WO1998000990A2

WO1998000990A2 - Local mobility telephony system

Info

Publication number: WO1998000990A2
Application number: PCT/IT1997/000143
Authority: WO
Inventors: Emilio Cancer; Giorgio Pellegrini; Sergio Giovanni Fogli
Original assignee: Telecom Italia S.P.A.
Priority date: 1996-06-28
Filing date: 1997-06-20
Publication date: 1998-01-08
Also published as: AU3273197A; ITRM960457A0; WO1998000990A3; IT1284181B1; ITRM960457A1

Abstract

Local mobility telephony system, wherein the cordless apparatus supplied to the subscriber is interfaced with transceiver localized devices, distributed inside the whole area of coverage concerned with this service; these devices are operative and individually connected to a specific telephone exchange which is provided with software/hardware means effecting the exchange of information and the intercommunication with the individual localized devices. The telephone exchanges communicate the information received from the localized devices, to a control point comprising a database of the subscribers admitted to this service, and a centre for code authentication.

Description

Descrlpt ion

Local mobility telephony system

Technical Field

The present invention generally relates to services concerning cordless telephone devices and more particularly it relates to a system for carrying out this service which can be provided to the user possessing a cordless terminal (according to the European standard ETSI-DECT (Digital Enhanced Cordless Telecommunications) with GAP profile (generic access profile)) and a fixed line, with the possibility of using its cordless telephone, besides inside its house, also in a public environment, outside the radius range covered by the "domestic" base and inside the zones covered by this service.

Background Art

There are already known some techniques for controlling local mobility telephone services complying with the aforesaid standard DECT or similar standards, but their serious drawback is that they cover territorial areas which are extremely reduced and that they are not directly joined to the fixed network of the national service.

In fact, the various systems for controlling this service are based on the utilization of a telephone exchange for cordless telephones which cannot control more than a certain limited number of cordless telephones, and therefore also the area managed by it will be limited. In this kind of control system, there is not provided any kind of information exchange among the telephone exchanges, allowing the user to pass from a covering area to the next with continuity.

In Japan there is provided a local mobility telephone service permitting to use a cordless telephone both in a "domestic" and in a public environment, in a territorial area comprising a whole city. However it is worth saying that the access standards are totally different (DECT in Europe and PHS in Japan), and also the managing system of this service, used by the Japanese companies, is different because the user of the Japanese system, in order to use this service also in a public local environment, is always forced to make use of a dialling code which is associated to a call between different districts, determining increased costs, as happens for the radiomobile service.

Actually, the service offered to the user by Japanese companies is not an extension of the service related to the fixed line, therefore it is not an upgrading of the services directly connected to the domestic use of the telephone.

Moreover , intercommunicating calls are not provided for in this kind of service and may be realized by means of terminal provisions, using a frequency other than the public one, and in a limited radius (about 200 between the two terminals).

Disclosure of the invention

The object of the present invention is to solve the problem of a local mobility telephony allowing the user possessing a cordless telephone to use the same telephone, besides in its home, also in the public zones covered by the local network system, on the basis of the sole number associated with the fixed line, in such a way that the local mobility service will actually form an extension of the complex of services already available to the fixed telephone.

Another object of the present invention is to provide a local mobility system incorporating the actual additional functions already present in the fixed line telephone service, with an access code authentication service .

Another object of the present invention is a local mobility telephony system wherein the coverage on the whole territory of Interest, allows a replacement of the transmitting/receiving station when the user passes from a coverage cell to another one.

Finally, a further object of the present invention is to provide a technique for controlling and carrying out local mobility telephone services, in a way that these services may be realized by employing telephone exchanges, protocols and usual hardware/software means already existing in the domain of public telephony. These and further objects which will result from the description are obtained by a local mobility telephony system characterized in that the cordless telephone activated in respect of a fixed line and supplied to the user, is interfaced with transceiver devices which are localized and uniformly distributed on the area of coverage associated to the service, wherein said transceiver devices are localized and individually connected with a particular telephone exchange provided with hardware and software means for controlling the information exchange and the intercommunication with the individual localized devices. As will be better explained in the following, the telephone exchanges communicate the information received by the localized devices to a control point of the service, comprising a database of the subscribers authorized to this service and a centre for code authentica ion.

The local mobility telephony system according to the present invention, in a set of possible configurations of the service supplied, allows:

- to make/receive a telephone-call by means of a cordless terminal in a public environment, only in the zones covered by the local subscriber network of the corresponding fixed line;

- to make telephone-calls from a cordless terminal in a public environment, in all covered zones, also different from those of the local subscriber's network of the corresponding fixed line, and to receive telephone-calls solely in the zones covered by the local subscribers network of the aforesaid fixed line; and

- to make/receive telephone calls by means of a cordless terminal in a public environment and in all covered zones, also different from those of the local subscriber's network of the corresponding fixed line.

Brief description of drawings

A detailed description of the local mobility telephone system will now be given for illustrative and non limitative purposes only, without limiting thereby its applications and possible extensions, according to an embodiment thereof, in which it is possible to make or receive telephone calls by means of a cordless telephone, in a public environment, only in the zones covered by the local subscriber's network of the corresponding fixed line, as shown in the drawings, in which:

Fig. 1 is a general view of the network architecture;

Fig. 2 is a schematic representation of the handling of a call being received;

Fig. 3 shows a schematic diagram illustrating the function of continuous updating of the terminal local ization. Best mode for carrying out the invention

In Fig. 1 there is indicated how the system of the invention is actually interposed between the cordless telephone 2 and the fixed line or the specific

"domestic" environment 1. It follows therefrom how the communication to the cordless telephone 2 is first of all interfaced with localized transceiver devices 3', n 3", ... 3 which are uniformly distributed on the whole territory where the local mobility telephony service is to be managed. In Fig. 1, from a graphical point of view, there is also schema ically shown how the cell coverage zones A and B are overlapped partially so as to allow a good continuity in the replacement of the transceiver stations, when the cordless telephone passes from one zone to the next. n The single devices 3', 3", ..., 3 distributed uniformly inside the territory to be covered, are effectively grouped together from a functional point of view, in order to be interconnected by a normal telephone cable to a specific telephone exchange 4', 4", ...4 , in each of which there is provided a functional block in order to control the intelligent intercommunication and the commutations with the n individual localized devices 3', 3", ... 3 .

It is obvious, already at this stage, that the cordless telephone is not directly linked with the "domestic" base, instead, it is interfaced with the telephone exchange of the corresponding zone, which has been supplied with hardware/software means to perform the commutation function of this service.

The system for controlling and carrying out the local mobility service, makes therefore use of network infrastructures 4, already existent for the normal operation of the fixed base network, and comprises also a control unit 6 of the service, associated to a database for storing in real time the territorial location of each cordless device, and to the code authent icat-ion center, for checking the access code of the terminal to the required service - in this way the possibility of illegal access to the local mobility telephony service is limited.

Therefore, as will be explained afterwards, on an already existent and tested infrastructure, embodied by the fixed network, supplementary functions will be located, which, according to one aspect allow to add new kinds of services for the users, and according to a second aspect, give a high reliability and safety to the new realized services, due to the fact that they are based on network infrastructures already tested for a long time.

The general procedure for putting into operation the aforesaid service states that telephone-calls receiving no answer from the fixed line 1 within a predetermined number of seconds, or which receive an answer but are addressed to the owner of the cordless telephone who is in a public place, are transferred to the cordless telephone itself. The transfer, after the answer from the fixed line, is performed in accordance with the direction of the user answering on the fixed line. If the owner of the cordless telephone, at the time the transfer is effected, is outside the cell coverage area, or is inside it but outside the local network managed by the local mobility service, or if his terminal is turned off, engaged or does not answer, telephone-calls are automatically transferred to a voice mail box associated to the number of the fixed line. The notification of the presence of new messages, if any, recorded in the voice mall box, is sent both to the fixed line and the cordless telephone making use of the cell public coverage .

The local mobility telephone system may be better understood with reference to Fig.2, where the functionality of the network intervening in the handling of a telephone call to the telephone managed with this local mobility system are examined in detail. After dialling of a number of a local mobility telephone 18, by the user 11, the connection with the telephone exchange XI of his telephone area is first of all obtained; thereafter, making the "home telephone" 24 ring, through the path 12, the possibility is firstly estimated, if the user being called is at home and can answer to the telephone call; if this is not the case, the database of the node 6 is Interrogated through the path 13 in order to find the actual location of the telephone apparatus being called, and in order to find under which public area/telephone exchange X3 it may be found. The node 6 asks through the path 15 the telephone exchange X3 , one of the reference numbers supplied thereto, this number being fed to the initial telephone exchange X2 , where it is used to route the telephone calls through the path 17, to the telephone exchange X3 , which, identifying it as a number for a user in local x mobility, activates the corresponding point 3 which is the nearest point with respect to the local mobility telephone being called.

The procedure for a telephone call effected by the user of a local mobility telephone is, according to the above description, intuitively analogous to that just disclosed for the case of the telephone-call to the user in local mobility. It must only be noted that the node

6, in case of a telephone-call from a user possessing a cordless telephone in local mobility, would previously perform the function of controlling the access code to the service.

In Fig. 3, there is schematically shown the passage of the cordless telephone 21 from an area covered by the telephone exchange XI, with the localisation group 3" detecting the presence of the telephone 21, to an area covered by the telephone exchange X3 , with the localisation group 3' carrying out the detection: during the passage from the area of the telephone exchange XI, to the area of the telephone exchange X3 , the updating of the information contained in the database of the node 6 related to the location of the telephone 21 and the loading of the profile information of the terminal from the node 6 to the station X3 , are performed through the paths 22, 23.

Moreover, only for illustrative and non- 1 imi tat ive purposes, a detailed description is hereinafter made, concerning" the fundamental performances offered by the control and practical carrying out of the local mobility telephone services according to the present invention. For clarity and conciseness of the disclosure, the following abbreviations are used: CM : cordless mobility

STC : centralized telephone answering system CM subscriber: subscriber of the CM service CM line: fixed line to which the CM service is associated CM number: number associated to the CM line CM local network : local network identified by the CM number CM terminal : cordless terminal according to the DECT standard (GAP profile) which is adequately set in order to be used also in a public environment. Domestic base: transceiving private station connected to the CM line. The CM terminal may take advantage both of the cell coverage from the public network (public profile) and of the domestic base coverage associated thereto (domestic prof i l e ) .

From the terminal point of view, the change in the type of coverage may be performed automa ically from the terminal itself, with a priority assigned to the domestic base and/or with other automatic or manual modalities depending on the terminal.

In the following the implementation examples 1.-5. will be considered.

1. Telephone-calls Incoming the CM line.

All calls directed towards the CM number are routed to the CM line, irrespective of the location and state of the CM terminal .

When the CM terminal is registered in a public environment, then:

- Telephone-calls incoming the CM line and obtaining an answer, are routed - if the user being called wishes so -, towards the CM terminal_?

- Telephone-calls incoming the CM line, not receiving an answer in a predetermined time interval, are automatically routed to the CM terminal, after sending of a free message informing the user effecting the telephone-call about the fact that the telephone-call is going to be transferred to the CM terminal;

- During forwarding of the message, the CM line continues to receive the current telephone call, in order to give the time to answer to the called person, if he is at home;

- If a telephone-call incoming the CM line receives an answer during the forwarding of the message, the latter is interrupted and the communication is establ ished.

When the CM terminal is registered in a domestic environment :

- If the STC function is in an active state, telephone calls incoming the CM line, not receiving an answer in a certain time interval after the occurrence of the condition "free line, no answer", are automatically directed towards the voice mail box associated to the respec ive CM number.

- In all other cases the telephone calls Incoming the CM line are handled like a telephone call directed to the fixed line not provided with the CM service.

2. Telephone calls incoming the CM terminal registered in a public environment.

It is possible to receive telephone-calls on the CM terminal registered in a public environment, provided that the latter is inside an area covered by the CM local network.

In case of a "free" CM terminal, a tone corresponding to this free state will be forwarded to the calling user; in case of an intercommunicating telephone call effected from a CM line and if the CM terminal is

"engaged", a tone corresponding to this state is forwarded to the calling subscriber.

In case of an intercommunicating call effected from a CM line, if, following the forwarding to the CM terminal it - 13 -

happens that the latter is outside the CM local network or, even if inside it, is outside the coverage, is turned off or "engaged" or in the state "free, no answer", telephone calls are automatically routed to the voice mail box related to the CM number in question. In case of a non intercommunicating call, supposing that after the routing towards the CM terminal, this latter is outside the CM local network, or inside it but out of the coverage, turned off, in the state "free, no answer" or "engaged", the telephone call is automatically routed to the voice mail box associated to the CM number.

3. Telephone calls originating from a CM line

A telephone call outgoing from the CM line is effected according to normal procedures provided for a terminal joined to a fixed line - not a CM line -, irrespective of the registration of the CM terminal, and if the latter Is registered in a public environment, the telephone call is performed from the respective condition of the terminal.

4. Telephone calls originating from a CM terminal in a publie envi ronment .

The user effects a telephone call outgoing from the CM terminal located in a public environment, by selecting the desired telephone number to be called on his/her CM terminal, provided that the telephone call originates from inside a cell coverage area of the CM local network and is compatible with the service profile associated to the user. It is possible to effect outgoing telephone calls from the CM terminal in a public environment inside the local CM network, irrespective of the condition of the CM line, In case the CM subscriber tries to effect a telephone call from a CM terminal, to an area of cell coverage not included in the CM local network, a message is forwarded which will inform the calling subscriber that it is impossible to effect outgoing telephone calls because the other telephone is located outside of the CM local network .

5. Intercommunicating function.

When the CM terminal is registered in a public environment :

- A telephone call from the CM line to the CM terminal and from a CM terminal in a cell coverage area of the CM local network, towards the CM line, is activated by means of the selection of a suitable code/key.

- Telephone calls generated activating the intercommunicating function are characterized at their destination (CM terminal or CM line) by a different r ing .

- It is not possible to originate calls from a CM line to a CM terminal and viceversa, by selecting the CM te1ephone nu ber .

When the CM terminal is registered in a domestic environment :

- it is not possible to originate intercommunicating calls from a CM line to a CM terminal and viceversa, with the above described modalities and which are valid only in case the CM terminal is registered in a public environment.

- The management of intercommunicating telephone calls when the terminal is registered in a domestic environment depends from the domestic base associated to the CM terminal .

6. On-line transfer function.

When the CM terminal is registered in a public environment :

- The telephone calls incoming the CM line, receiving an answer, may be transferred to the CM terminal on indication of the called subscriber.

- The function for on-line transfer is activated from the CM line, during conversation, through the selection of an appropriate code/key.

- After activation of the on-line transfer function, a message is forwarded to the CM line, informing of the imminent telephone call transfer, followed by the engaged tone.

When the CM terminal is registered in a domestic environment, it is impossible to activate the on-line transfer function.

7. Centralized telephone answering system. When the CM terminal is registered in a public environment :

- the STC function associated to the CM service is always in the active state, - a telephone call directed to a CM number and successively routed to the CM terminal, is automatically transferred to the voice mail box associated to the CM telephone number if one of the following conditions occurs:

- CM terminal turned off or out of cell coverage;

- CM terminal Inside a covered area but outside of the local network;

- CM terminal inside a covered area of the CM local network, not answering in a predetermined time;

- CM terminal inside a covered area of the local CM network and "engaged" (only in case of non intercommunicating telephone calls).

When the CM terminal is registered in a domestic environment :

- The CM subscriber may do what follows, by means of an appropriate interactive procedure effected from the CM line: a) ac ivate/deactivate the STC function; b) interrogate the state of the STC;

- The default state of the STC will be the active one.

- A telephone call directed to a CM telephone number is automatically transferred to the voice mail box associated to the CM telephone number, if the STC function is in the active state and only if the telephone call does not receive an answer in a certain time period.

- The execution of the aforesaid procedures, when the terminal is registered in a public environment, has no effect on the STC function which will always be in the active state. - When a CM terminal registered in a public environment is registered in a domestic environment, the STC state will be that set by the subscriber, before the last registration of the terminal in a public environment. The notification of new recorded messages present in the vocal box associated to the CM telephone number, is effected by means of a tone from the exchange, which is modified after lifting the telephone, and which is sent both to the CM line and to the CM terminal registered in a public environment, inside an area of the coverage, also outside of the CM local network.

In the following optional functions are described, which preferably should be specifically required at the time of subscribing the CM service, or should be required afterwards by the CM subscriber. A - Uncondi ioned routing to the CM terminal registered in a public environment. By means of. an appropriate procedure effected from the CM line, the user has the possibility to activate a function allowing to route to the CM terminal registered in a public environment, all telephone calls directed to the CM telephone number, which, otherwise, would be routed to the CM line.

When the CM terminal is registered in a public environment, if the function for unconditioned routing to the CM terminal is in the active state, telephone calls directed to the CM line are automatically routed to the CM terminal, by previous forwarding of a message without charge to the calling subscriber.

When the function for unconditioned routing is active, after lifting the telephone from the CM line, a particular tone will be forwarded; the function for unconditioned routing is automatically deactivated when the CM terminal is registered in a domestic environment.

The function of unconditioned routing may also be deactivated by means of an appropriate procedure effected from the CM line.

B - Disabling

The CM subscriber may request, through a management procedure, the disabling/enabling of outgoing telephone calls from the CM terminal, registered in a public environment, towards international destinations and according to the disabling classes provided for by POTS subscribers .

C - Autodisabl ing .

The CM user may, through an interactive procedure effected from the CM line or from the CM terminal registered in a public environment, choose to disable/enable the outgoing telephone calls from the CM terminal registered in a public environment, according to the same filtering typologies indicated in the above paragraph.

In conclusion, the CM service is a service associated to the fixed line, which can be regarded as a further development of the functions and performances of the fixed line itself.

The service allows to effect telephone calls from the cordless telephone in a public environment, on condition that we are in the coverage area of the CM local network, for any destination whatever, local, national or interna ional.

The mobility degree being offered allows to maintain in the active state, a telephone call from/to a cordless telephone inside a public environment, when the cordless telephone is displaced at the velocity of a pedestrian .

Industrial applicability

The service will initially be made available in certain local networks. The coverage will be guaranteed in a continuous way in the local area (all principal streets, squares, etc.) and also in limited areas, with a high traffic density and of particular interest for the service involved. Later on, it may be extended to larger territories.

Claims

C l a i ms

1. Local mobility telephony system characterized in that a cordless telephone apparatus supplied to the subscriber,^' is interfaced with transceiver localized n devices (3', 3", ... 3 ) distributed on the whole area concerned with this telephone service in local mobility, said transceiver localized devices being interconnected individually to a specific telephone exchange (4 ',...4 ), each telephone exchange being provided with the hardware/software means for controlling the information exchange and the intercommunication with the individual localized devices, said telephone exchanges communicating the information received from the localized devices, to a control unit (6) of the service, which includes a database of the subscribers having access to the service and a code authentication centre.

2. Local mobility telephony system according to the preceding claim, characterized in that it comprises means for controlling and managing telephone calls, which after dialling of a number of a local mobility telephone, realize firstly the connection to the telephone exchange associated to the fixed line of the subscriber in local mobility, evaluating the possibility that the called subscriber is at home and can answer, by letting its telephone connected to the fixed line ring; said means inquiring, if the above case does not occur, the database of the node (6) in order to find out the actual location of the called telephone apparatus and under which public area/telephone exchange it may be traced, wherein the node (6) asks this receiving telephone exchange a number among the reference numbers supplied thereto, in order to sent it to the initial telephone exchange, wherefrom said number included in the local subscriber network of the fixed line, is used to route the telephone call through the fixed line (17) towards the receiving telephone exchange, which recognizes it as a number of a subscriber in local mobility and activates the corresponding transceiving points which are the nearest to the called local mobility telephone.

3. Local mobility telephony system according to the preceding claims, characterized in that it comprises means for controlling and managing the telephone calls not receiving an answer from the fixed line within a predetermined number of seconds, or which receive an answer but are addressed to the owner of the cordless telephone who is in a public environment, by routing these telephone calls towards the cordless telephone, the transfer being effected after the answer from the fixed line, and according to the instructions of the user who answers to the telephone call.

4. Local mobility telephony system, according to the preceding claims, characterized in that it comprises means for controlling telephone calls and for enabling to make/receive telephone calls from a cordless telephone in a public environment, in all areas covered by the local subscriber network of the corresponding fixed line.

5. Local mobility telephony system according to claims 1, 2 and 3, characterized in that it comprises means for controlling telephone calls and for enabling telephone calls effected from a cordless telephone in a public environment inside anyone of the covered areas, even those which are different from the fixed line local subscriber network, and controlling/enabling telephone calls received solely in the areas of coverage of the local subscriber network of said fixed line.

6. Local mobility telephony system, according to claims 1, 2 and 3, characterized in that it comprises means for controlling telephone calls and for enabling to effect/receive telephone calls from a cordless telephone in a public environment in any of the coverage areas, even those different from the areas of the local subscriber network of the corresponding fixed line.

7. Local mobility telephony system, according to claims 1,2,3,4 and 5, characterized in that it comprises storage means including a voice mail box associated to the telephone number of the fixed line, which in case the owner of the cordless telephone, at the time of the transfer, is outside of the coverage area or outside the local network of the corresponding subscribed fixed line, has its terminal turned off, does not answer or is "engaged", will record the automatically transferred telephone calls, wherein the notification of the presence of new recorded messages, if any, inside said storage means including the voice ail box, is forwarded both to the fixed line and to the cordless telephone which makes use of the public coverage system.

8. Local mobility telephony system according to claims 1, 2, 3, and 6, characterized in that it comprises storage means with a voice mail box associated to the number of the fixed line, which in case the owner of the cordless telephone, at the time of the transfer is outside the coverage, has its terminal turned off, or does not answer, or is engaged, will record the automatically transferred telephone calls, wherein the notification of the presence of new recorded messages, if any, in said storage means including a voice mail box, is forwarded both to the fixed line and to the cordless telephone which makes use of the public coverage system.

9. Local mobility telephony system according to preceding claims, characterized in that it comprises means for detecting and controlling the passage of the cordless telephone in the active state, from the area covered by a first telephone exchange to the area covered by a second telephone exchange, said detection and control means effecting the updating of the information contained in the database of the node (6) relatively to the location of the telephone apparatus, and the loading of the profile information of the terminal, from the node (6), to the second telephone exchange .

10. Local mobility telephony system according to the preceding claims, characterized in that it comprises physical means via cable, connecting the localized transceiver devices to the corresponding telephone exchanges .

11. Local mobility telephony system according to the preceding claims, characterized in that it takes advantage of the network in rastructures already existing for the intercommunications and commutations in the fixed network.

12. Local mobility telephony system according to the preceding claims, characterized in that it takes advantage of network infrastructures designed for the purpose of effecting Intercommunications and commutations in the fixed network.

13. Local mobility telephony system according to the preceding claims, characterized in that it comprises an authentication centre for the codes, inside the node (6) actuating the control on the service, which controls the access code of the subscriber for allowing access to the desired service.