Extension of a local area phone system to a wide area network

• US 20040072593A1
• Filed: 12/09/2002
• Published: 04/15/2004
• Est. Priority Date: 10/10/2002
• Status: Active Grant

• Current Assignee: F Poszat Hu LLC (Intellectual Ventures LLC)
• Original Assignee: Lon Communication Mgmt LLC (Intellectual Ventures LLC)
• Inventors: Robbins, Barry R., Umpleby, Katherine White, Stensrud, William R.
• Granted Patent: US 7,826,868 B2
• Time in Patent Office: Days
• US Class Current: 455/560
• CPC Class Codes: H04M 1/2535 adapted for voice communication over an Internet Protocol [IP] network Voice over Internet Protocol (VoIP) network equipment and services H04M7/006; implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP] H04L69/16
• CPC Class Codes: H04M 1/724 User interfaces specially adapted for cordless or mobile telephones
• CPC Class Codes: H04M 2203/1091 Fixed mobile conversion
• CPC Class Codes: H04M 2207/20 hybrid systems
• CPC Class Codes: H04M 3/42314 in private branch exchanges
• CPC Class Codes: H04M 7/006 Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 7/12 for working between exchanges having different types of switching equipment, e.g. power-driven and step by step or decimal and non-decimal
• CPC Class Codes: H04M 7/1235 where one of the core networks is a wireless network
• CPC Class Codes: H04M 7/1255 where the switching fabric and the switching logic are decomposed such as in Media Gateway Control
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

A soft switch providing wireless PBX voice services to a local area network (WLAN) is used to extend PBX functionality to the cellular domain. A dual mode remote unit is capable of receiving signals both in the cellular system as well as the WLAN. The cellular system is comprised of a data-bearing path and a voice-bearing path. When the dual mode remote unit is within the WLAN, it communicates both voice over IP (VoIP) signaling as well as session initiation protocol (SIP) control signaling over the WLAN. When the remote unit is outside the WLAN, it communicates voice signaling over the voice-bearing path of the cellular network using a standard cellular voice channel. In parallel, it uses the data-bearing path of the cellular network to transmit SIP control signaling.

Claims

1. A soft switch for use in cooperation with a communication system, including a cellular network having a voice-bearing path and a data-bearing path and a wireless local area network, said soft switch comprising:

a first gateway configured to be coupled to said voice-bearing path of said cellular network; and

a gateway controller module in communication with said first gateway and configured to provide Private Branch Exchange (PBX) services to said wireless local area network and further configured to switch a voice call over said voice-bearing path of said cellular network using said first gateway, said gateway controller module including

a call control function module configured to be coupled to said wireless local area network and said data-bearing path of said cellular network to create messaging concerning said voice call for transmission over said data-bearing path of said cellular network.

2. The soft switch of claim 1:

wherein said call control function module is configured to receive a session initiation protocol (SIP) message over said data-bearing path indicating a called number; and

wherein said gateway controller module is configured to correlate said SIP message with said voice call and to connect said voice call to said called number.

3. The soft switch of claim 1 wherein said call control function module is configured to send a session initiation protocol (SIP) message indicating a calling party to a called remote unit over said data-bearing path and wherein said gateway controller module is further configured to correlate an incoming call from said called remote unit received over said voice-bearing path with an incoming call from said calling party to facilitate a connection therebetween.

4. The soft switch of claim 3 wherein said incoming call from said called remote unit specifies a surrogate number as a surrogate called party.

5. The soft switch of claim 1:

wherein said call control function module is configured to receive a session initiation protocol (SIP) message over said data-bearing path indicating a called number; and

wherein said first gateway is configured to suspend, in response to said SIP message, voice-bearing transmissions of said voice call while maintaining an allocated channel over said voice-bearing path.

6. The soft switch of claim 5 wherein, said first gateway is further configured to establish a call with said called number using said allocated channel.

7. The soft switch of claim 1 wherein said gateway controller further comprises a mobility manager module coupled to said call control function module and configured to store location information received in a session initiation protocol (SIP) message over said data bearing path.

8. The soft switch of claim 7 wherein said gateway controller module is further configured to switch said voice call over said voice-bearing path based upon said stored location information.

9. The soft switch of claim 1 wherein said data-bearing path is a General Packet Radio Service (GPRS) path.

10. The soft switch of claim 9 wherein said messaging concerning said voice call is session initiation protocol (SIP) messaging.

11. The soft switch of claim 1 wherein said data-bearing path is a Code Division Multiple Access (CDMA) path.

12. The soft switch of claim 11 wherein said messaging concerning said voice call is session initiation protocol (SIP) messaging.

13. An apparatus for call connection comprising:

means for sending a first SIP invite message to a remote unit over a data-bearing path of a cellular network indicating a call establishment attempt; and

means for sending a corresponding initiation message to said remote unit over a voice-bearing path of said cellular network.

14. The apparatus of claim 13 further comprising:

a media gateway coupled to a legacy mobile switching center over a standard Public Switched Telephone Network (PSTN) link; and

wherein said means for sending said corresponding initiation message comprises means for sending a call initiation message over an IP network to said media gateway.

15. A method of call connection for use in a communication system including a cellular network having both a data bearing path and a voice bearing path for communicating with remote units, the method comprising:

sending a first SIP invite message to a remote unit over said data-bearing path of said cellular network indicating a call attempt; and

sending a corresponding initiation message to said remote unit over said voice-bearing path of said cellular network.

16. The method of claim 15 further comprising:

receiving a call initiation request for said remote unit; and

determining whether said remote unit is present within an IP based wireless local area network.

17. The method of claim 15 wherein said sending said first SIP invite message is conditioned upon determining a location of said remote unit.

18. The method claim 15 of wherein sending said corresponding initiation message comprises sending an IP call initiation message over an IP network to a media gateway coupled to a legacy mobile switching center over a standard Public Switched Telephone Network (PSTN) link.

19. A telephone switch comprising:

means for receiving a Session Initiation Protocol (SIP) invite message over a data-bearing path of a cellular network, said SIP invite specifying a called party and a calling party;

means for receiving a Public Switched Telephone Network (PSTN) call initiation from said calling party over a voice-bearing path of said cellular network, said call initiation specifying a surrogate called party; and

means for switching a call leg corresponding to said calling party to a call leg corresponding to said called party to establish a voice call therebetween.

20. The telephone switch of claim 19 further comprising:

means for receiving a second SIP message over said data-bearing path of said cellular network from said calling party; and

means for acting upon said second SIP message to control said voice call.

21. A method of switching a telephone call comprising:

receiving a SIP invite message initially transmitted over a data-bearing path of a cellular network by a calling party, said SIP invite message specifying a called party and the calling party;

receiving a PSTN call initiation from said calling party over a voice-bearing path of said cellular network, said call initiation specifying a surrogate called party; and

switching a call leg corresponding to said calling party to a call leg corresponding to said called party to establish a voice call therebetween.

22. The method of claim 21 wherein said surrogate called party is a PBX telephone number associated with said calling party.

23. The method of claim 21 wherein said surrogate called party is a dummy telephone number.

24. The method of claim 21 further comprising:

receiving a second SIP message over said data-bearing path of said cellular network from said calling party; and

acting upon said second SIP message to control said voice call.

25. The method of claim 24 wherein said second SIP message specifies an attended transfer.

26. The method of claim 24 wherein said second SIP message specifies a transfer to voice mail.

27. The method of claim 24 wherein said second SIP message specifies establishment of a conference call.

28. A method of establishing a telephone connection comprising:

sending a PSTN call initiation message from a cellular subscriber device specifying a surrogate called number; and

sending an invite message from said cellular subscriber device over a data-bearing path of said cellular network specifying an actual called number.

29. The method of claim 28 wherein said invite message was a skinny station protocol.

30. The method of claim 28 wherein said invite message is a SIP message.

31. The method of claim 28 wherein said surrogate called number is assigned to a soft switch configured to provide PBX services to a wireless local area network.

32. The method of claim 28 further comprising conducting a voice call to said actual called number via a call path that includes a soft switch.

33. The method of claim 32 further comprising sending a second message to said soft switch to control said voice call.

34. An apparatus for establishing a telephone connection comprising:

means for sending a PSTN call initiation message specifying a surrogate called number; and

means for sending an invite message over a data-bearing path of a cellular network specifying an actual called party.

35. An apparatus for establishing a telephone connection comprising:

means for receiving a call initiation message designating a remote unit by an identifier;

means for sending a PSTN call initiation message to said remote unit designated by a cellular telephone number different from said identifier; and

means for sending an SIP invite message over a data-bearing path of a cellular network to said remote unit.

36. A method of establishing a telephone connection comprising:

receiving a call initiation message designating a remote unit by an identifier;

sending a call initiation message specifying said remote unit designated by a cellular telephone number different from said identifier;

sending an SIP invite message over a data-bearing path of a cellular network to said remote unit.

37. The method of claim 36 wherein said identifier is a PBX assigned telephone number.

38. The method of claim 36 wherein said identifier is a Uniform Resource Locator (URL).

39. The method claim 36 wherein said identifier is an IP address.

40. The method of claim 36 wherein said SIP invite message specifies a calling party which sent said call initiation message.

41. The method of claim 40 wherein said call initiation message is a PSTN message.

42. The method of claim 41 wherein said PSTN message is sent in an IP format.

43. The method of claim 41 wherein said PSTN message is sent in an IP format to a media gateway.

44. The method of claim 43 wherein said PSTN message specifies a dummy calling party for insertion by said media gateway into a standard caller ID format.

45. The method of claim 36 further comprising sending a second SIP invite message over said data-bearing path of said cellular network to a second remote unit.

46. The method of claim 45 further comprising receiving a third SIP message from said second remote unit, said third SIP message controlling communication with said remote unit.

47. The method of claim 46 wherein said third SIP message specifies a call acceptance by said remote unit.

48. A method of placing a call comprising:

sending a call initiation message specifying a telephone number associated with a soft switch as a called party;

wherein said call initiation message is sent over a voice-bearing path of a cellular network; and

sending an SIP invite message over a data-bearing path of said cellular network to said soft switch, said SIP invite message specifying an actual called party.

49. A device for placing a call comprising:

means for sending a call initiation message specifying a telephone number associated with a soft switch as a called party;

wherein said call initiation message is sent over a voice-bearing path of a cellular network; and

means for sending an SIP invite message over a data-bearing path of said cellular network to said soft switch, said SIP invitation message specifying an actual called party.

50. A communication system comprising a soft switch configured to communicate SIP signaling over a data-bearing path of a cellular system and configured to communicate PSTN signaling in IP format to a media gateway associated with said cellular system.

51. The communication system of claim 50 wherein said media gateway translates said PSTN signaling in IP format to standard PSTN signaling and outputs said standard PSTN signaling to a legacy mobile switching center.

52. A communication system comprising:

a telephone switch that communicates SIP signaling over a data-bearing path of a cellular system and having an output for communicating PSTN signaling in IP format over an IP network; and

a media gateway coupled to said IP network and configured to receive said PSTN signaling in IP format and translate said PSTN signaling in IP format into standard PSTN signaling.

53. An apparatus such as a remote unit or a telephone switch comprising:

means for receiving a SIP invite message over a data-bearing path of a cellular network, said SIP invite message specifying a called party and a calling party;

means for receiving a call initiation message over a voice-bearing path of said cellular network; and

means for correlating said SIP invite message with said call initiation message.

54. An apparatus such as a remote unit or a telephone switch comprising

means for receiving a SIP invite message over a data-bearing path of a cellular network, said SIP invite message specifying a called party and a calling party;

means for sending a call initiation message over a voice-bearing path of said cellular network in response thereto.

55. A method of call processing comprising:

receiving a SIP invite message over a data-bearing path of a cellular network, said SIP invite specifying a called party and a calling party;

receiving a call initiation message over a voice-bearing path of said cellular network; and

correlating said SIP invite message with said call initiation message.

56. The method of claim 55 further comprising displaying information regarding said calling party on a user interface.

57. The method of claim 55 further comprising:

in response to said SIP invite message, receiving a user acceptance; and

automatically sending a call accept message in response to said call initiation message.

58. The method of claim 55 wherein correlating comprises comparing caller ID information received over said voice-bearing path of said cellular network with said calling party.

59. The method of claim 55 wherein correlating comprises comparing caller ID information received over said voice-bearing path of said cellular network with one or more dummy numbers.

60. The method of claim 55 further comprising:

responding with a call accept message to establish a voice call; and

sending a session initiation protocol (SIP) message to control said voice call.

61. The method of claim 55 further comprising:

initiating a first call leg to said called party;

accepting said call initiation message and thereby establishing a second call leg; and

switch said first call leg to second call leg to establish a complete call from said calling party to said called party.

62. A method of call processing comprising:

receiving a SIP invite message over a data-bearing path of a cellular network, said SIP invite specifying a called party and a calling party;

sending a first responsive call initiation message over a voice-bearing path of said cellular network to said calling party; and

sending a second responsive call initiation message to said calling party.

63. A method of call processing comprising:

receiving a SIP invite message over a data-bearing path of a cellular network, said SIP invite specifying a calling party;

automatically sending a responsive call initiation message over a voice-bearing path of said cellular network;

commanding a user interface to provide an alert to a user; and

awaiting an indication of user acceptance.

64. A method of switching a telephone call comprising:

receiving a SIP invite message over a data-bearing path of a cellular network, said SIP invite specifying a called party and a calling party;

initiating a first leg of a voice call to said called party;

initiating a second leg of said voice call to said calling party; and

switching said first leg to said second leg to establish said voice call therebetween.

65. The method of claim 64 wherein initiating said second leg comprises initiating a call to said called party using a cellular telephone number assigned thereto.

66. An apparatus for switching a telephone call comprising:

means for receiving a SIP invite message over a data-bearing path of a cellular network, said SIP invite specifying a called party and a calling party;

means for initiating a first leg of a voice call to said called party;

means for initiating a second leg of said voice call to said calling party; and

means for switching said first leg to said second leg to establish said voice call.

67. A remote unit comprising:

a cellular front end configured to receive information over a data-bearing path and a voice-bearing path of a cellular network;

an SIP processor module coupled to said cellular front end and configured to process SIP messaging received over said data-bearing path; and

a controller for correlating said SIP messaging received over said data-bearing path with a voice call received over said voice-bearing path.

68. The remote unit of claim 67 wherein said SIP processor module is further configured to send a SIP registration message indicating a location of said remote unit.

69. The remote unit of claim 67 wherein said SIP processor module is further configured to send SIP signaling during a voice call placed over said voice-bearing path.

70. The remote unit of claim 67 further comprising a wireless local area network front end coupled to said SIP processor module and configured to receive SIP and VoIP signaling over a wireless local area network.

71. A method of registration comprising:

detecting a departure from the coverage area of a wireless local area network; and

sending a registration message over a data-bearing path of a cellular network in response to said departure.

72. The method of claim 71 wherein said registration message is a session initiation protocol message.

73. The method of claim 71 further comprising receiving said registration message at a soft switch and storing corresponding information for later use in call routing.

74. A soft switch comprising:

a PSTN port;

an internet protocol port;

a trunking gateway coupled to said internet port and said PSTN port and configured to translate between voice over IP packets and legacy voice format signaling; and

a signaling gateway coupled to said internet port and said PSTN port and configured to translate between PSTN control signaling in IP format and traditional PSTN control signaling.

75. The soft switch of claim 74 wherein said signaling gateway is further configured to transmit an artificial caller ID identifier on said PSTN port in response to instructions received over said internet protocol port.

76. A method of call initiation from a cellular subscriber device comprising:

receiving an indication of a user'"'"'s intention to place a call;

initiating a cellular call to a predetermined surrogate number; and

subsequently, receiving an indication of a phone number from said user.

77. The method of claim 76 wherein said step of receiving said indication of said user'"'"'s intention comprises receiving an indication of a first digit of said phone number.

78. The method of claim 76 further comprising transmitting said phone number over a data-bearing path of a cellular network.

79. A method of call initiation from a cellular subscriber device comprising the step of:

receiving an indication of a user'"'"'s intention to place a call;

sending an IP message over a data bearing path of a cellular network, said IP message signaling a receiving switch to initiate a call to said cellular subscriber device; and

subsequently, receiving an indication of a phone number.

80. The method of claim 79 wherein receiving said indication comprises receiving an indication of a first digit of said phone number.

81. The method of claim 79 further comprising transmitting said phone number over said data-bearing path of said cellular network.

82. A soft switch for use in cooperation with a communication system, including a wide area network having a wireless voice-bearing path and a wireless data-bearing path and a local network, said soft switch comprising:

a first gateway configured to be coupled to said wireless voice-bearing path of said wide area network; and

a gateway controller module in communication with said first gateway and configured to provide Private Branch Exchange (PBX) services to said local network and further configured to switch a voice call over said wireless voice-bearing path of said wide area network using said first gateway, said gateway controller module including

a call control function module configured to be coupled to said local network and said wireless data-bearing path of said wide area network to create messaging concerning said voice call for transmission over said wireless data-bearing path of said wide area network.

83. The soft switch of claim 82 wherein said wide area network is a cellular network.

84. The soft switch of claim 82 wherein said local network is a wireless local area network.

85. The soft switch of claim 84 wherein said wireless local area network is configured in accordance with a wireless protocol.

86. The soft switch of claim 85 wherein said wireless protocol is 802.11b.

87. The soft switch of claim 82, wherein said wide area network is configured to transmit control signals and voice information to a remote unit.

88. The soft switch of claim 82 wherein said call control function module is configured to receive a session initiation protocol (SIP) message over said wireless data-bearing path indicating a called number;

and

wherein said gateway controller module is configured to correlate said SIP message with said voice call and to connect said voice call to said called number.

89. The soft switch of claim 82 wherein said call control function module is configured to send a session initiation protocol (SIP) message indicating a calling party to a called remote unit over said wireless data-bearing path and wherein said gateway controller module is further configured to correlate an incoming call from said called remote unit received over said voice-bearing path with an incoming call from said calling party to facilitate a connection therebetween.

90. The soft switch of claim 89 wherein said incoming call from said called remote unit specifies a surrogate number as a surrogate called party.

91. The soft switch of claim 82 wherein said call control function module is configured to receive a session initiation protocol (SIP) message over said wireless data-bearing path indicating a called number;

and

wherein said first gateway is configured to suspend, in response to said SIP message, voice-bearing transmissions of said voice call while maintaining an allocated channel over said voice-bearing path.

92. The soft switch of claim 91 wherein said first gateway is further configured to establish a call with said called number using said allocated channel.

93. The soft switch of claim 82 wherein said gateway controller further comprises a mobility manager module coupled to said call control function module and configured to store location information received in a session initiation protocol (SIP) message over said wireless data bearing path.

94. The soft switch of claim 93 wherein said gateway controller module is further configured to switch said voice call over said wireless voice-bearing path based upon said stored location information.

95. The soft switch of claim 82 wherein said wireless data-bearing path is a General Packet Radio Service (GPRS) path.

96. The soft switch of claim 82 wherein said messaging concerning said voice call is session initiation protocol (SIP) messaging.

97. The soft switch of claim 82 wherein said wireless data-bearing path is a Code Division Multiple Access (CDMA) path.

98. The soft switch of claim 97 wherein said messaging concerning said voice call is session initiation protocol (SIP) messaging.

99. A media gateway controller configured to control transmission and reception of voice-bearing signals between a public switched telephone network (PSTN) and an internet protocol (IP) backbone, and configured to control transmission and reception of data signals between said PSTN and said IP backbone, said IP backbone and said PSTN further coupled to a cellular network, said voice-bearing signals and said data signals destined for communicating with one or more dual mode subscriber devices, said media gateway controller comprising:

a call control and signaling function module configured to create and process said data signals received from and transmitted to said cellular network via said IP backbone;

a connection session manager module configured to correlate voice-bearing signals received from and transmitted to said cellular network via said PSTN with voice-bearing signals received and transmitted over said IP backbone; and

an access session and mobility manager module configured to monitor locations of said one or more subscriber devices.

100. The media gateway controller of claim 99, further comprising an operation support system (OSS) agent module configured for an administrator to control and monitor said media gateway controller.

101. The media gateway controller of claim 100, further comprising a third party application gateway module configured for a third party to interface with said media gateway controller.

102. The media gateway controller of claim 99, wherein said voice-bearing signals are received from said PSTN over a voice over PCM connection.

103. The media gateway controller of claim 99, wherein said data signals are received from said PSTN over a common-channel signaling protocol.

104. The media gateway controller of claim 103, wherein said common-channel signaling protocol is ISDN User Part (ISUP).

105. The media gateway controller of claim 104, wherein said ISUP defines a protocol and procedure used to set-up, manage, and release circuits that carry voice-bearing signals and data signals to said PSTN.

106. The media gateway controller of claim 99, wherein said voice-bearing signals are received from and transmitted to said IP backbone using a VoIP protocol.

107. The media gateway controller of claim 106, wherein said VoIP protocol is RealTime Transport Protocol (RTP).

108. The media gateway controller of claim 99, wherein said data signals are received from said IP backbone using a session initiation protocol (SIP).

109. A method performed by a soft switch for connecting a call initiated by a dual mode subscriber device with a PSTN party, the method comprising:

receiving a session initiation protocol (SIP) invite message over a cellular data path designating said PSTN party;

processing said SIP invite message by said soft switch;

generating a SIP trying message;

sending said SIP trying message to said dual mode subscriber device;

receiving an initial address message (IAM) message designating a surrogate called party in response to a call initiation message from said dual mode subscriber device;

correlating said SIP invite message with said LAM message by reference to said surrogate called party;

sending an address complete message (ACM) to said PSTN party in response to receiving said IAM message;

creating a second IAM message;

sending said second IAM to the PSTN party;

receiving a second ACM message on behalf of the PSTN party;

receiving an answer message (ANM) on behalf of the PSTN party;

connecting a bi-directional audio path so that said PSTN party is connected to said dual mode subscriber device, wherein said dual mode subscriber device can use SIP signaling to activate a communication feature.