MXPA98002578A - System and method for processing telephone calls interrumpi - Google Patents

Abstract

A method and an apparatus for processing interrupted calls. If, during a call established between two communication devices, a node of the telecommunication network determines that a communication link with one of the devices has been interrupted, the node determines the cause of the interruption of the communication link and sends a message from the condition to the uninterrupted communication device. If an attempt for a new connection is adequate, the node attempts a new connection with the interrupted device. If an attempt for a new connection is inappropriate, or if the attempt for a new connection is unsuccessful, the uninterrupted communication device connects to a voice mail node. If the attempt for a new connection is successful, the call between the two communication devices will be reset

Description

SYSTEM AND METHOD FOR PROCESSING INTERRUPTED TELEPHONE CALLS Field of the invention This invention relates generally to the processing of telephone call telecommunications and more particularly to the processing of interrupted calls.

BACKGROUND OF THE INVENTION Although current telecommunication systems are generally highly reliable, there are times when a telephone call established between two devices can be prematurely interrupted. In a wired telecommunication system, established calls are very infrequently interrupted.

REF: 27073 In a wireless telecommunication system, such as a cell phone system, established telephone calls are interrupted more frequently than in the cabling system. There are several reasons why a telephone call with a cordless telephone can be interrupted. One reason why calls • are interrupted is that the cordless phone has left the coverage area of the wireless system. As is well known, cellular telephone systems are divided into storage units, each of which is served by a base station that communicates with wireless telephones (for example, mobile telephones) located inside the storage unit. All storage units together form the coverage of the cellular system area. If a mobile phone travels outside the coverage area, the wireless communication channel between the mobile phone and the wireless system may be lost and the call may be interrupted. In some cases, the mobile phone can enter the coverage area of another cellular service provider. In this case, the call can continue only if the mobile phone has traveler privileges in this other cellular system.

Another reason why an established call can be interrupted in a cellular system is due to manual disconnection. As it is well known, when a mobile phone travels from one storage unit to another storage unit, the call is manually disconnected from a base station serving the storage unit one with the base station serving the other storage unit. In some cases the base station serving the other storage unit may not have any of the radio channels available for communication with the mobile telephone at the time of manual disconnection. In this case the call established with the mobile phone can be interrupted. Another reason for calls to be interrupted in a cellular system are coverage failures, which are areas in the geographical attention area that do not receive a signal from the system for any reason. Such coverage failures include both indoor and outdoor areas. If a mobile phone enters a coverage failure where coverage is not adequate, radio communication with the base service station may be lost and the call may be interrupted. Calls in a cellular system can also be interrupted due to RF interference and equipment failure.

Interrupted calls are very inconvenient for users. The restoration of the call is left to the parties of the call and neither party knows the intention of the other party. This can result in both parties trying to call the other party, causing the connection to hang. Alternatively, both parties can assume that the other party will initiate the call, resulting in a non-reestablishment of the call. The situation of the interrupted call gets worse when there is no indication to the other party of the reason for the interruption of the call.

Interrupted calls often result in one party not being able to communicate fully with the other.

Thus there is a need for an improved method and apparatus for processing interrupted calls in telecommunication networks.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides an improved system and method for processing interrupted calls' in a telecommunications network. According to the invention, if it is determined during an established call between at least two communication devices that a connection in one of the devices has been interrupted, the system should automatically attempt to reconnect the interrupted communication device if appropriate. If the attempt of the new connection is successful, the system can re-establish the call between at least two communication devices. In addition, the system can send a reset indication on one or the other, or both, communication devices to indicate that the call has been re-established.

If it is determined that an attempt to reconnect the interrupted communication device has not been adequate, or if the attempt to reconnect the interrupted communication device has been unsuccessful, then the other communication device, which is still connected to the system, may directing a voice mail so that the user of the communication device still connected can leave a message for the user of the communication device that was interrupted.

According to another aspect of the invention, in addition to attempting to automatically reconnect the interrupted communication device and restoring the call, a condition message is sent to the communication device still connected and indicates that the connection to the interrupted device has been interrupted. In addition, the cause of the interrupted connection can be determined and the message of the situation can include the reason why the connection was interrupted.

In an advantageous embodiment, the interrupted communication apparatus is a wireless telephone in communication with a wireless cellular network by means of a wireless communication link and the steps of the invention are performed by a wireless network node.

Thus, the present invention provides an improved system and method for processing interrupted telephone calls in which more information is provided to. the users of the system and which increases the possibility that the communication between the users can continue through either the re-establishment of the call or through the voice mail.

These and other advantages of the invention may be clearly ordinary in the experience of the art with reference to the following detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 shows a communication network within which the present invention can be implemented.

Fig. 2 is a flow chart showing the steps to be developed according to the invention.

Detailed description Fig. 1 shows a communication network 100 within which the present invention can be applied. The network 100 includes the Public Switched Telephone Network (PSTN) 120 which is a landline network, and a wireless cellular network 122. The PSTN 120 and the wireless cellular network 122 are connected by a communication connection 124.

The PSTN 120 comprises a central office switch (CO) 104 connected to an exchange current switch (IXC) 106. The PSTN 120 contains multiple CO and IXC, but only one CO and one IXC are shown in Fig. 1. for clarity. The architecture of the PSTN is well known in the art and is not described in more detail here.

The wireless cellular network 122 comprises a base station (BS) 114 connected to a mobile switching center (MSC) 110. The MSC 110 also connects to a voice mail node 108 and a home registrar database (HLR). 126. The MSC 110 connects the wireless cellular network 122 to the PSTN 120 via a communication connection 124. As is well known, wireless cellular networks, such as the network 122, generally contain a plurality of base stations, each of these communicates with the mobile stations within the geographical service area (storage unit) of the base station. The geographic area of all the storage units gathered together is the coverage area of the wireless cellular network. The storage unit within such mobile station operating is called the storage unit in service, and the base station within the storage unit in service is called the service base station. Each base station connects, and is controlled by, an MSC. The MSC connects to a service BS is the service MSC. Depending on the architecture, a wireless cellular communication network may have more than one MSC, with each MSC controlling a plurality of BS's. The MSC connects the wireless cellular communication network with other networks, such as the PSTN, other wireless networks, and other data networks (e.g., Internet).

For ease of illustration, Fig. 1 shows an MSC 110 connected to a BS 114. As shown in Fig. 1, a mobile telephone 116 communicates with a server BS 114 via a wireless communication channel 118. The protocol wireless communication channel 118 may be, for example, the air interface described TIA / EIA Interim Standards IS-136.1, 800 MHz TDMA Cellular Radio interconnect-station Compatibility mobile- base- station Digital Control channel, December 1994, Association of the Telecommunications Industry (hereinafter "IS-136"), which is incorporated herein by reference.

A conventional call between a landline telephone 120 and a mobile telephone 116 may be established as follows. For purposes of illustration it is assumed that the mobile telephone 116 registers in the wireless cellular network 122 such that the MSC 110 knows that BS is the serving BS. In this illustration, BS 114 is assumed to be the service BS. A calling party dials the telephone number associated with the mobile telephone 116 in the telephone 102. The CO 104 receives the dialed digits and the routes of the calls to IXC 106. The IXC 106 directs the call to MSC 110. The MSC 110 directs the call to BS 114 with instructions for the BS 114 to establish a wireless communication channel 118 with the mobile telephone 116. In this manner a call is established between the landline telephone 102 and the mobile telephone llß. The MSC 110 stores in its memory 130 the telephone number of both the mobile telephone 116 and, if available, the landline telephone 102 in conjunction with the call. The telephone number of the landline phone 102 can be received by the MSC 110 as an automatic number identification (ANI). The information from IXC 106 is a well-known way. The route of the telephone calls described above through the communication networks are well known in the art.

As described above in the background section, once a call has been established with a mobile phone, there are several possible reasons why the wireless communication channel 118 may be lost. Some reasons are listed below in the table 1: Table 1 The mobile phone travels outside the coverage area The manual disconnection of the storage unit with insufficient channel is communication failures in the coverage Errors in MSC interference from other RF sources It is assumed for purposes of illustration that the communication channel 118 between the mobile telephone 116 and the BS 114 was interrupted for some reason. The steps developed in accordance with the present invention are shown in Fig. 2. As is well known, the MSC 110 is an intelligent switching apparatus and contains a processor 128 connected to the memory 130. The memory 130 contains instructions of a program which are executed by the processor 128 which controls the operation of the MSC 110. The memory 130 may have a RAM, ROM, magnetic disk, optical disk, or other type of computer storage medium. In addition, the memory 130 may have some combination of such computational storage means. The MSC 110 may also contain components to perform other functions of the MSC (for example address) but these other components are not described here and may be well known to one skilled in the art. Although the functions of MSC 110 have been described here as being controlled by the processor 128 execute instructions of the stored computer program, it is understood that such functions can also be performed by a set of devices or in combination of a programming elements and a set of devices.

Referring now to Fig. 2, in step 202 the MSC 110 detects an interrupted call. The MSC 110 is able to detect when a communication channel between a BS and a mobile telephone has been interrupted by, for example, by recognizing a loss of the information signaled on the digital traffic of the channel in a way that is well known in the art. In steps 204 the MSC 110 determines the cause of the interruption. A method to determine the cause of the interrupted call is to analyze the list of the mobile assisted disconnection (MAHO) sent to the MSC 110 from the mobile telephone 116. According to IS-136 each of the mobile telephones measure the intensities of the signals that are received from the base stations in nearby storage units, and periodically transmits this list of signal intensities (the MAHO list) to the MSC 110 using the list to determine how often the disconnection is manual for this telephone mobile. This is possible, when analyzing the MAHO list sent by a mobile phone, to determine that the mobile phone has moved away from the coverage area of the wireless cellular network. The MSC 110 can also determine the cause of the interruption when developing a statistical and RF analysis of the system. For example, exceeding the time of calls at a particular geographical location may be subject to interruption. Through a statistical analysis the MSC 110 may be able to determine that a call has been interrupted while the mobile telephone 116 is within this geographical area has been interrupted due to a failure in the coverage. Similarly, if the call was interrupted in an area that has otherwise been statistically low in interrupted calls, the MSC 110 may determine that the call was interrupted due to intermittent RF interference from other RF sources.

In step 206, the MSC 110 sends a condition message to the telephone 102. It is noted that although the wireless communication channel 118 between the BS 114 and the mobile telephone 116 has been interrupted, there is still a connection between the telephone 102 and the MSC 110 by means of the CO 104, the IXC 106, and a communication link 124. The MSC 110 cares for this established connection although the interrupted communication channel 118 has been detected. Thus, in step 206, the MSC 110 generates a voice message using an interactive voice response (IVR) processor 112. IVR processors are well known and are not described in detail here. It is noted that in Fig. 1 the IVR processor 112 is shown as part of MSC 110. In alternative modes the IVR processor 112 may have a separate node in the network which is in communication with the MSC 110.

It is assumed for purposes of illustration that the reason why the communication channel was interrupted was that the mobile telephone 116 entered a storage unit where the BS in service did not have a radio communication channel available and therefore the disconnection manual was unsuccessful. In step 206 a voice message such as: "The mobile client with whom you were connected has traveled to a place where radio communication is temporarily not possible", is sent to telephone 102 from the IVR 112 processor in the MSC 110.

In step 208 the MSC 110 determines whether an attempt to reconnect is appropriate. Depending on the reason why the communication link was interrupted, an attempt to reestablish a wireless communication channel with the mobile telephone 116 may or may not be adequate. Table 2 below indicates in what circumstances an attempt for a new connection is appropriate.

Table 2 In the case where the mobile telephone 116 travels outside the coverage area of the wireless network 122, there is a low probability that the mobile telephone 116 enters the coverage area again within a multiple frame of short time, therefore the system does not try to reestablish communication in this case. In the case where the mobile telephone 116 has entered a storage unit that has insufficient radio channels for a successful manual disconnection, it is appropriate to attempt a brief connection again after the call has been interrupted. In such a case, it is possible that the radio channel becomes briefly available after the call was interrupted because some other mobile phone operates at the end of the storage unit a call and thus vacates a radio channel for the mobile phone 116. In the case where the mobile telephone 116 has entered a coverage failure, it is appropriate to initiate a brief connection again after the call has been interrupted. In this case, it is possible that as the mobile telephone 116 moves, it leaves a coverage failure briefly after entering it. In the case of an MSC error, it is appropriate to initiate a short connection again after the call has been interrupted. For example, one type of MSC error is when the communication link between the service base station and the previous mobile telephone is cut off to establish a new communication link between the mobile telephone and a new base station during manual disconnection. In this situation, it is appropriate to try a brief connection again after the call has been interrupted. In the case of interference from another RF source, it is appropriate to attempt a short connection again after the call was interrupted because it is possible that the source of the RF interference has been removed.

If it is determined in step 208 that a connection again with the mobile telephone 116 is not adequate, then in step 218 the MSC 110 directs the call of the telephone 102 to the voice mail node 108. In addition, the MSC 110 by means of of the IVR 112 processor may send a message to the user on the telephone 102 indicating that the connection should not be attempted again and that the call has been transferred to the voice mail. When connected to the voice mail node 108, the user of the telephone 102 can then leave a message for the user of the mobile telephone 116. The method reaches the end in step 220. In an alternative mode, instead of automatically directing the call of the telephone 102 to the mail node of the voice 108, the telephone 102 user can be presented with the opinion of whether he / she wants to be connected to the voice mail node 108 ..

If it is determined in step 208 that the connection back to the mobile telephone 116 is adequate, then in step 210 the MSC 110 attempts to reestablish a wireless communication channel with the mobile telephone 116. This step may be accompanied by a message from the MSC. 110, by means of the IVR 112 processor, with the landline telephone 102 indicating that an attempt to reconnect is in progress. The attempt of a new connection with the mobile telephone 116 may include steps similar to these when a new call is received on the mobile telephone 116 in the MSC 110. As described above in conjunction with the description of the route of the original call, the MSC 110 stores in its memory 130, the telephone number of both the mobile telephone 116 and, if available, the landline telephone 102. Thus, the attempt to reconnect can include the MSC 110, by means of the BS 114 (or some other BS connected to the MSC 110 if appropriate), which combines the mobile telephone 116 to indicate that a call exists for the mobile telephone 116. It is well known that the collating of a mobile telephone indicates that there is a call waiting for the phone and it is not described in detail here. In an alternative mode, instead of automatically attempting to reestablish a wireless communication channel with the mobile telephone 116, the landline phone user 102 can be presented with the opinion that he / she wants to connect again with the mobile telephone 116, If the landline telephone user 102 chooses not to reconnect with the mobile telephone 116, the call may be directed to a voice mail node 108 as described above in conjunction with step 218.

In step 212 it is determined whether the attempt for a new connection was successful. This determination can be made, for example, by trying to connect again for a period of time, and if the new connection was not made within this period of time, the attempt to connect again is considered unsuccessful. Alternatively, this determination can be made by trying to connect again for certain numbers of attempts, and if the new connection is not made within a number of attempts, the attempt to connect again is considered unsuccessful.

If it is determined in step 212 that the attempt to connect again was not successful, then the control is passed to step 218 in which the telephone 102 connects to the voice mail node 108 as described above. If it is determined in step 212 that the attempt to connect again was successful, then in step 214 the MSC 110 restores the telephone call between the telephone 102 and the mobile telephone llß. This can be done, for example, by making a connection derived from the connection between the telephone 102 and the MSC 110, such connection was created by the MSC 110, with the connection established again with the mobile telephone 116. In addition, immediately prior to the The connection derived from the calls, the MSC 110, by means of the IVR 112 processor or other means, can send an indication of a new connection to the telephone 102 indicating that the attempt to connect again was successful. Such indication of a new connection may be, for example, a message in the voicemail, a distinctive sound, an alphanumeric message in conjunction with a visual screen (eg, called ID) or a DTMF tone is sent to the telephone 102. Also immediately prior to the derivative connection of the calls, the MSC 110, by means of the IVR 112 processor or other means, can send an indication of a new connection with the mobile telephone 116 indicating that the current call has previously restored the call. interrupted The method ends in step 220.

In an alternative embodiment as shown in Fig. 2, step 206 may be incorporated into step 210 and step 218 such that the condition message is sent to the uninterrupted device after the MSC 110 has determined an attempt to do so. a new connection is adequate in step 208.

The preceding Detailed Description is understood to be in each exemplary and exemplary, but not restrictive, aspect of the invention disclosed herein, not determined by the Detailed Description, but by the claims as interpreted according to the full extent allowed. by the laws of patents. It is understood that the embodiments shown and described herein are only illustrative of the principles of the present invention and that various modifications may be applied by one skilled in the art without departing from the perspective and concept of the invention. For example, the modality described in the Detailed Description shows the MSC 110 which develops the steps of the invention when a communication link with the mobile telephone 116 was interrupted. In a similar manner, the MSC 110 can be configured to develop the steps of the invention when a communication link with a landline phone is interrupted. In addition, the CO 104 or IXC 106 can be configured to develop the steps of the invention when a link to the landline telephone 102 or the mobile telephone 116 is interrupted. Thus, the present invention is not limited to any particular type of communication device or network node, but the principles of the invention can be applied to any combination of communication devices and equipment of the network. Such modalities may be implemented by some person skilled in the art giving the disclosure here.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Having described the invention as above, the content of the following is claimed as property.

Claims (24)

1. A method for processing a telephone call between at least two communication devices, characterized in that it comprises the steps: determining, during a call established between said communication devices, that a connection with one of said communication devices has been interrupted; connect again with said communication device; and restore said telephone call.

2. The method of claim 1, characterized in that it further comprises the step of: sending an indication of a new connection with the other communication device on a successful new connection with said communication device one.

3. The method of claim 1, further comprising the step of: sending the condition of the message to the other communication apparatus indicating that the connection to the communication apparatus one has been interrupted.

4. The method of claim 1, characterized in that said condition of the message further indicates the reason why said connection with the communication apparatus one has been interrupted.

5. The method of claim 1, characterized in that it further comprises the step of: determining the telephone number of said communication device one of a switch of the network.

6. The method of claim 1, characterized in that said communication device one is a wireless telephone.

7. The method of claim 1, characterized in that said communication device one is a landline telephone.

8. A method for processing a telephone call between at least two communication devices, wherein at least one of said communication devices is a wireless communication device operating in conjunction with a wireless communication network having a coverage area, said The method is characterized in that it comprises the steps of: determining, during a call established between said communication apparatuses, that a connection with said wireless communication apparatus has been interrupted; and try a new connection with said communication device.

9. The method of claim 8, characterized in that it further comprises the step of: determining that said connection with said wireless communication apparatus has been interrupted because no radio channel is available; and periodically attempting to connect again with said wireless communication device.

10. The method of claim 9, further comprising the step of: connecting the other communication apparatus to the voice mail if said periodic attempts for a new connection fail within a period of time.

11. The method of claim 9, further comprising the step of: connecting the other communication device to the voice mail if said periodic attempts for a new connection fail in several attempts.

12. The method of claim 8, characterized in that it further comprises the step of: determining the telephone number of said wireless communication device of a network switch. ?

13. A system for processing a telephone call between at least two communication devices, characterized in that it comprises: means for determining, during a call established between said communication devices, whether this connection with one of said communication devices has been interrupted; the means for reconnecting with said communication apparatus one; and the means to restore said telephone call.

14. The system of claim 13 further comprises: means for sending an indication of a new connection to the other communication device on a successful new connection with said communication device one.

15. The system of claim 13 further comprises: means for sending a condition message to another communication device indicating that the connection to the communication apparatus one has been interrupted.

16. The system of claim 15, characterized in that said condition message indicates the reason why said connection with the communication apparatus one has been interrupted.

17. The system of claim 13, characterized in that it further comprises the step of: the means for determining the telephone number of the communication device one of a network switch.

18. The system of claim 13, characterized in that said communication device one is a wireless telephone.

19. The system of claim 13, characterized in that said communication device one is a landline telephone.

20. A system for processing a telephone call between at least two communication devices, characterized in that at least one of said communication devices is a wireless communication device operating in conjunction with a wireless communication network having a coverage area, said system comprises: means for determining, during a call established between said communication apparatuses, that a connection with said wireless communication apparatus has been interrupted; And the means to try a new connection with said wireless communication device.

21. The system of claim 20, characterized in that it further comprises: means for determining that said connection with said wireless communication devices has been interrupted because no radio channel is available; and the means for periodically attempting to connect again with said wireless communication device.

22. The system of claim 21, characterized in that it further comprises: means for connecting the other communication device to the voice mail if said periodic attempts for a new connection fail within a period of time.

23. The system of claim 21, characterized in that it further comprises: means for connecting the other communication device to the voice mail if said periodic attempts for a new connection fail in several attempts.

24. The method of claim 20, characterized in that it further comprises: means for determining the telephone number of said wireless communication device of a network switch.