data for each call
  Monitoring of run times between paging and acknowledgment
  Storage of the last paging zone
  acknowledgment status

The PNC 7 checks and compares the data as to whether a short message contains information for acknowledging a transmitted call. The PNC must also monitor the transit times between the call being sent and the acknowledgment, and then decide whether the call should be sent again.

According to FIG. 4, there is a further and inexpensive possibility of realizing the use of a special gateway computer 14 . The gateway computer is an aid with which access to the mobile radio network 5 is created.

This makes it possible to monitor signal flows in the network and to represent, to simulate special signal flows and in feed the grid and with external components communicate.

The gateway computer is a computer with an SS # 7 protocol stack and a connection to the SS # 7 network, which, after appropriate programming, can perform exactly the tasks described like a multilink monitoring system. By adding a component to the multilink monitoring system 14 , which can also actively send signaling messages SS # 7, the functions described above can be achieved without modification of the existing Short Message Service Center (according to concept 1 ).

The databases for assigning subscriber and device identifiers, for determining the location information and for storing the status information of radio calls can, for. B. be implemented on a separate database server, similar to Concept 1 , which is connected to the gateway computer 14 via a suitable interface 16 in order to relieve it of complex database operations. The gateway computer 14 is connected to the switching center 7 of the paging system 1 via a suitable interface 17 . With a configuration tailored to this application, the gateway computer essentially consists of two components:

a. Module for SS # 7 communication

This module provides analogous to the interworking entity of the SMSC is the interface to the SS # 7 network and has the Ability to generate and send GSM MAP messages as well as decode incoming GSM MAP messages. Thereby the system can communicate with GSM network components and the GSM MAP procedures for acknowledgment and localization To run.

b. Module for communication via network

The multilink monitoring system is activated via this component a network for communication with the PNC is connected.

Fig. 5 shows a further possibility of the network connection between a GSM mobile telephone network 5 and a paging network ERMES. 1 The network architecture used essentially corresponds to that of concept 1 according to FIG. 3.

The connection of the GSM network 5 to the paging network 1 , for. B. via an X.25 interface, is in turn achieved by a gateway implemented in the SMSC 10 . The SMSC 10 is connected to the GSM network 5 via an SS # 7 interface. The paging area code (paging zone code) broadcast periodically by the ERMES paging network 1 is received by the terminal 3 and transmitted by short message to the SMSC 10 (signal 4 ') and from there via the X.25 interface to the PNC 7 of the paging network. The paging network thus “knows” where the paging receiver 3 is located, so that a targeted transmission of a paging call to the respective terminal 3 is possible. The GSM location update procedure for the call zone determination of the terminal 3 is not required.

Under certain circumstances, it is possible that a location update (signaling 24 ) is carried out automatically when the terminal 3 is logged into the GSM network 5 . However, by using the transmitted paging area code, it is not necessary to convert the determined GSM location into a corresponding paging zone and to notify the PNC 7 .

The possibilities for localizing the terminal are described with reference to FIGS. 2 and 3:
The service center 12 receives the request from the paging network 1 via the cross-network interface 13 to determine the (last known) location of a terminal 3 . The IW entity 11 uses a signaling procedure to determine the identifier of the GSM switching center (MSC), which supplies the subscriber at the moment. The MSC identifier is converted into a corresponding paging zone in the service center 12 or in the paging switching center 7 . This works across the GSM network and can even be used for international paging zones thanks to international roaming (GSM and ERMES). GSM networks are divided into different MSC areas, which can be allocated to the corresponding paging zones of the paging network. The determined paging zone is transmitted to the paging network 1 and the paging is then deliberately transmitted only in this zone. This leads to immense airtime savings.

In the service center 12 , a database entry is created which contains the status and important parameters for the paging or the acknowledgment of the paging.

If the GSM mobility management is to be used in full, it makes sense that the special terminal 3 does not send an "IMSI Detach Message". The transmission of the location information is prevented by the transmission of an IMSI detach message each time the GSM terminal is switched off, but this is undesirable in the application according to the invention. If the transmission of the IMSI Detach Message is nevertheless permitted, the procedure does not return an MSC identifier if the mobile radio device is switched off. For a sensible use of the mobility management, however, it is necessary according to the invention that an MSC identifier is always returned, which indicates the location of a mobile radio telephone at the MSC level.

As explained, it makes sense to use the IMSI Detach Message suppress, however, it is not mandatory to to use the invention.

It is not possible to send the IMSI Detach Message suppress, before sending the radio message through a "system call" prompting the terminal, a Perform location update in the GSM network and thus a To enable determination of the living area.

The normal operating state of the terminal is switched off Energy saving reasons a constantly on Paging receiver and only for the location and the Acknowledgment must be activated GSM mobile radio part.

Application and possibilities of localization

The location update procedure in the GSM network (for Location determination) can - for reasons of energy saving - over a timer can be carried out cyclically / periodically (automatic switching on of the mobile radio component and Implementation of a location update) or manually Pressing a button as a "follow me" function. Would be conceivable also programming this timer by a special one Paging or a short message, depending on the mobility of the Setting different timer values.

If the mobile radio part of the terminal 3 is switched off for a long time or there is no radio contact, then a GSM location update cannot be carried out and the terminal may already be in a different area than the determined paging zone.

Localization by transmission of the paging area code with Short message (e.g. at ERMES)

The paging network 1 regularly (at intervals of less than one second) sends out the current paging area, ie the paging zone identifier.

The terminal 3 receives and stores this current paging area and sends the paging area to the gateway 20 by means of an SMS mobile originated procedure via the GSM return channel 4 . The PNC 7 is informed via the gateway 20 and an update of the paging area is carried out there in the database for the respective subscriber entry (paging area update).

The terminal can use the paging area code broadcast constantly by comparison with the stored "old" paging Check area code to see if it is in a new paging area staying. The terminal recognizes that it is in a new one Paging area or the stored information about the paging area is lost becomes a paging area Update started. Through this paging area update procedure can be ensured that radio calls are always in the current Paging area will be sent.

In this concept, the GSM location update is only used for this required, the GSM component of the terminal in the GSM network log in and thereby send short messages enable.

The individual acknowledgment options are shown below presented in more detail. A change from manual to automatic acknowledgment can be set on the end device his.

Acknowledgment of a radio call

The following section describes the procedure for Acknowledgment of a paging call via the Short Message Service.  

The procedure can be analogous to the concepts described be applied. The acknowledgment function is in the first Line used to indicate to the system that a paging successfully transmitted and received by the participant is and therefore no renewed paging is necessary (Acknowledge). In a further stage from Participant user information (predefined or freely defined Reply to the call) with the acknowledgment in a short Message are sent (extended acknowledge).

Special short messages can be sent from the terminal 3 to acknowledge a received radio call. To do this, you first need to log into the GSM network. The terminal sends a short message to the Short Message Service Center 10 . The service center 12 recognizes a short message which is to acknowledge a radio call. Certain parameters and possibly the text of the short message, which identify a paging, are determined / extracted by the service center 12 and corresponding information is transmitted to the paging network 1 , for example if the service center 12 recognizes, on the basis of the entries in the status database, that a Paging has been acknowledged. The entry in the status database and the short message in the SC can then be deleted.

Automatic acknowledgment by end device

When a radio call is received, the Acknowledgment of the radio call (if there is GSM radio coverage). The pager switches this via the internal interface Mobile part and there is an automatic Acknowledgment via GSM after logging into the GSM network.

Manual acknowledgment

With manual acknowledgment, the pager switches this Cellular part when receiving a message. Then done the acknowledgment manually by pressing Quittierungsknopfes.  

Advantage: very high stand-by times of the recipient low energy consumption of the cellphone part.

Generate a short message

After receiving a radio call, the logic of the terminal 3 generates a short message which contains all the data which are required to acknowledge the radio call. Data contained in the call (e.g. serial number of the message), system parameters (e.g. date and time of receipt) and data from the SIM card can be used for this. Information on the MSISDN of the subscriber, the destination address and the service center address must be available.

This is a "pure" acknowledgment d. H. the message to the Paging network that a specific paging broadcast and has been received, possible.

In addition to the pure acknowledgment "receive call", there is the option of transmitting additional user data to the gateway by transferring predefined answers (contained in the call) or self-defined texts in the short message to be formed. This user data can be transmitted from the gateway 20 to the PNC 7 by the acknowledgment procedure.

Other functions / applications

• - The change from manual to automatic acknowledgment is adjustable on the terminal.
• - The subscriber can use the acknowledgment function for radio calls Switch active or passive in the paging system.
• - A non-acknowledgment of a message in one predefined period of time results in a repeat call.
• - A non-acknowledgment of a message in one predefined period or after repeated Call repetition has e.g. B. a nationwide call to Episode. If there is still no acknowledgment, could a corresponding information to an alternative pager / SMS The recipient or fax number can be deducted.
• - A manual acknowledgment via each DTMF telephone is through Entry of an acknowledgment code possible  
• - A confirmation of receipt can be in a corresponding Software can be integrated.
• - A confirmation of receipt can be sent via a Information service (e.g. voice server) can be requested.

In the simplest case, manual acknowledgment can also take place directly via the GSM terminal or any DTMF-capable telephone 18 , as shown in FIG. 7. A location determination with the "economy" solution is not practical since the GSM terminal and pager are physically separate devices. The pager is operated in its normal paging zones or the call is only sent in these zones.

For an acknowledgment via DTMF-capable telephones, either the code can be filtered out of the PNC 7 when a special dialing number is selected, or a further access 19 to the SMSC 10 must be created and the acknowledgment message identified and evaluated there.

Regardless of the method used, the following basic procedure results:
If a radio call is sent, the recipient of the message can carry out the acknowledgment directly via his GSM terminal or via any DTMF-capable telephone 18 . He has a personal acknowledgment code and receives e.g. B. for numeric and text calls via the call numbering function, the number of the radio call that must be acknowledged is communicated. Parameter transfers are also possible, e.g. B. Yes: 007; No: 4711 ..

As an example, the acknowledgment code can be structured as follows:
Access number for entering the acknowledgment code: 016x
Recipient's phone number: 1234567
Number of the call to be acknowledged: 2
Acknowledgment code: 007 (for yes)
Complete acknowledgment code: 016x 1234567 2 007

In addition to the pure acknowledgment "radio call received", there is also the Possibility of passing parameters on the radio calls in GSM staggered responses, e.g. B. Yes, no, I call back etc. These predefined - but also by the participant self definable - answers can be selected and with the Acknowledgment signal are sent back.

The possible terminal configurations for using the method according to the invention will be described in more detail below with reference to FIG. 6.

A terminal 3 consists of the components paging module 25, GSM module 26 and controller 27 . An external switch 28 can be provided, via which the user can switch off the GSM module in order to save battery capacity.

The terminal preferably has a display and additional control buttons (not shown). The Power is supplied by batteries or rechargeable batteries.

Paging module 25

The paging module 15 contains all the functionalities of a known paging receiver. These may have been expanded to include additional functionalities:

• - Controlled by the controller 27 , the paging module can switch between the locking mode and non-locking mode.
• - It informs the controller 27 of the receipt of a paging message so that the message can be confirmed.
• - It informs the controller 27 of the loss of service on the current paging frequency
• If the paging module 25 is in the locking mode and the radio supply for the current paging frequency is no longer sufficient to receive paging messages, all paging frequencies are scanned. The list of those frequencies for which there is sufficient radio coverage is sent to the controller.
• The subsequence mask (SM) must be transmitted to the controller 27 on request.
• - A change in the SM, z. B. on the paging Air interface, must be communicated to the controller.

GSM module 26

The GSM module 26 consists of the mobile equipment and the SIM (Subscriber Identity Module). At least the functionalities that are required for acknowledgment operation are implemented in the GSM module. External modules such as keyboard, display, microphone and loudspeaker can be omitted. The GSM module is switched on or off by the external switch 28 . The GSM module can be activated or deactivated by the controller 27 . A switched-off GSM module cannot be activated by the controller 27 until it is switched on again via the switch 28 .

The SIM in the GSM module is a standard SIM according to GSM 11.11 . To operate the GSM module, the PIN on the SIM must be deactivated. From the perspective of a GSM network, an activated GSM module 26 behaves like a GSM terminal:

• - The activation of the GSM module 26 corresponds to the switching on of a GSM telephone by the subscriber. The GSM module will log into an available GSM network.
• An activated GSM module can transmit a GSM short message (SMS-MO) to the PNC specified by the controller at the request of the controller 27 .
• - If the GSM module is deactivated, there may be a Logout in the GSM network using IMSI detach.

The GSM module informs the controller 27 of the state of its mobility management (mm) sublayer, and of the success or failure of a text message sent.

Controller 27

The controller 27 connects the paging module 25 and the GSM module 26 of the terminal 3 and controls activation, sending of short messages and deactivation of the GSM module 26 . Triggered by the Fukruf module 25 , the controller 27 executes two procedures, the paging area update procedure and the acknowledge procedure.

The controller 27 can be implemented as an independent assembly or as a process in the control computer.

Paging area update procedure

With the paging area update procedure, the controller 27 ensures that the PNC is able to send messages to the terminal again after the loss of the old paging area. If the paging module 25 is in locking mode and the radio supply to the locked paging area is no longer provided, the controller 27 is informed of this and starts the paging area update procedure.

In the first step, the paging module scans the available paging frequencies. The result is transmitted to the controller, which then carries out one of the following mechanisms:

• 1. The operator ID (OPID) of one or more paging areas is identical with the home OPID (OPIDhome) or with the last used OPID:
  The controller 27 selects a paging area for this OPID. The selection is made with an equally distributed probability function.
  The controller 27 activates the GSM module 26 and transmits the selected paging area (OPID, PA) with a GSM SMS to the PNC. After successful transmission, the paging module 25 is brought into the locking state.
• 2. 2) a) Neither a paging area of the last used one nor the home OPID are found:
  The paging module 25 is brought into the non-locking state, whereby paging messages are expected on all available frequencies.
• 3. The GSM module 26 is activated and the list of the available OPIDs and paging areas is transmitted to the PNC via a GSM SMS. From this list, the PNC can select a network operator suitable for paging roaming and use it to transmit messages.
• 4. As long as the terminal 3 is in the non-locking state, the available OPIDs and paging areas are continuously determined. If the list determined here differs from the last one transmitted, then if OPIDhome is not available, 2b) is executed, otherwise 1). It may be necessary to define a waiting time between two transmissions according to 2b). After the transmission of the short message, the GSM module 26 is deactivated.

If the external switch 28 of the terminal 3 is OFF, the GSM module 26 is not activated. The transmission of information to the PNC is considered to have failed and will be suspended until it is switched on.

The activation of the GSM part 26 and the transmission of an SMS should preferably take place during the time in which the paging pager does not expect any messages. This could be done by evaluating the subsequence mask (SM).

If the transmission of the parameters to the PNC fails, the controller 27 deactivates the GSM module 26 and tries a new paging area update attempt after a time to be defined. The paging module is brought into the non-locking state. As the number of unsuccessful paging area update attempts increases, the waiting time increases. The number of attempts is unlimited.

Paging area detach

The switching off of the GSM module 26 could be communicated to the PNC by a paging area detach. In this case, the GSM module 26 is activated before switching off, an SMS with content to be defined is sent and the GSM module 26 is then deactivated. The paging module 25 is brought into the non-locking state. If the transfer fails, no further attempt is made.

Acknowledge procedure

The controller 27 starts an acknowledge procedure as soon as the paging module 25 indicates the receipt of a paging message. Initially, the subscriber is shown the receipt of the message and is given the opportunity to select a manual confirmation (manual acknowledge). Thereafter, the controller 27 activates the GSM module 26 and transmits the confirmation for all not yet confirmed paging messages, in the order of receipt, to the paging network center (PNC) in addition to those in the software of the Predefined responses of the terminal, these can be expanded by any responses received with the paging message. If the manual confirmation does not take place within a defined time, an automatic confirmation takes place. As with manual confirmation, the GSM module is activated and a short message is sent to the paging network center (PNC) as confirmation for all pending messages that have not yet been confirmed, in the order in which they were received. After successful transmission of all confirmations, the GSM module is deactivated. The short message sent when a call is acknowledged contains the parameters RIC, paging area (OPID, PA) in which the message was received, time stamp and acknowledgment number in addition to the response that may have to be transmitted.

By transferring the paging area, an implicit paging area update is carried out with the confirmation. If the transmission was successful, the paging module 25 is lured to the OPID and PA transmitted in the process.

Failure of the acknowledge procedure

If the acknowledge procedure fails (automatically or manually), the GSM module 26 is deactivated. After a time to be defined, another acknowledge attempt is carried out. The waiting time increases with the number of unsuccessful attempts. The number of attempts is limited. The unsuccessful transfer due to a lack of radio coverage is displayed to the subscriber, so that the subscriber has the opportunity to enter the GSM coverage area. Another attempt to transmit the receipt can be started by the participant pressing a button. The subscriber is informed of the successful transmission or the final failure to acknowledge messages.

Personalization of the end device

Since a standard SIM is used, the Personalization as with any GSM SIM. Here, however the PIN is deactivated.

The personalization of the terminal 3 is carried out as for the known pagers by the manufacturer or network operator. Not only RIC and SM are communicated here, but also the PNC number (SMS service center number). The RIC, SM and PNC number are stored in a non-volatile memory in the terminal.

Possible developments of the invention

If the subscriber has switched off his GSM terminal and is standing in GSM to send an SMS message for transmission redirected to his pager.

International roaming: There is international roaming Agreement with a foreign GSM network operator, the Service can also be used abroad if there is a corresponding paging system exists.

Intelligent Network IN functionality for enhanced call Forwarding: If mobile subscribers are not available and an important telephone call cannot be placed through it a call is transmitted with the Prompt to turn on the cellular phone or to to enter the coverage area of the mobile network. The  Call forwarding conditions can originate as well be selectable depending on the time.

Call forwarding for important messages: alerting by Paging for urgent short message that is not broadcast can. The call forwarding conditions can originate - as well as being time-dependent.

Claims (25)

1. A method for expanding a unidirectional paging network to a quasi bidirectional paging network, the transmission of paging to a terminal via the paging network and a transmission of acknowledgment signals and / or other signals and messages from the terminal to a telecommunications network, characterized in that the telecommunications network GSM cellular network ( 5 ), and the transmission of signals between the terminal ( 3 ) and the GSM cellular network ( 5 ) in the form of a short message message (SMS) via a signaling channel, and that the paging network via an interface ( 6 ) is connected in the form of a direct data connection to the GSM mobile radio network ( 5 ), so that direct data exchange between the paging network ( 1 ) and the GSM mobile radio network ( 5 ) is possible, and which are transmitted to the GSM mobile radio network ( 5 ) Forwarded signals over the direct data connection ( 6 ) to the paging network ( 1 ) and d be processed locally. 2. The method according to claim 1, characterized in that the interface between a short message service center SMSC ( 10 ) of the GSM network ( 5 ) and a paging network controller PNC ( 7 ) of the paging network ( 1 ) is provided. 3. The method according to claim 1, characterized in that the interface between a gateway computer ( 20 ) of the GSM network ( 5 ) and a paging network controller PNC ( 7 ) of the paging network ( 1 ) is provided. 4. The method according to any one of claims 1 to 3, characterized in that the paging network controller PNC ( 7 ) via the interface, a GSM Mobile Application Part (MAP) protocol procedure in the GSM network ( 5 ) can be initiated to the location of the Terminal ( 3 ) within the GSM network ( 5 ) to be determined. 5. The method according to any one of claims 1 to 3, characterized in that the paging network controller PNC ( 7 ) via the interface, a location update procedure can be initiated in the GSM network to the location area of the terminal ( 3 ) within the GSM To determine network ( 5 ). 6. The method according to any one of claims 1 to 5, characterized in that the location area of the terminal ( 3 ) in the GSM network ( 5 ) is assigned to a corresponding GSM switching center ( 8 ) and from this a corresponding paging zone of the paging network ( 1 ) is determined can be. 7. The method according to any one of claims 1 to 6, characterized in that the paging network ( 1 ) constantly sends out paging zone information, receives this from the terminal ( 3 ) and via the GSM return channel ( 6 ) to the paging network controller ( 7 ) is sent back to determine the location of the terminal ( 3 ) within the paging network ( 1 ). 8. The method according to any one of claims 1 to 7, characterized in that the paging signal is only transmitted in the corresponding paging zone in which the terminal ( 3 ) was last located. 9. The method according to any one of claims 1 to 8, characterized in that the databases required for assigning subscriber and device identifiers, for determining location information and for storing the status information of paging in the Short Message Service Center SMSC ( 10 ) of the GSM network ( 5 ) are set up. 10. The method according to any one of claims 1 to 8, characterized characterized that the required databases for assignment  of subscriber and device identifiers to determine Location information and for storing the Status information of calls in a database server are set up. 11. The method according to any one of claims 1 to 10, characterized in that the databases required for assigning subscriber and device identifiers, for determining location information and for storing the status information of radio calls in the paging network controller ( 7 ) are set up. 12. The method according to any one of claims 1 to 11, characterized characterized in that an unacknowledged call repeats is sent out. 13. The method according to any one of claims 1 to 12 thereby characterized in that an unacknowledged call in a previously defined call zone is sent. 14. The method according to any one of claims 1 to 13, characterized characterized in that an unacknowledged paging occurs several times in a constantly increasing call radius is transmitted. 15. The method according to any one of claims 1 to 14, characterized in that the paging is sent out in the entire paging network and automatically triggers a location determination of the receiver (location update procedure) in the GSM network ( 5 ) when received in the terminal ( 3 ). 16. The method according to any one of claims 1 to 17, characterized in that the paging in a foreign, with the own paging network ( 1 ) via data exchange lines at least temporarily connected paging network is transmitted and that a transmission of acknowledgment signals and / or other signals and messages on Signaling channels of a third-party telecommunications network takes place, which is located in the area of the third-party paging network, and that the signals and messages are forwarded to the GSM mobile radio network ( 5 ) assigned to the own paging network, from which the transmitted signals via direct data connections ( 6 ) to the own paging network ( 1 ) forwarded and processed there. 17. Device for expanding a unidirectional paging network to a quasi bidirectional paging network, the paging network being set up for sending paging calls to a terminal, and a GSM mobile radio network is provided, via which acknowledgment signals and / or other signals and messages are transmitted by the terminal , characterized by a direct data connection ( 6 , 13 , 17 ) between a gateway ( 20 ) of the GSM mobile radio network ( 5 ) and a switching center ( 7 ) of the paging network ( 1 ), via which data connection ( 6 , 13 , 17 ) acknowledgment and location information is transmitted. 18. Device according to claim 17, characterized in that the gateway ( 20 ) is realized by a short message service center ( 10 ). 19. The device according to claim 17, characterized in that the gateway ( 20 ) is realized by a gateway computer. 20. Device according to one of claims 17 to 19, characterized in that a database ( 12 ) for storing and processing subscriber-specific and paging-specific data is set up in the gateway ( 20 ). 21. Device according to one of claims 17 to 19, characterized in that a database for storing and processing subscriber-specific and paging-specific data is set up in the switching center ( 7 ) of the paging network. 22. Terminal for use in a unidirectional paging network, which is expanded to a quasi bidirectional paging network, the transmission of radio calls to the terminal via the paging network, and a transmission of acknowledgment signals and / or other signals and messages from the terminal via a GSM Mobile radio network takes place, characterized in that the terminal ( 3 ) is prepared for operation in both networks and comprises a paging module ( 25 ) for receiving conventional paging signals, an at least SMS-compatible mobile radio module ( 26 ), and a control unit ( 27 ) for connecting the paging module ( 25 ) to the mobile radio module ( 26 ) and for controlling activation, deactivation of the modules ( 25 , 26 ), for sending acknowledgment messages and initiating the paging area update procedure and / or cellular location update procedure. 23. Terminal according to claim 22, characterized in that the personalization of the mobile radio module ( 26 ) is carried out by a standard SIM. 24. Terminal according to claim 22 or 23, characterized in that it has a switching device ( 28 ) through which the mobile radio module ( 26 ) can be switched off manually. 25. Terminal according to one of claims 22 to 24, characterized characterized in that it is a full cell phone includes.