MXPA99003940A - A method of providing a delayed connection announcement to a mobile subscriber within a radio telecommunication system - Google Patents

Abstract

A method is disclosed for alerting a mobile subscriber within a radio telecommunication system to wait for the connection of an incoming call which may have a delayed connection time due to network congestion or the implementation of flexible alerting features utilizing alert-and-answer-before-routing techniques. In flexible alerting extension phone service, each one of a plurality of mobile stations is assigned to a single pilot directory number (PDN), and a home location register (HLR) (12) in an originating exchange maintains a list of parameters identifying each visited mobile switching center (V-MSC) (13-15) in which mobile stations identified with the PDN are believed to be currently located. The HLR (12) places a forward service indicator code in the routing request messages (22) that it sends to the V-MSCs (13-15). After all mobile stations identified with the PDN are paged, voice channels (26) are sized with those that responded. Alerting signals (29) are sent to responding mobile stations, and the V-MSCs transmit a delayed connection message (34) to the answering mobile stations. While the V-MSCs (13-15) return routing numbers to the HLR (12), the message (34) may be repeated periodically. If more than one routing number is returned to the HLR, the HLR selects a single mobile station to receive the call. The delayed connection announcement (34) is stopped when a voice trunk (41) is established between the originating MSC (11) and the V-MSC (15) serving the selected mobile station (28).

Description

"A METHOD OF PROVIDING A DELAYED CONNECTION ANNOUNCEMENT TO A MOBILE SUBSCRIBER, WITHIN A RADIO TELECOMMUNICATION SYSTEM " BACKGROUND OF THE INVENTION TECHNICAL FIELD OF THE INVENTION This invention relates to radio telecommunication systems and, more particularly, to a method of providing an advertisement to a called mobile subscriber, indicating that the connection in an incoming call can be delayed.

DESCRIPTION OF THE RELATED TECHNIQUE In radio communications networks, multiple telephone exchanges can operate together, each telephone exchange being defined as the service area ~ of a mobile switching center (MSC). A mobile subscriber can roam from telephone exchange to telephone exchange and at any given time, the telephone exchange on which the subscriber is operating is referred to as a service MSC. An incoming call to the mobile subscriber may originate in an MSC of source and routed to the service MSC for 'delivery to the mobile subscriber. When an incoming call is received for a mobile subscriber in a radio telecommunication system, a system operator can selectively retain a radio voice channel in the mobile station and alert the mobile subscriber before a voice trunk is established between the telephone exchanges of origin and service. Systems that use this feature of alerting and answering before routing can experience significant delays between the time the mobile subscriber is alerted and the call is delivered. In addition, the increased demands of the cellular system resources, as well as other commercial services, which use the implementation of alerting and answering before routing, can lead to unexpected delays in the delivery of the call. As a result, the called party can terminate the call prematurely by hanging up the phone before the call delivery is completed, thus creating a loss of revenue for system operators. Although a prior art solution to the aforementioned deficiency and limitations of alerting a called party before establishing a voice trunk is not known in the prior art teachings, the North American Patent Number 4, 72 * 3, 273 granted to Diesel and others (Diesel) discloses the subject matter that has some relationship with the matters disclosed herein. Diesel discloses a method of sending calls that allows the called party to selectively send the alerted calls in first establishing a voice channel or requiring the called party to answer the call. This discretional call sending feature uses an out-of-band signaling channel to receive and transmit the calling party's information. The Diesel review does not disclose any teaching or suggestion of a system or method, such as that disclosed herein, to notify a called party to wait for the delayed connection of an alert alert of the answered call. It would be a distinct advantage to have a method in a radio telecommunication system to notify a called party to wait for the delayed reception of an incoming call after responding to a call alert and thus increase the percentage of the call. incoming calls completed.

COMPENDIUM OF THE INVENTION In one aspect, the present invention is a method for delivering an incoming call to a mobile station called in a radio telecommunication system having an originating mobile switching center (MSC), a local location register (HLR), and a visited mobile switching center (V-MSC) where the called mobile station is operating. The method begins by receiving the call from the incoming MSC and informing the V-MSC that the incoming call invokes a particularity of alert and response before routing. This is followed by transmitting an alert signal from the V-MSC to the mobile station called; transmitting, from the V-MSC to the called mobile station, a delayed condition message when the called mobile station answers the alert signal; and route the incoming call to the called mobile station. In another aspect, the present invention is a method within a radio telecommunication system of notifying a mobile subscriber that awaits the connection of an incoming call that may have a delayed connection time. The radio telecommunication system includes an originating telephone exchange having a local location register (HLR) and a mobile originating switching center (MSC), a plurality of "visited mobile-switching centers." V-MSC ) and a plurality of stations mobile Each of the plurality of mobile stations is assigned to a single pilot directory number (PDN), and the HLR maintains a list of parameters identifying each V-MSC where at least one mobile station identified with the PDN is created. _which is currently located. The method starts receiving a call addressed to the PDN in the HLR from the originating telephone exchange; transmitting, from the HLR, an individual routing request message having an advance service indicator code to each of the identified V-MSCs; and receiving, in each identified V-MSC, the routed request message having the advance service indicator code. This is followed by radiolocation from each identified V-MSC, each identified mobile station located therein; receiving, in at least one of the identified V-MSCs, a radiolocation response from at least one of the identified mobile stations located therein; and retaining a voice channel between each identified V-MSC that receives a radiolocation response and at least one mobile station in response located therein. The method continues to transmit an alert signal from each receiver identified V-MSC to the mobile radiolocation response stations located therein; determine which of the mobile answering stations answered the signal of alert; and transmitting, from each of the V-MSCs, identified receptors a delayed connection message to the first or more of the responding mobile stations located therein. Finally, the method determines by transmitting from each V-MSC having at least one mobile station answering, a routing number for the mobile stations answering the HLR, and selectively routing the incoming call to one of the mobile stations that answer .

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood and its numerous objects and advantages will become more apparent to those skilled in the art with reference to the following drawing, together with the accompanying specification, in which: Figure 1 is a message flow diagram illustrating the flow of messages involved to implement a flexible alert extension telephone system in a radio telecommunications network; and Figure 2 is a flowchart of the message illustrating the flow of messages used in the preferred embodiment of the present invention, when a delayed connection message is implemented to the called subscribers, using the flexible alert extension telephone system of Figure 1.

DETAILED DESCRIPTION OF THE MODALITIES The present invention is a method of providing an announcement to a called mobile subscriber, indicating that the connection of an incoming call can be delayed. The delays can be caused by network congestion or by features, such as search groups and flexible alert, which delay the establishment of a voice trunk between the originating and service telephone entries until the subscriber answers the incoming call. An example of a particularity of alerting and answering before routing is a flexible alert mobile extension telephone service. The extension telephone service is implemented having a single Pilot Directory Number (PDN) assigned to each of the plurality of mobile stations. A local location register (HLR) maintains a list of parameters to identify the plurality of mobile stations and their respective locations within the network. Each of the parameters within the list identifies one of the plurality of mobile stations of one of the plurality of MSC where it is believed that the identified mobile station is currently located. When a PDN call is received at a gate mobile switching center (G-MSC), the G-MSC of the originating telephone exchange sends a location request invocation message (LOCREQ) to the HLR. In response, the HLR transmits an individual routing request invocation message (ROUTREQ) to each one -of the plurality of MSCs identified as currently serving a mobile station associated with PDN. Each MSC that receives a ROUTREQ invocation message radiolocalises each of the plurality of associated mobile stations that shuffle within its service area. Upon receiving a radiolocation response from at least one of the plurality of radiolocated mobile stations, each radiolocation MSC retains a voice channel with the mobile station responding and sends an alert signal (call) to the responding mobile station indicating an incoming extension telephone call. If "the mobile station is active and the subscriber answers the alert signal, the subscriber is placed in silent retention while the MSC sends a message of the return result ROUTREQ to the HLR with the routing number of the mobile station responding. If a plurality of the mobile subscribers answered the call, then more than one routing number is returned to the HLR from one or more of the MSCs. The HLR follows the pre-established criteria to select a single mobile station to complete the call. The * "" HLR then instructs the MSCs to release the retained voice channels with the other unselected mobile stations, and the call is then routed to the selected subscriber. The EIT / TIA signal sending standards typically followed for incoming calls to a PDN are indicated in the IS-41 Intersystem Signal Standard, as well as air interface standards such as IS-54, and IS -136, which are incorporated herein by reference. A problem with the systems that use this and the other features of alerting and answering before the routing, is that the voice connection with the calling party is delayed, and the called party can terminate the call prematurely by hanging the telephone before the delivery of the call is completed. The flexible warning characteristic of the extension telephone service described above involves simultaneously radiolocalizing and alerting the different cellular subscribers located in the multiple-service telephone exchanges before connecting a voice trunk between the originating MSC and the service MSC. Once a called subscriber answers, the network stops alerting the other remaining subscribers and establishes a _voz trunk between the originating HSC and the selected service MSC. While the trunk is being established, however, the called party does not hear the calling party and may hang the telephone prematurely during the delayed reception of the incoming call. Referring first to Figure 1, a message flow diagram illustrating the flow of the messages involved to implement a flexible alert extension telephone system in a radio telecommunications network is illustrated. Illustrated are a G-MSC 11, a HLR 12, and a plurality of V-MSC 13-17. Upon receipt of a call to be terminated in a group of mobile stations associated with a PDN, the G-MSC 11 of the calling station sends a request-location message to the HLR 12. The HLR 12, a in turn, it transmits the routing request messages 22- to all V-MSC 13-15, where the mobile stations can be located. The V-MSCs send radiolocation signals to the mobile stations in their respective service areas at 23, and can receive the paging responses 23a. If an associated mobile station, for example MSa 24 in V-MSCa (13) is busy, then the V-MSCa notifies HLR 12 of the "occupied" condition in 25.

The process of calling for MSa is then terminated. Also, if there is no radiolocation response from MSa, then V-MSCa notifies HLR 12 of the "no response" condition, and the call process for MSa is again terminated. All V-MSCs can be terminated from the call process if all associated mobile stations in a V-MSC are busy, or if none of the unoccupied mobile stations respond to a radiolocation from the V-MSC. If the remaining mobile stations respond to the radiolocations then their respective V-MSCs, for example V-MSCb and V-MSCn connect the radio voice channels 26 with MSb 27 and MSn 28. V-MSCb and V-MSCn then send an alert message (ie, a ring tone) to the mobile stations at 29. For the user's convenience, a different ring tone may be employed to imply that the call being placed is a PDN call at instead of a normal call. If the subscribers of the mobile stations terminating in V-MSCb and V-MSCn answer the telephone in response to the ring tone at 31, the V-MSCb and V-MSCn first place the subscriber in a hold condition at 32, and then they return the subscriber's vagabond number to HLR 12. On the other hand, if- terminating subscriber does not answer the call, the mobile station is removed from the calling process by the HLR after a predetermined period. During the receipt of the roaming routing numbers the HLR 12 selects a routing number in 34 based on a selection criteria such as (i) the first to answer; (ii) the nearest location; (iii) a predefined priority algorithm. Once the tramp routing number is selected, the HLR12 returns the selected tramp routing number (for example MSn) at 35, to the G-MSC 11 of the calling station, and sends a message 36 of Release Resources to the V-MSC not selected. The voice channels to the unselected mobile stations (for example MSb) are released at 37. At 38, the G-MSC routes the call to the V-MSC of the selected routing number, for example "V-MSCn, which at its Once again, the conversation call is re-established. Referring now to Figure 2, a message flow diagram illustrating the message flow used in the preferred embodiment of the present invention is illustrated when implementing a delayed connection message to subscribers called using the flexible alert extension telephone system in Figure 1. It should be understood that even when the preferred embodiment of the present invention is shown as being associated with a flexible alert extension telephone system, the invention is equally applicable to any type of call, which can to experience a delay between the alerting of the called subscriber and the connection of the_ call. A G-MSC 11, a HLR 12 and a plurality of V-MSC 13 to 17 have been illustrated. During the receipt of a call that invokes a particularity of alerting and answering before the routing (for example, a call to be terminated in a group of mobile stations associated with a PDN), the G-MSC 11 originating from the calling station sends ~ a location request message 21 to the HLR 12. In the preferred embodiment, the HLR then determines that the The call invokes a particularity of alerting and answering before routing and includes a code indicating ! advancement service in the request messages 22 | routed by identifying the call as one that "requires an announcement to the mobile station called that it can I 20 delay the connection of the call. In an alternative mode, the G-MSC can I optionally include the service indicator code of i i advance in the location request message 21, I thereby identifying the call as one that requires an announcement to the mobile station called that the connection of the call can be delayed. Therefore, if the location request messages are to be sent to no more than one HLR, each HLR is informed that the call requires an announcement to the mobile station called that the call connection may be delayed. In a second alternative mode, each V-MSC 13-15 is programmed to recognize that each long-distance call invokes a particularity of alerting and answering before routing, since most long-distance calls require more time to be established than local calls When the V-MSC receives a request message 22 to route from the HLR 12, the incoming call is identified as a long-distance call. Therefore, the V-MSC sends an announcement to the mobile station called that the connection of the call can be delayed. Upon receipt of the request messages 22 to route in V-MSCa-n 13-15, the V-MSCs send paging signals to the mobile stations in their respective service areas at 23 and can receive the paging responses 23a. For mobile stations responding to radiolocations, their respective V-MSCs, for example, V-MSCb and V-MSCn, connect the radio voice channels 26 in the mobile stations. The V-MSCs then send a warning message (ie, the i ring tone) to the mobile stations in 29. For the convenience of the user, a dial tone can be used. ! different call to give to understand that the call that is Is placing is a PDN call instead of a call ! 5 normal. | If the subscribers of the mobile stations of | termination on V-MSCb and V-MSCn answer the phone on I answer the ringtone at 31, the V-MSCb and V-MSCn will I program to start an announcement 34 through the voice channels 26 retained towards mobile stations that answer. The announcement informs the subscribers that it can 'have a delay to complete the restoration of a ! call. This ad can be a one-ad It can be repeated periodically as needed. j 15 In the preferred mode, the ad is a voice announcement ! however, a signal sending message may also be used through the air interface. The V-MSCs then They return the vagabond routing number of the subscriber in 33 to HLR 12. Upon receipt of routing numbers I 20 homeless, the HLR 12 selects a number to route "in | 35 based on the selection criteria such as (i) ! first to answer; (ii) closer application; or (iii) I a predefined priority algorithm. ! Once a routing number j 25 hobo is selected, the HLR 12 returns the routing number selected vagabond (for example the MSn) at 36, to the G-MSC 11 of the calling station, and sends a message 37"from Release Resources to the unselected V-MSCs." The voice channels to the unselected mobile stations (for example MSb) are released in 39. Optionally, in 38, the V-MSCb can be programmed to send a second announcement to MSb announcing that MSb has not been selected announcing that MSb has not been selected and that the call is being routed to Another mobile station The voice channel to MSb is then released at 39. At 41, the G-MSC routes the call to the V-MSC of the selected roaming number for example V-MSCn The V-MSCn then stops the delay announcement call setup at 42, and set the call for conversation at 43. The method illustrated in Figure 2 can be used selectively by system operators in relation to the peculiarities of the cellular system such as search groups and flexible alert, in d where delays may occur between a response of the called party and the connection of a voice trunk between the calling and called parties. Each V-MSC is modified to send an announcement to the mobile stations associated with a PDN stating that the connection of the call may be delayed. In this way, the called subscribers are more likely to stay on the line until they are complete the delivery of the call. The delayed connection message may be sent at the same time as the V-MSC sends a routing number for the mobile stations answering the HLR. Optionally, the delayed connection message may be repeated periodically until the voice trunk is established between the originating MSC and the V-MSC. The V-MSC may be made to send the delayed connection message including a forwarding service indicator code _ in the request message to route from the HLR. The HLR adds the forward service indicator code when the incoming call is to a PDN. Alternatively, the operator may select to use the delayed connection message during times of high congestion when the call connection times exceed a predefined threshold. Therefore, it is believed that the operation and construction of the present invention will be apparent from the foregoing description. The method of the apparatus and system that are shown and described have been characterized as being preferred. However, it will be readily apparent that even though the preferred embodiment of the present invention is shown as being associated with a flexible alert extension telephone system, the invention is equally applicable to any type of call that may experience a delay between the alerting of the called subscriber and the connection of the call. Therefore, various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the following claims.

Claims (11)

CLAIMS:

1. A method for delivering an incoming call to a mobile station called in a radio telecommunication system having an originating mobile switching center (MSC), a local location register (HLR), and a visited mobile switching center ( V-MSC) wherein the called mobile station is working, the method comprises the steps of: receiving the incoming call on the originating MSC; inform the V-MSC that the incoming call invokes- a particularity of alerting and answering before the routing; transmitting an alert signal from the V-MSC to the called mobile station; transmitting, from the V-MSC to the called mobile station, a delayed connection message when the called mobile station answers the alert signal; and route the incoming call to the called mobile station.

2. The method of delivering an incoming call to a mobile station called in a radio telecommunication system of claim 1, wherein the step of informing the V-MSC of the incoming call I invokes a particularity of alerting and answering before Routed, it includes the steps of: transmitting, from the originating MSC to the HLR, a Location request message requesting a ; 5 location of the mobile station called; determine, within the HLR, if the call from 1 entry invokes a particularity of alerting and answering Before the routed; transmit, from the HLR to the V-MSC, a message of the request to route that has a code indicating the 'advance service when determining that the incoming call invokes a particularity of alerting and answering before routing; and I receive, in the V-MSC, the i 15 request message to be routed that has the advance service indicator code.

3. The method of supplying a call of! input to a mobile station called in a radio telecommunication system of claim 1, wherein 20 the step of informing the V-MSC that the incoming call I 1 invokes a particularity of alerting and answering before 1 routed, includes the steps of: i determining, within the originating MSC, whether the i called call invokes a particularity of alerting and I answer 25 before the routed; transmitting, from the originating MSC to the HLR, a location request message that includes an advance service indicator code; transmitting from the HLR to the V-MSC, a routing request message that includes the forwarding service indicator code when determining that the incoming call invokes a particularity of alerting and answering before routing; and receiving, in the V-MSC, the routing request message including the forward service indicator code.

4. The method of delivering an incoming call to a call service station in a radio telecommunication system of claim 1, wherein the step of informing the V-MSC that the incoming call invokes a particularity of alerting and answering before routing, it includes the steps of: programming the V-MSC so that it recognizes that each long-distance call invokes the particularity of alerting and answering before routing; and informing the V-MSC of the incoming call is a long distance call.

5. The method of delivering an incoming call to a mobile station called, in a radio telecommunication system of claim 1, which also understands, after the step of informing the V-MSC that! the incoming call invokes a particularity of alerting and answering before routing, the steps of: 1 radiolocalizing from the V-MSC, to the mobile station i 5 called; j receiving, in the V-MSC, a radiolocation response from the called mobile station; and 'retain a voice channel between the V-MSC of the I mobile station called. I 10

6. The method of delivering an incoming call i to a so-called mobile station, in a radio telecommunication system of the _ reivindicació _ 1, which 'further comprises, after the step of transmitting a delayed connection message, the step of transmitting, from the 15 V-MSC to the HLR, and a routing number for the called mobile station.

7. A method of delivering an incoming call to a called mobile station, in a system of | telecommunication radio that has a center of I 20 mobile originating switching (MSC), a location register! Local (HLR), and a visited mobile switching center ((V-MSC) wherein the called mobile station is I running, the method comprises the steps of: receiving the incoming call in the MSC Ce I 25 origin; transmitting from the originating MSC to the HLR, a location request message requesting a location from the called mobile station; determine, within the HLR, if the incoming call invokes a particularity of alerting and answering before routing; transmitting, from the HLR to the V-MSC, a routing request message having an advance service indicator code, upon determining that the incoming call invokes a particularity of alerting and answering before routing; receive, in the V-MSC, the routing request message that has the advance service indicator code; radiolocate from the V-MSC, the so-called mobile station; receiving in the V-MSC, a response from the radiolocation from the called mobile station; retaining a voice channel between the V-MSC and the called mobile station; transmit an alert signal from the V-MSC to the called mobile station; transmitting, from the V-MSC to the called mobile station, a delayed connection message when the called mobile station answers the alert signal; transmitting, from the V-MSC to the HLR, a routing number for the called mobile station; and 1 route the incoming call to the station 'mobile call. 5

8. A method of notifying a called mobile station of a delayed entry call within a , radio communication system having a home exchange that has a local location register (HLR) and a home mobile switching center j 10 (MSC), a plurality of mobile switching centers I visited (V-MSC) and a plurality of mobile stations, each of the plurality of mobile stations being assigned to a single pilot directory number (PDN), in j where the HLR maintains a list of parameters that I 15 identify each V-MSC where at least one station 1 mobile identified with PDN * is believed to be located in the ! The present method comprises the steps of: i receiving a call addressed to the PDN in the HLR of the originating telephone exchange; 20 transmit, from the HLR, a request message I to route individual that has a forward service indicator code towards each of the identified V-MSCs; receiving, in each V-MSC, the routing request message 1 having the forwarding service indicator code; radiolocate from each identified V-MSC, and 5 each identified mobile station located therein; i receive, in at least one of the identified V-MSCs, a radiolocation response from 1 at least one of the mobile stations identified i located therein; 10 retain a voice channel between each V-MSC I identified that it receives a radiolocation response I I and at least one responding mobile station located in I i the same; transmit a warning signal "from each V-MSC 15 identified the receiver to at least one mobile station | of response located in it; I j determine which of the mobile i response stations answered the alert signal; | transmit from each receiver identified V-MSC, 20 a delayed connection message to at least one mobile answering station located therein; j transmit from every V-MSC that has at least ! a mobile station answering, a number of routing i for at least one mobile station that answers towards the i 25 HLR; selectively route the incoming call to one of the mobile stations that answer.

9. The method of notifying a called mobile station of a delayed entry call within a 5 radio communication system of claim 8, , which also includes releasing the voice channels between each Identified V-MSC of the mobile stations that were not selected for routing the call. i

10. The method of notifying a mobile station The call of a delayed input call within a radio telecommunication system of claim 9 i further comprising, before releasing the voice channels between each identified V-MSC of the mobile stations that [were not selected for the routing of the call, the I 15 step of transmitting, from each receiver identified V-MSC, I a message to the mobile stations that i i was not selected for routing the call, manifesting the i message of the incoming call has been routed to another mobile station. I 20 11, The method of notifying a mobile station i | call of a delayed entry call within a | radio telecommunication system of the claim '8, where the step of transmitting, from each V-MSC I I identified receiver, a delayed connection message 25 towards at least one mobile station that answers that i includes repeatedly transmitting the delayed connection message while the incoming call is delayed. 12. The method of notifying a called mobile station of a delayed entry call within a 5 radio telecommunication system of the claim 11, wherein the step of repeatedly transmitting the delayed connection message while the incoming call is delayed, includes holding back the transmission of the delayed connection message when the incoming call is routed 10 to one of the mobile stations that answer. 13. The method of notifying a called mobile station of a delayed entry call within a radio telecommunication system of the claim 8, which further comprises the step of transmitting, from the MSC I! 15 of origin to the HLR of the originating telephone exchange, a | location request message that includes a code and advance service indicator. SUMMARY OF THE INVENTION A method is disclosed for alerting a mobile subscriber within a radio telecommunication system to wait for the connection of an incoming call which may have a delayed connection time due to network congestion or the implementation of the flexible warning features using alert and answer techniques before routing. In the flexible alert extension telephone service, each of the plurality of mobile stations is assigned to a single pilot directory number (PDN), and a local location register (HLR (12) in a home exchange maintains a list of parameters that identify each visited mobile switching center (V-MSC) (13-15) where the mobile stations identified with the PDN are believed to be currently located.The HLR (12) places a code indicator of Forwarding services in the routing request messages (22) sent to the V-MSCs (13-15) After all mobile stations identified with the PDN are radiolocated, the "voice" channels (26) are retained with those that responded The alert signals (29) send to the mobile stations that respond and the V-MSCs transmit a delayed connection message (34) to the mobile stations that answer. While the V-MSC (13-15) return the routing numbers to the HLR (12) the message (34) may be repeated periodically. If more than one number is returned to the HLR, the HLR selects a single mobile station to receive the ca

ll. The announcement of the delayed connection (34) is stopped when a voice trunk (41) is established between the originating MSC (11) and the V-MSC (15) serving the selected mobile station (28).