METHOD OF HANDLING TELEPHONE CALLS
TECHNICAL FIELD OF THE INVENTION
This invention relates to a method of handling telephone calls, and to a switch which carries out such a method, dealing with a situation in which a call is unanswered by the called party. Specifically, the invention relates to a method of alerting the called party to the fact that he has received a call which he has not answered. DESCRIPTION OF RELATED ART
A telephone call may be unanswered by the called party either because he is away from his phone, or unable or unwilling to answer telephone calls at the relevant time, or because his phone was busy with another call. Calls may also be unsuccessful because of network congestion or because the called party cannot be reached by the network.
Many systems are known for dealing with at least some of these situations in which a call does not reach a stage at which it is answered by the called party. For example, the call may be diverted to a different number, or the called party may be able to leave a message, either on an answering machine or a voice-mail system. Also, systems are known which use the fact that the calling party's number is transmitted with the call. Returning to his telephone after a period of absence, a subscriber can then check the number of the calling party on the last call made to him, and can use that information to determine whether there has been a call which he has been unable to answer. In addition, telephone equipment is known which stores and displays the numbers of the most recent calling parties.
However, these options have various limitations. For example, diversion of the call to another number relies on the availability of another person to answer the call, and the ability and willingness of that
person to take a message and transmit it correctly to the intended recipient. Solutions which require the calling party to leave a message are often disliked by callers, and are not especially convenient for called parties. Relying on the stored number of the last calling party means that only the last caller (out of perhaps many such callers) can be contacted. Finally, telephone apparatus which stores numbers of all incoming calls may be expensive, and only allows the called party to obtain the necessary information when he has direct access to the telephone apparatus.
JP-A-06-152843 discloses a system in which a calling subscriber encodes a fax, to be sent to a shared fax machine, with information relating to the individual addressee thereof . When the fax is received, the shared fax machine uses that encoded information to generate a voice signal for transmission as a call to the addressee's telephone, to inform him of the arrival of the fax. In the event that the addressee does not answer the telephone call, an electronic mail message is sent to the addressee.
However, this system requires that the calling subscriber should encode the fax with a special header containing the required information. In the case of a voice call, the calling subscriber needs to give additional information to a voice recognition service. SUMMARY OF THE INVENTION
The present invention seeks to overcome at least some of the limitations associated with the prior art. For example, an object of the invention is to allow a called party to obtain details of all calls which he has been unable to answer. Moreover, a further object of the invention is to provide information to the called party, without requiring the calling parties to leave messages or otherwise interact with the system in any way.
In particular, the system in accordance with the invention relies on a subscriber having an e-mail address. Then, when the subscriber receives a telephone call which he is unable to answer, the system notes the number of the calling party, and transmits to the called party an e-mail message which indicates that number .
This allows the subscriber to obtain details of every person who has attempted to call him, wherever he has access to e-mail.
Aspects of the invention relate to the method of handling calls, and to exchanges which incorporate this eature .
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic illustration of a communications network used in the method according to the invention.
Figure 2 is a schematic illustration of an alternative communications network for use in the method according to the invention.
Figure 3 is a flowchart illustrating the method of the invention. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Figure 1 illustrates the equipment required for putting the invention into effect. The telephone exchange building 2 contains a telephone switch 4, which has a connection 6 to its subscribers. The switch 4 also has a connection 8 to the public network 10, in this case a PSTN. The connection 8 uses an appropriate protocol, such as C7.
The exchange is described here as a public telephone exchange, although the same system can be used on a private exchange or PBX.
The switch 4 is also connected via an intra- exchange LAN 12, using the TCP/IP protocol, to a computer 14. Any computer, such as a PC or a
workstation, may be used, though a more robust hardware platform is preferred. The computer 14 includes an e- mail call record server 16, which is connected to a gateway 18. The gateway 18 is connected via a connection 20 using the TCP/IP protocol to a computer network 22, for example the internet or an intranet.
A conventional exchange includes a telephone switch, and an intra-exchange LAN. Thus, the LAN 12 shown in Figure 1 has functions other than those relating to the present invention. It is therefore necessary to take precautions to ensure the security of the LAN 12. It is envisaged that the gateway 18 should be a standard gateway package, including standard firewall software to ensure security of the LAN 12, while the gateway is connected to the computer network 22. However, to further enhance security, the gateway may be placed on a separate machine to ensure clear separation between the LAN 12 and the computer network 22. In the embodiment shown in Figure 1, each telephone exchange includes a respective connection to the internet. However, it is possible to reduce the need for additional equipment by providing a central connection point, for connection to the internet, processing data received from a large number of telephone switches .
Figure 2 shows the equipment required for putting the invention into effect in this way. In Figure 2, features which correspond to features of the equipment shown in Figure 1 are identified by the same reference numeral. In Figure 2, the telephone exchange 2 contains a telephone switch 4, having a connection 6 to its subscribers, and a connection 8 to the public telephone network 10. Moreover, a computer 14 includes an e-mail call record server 16 and a gateway 18, the gateway 18 having a connection 20 to a computer network
22. In the Figure 2 embodiment, however, the connection between the switch 4 and the computer 14 is by way of an interexchange network 24 using the TCP/IP protocol. The connection 24 could use a direct connection, or a semi-permanent connection via the telephone switch 4. The computer 14 is located at a central node 26, and may have connections to a large number of telephone exchanges .
Figure 3 is a flowchart illustrating the procedure carried out by the switch 4, including its associated memory devices and data processing unit (not shown) . For each subscriber connected to the switch 4, it is determined whether that subscriber has the e-mail call record service. That information is stored in a subscriber information database. When an incoming call is received at the switch 4, as in step 52, it is first determined, in step 54, whether the called subscriber has the e-mail call record service. If not, the process passes to step 56, and the call proceeds normally. If the called subscriber has the service, the process passes to step 58, in which the telephone number of the calling subscriber is fetched, in a conventional way, and is stored in a memory device. Then, in step 60, the call to the called subscriber is set up in the usual way, and, in step 62, the switch monitors whether the call is answered. If it is, the process passes to step 64, and the call proceeds normally. If the call is not answered, either because the call cannot be connected to the called subscriber's phone, or because the called subscriber's phone is busy, or because the called subscriber does not answer the phone, the process passes to step 66. In that event, an e-mail message is sent to the called subscriber. Specifically, a message will be sent from the switch 4 to the e-mail call record server 16 using the TCP/IP protocol, the message containing the
telephone number of the called subscriber and the telephone number of the calling subscriber. The message should preferably also include the current date and time. The e-mail call record server 16 is equipped to process messages received from a switch 4, and contains a database which is able to translate telephone numbers of called subscribers into their e-mail addresses. The e-mail call record server 16 then sends an e-mail message through the gateway 18 and connection 20 over the computer network 22 to the e-mail address which corresponds to the telephone number of the called subscriber. The e-mail message contains the telephone numbers of the calling subscriber and the called subscriber, and the date and time transmitted in the message from the switch 4.
This system has the advantage that the called subscriber has a way to keep track of all unanswered calls, without requiring the callers to take any particular action, such as leaving messages. Also, the system is particularly flexible in allowing the called subscriber to keep track of the calls. He is able to receive notification of all unanswered calls wherever he may be, without requiring contact with his telephone, by using existing internet or intranet e- mail redirection services. For example, a user who is out of the country, but has access to e-mail, can receive notifications of calls received on his home telephone number while he is away. As an alternative, the subscriber may have access to a service which allows him to enter a number of pre-defined e-mail addresses, and then to select one of those addresses using his telephone. Similarly, the user may be able to use his telephone to switch the service on or off. In addition, although the system is described herein with reference to calls arriving at the exchange
via the PSTN, one use of the system may be in a mobile network, for use by mobile subscribers, so that they receive notification of calls that fail, for example because their phone is switched off, or out of range, or otherwise unavailable.
In a particularly advantageous development of the invention, the user, on receiving the e-mail notification, may be able to place a return call. This could use the existing e-mail reply arrangements, with the e-mail call record server 16 further being programmed to process incoming reply e-mail messages, to initiate a telephone call between the calling subscriber and the called number.
There is thus disclosed a system which allows a subscriber to be informed of every unanswered call, without requiring callers to leave messages or otherwise interact with the system.