Method and apparatus for increasing the answering probability of calls to mobile radio terminals

• US 5,950,128 A
• Filed: 09/04/1996
• Issued: 09/07/1999
• Est. Priority Date: 04/17/1991
• Status: Expired due to Term

• Current Assignee: Optis Wireless Technology, LLC (Brevet Capital)
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Ghisler, Walter
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Nguyen, Lee
• Application Number:
  US08/708,113
• Time in Patent Office: 1,098 Days
• Field of Search: 455/426, 455/459, 455/432, 455/433, 455/461, 455/445, 455/38.4, 455/458, 455/556, 340/825.44
• US Class Current: 455/426.1
• CPC Class Codes: H04W 4/16 Communication-related supplementary services, e.g. call-transfer or call-hold
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: H04W 68/12 Inter-network notification
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A radio communication system is disclosed comprising a Public Land Mobile Network (PLMN) where mobile radio telephones communicate with at least one mobile services switching center via corresponding base stations and where a home location register is connected to the at least one mobile services switching center. A wide area paging system sends out paging signals from at least one paging system accessible to the at least one mobile services switching center. A plurality of mobile radio telephones register their whereabouts in the home location register each time they are switched on. A plurality of pagers are associated with but physically separate from the mobile telephones. The paging system is accessed by the mobile services switching center for performing a page to a called subscriber when the called subscriber'"'"'s mobile radio telephone is in an off state or cannot be reached for other reasons. An incoming call to the mobile telephone is parked until the mobile telephone is switched on and registered with the home location register and the mobile services switching center parking the incoming call is informed of the active state of the mobile telephone and is provided with a roaming number. The mobile services switching center then calls the activated mobile telephone using a page over the cellular network and the mobile telephone answers the incoming call. If the mobile telephone is not switched on and does not register within a specified time after parking the incoming call, a time out will occur and disconnect the parked incoming call.

Claims

1. A radio communication system, comprising:

a public land mobile network where mobile radio terminals communicate with at least one mobile services switching center via corresponding base stations and where a home location register is connected to said at least one mobile services switching center;

a wide area paging system for sending out paging signals wherein said paging system is accessible by said at least one mobile services switching center;

a plurality of mobile radio terminals which register their whereabouts in the home location register when they are switched on;

a plurality of pagers each associated with but separate from a particular one of said plurality of mobile radio terminals;

whereby said paging system performs a page to a called subscriber when the called subscriber cannot be reached via said public land mobile network and whereby an incoming call to said one of said plurality of mobile radio terminals is parked until the mobile radio terminal is manually switched on and registers with the home location register and the mobile services switching center parking the incoming call is informed of the activation of the mobile radio terminal and is provided with a roaming number; and

whereby said mobile services switching center then calls the activated mobile radio terminal using a page over said public land mobile network and the mobile radio terminal answers the incoming call.

2. The system according to claim 1, wherein at least one pager contains at least one display screen.

3. The system according to claim 2, wherein said page includes a telephone number of the calling party which is displayed on said at least one display screen.

4. The system according to claim 3, wherein said incoming call is parked for up to a first limited predetermined period of time T1.

5. The system according to claim 4, wherein a second period of time T2 is stored in said pager and counted down on a display screen on said pager, wherein T2 is less than or equal to T1.

6. The system according to claim 5, wherein the telephone number of the calling party is kept stored in said pager until reset by a cancellation message from the mobile services switching center via said wide area paging system to said pager when an associated incoming call has been answered by the called party.

7. The system according to claim 5, wherein said second period of time T2 is sent to said pager during said page.

8. The system according to claim 1, wherein said home location register comprises a category storage means for flagging the identity of mobile radio terminals which have associated pagers.

9. The system according to claim 2, wherein said pager comprises:

means for storing telephone numbers of calling parties; and

means for marking said stored telephone numbers to indicate which calls have been answered, wherein said pager receives a signal from said paging system indicating which stored telephone numbers should be marked.

10. A method for connecting a call from a first user with a first terminal to a second user with a second terminal said second terminal being of a cellular radio type in a communication system containing a cellular communication system and a paging system, wherein a pager is associated with but separate from said second terminal, comprising the steps of:

attempting a call from said first terminal to said second terminal;

routing the call to a mobile services switching center;

requesting a roaming number for said second terminal from a home location register;

indicating to said mobile services switching center that said second terminal cannot be reached and sending a special code which indicates that said second terminal has said pager associated with said second terminal and sending a first number to said mobile services switching center, said first number being the number of said pager;

sending a paging request to said paging system asking that said pager be paged using said first number;

sending said page to said pager;

when said second user receives said page, said second user manually activates said second terminal, wherein when said second terminal is activated, said second terminal registers with said home location register;

periodically requesting a roaming number of said second terminal from said home location register by said mobile services switching center;

sending said roaming number to said mobile services switching center in response to said periodic requests after said second terminal has registered with said home location register;

connecting said first and second terminals using said roaming number.

11. A method for connecting a call according to claim 10, further comprising the step of:

asking said first user to wait while said page is being performed.

12. A method for connecting a call according to claim 10, further comprising the step of:

starting a timeout timer when said mobile services switching center requests said page, wherein said mobile services switching center terminates said call if the second user does not respond to said page within a first specified period of time.

13. A method according to claim 10, wherein said pager comprises at least one display screen.

14. A method according to claim 13, wherein said page includes a telephone number of the calling party which is displayed on said at least one display screen.

15. A method according to claim 12, wherein a second specified period of time is counted down on a second display screen on said pager, the second specified period being shorter than the first specified period to allow time for paging.

16. A method according to claim 15, wherein said second specified period of time is stored in said pager and begins to count down when the page is received.

17. A method according to claim 10, wherein said second user enters a personal identification number when deactivating said second terminal rather than when activating said second terminal so as to speed up the registration process when switching on said second terminal.

18. A method according to claim 13, further comprising the steps of:

storing telephone numbers of calling parties in said pager;

marking stored telephone numbers of calls which have been answered, wherein said markings are displayed along with the telephone number on said at least one display screen.

19. A method for connecting a call from a first user with a first terminal to a second user with a second terminal said second terminal being of the cellular type in a communication system containing a cellular communication system and a paging system, wherein a pager is associated with but separate from said second terminal, comprising the steps of:

attempting a call from said first terminal to said second terminal;

routing the call to a mobile services switching center;

requesting a roaming number for said second terminal from a home location register;

indicating to said mobile services switching center that said second terminal cannot be reached and sending a special code which indicates that said second terminal has said pager associated with said second terminal and sending a first number to said mobile services switching center, said first number being the number of said pager;

sending a paging request to said paging system asking that said pager be paged using said first number;

sending said page to said pager;

when said second user receives said page, said second user manually activates said second terminal, wherein when said second terminal is activated, said second terminal registers with said home location register;

determining in said home location register whether a request has been stored within a first specified period of time for a roaming number of said second terminal;

sending said roaming number to said mobile services switching center if a request has been stored within said first specified period of time; and

connecting said first and second terminals using said roaming number.

20. A method for connecting a call according to claim 19, further comprising the step of:

asking said first user to wait while said page is being performed.

21. A method for connecting a call according to claim 19, further comprising the step of:

starting a timeout timer when said mobile services switching center requests said page, wherein said mobile services switching center terminates said call if the second user does not respond to said page within a second specified period of time.

22. A method for connecting a call according to claim 19, wherein said second user enters a personal identification number when deactivating said second terminal rather than when activating said second terminal so as to speed up the registration process when switching on said second terminal.

23. A method according to claim 19, wherein said pager comprises at least one display screen.

24. A method according to claim 23, wherein said page includes a telephone number of the calling party which is displayed on said at least one display screen.

25. A method according to claim 21, wherein a third specified period of time is counted down on a display screen on said pager, the third specified period being shorter than the second specified period to allow time for the paging.

26. A method according to claim 25, wherein said third specified period of time is stored in said pager and begins to count down when the page is received.

27. A method according to claim 26, wherein said third specified period of time is sent to said pager during the page.

28. A method for connecting a call from a first user with a first terminal to a second user with a second terminal said second terminal being of the cellular type in a communication system containing a cellular communication system and a paging system, wherein a pager is associated with but separate from said second terminal, comprising the steps of:

attempting a call from said first terminal to said second terminal;

routing the call to a mobile services switching center;

requesting a roaming number for said second terminal from a home location register;

receiving said roaming number at said mobile services switching center along with a special code which indicates that said second terminal has said pager associated with said second terminal and also receiving a number for said pager;

setting up said call with said second terminal using said roaming number;

sending a paging request to said paging system asking that said pager be paged using said number for said pager when said call is not answered within a first predetermined period of time T_a after the step of setting up said call;

sending said page to said pager;

completing connection of said call to said second terminal if said second user answers said second terminal within a second predetermined period of time T_b after the page has been requested; and

terminating said call if said second user does not answer said second terminal within said second predetermined period of time T_b.

29. A method for connecting a call according to claim 28, further comprising the step of:

asking said first user to wait while said page is being performed.

30. A method for connecting a call according to claim 28, wherein said second user enters a personal identification number when deactivating said second terminal rather than when activating said second terminal.

31. A method according to claim 28, wherein said pager comprises at least one display screen.

32. A method according to claim 31, wherein said page includes a telephone number of the first user which is displayed on said at least one display screen.

33. A method according to claim 28, wherein a third period of time T_c is counted down on a display screen on said pager, wherein T_c is less than or equal to T_b.

34. A method according to claim 28, wherein said third period of time T_c is stored in said pager and begins to count down when the page is received.

35. A method according to claim 28, wherein said third period of time T_c is sent to said pager during the page.

36. A mobile services switching center in a system comprising a cellular mobile radio system and a wide area paging system, said wide area paging system being used for alerting said called subscriber simultaneously with alerting via said cellular mobile radio system when said subscriber does not react within a first predetermined time period to alerting signals via said cellular mobile radio system in response to an originating call, said mobile services switching center comprising:

means for requesting and receiving a category of said called subscriber and a roaming number for setting up said connection to said called subscriber;

means for alerting said called subscriber via said cellular mobile radio system;

means for determining that said called subscriber has not responded within said first predetermined time period to paging signals via said cellular mobile radio system and that the subscriber is of a category K indicating that the subscriber may simultaneously be alerted via a separate pager associated with the subscriber'"'"'s cellular mobile radio terminal;

means for parking said originating call and asking the calling subscriber to wait while performing a wide area page to said separate pager;

means for waiting in the mobile services switching center up to a second predetermined time period to give the called subscriber an opportunity to answer via said cellular mobile radio system; and

means for setting up said connection via said cellular mobile radio system between the parked originating call and the called subscriber when the called subscriber answers to said wide area page by using said cellular mobile radio system.

37. A mobile services switching center in a system comprising a cellular mobile radio system and a wide area paging system, said wide area paging system used for alerting said called subscriber when said subscriber'"'"'s cellular mobile radio terminal is in an off state, said mobile services switching center comprising:

means for requesting and receiving a category, an on-off status and if the on-status applies a roaming number for a called subscriber;

means for parking an originating call and asking the calling subscriber to wait while performing a wide area page for said called subscriber via said wide area paging system;

means for waiting in the mobile services switching center up to a specified time period to give the called subscriber an opportunity to manually switch on the called subscriber'"'"'s cellular mobile radio terminal thereby registering and informing the said cellular mobile radio system of the subscriber'"'"'s location;

means for setting up in a known way a connection via said cellular mobile radio system between the parked originating call and the called subscriber after a variable time period;

wherein said variable time period depends on the time the called subscriber waits before manually switching on the subscriber'"'"'s cellular mobile radio terminal, thereby informing on the subscriber'"'"'s location and thereby enabling the mobile services switching center to receive a roaming number and to set up said call and whereby the mobile services switching center does not set up a call if the called subscriber chooses not to switch on said cellular mobile radio terminal during said specified time period.