WO1998051116A2

WO1998051116A2 - Call forwarding in isdn networks

Info

Publication number: WO1998051116A2
Application number: PCT/SE1998/000825
Authority: WO
Inventors: Leif Abrahamsson
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ); Telia Ab
Priority date: 1997-05-07
Filing date: 1998-05-05
Publication date: 1998-11-12
Also published as: SE9701717D0; AU7461598A; WO1998051116A3

Abstract

A method and device are described which allow an ISDN subscriber to forward incoming calls to a third party using a control device at the subscriber. To forward a call, a connection is set up on an idle B-channel to the third party and interconnecting the incoming an outgoing calls by means of the control device. Calls can be forwarded in dependence upon the type of call (speech, fax, etc.) or upon the origin of the call. Incoming fax messages can be converted to e-mail messages.

Description

t ...

Method and device in ISDN network

Technical Field

The present invention relates to Integrated Services Digital Networks (ISDN), and in particular to the selection and prioritizing of incoming calls in such a network.

Background

With the introduction of mobile phones, the availability of the end user has increased dramatically. However, this availability has also demonstrated the need for privacy. Today, a subscriber is either reached by everybody or by nobody, and there is no way to filter incoming calls in dependence of the caller.

In the PSTN network calls may be forwarded to a specified terminal using the call forward service. This service only allows one number to be specified, to which all calls will be forwarded, independently of the type of call, or the originator of the call.

The only known solution to this problem is found in business exchanges (PABXs), where the PABX itself or an operator can let some calls through and reject other calls. For private subscribers, and for businesses that are too small to have a PABX, no solution is known.

An ISDN (Integrated Services Digital Network) connection offers three channels on the same physical link: two circuit switched B channels of 64kbit/s each for dial-up access for data or speech connections and one packet switched D channel. The total bandwidth of the D channel is 16 kbit/ s, but the effective capacity for control information or data is 9.6 kbit/s. A protocol known as LAPD (Link Access Procedure for D channel) is used for communication on the D channel.

US Patent Specification 5, 220, 599 discloses an ISDN communication terminal adapted to identify and notify the person, among a number of persons, for whom an » «. mcoming call is intended. This patent specification is, however, concerned with selecting the right receiver of a call among subscribers connected to the ISDN communication terminal.

Summary of the Invention

It is an object of the present invention to provide an apparatus that will enable private subscribers and small businesses to control incoming voice, fax and e-mail traffic, and to be reachable by the desired people regardless of their current location.

This object is achieved by using a standard ISDN connection, controlled by a

Personal Computer (PC) or a workstation equipped with software which will allow it to select and prioritize between the incoming calls. This PC or workstation is referred to in this document as a Personal Multimedia Exchange (PMMX).

Incoming calls may be forwarded to a specified terminal any type of terminal in any telecommunications network. An incoming call on one of the B channels is forwarded by establishing a connection to the specified terminal on the other B channel and interconnecting the B channels. In this way a connection is established from the calling party to the subscriber. The interconnection of the connections on the B channels may be carried out in the PMMX, or a telephone exchange may be instructed to interconnect the connections.

The subscriber may specify how incoming calls, e-mails etc. are to be handled at any given time dependent on the originator of the call or e-mail, in a subscriber profile.

For example, at a time when the subscriber does not want to be disturbed, but still has to be reached by his/her spouse, or by certain colleagues, it may be specified that incoming calls from should be forwarded to the subscriber's phone. Any other incoming calls should be rejected, and the caller should be allowed to make a i ... message. At the same time, incoming e-mail from one of the colleagues should be received at once.

A caller may be identified in several different ways: - by the number from which he/she is calling

- by a PIN code, which may be entered from any terminal

- by voice recognition

Different profiles may be set up at the same time, to be valid, for example, at different times of the day. The profile may also be changed at any given time.

Brief Description of the Drawings

Figure 1 illustrates schematically the connection from the ISDN subscriber via the

ISDN network to the Internet according to the invention; Figure 2 illustrates the connection from the ISDN subscriber via the ISDN network to the Internet in more detail;

Figure 3 is a flow chart of the actions required to install and activate the services according to the invention; and

Figure 4 is a flow chart of the actions to be taken when a subscriber wishes to set up a profile according to the invention.

Detailed Description of Embodiments

Figure 1 shows an ISDN connection to a computer network for retrieving data according to the invention. In a preferred embodiment, the computer network is the Internet, but similar connections may be set up to any computer network, for example a network which allows an X.25 or Internet Protocol (IP) connection. An enhanced ISDN terminal known as a PMMX (Personal Multimedia Exchange) 1 is connected to an ISDN exchange 3. The ISDN exchange is connected via an Internet access server 5 to the computer network 7. Other servers 9 are connected to the data network as well. The PMMX is a workstation, a PC or a local router, configured as described in connection with Figure 3.

The PMMX does not have a fixed IP address, but obtains an IP address from the IP handler each time a connection is set up. The IP address is returned each time a connection is ended.

The PMMX contains a user interface for the handling of the three ISDN channels and for handling operation and maintenance functions in the network, and also contains functions for utilizing the IP interface included in the Personal Computer (PC), workstation or router used.

A user may log in to the PMMX with a user identity and a password, or in any other way known in the art, for example with voice recognition.

Figure 2 shows the connection from a subscribers PMMX 1 ' to a data network, which in this embodiment in the Internet 7' in more detail. As before, the PMMX is used to handle the two B channels and the D channel of an ISDN connection. The PMMX 1 ' is connected to an ISDN network 11, comprising at least one ISDN exchange.

The ISDN network 11 is in turn connected via a 2 Mbit/ s PRI (Primary Rate Interface) to an ISDN router 13 for connecting the two B channels to the Internet 7'.

The ISDN network 11 is also connected via a PHI (Packet Handler Interface) to a packet handler 15, which may be an ordinary packet handler used as a gateway to an X.25 network 17. The packet handler is connected via an interface II to a D channel router 19 for connection to the Internet 7'. The connection from the ISDN network 11 via the packet handler 15 and the D channel router 19 is used for the data transmission on the D channel. It will be obvious to the skilled person that the ISDN router and the D channel router may be implemented as one unit.

The ISDN router 13 and the D channel router 19 are connected via an Ethernet connection 21 to a router 23, which is connected to the data network 7', and connection means 25 for authentication of the user and activation of the IP address and other IP parameters. For an Internet connection, the means 25 will comprise a Dynamic Host Configuration Protocol (DHCP) server, a Remote Authentication Dial-in User Service (RADIUS) and a Domain Name Server (DNS) 25.

The ISDN router 13, the D channel router 19, the router 23 and the connection means 25 constitute the Internet packet handler IPH. For connection to another data network than the Internet, the router 23 and the connection means 25 would have to be adapted to this kind of data network.

In this way, the D channel may be used as a permanent connection to any data network, for example, the Internet. However, this channel is also needed to control the use of the two B channels. This is solved by utilizing the fact that the D channel is a packet switched channel, with a well defined protocol: the LAPD (Link Access Procedure for channel D). The ability to use the D channel for transfer of user data is defined in the ISDN standard X.31.

The header information in each packet transmitted on the D channel includes, in the Service Access Point Identifier (SAPI) field, information about the type of information included, according to the LAPD protocol. Control information for the B channels is denoted "0" in the SAPI field. Data communication, for example with the Internet, which should simply be transmitted through the ISDN exchanges, is denoted " 16" in the SAPI field.

In a preferred embodiment, the connection between the PMMX and the packet handler is set up by dialling the number of the packet handler. Then all packets « -. intended for the packet handler are marked with " 16" in the SAPI field, so that they will be transmitted through the telephone network 11 directly to the packet handler.

In another embodiment, certain major networks, such as the Internet, may be identified by individual digits in the LAPD protocol. For example, data packets intended for the Internet might be identified by the digit " 17", which is currently not used in the LAPD protocol. In this embodiment it would not be necessary establish a connection to a packet handler; all cells with the digit " 17" in the SAPI field would automatically be transmitted to the data network.

In this way, the channel may be used for data communication and then, when the need arises, for control information about the B channels, by including one or more data packets identified as intended for the switch, while still maintaining the data connection to the Internet, as shown in figure 1.

Figure 3 is a flow chart of the actions to be taken to install the PMMX software. Step 100: The ISDN terminal is installed and configured in the way common in the art.

Step 102: The additional software and hardware needed in the PMMX is installed.

Step 104: The PMMX monitor, which is the management application used to control the function of the ISDN is installed.

Figure 4 is a flow chart of the actions to be taken when a subscriber wants to set up a subscriber profile. This may be done in a graphical interface available on the

PMMX, or by entering commands.

Step 110: The subscriber enters the name of the person to be registered.

Step 112: The subscriber specifies how this person should be required to identify himself/herself. All calls from a specific A number may be accepted, or a

PIN code may be required. The PIN code will be entered using DTMF (Dual-Tone Multi-Frequency) signalling in a way common in the art. Different PIN codes may be used for different people, so that the subscriber may change the list without having to notify all the people on the list. Voice recognition may also be used to identify callers.

Step 114: The subscriber specifies how incoming telephone calls from this person should be handled. The options are, for example:

- Ignore: the incoming call is ignored - Accept without notification: the caller is allowed to leave a voice mail message. The subscriber is not notified.

- Accept with notification: the caller is allowed to leave a voice mail message. The PMMX calls the subscriber's telephone and repeats the voice message. - Forward call: the incoming call is accepted and forwarded to the subscriber's telephone.

The subscriber's telephone may be any type of telephone in any part of the telecommunications network.

Step 116: Should more callers be listed? If yes, go to step 110; if no, go to step 118.

Step 118: The subscriber registers how all incoming calls not specified above are to be handled. This may be any of the actions listed in step 114.

Step 120: The subscriber registers the e-mail addresses from which incoming mail should always be forwarded. If the e-mail is a voice mail, the voice mail itself may be forwarded to the subscriber's telephone, otherwise a notification will be sent to the subscriber's telephone or pager. Mail from any other address will be accepted, but the subscriber will not be notified. It is also possible to specify that e-mail from certain addresses should be rejected. Step 122: The subscriber specifies if e-mails of a specific priority class are to be handled in a certain way. For example, he may want to be notified about all e-mails marked as urgent.

Step 124: Should more e-mail addresses be listed? If yes, go to step 120; if no, go to step 126.

Step 126: The subscriber registers the fax numbers from which incoming faxes should always be forwarded. A notification will be sent to the subscriber's telephone or pager. Mail from any other address will be accepted, but the subscriber will not be notified. It is also possible to specify that faxes from certain numbers should be rejected. The incoming fax itself may be converted to an e-mail message or sent to a fax machine in the conventional way.

Step 128: If desired, the subscriber may specify a PIN code, so that a caller may send a fax from any fax machine, if the correct PIN code is entered. Different PIN codes may be used for different people, so that the subscriber may change the list without having to notify all the people on the list.

Step 130: Should more callers be listed? If yes, go to step 126; if no, go to step 132.

Step 132: The subscriber specifies the telephone number to which calls and notifications about e-mail or faxes should be forwarded. Different numbers may be specified for the different applications. For example, notifications about e-mail may be sent to a pager, whereas calls are forwarded to the subscriber's fixed or mobile telephone. A priority list may be set up so that, for example, the call will first be forwarded to the fixed telephone, and if it is not answered, it will be forwarded to the mobile telephone.

Forwarding the call in step 114 is preferably carried out in the following way: When an incoming call on one of the B channels is to be forwarded to the subscriber, a forward call connection is set up to the specified terminal on the other B channel. The two connections may then be interconnected so that a connection is established between the calling party and the subscriber.

The logic for establishing the forward call connection to the subscriber's terminal must be found in the PMMX. The logic for interconnecting the calls on the two B channels may also be found in the PMMX. Alternatively, the PMMX may instruct a telephone exchange, through the D channel, to interconnect the calls. This function is included in the LAPD protocol, described above.

Claims

1. A method of controlling the access to a subscriber in an ISDN network, said subscriber being connected to the ISDN network by means of a control device (1), characterized by the following steps:

- specifying at least one terminal in any part of the telecommunications network, to which incoming calls may be forwarded;

- when an incoming call from a calling party is received on one B channel of the ISDN connection: - establishing a connection on another B channel of the ISDN connection to the specified terminal.

2. A method according to claim 1, characterized by interconnecting the two B channels to establish one connection from the calling party to the specified terminal.

3. A method according to claim 1 or 2, characterized in that the two B channels are interconnected by the control device (1).

4. A method according to claim 1 or 2, characterized by ordering a telephone exchange in the telecommunications network to connect the two B channels.

5. A method according to any one of the preceding claims, characterized by specifying a telephone to which incoming speech calls should be forwarded.

6. A method according to any one of the preceding claims, characterized by specifying a fax machine to which incoming faxes should be forwarded.

7. A method according to any one of the preceding claims, characterized by specifying a computer address to which incoming e-mail and/or faxes should be forwarded.

8. A method according to any one of the preceding claims, characterized by specifying how an incoming call should be handled in dependence of the origin of the call.

9. An apparatus (1) for controlling the access to a subscriber in an ISDN network, characterized in that it comprises

- means for registering the identity of at least one terminal in a telecommunications network to which incoming calls may be forwarded; - means for establishing a connection on an idle B channel to the registered terminal.

10. An apparatus according to claim 9, further comprising means for interconnecting an incoming call on a first B channel and the established connection.

11. An apparatus according to claim 9 or 10, further comprising means for allowing a subscriber to specify how an incoming call is to be handles in dependence of the origin of the call.

12. An apparatus according to any one of the claims 9 - 11, further comprising means for establishing a connection to the registered terminal when an e-mail is received from one of a number of e-mail addresses specified by the subscriber.

13. An apparatus according to any one of the claims 9 - 12, further comprising means for converting incoming faxes to e-mails.

14. An apparatus according to any one of the claims 9-13, further comprising means for handling incoming calls in dependence of the origin of the call.