MXPA06006178A - Session initiation protocol (sip) based user initiated handoff - Google Patents

Abstract

Method and apparatus for providing a solution to the handoff problem includes negotiation of new media codes (coders/decoders) for utilization in cases where the two devices involved in the handoff are incompatible. Although mobile IP (MIP) is presently utilized to perform handoff procedures, this technique lacks a trigger mechanism to initiate handoff between two different devices which communicate with two different networks or one common network. In addition, MIP does not address the issue of compatibilities between media types, codes and supported bit rate. The handoff utilizes a session protocol (SIP) message for handoff.

Description

SESSION INITIATION PROTOCOL (SIP) BASED ON SWITCH INITIATED BY THE USER FIELD OF THE INVENTION The present invention relates to performing a switching or handoff between two devices that use different technologies and that are connected to an Internet Protocol (IP) network, by means of two different systems. More particularly, the present invention relates to a method and apparatus for carrying out a switch, using SIP protocol conducted during real-time sessions between said different devices, and either said different networks or a common network.

BACKGROUND OF THE INVENTION The session initiation protocol (SIP) is used to initiate and modify a multimedia session in the Internet Protocol (IP) network. For example, the SIP is used in one of a universal mobile telecommunications system (UMTS) network to establish a multimedia session between two users, where at least one of the users operates in the ÜMTS system. However, the SIP protocol has not been used until now as a mechanism to carry out switching between different devices operating in different systems.

BRIEF DESCRIPTION OF THE INVENTION The present invention is characterized by a method and apparatus for providing a unique solution to the switching problem, including negotiation of codees (encoders / decoders) of new means for use in cases where the two devices involved in the switching are incompatible. Although mobile IP (MIP) is currently used to carry out switching procedures, this technique lacks a trigger mechanism to initiate switching between two different devices communicating with two different networks or a common network. In addition, the MIP does not cover the issue of compatibility between media types, codecs and bit rate supported.

BRIEF DESCRIPTION OF THE FIGURES The present invention will be understood from a consideration of the accompanying figures, where reference is made to similar elements through similar reference numerals, where: Figure 1 is a simplified schematic diagram of a network architecture incorporating two devices incompatible and two different systems that communicate with these devices. Figure 2 is a flow diagram showing how a switch from a wireless local area network (WLAN) network user to an ÜMTS network user is triggered from the WLAN network. Figure 3 is a flow diagram showing how a switch from a WLAN network user to a UMTS network user is triggered from a UMTS network. Figure 4 is a flowchart similar to that of Figure 2, where the switching is performed from the UMTS user to the WLAN network user and is triggered from the WLAN network. Figure 5 is a flowchart similar to that shown in Figure 3, where switching is performed from a WLAN network user to a UMTS network user and is triggered from the UMTS network.

DETAILED DESCRIPTION OF THE PREFERRED MODALITIES With reference to the network architecture 10 of Figure 1, two different wireless devices 12 and 32 are shown therein, wherein the device 12 is a personal computer (PC) with a WLAN card 13 which allows the device 12 to establish a wireless communication with an access point / access router (AP / AR) of WLAN 14. PC 12 can be a desktop or laptop computer and is equipped with a WLAN card 13 and is capable of establishing a wireless communication with a WLAN 14, through a suitable interface (not shown, for simplicity). The PC 12 is coupled to the AAA unit 16 through the WLAN 14 to establish access, authorization and accounting (AAA) to 16 and is coupled through an Internet Protocol (IP) network 18 and a router 20 to a server 22 to communicate with a called subscriber or for example, another source (not shown) in the network. The user equipment (UE) 32, which may be a wireless cellular telephone, a wireless PDA device or other similar device with similar capabilities, is adapted for wireless communication with a third generation collaborative project system (3GPP) 23. The UE 32 communicates with the system 23 that receives a wireless message from the UE 32, through the antenna 30 which couples the communication to a general packet radio service (GPRS) general support node (GSN) 28.

The message is also transported from the GSN 28 to a resident subscriber server (HSS) 26 and an AAA 24 (similar to AAA 16) for access, authentication and accounting. The resident subscriber server (HSS) 26 performs various database functions, such as the residence location registration (HLR) function, which provides routing information for completed mobile calls and short message service and retains information user subscription that is distributed to the relevant visitor location record (VLR), which is not shown, for simplicity, or is distributed to the in-service GPRS support node (SGSN). The AAA 24 reliably determines the identity and privileges of the EU and monitors the activities of the EU. A description will now be provided to carry out a switch using SIP when a user considers it convenient to switch an existing multimedia session between two different types of networks. The two different networks of the example to be followed are a WLAN network 14 and a 3GPP UMTS network 23. The switching will be described as from a PC, such as the PC 13 shown in Figure 1 and equipped with a WLAN card 13, a a user equipment (UE) 32 which can be a cell phone or the like, which optionally can also be equipped with image viewing and reception capability, to accommodate a multimedia session in accordance with 3GPP standards. With reference to Figure 2, where a switch is triggered by the WLAN network 14, it is contemplated that there is a real-time session between the PC 12 and the one receiving the call that is represented in Figure 1 as a real-time session. , where the PC 12 / board WLAN 13 communicates with the WLAN network 14 shown in SI, where the WLAN network 14 communicates with the IP network 18, which is shown in S2, where the IP network 18, at its Once, it provides bilateral communication between PC 12 and server 12, which is shown in S3. At this time, neither the UE 32 nor the PC 12 communicate with a UMTS network 23. The user of both the PC 12 and the UE 32 turn on the UE 32 and establish a connection with the UMTS network 23, in S4, S5 and S6. The user then decides to trigger a switch from the PC 12 to the UE 32 in S7 and communicates this switch request, in S8, to the WLAN network 14. The WLAN network 14, in S9, transmits a SIP message, which can either be adopted the form of a SIP switch message or a SIP invitation that is accompanied either by a target IP address or by an e-mail address or a telephone number. This is transported through an IP network 18, in S10, to a server 22. The server 22 transmits a SIP 200 (OK) message, in Sil, to confirm the switching message (HO). The PC 12 equipped with WLAN receives the confirmation SIP 200 OK and, in S12, sends a confirmation (ACK) SIP to the server 22. The server 22 transmits a SIP invitation establishing a list of media types, IP addresses, bit rates , codes and the like, in S13, which, in turn, is transported through the IP network 18 to the UMTS network 23, in S14 and, in turn, from the UMTS network 23 to the UE 32, in S15. The UE 32, when receiving the SIP invitation, in S16, transmits an OK SIP 200 message confirming the types of media, codecs, bit rate and acceptable IP addresses. This is transferred through the UMTS network 23 to the IP network 18 at S17, where the IP network 18 transports this message to the server 22, at S18. The server 22, upon receiving the OK SIP 200 from the UE 32, at S19, carries a SIP acknowledgment (ACK) to the UE 32, thus completing the real-time session switching from the PC 12 with WLAN capability to the UE 32 , where the communication of the session in real time is now established between the UE 32 and a given source through a UMTS network 23, at S20, where the network 23 transports this bilateral communication to the IP network 18 at S21 and the network IP 18 transports this bilateral communication between the IP network 18 and the server 22, in S22. The user ends the session between PC 12 and WLAN 14, at S23.

Figure 3 shows how a switch from a PC 12 to a UE 32 is triggered from the UMTS network. Initially, it is contemplated that the multimedia session in real time, which may be voice over Internet protocol (VoIP) or video, is currently occurring as represented by the bilateral communication SI between PC 12 with WLAN card 13 and the WLAN network 14 as represented by step SI, where the bilateral communication of this session between the WLAN network 14 and the IP network 18 is shown in S2 and the bilateral communication between the IP network 18 and the server 22 is shown in S3. It is assumed that the user considers it convenient to carry out a switching from the PC 12 to the UE 32. This is initiated by starting the UE 32, at S4, in order to connect the UE 32 to the UMTS network, as shown in S5 and the IP network 18, as shown in Sß. Once the connection to the UE 32 is established and the user decides to trigger a switch to the UE 32, in S7, the UE 32, in S8 sends a SIP message which can be either a new SIP switching message or a message SIP invitation with the new information elements to identify the existing session. This message is transferred through the UMTS network 23 to the IP network 18, in S9, and thus to the server 22, in S10. The server 22, upon receiving the SIP message, transmits an OK SIP 200 to confirm the message HO that is transported, in Sil, to the IP network 18 which then transports this message, in S12 to the UMTS network 23, which, in its once, it carries the message OK SIP 200 to the UE 32 in S13. The UE 32, at S14, responds to the OK SIP 200 message by sending a SIP acknowledgment to the server 22, thus establishing the real-time session, which originally included a PC 12 as a participant, to the UE 32, as shown in S15, S16 and S17. It should be noted that the steps S15, S16 and S17 are substantially the same as the steps S20, S21 and S22 shown in Figure 2. Once the switching is completed, the server 22, in S18, transmits a SIP BYE to finalize the Real-time session in the WLA network. This is transported to the IP network 28, in step S18, which, in turn, transports the message to the WLAN network 14, in S19 which, in turn, transports the message to the PC 12, in S20. The PC 12, equipped with the WLAN card 13, sends an OK SIP 200 response to confirm the completion, response that is transported to the WLAN network 14 in S21 and is, in turn, transported to the IP network 18 in S22. The IP network 18, in turn, transports the OK SIP 200 message to the server 22 in S23. Upon receiving this message, the server 22 sends a SIP confirmation (ACK SIP) that is initially transported to the IP network 18, at S24, which transfers the ACK SIP message to the WLAN 14 at S25, where the WLAN network 14 transfers the message ACK SIP to PC 12 with WLAN card 13, in S26. With reference to Figure 4, where a switch is triggered from the WLAN network 14, it is contemplated that there is a real-time session between the UE 32 and a remote party that is represented as a real-time session where the UE 32 communicates. with the UMTS network 23, as shown in SI, the UMTS network 23 communicates with the IP network 18, as shown in S2, the IP network 18 provides, in turn, the bilateral communication between the UE 32 and a subscriber called through server 12, as shown in S3. The user, in S4, turns on the PC 12 and establishes a connection with the WLAN network, in S5, and the IP network 18, in S6. The user then decides to trigger a switch to the PC 12, in S7, and communicates a SIP switching request, in S8, to the IP network 18, and the server 22, in S9. The SIP message may take the form of either a SIP switching message or a SIP invitation accompanied by either a target IP address or an e-mail address or a telephone number. This is transported through an IP network 18, on S9, to server 22. ' The server 22 transmits a message (OK) SIP 200 to the PC 12, at S10, to confirm the switching message (HO). The PC 12 equipped with WLAN, receives the confirmation (OK) SIP 200 and, in Sil, sends a confirmation (ACK) SIP to the server 22. The server 22 transmits a SIP invitation establishing a list of media types, IP addresses, bit rates, codees and the like , in S12, which, in turn, is transported through the IP network 18 to the WLAN network 14, in S13 and, in turn, from the WLAN network 14 to the PC 12, in S14. PC 12, upon receipt of the SIP invitation, at S15, transmits an OK SIP 200 message to WLAN 14 confirming the types of media, codecs, bit rate and acceptable IP addresses. The OK SIP 200 is transferred to the IP network 18 through the WLAN network 14, in S16, and through the IP network 18 to the server 22, in S17. The server 22, upon receiving the OK SIP 200 from the PC 12, at S18, carries a confirmation (ACK) SIP to the WLAN 14 and then to the PC 12, through the WLAN network 14, at S19, thus completing the session switching in real time from UE 32 to PC 12 with WLAN capability. The communication of the session in real time is thus established between the PC 12 and a given source through a WLAN network 14 and the IP network 18. The bilateral communication is between the WLAN network 14 and the PC 12 in S20, IP network 18 in S21, and between IP network 18 and server 22, in S22. The user can end the session in the WLAN network 14, in step S23. Figure 5 shows the way in which a switch from a UE 32 to a PC 12 is triggered from the UMTS network 23. Initially, it is contemplated that the multimedia session in real time, which may be voice over Internet Protocol (VoIP) or video, is currently occurring as represented by the bilateral communication between the UE 32 and the UMTS network 23, as represented by step SI, where the bilateral communication of this session between the UMTS network 23 and the IP network 18 is shown in S2 and the bilateral communication between the IP network 18 and the server 22 is shown in S3. It is assumed that the user considers it convenient to carry out a switchover from the UE 32 to the PC 12. This is started by turning on the PC 12, in S4, so as to connect the PC 12 to the WLAN network 14, as shown in FIG. S5 and IP network 18, as shown in S6. Once the connection to the PC 12 is established and the user decides, in S7, to trigger a switch to the PC 12, the UE 32, in S8, sends a SIP message which can be either a new SIP switching message or well a SIP invitation message with the new information elements to identify the existing session. This message is transferred through the network 23 to the IP network 18, in S9, and thus to the server 22, in S10. The server 22, upon receiving the SIP message, transmits an OK SIP 200 message to confirm the message HO that is transported, in Sil, to the IP network 18 which then transports this message, in S12, to the WLAN network 14, which, in turn, it transports the message OK SIP 200 to PC 12 in S13. The PC 12, at S14, responds to the OK SIP 200 message by sending a confirmation (ACK) SIP to the server 22 through the WLAN network 14, at S14, the IP network 18, at S15 and then from the IP network 18 to the server 22, at S16, thus establishing the session in real time, which originally included an UE 32 as a participant, and which is now switched to PC 12, as shown in S17, S18 and S19. The server 22, in S20, sends a BYE SIP to the IP network that transports it to the UMTS network 23 in S21, which in S22 transports it to the UE 32. The UE 32 sends an OK SIP 200 response to confirm the completion, response which is transported to the UMTS network 23, in S23 and is, in turn, transported to the IP network 18, in S24, which, in turn, transports the message OK SIP 200 to the server 22, in S25. Upon receiving this message, the server 22 sends a confirmation (ACK) SIP that is initially transported to the IP network 18, at S26, which transfers the ACK SIP message to the UMTS 23, at S27, where the UMTS 23 network transfers the message ACK SIP to UE 32, in S28.

Claims (14)

1. Method for switching a real-time session from a first type of wireless device to a second type of wireless device different from the first type of wireless device, where the first type of wireless device conducts a session in real time through a first type of wireless device network and the second type of wireless device is capable of conducting a session in real time through a second type of network different from the first type of network, comprising: the second type of wireless device that is activated to initiate a switching to the first type of wireless device; the second type of wireless device that responds to the activation establishes communication with the second type of network; the second type of wireless device that transports a session initiation protocol (SIP) message to the second type of network, requesting a switch (HO) from the first to the second type of wireless device; the second type of network, which responds to the SIP message, transmits to the second type of wireless device an acceptance of the HO request; the second type of wireless device that responds to the acceptance message, sends a confirmation (ACK) SIP; and the switching is completed by the second type of network, whereby the real-time session continues with the first type of wireless device that is replaced by the second type of wireless device.

2. Method according to claim 1, wherein the second type of network, which responds to the SIP ACK, transmits an end signal to the first type of wireless device.

3. Method according to claim 2, wherein the first type of wireless device that responds to the reception of the message of completion of the session in real time, sends a confirmation message.

4. Method according to claim 3, wherein the second type of network, which responds to the message confirming the completion received from the first type of wireless device, sends an ACK SIP to the first type of wireless device.

5. Method according to claim 3, wherein the first type of wireless device ends its participation in the session in real time after sending the confirmation message.

6. Apparatus for switching a session in real time from a first type of wireless device to a second type of wireless device different from the first type of wireless device, where the first type of wireless device conducts a session in real time through a first type of network and the second type of wireless device is capable of conducting a session in real time through a second type of network different from the first type of network, comprising: the second type of wireless device with means to initiate a switch to the first type of wireless device when activated; means that respond to the activation to establish communication with the second type of network; means for transporting a session initiation protocol (SIP) message to the second type of network, requesting a switch (HO) from the first to the second type of wireless device; the second type of network comprises: means responsive to the SIP message for transmitting an acceptance of the HO request to the second type of wireless device; and the second type of wireless device comprises: means that respond to the acceptance message to send a confirmation (ACK) SIP; whereby the switching is completed by the second type of network, where the real-time session continues with the first type of wireless device that is replaced by the second type of wireless device.

7. Apparatus according to claim 6, wherein the second type of network further comprises: means responsive to the SIP ACK for transmitting an end signal to the first type of wireless device.

8. Apparatus according to claim 7, wherein the first type of wireless device further comprises: means responsive to receiving the finished message of the session in real time, to send a confirmation message.

9. Apparatus according to claim 8, wherein the second type of network further comprises: means responsive to the message, confirming the completion received from the first type of wireless device to send an SIP ACK to the first type of wireless device.

10. Apparatus according to claim 8, wherein the first type of wireless device further comprises: means for terminating the participation of the first type of wireless device in the real-time session, after sending the confirmation message.

11. Apparatus according to claim 6, wherein the first type of network is one between a wireless local area network (WLAN) and a wireless wide area network (WWAN).

12. Apparatus according to claim 6, wherein the second type of network is one between a wireless local area network (WLAN) and a wireless wide area network (WWAN).

13. Apparatus according to claim 11, wherein the first type of wireless network further includes an access point (AP).

14. Apparatus according to claim 11, wherein the second type of wireless network further includes an access point (AP).