WLAN-To-WWAN Handover Methods And Apparatus Using A WLAN Support Node Having A WWAN Interface

• US 20080102843A1
• Filed: 10/26/2006
• Published: 05/01/2008
• Est. Priority Date: 10/26/2006
• Status: Active Grant

• Current Assignee: Research In Motion Limited (Blackberry Limited), Mcmaster University
• Original Assignee: Mcmaster University
• Inventors: Azhari, Seyed Vahid, Todd, Terence D.
• Granted Patent: US 8,095,175 B2
• Time in Patent Office: Days
• US Class Current: 455/445
• CPC Class Codes: H04W 36/144 over a different radio air interface technology
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

Methods and apparatus for use in switching communication operations between a wireless local area network (WLAN) (e.g. an IEEE 802.11-based network) and a wireless wide area network (WWAN) (e.g. a cellular telecommunications network) for a mobile communication device are disclosed. A network support node which is utilized to facilitate such transitioning has a first communication interface (e.g. an Ethernet interface) for connection with a communication network which includes the WLAN and a second communication interface (e.g. a cellular radio air interface) for communicating with a base station of the WWAN over a wireless communication link. The mobile device initially operates in the WLAN in a communication session with another communication device. During the session, the network support node receives an indication that the mobile device is transitioning from the WLAN to the WWAN. In response to receiving the indication, the network support node causes a message to be sent which instructs a router of the communication network to communicate voice data of the session to it. In response to the message, the network support node receives voice data of the session from the router through its first communication interface. The network support node communicates the voice data with the mobile device via the WWAN through its second communication interface over the wireless communication link with the base station. These communications are performed at least while communication operations for the mobile device are being switched from the WLAN to the WWAN. Advantageously, disruption of communications during the WLAN-to-WWAN transition is reduced or eliminated.

Claims

1. A method for use in switching communication operations between a wireless local area network (WLAN) and a wireless wide area network (WWAN) for a mobile communication device which operates in the WLAN in a communication session with another communication device, the method comprising the acts of:

providing a network support node which is adapted to communicate with a communication network which includes the WLAN and adapted to communicate with a base station of the WWAN over a wireless communication link;

receiving, at the network support node from the communication network, voice data of the communication session between the mobile communication device and the other communication device; and

communicating, with the mobile communication device, the voice data of the communication session via the WWAN over the wireless communication link with the base station at least while communication operations for the mobile communication device are being switched from the WLAN to the WWAN.

2. The method of claim 1, wherein the WLAN comprises an IEEE 802.11-based network and the WWAN comprises a cellular telecommunications network.

3. The method of claim 1, wherein the communication session comprises a Voice over IP (VoIP) communication session.

4. The method of claim 1, further comprising:

causing, at the network support node, an additional communication session to be established and maintained with the mobile communication device for communicating the voice date of the communication session between the mobile communication device and the other communication device.

5. The method of claim 1, wherein the network support node is adapted to communicate with the communication network via a wired communication interface.

6. The method of claim 1, wherein the act of receiving the voice data is performed in response to a transition indication of the mobile communication device from the WLAN to the WWAN.

7. The method of claim 1, further comprising:

receiving, at the network support node, and indication that the mobile communication device is transitioning from the WLAN to the WWAN; and

in response to receiving the indication, causing a message to be sent to a router in the communication network for receiving the voice data.

8. The method of claim 1, further comprising:

receiving at least one of an IP address and a link layer address of the mobile communication device; and

wherein the act of receiving the voice data of the communication session comprises the further act of receiving voice data which is addressed to the at least one of the IP address and the link layer address of the mobile communication device.

9. The method of claim 1, which is embodied as a computer program product comprising a computer readable medium and computer instructions stored in the computer readable medium which are executable to perform the acts of receiving and communicating of the method.

10. A network support node for use in switching communication operations between a wireless local area network (WLAN) and a wireless wide area network (WWAN) for a mobile communication device which operates in the WLAN in a communication session with another communication device, the network support node comprising:

one or more processors;

a first communication interface coupled to the one or more processors and adapted for connecting to a communication network which includes the WLAN;

a second communication interface coupled to the one or more processors and comprising a wireless communication interface adapted for communications with a base station of the WWAN over a wireless communication link;

the one or more processors being adapted to;

receive, from the communication network via the first communication interface, voice data of the communication session between the mobile communication device the other communication device; and

communicate, with the mobile communication device, the voice data of the communication session via the WWAN over the wireless communication link with the base station at least while communication operations for the mobile communication device are being switched from the WLAN to the WWAN.

11. The network support node of claim 10, wherein the WLAN comprises an IEEE 802.11-based network and the WWAN comprises a cellular telecommunications network.

12. The network support node of claim 10, wherein the first communications interface comprises an Ethernet communication interface.

13. The network support node of claim 10, wherein the one or more processors are further adapted to:

cause, via the second communication interface, an additional communication session to be established and maintained with the mobile communication device for communicating the voice data of the communication session between the mobile communication device and the other communication device.

14. The network support node of claim 10, wherein the one or more processors are further operative to:

receive, via the first communication interface, a message which is indicative of a transition of the mobile communication device from the WLAN to the WWAN; and

in response to the message which is indicative of the transition, cause a message to be sent to a router in the communication network for receiving the voice data.

15. The network support node of claim 10, wherein the one or more processors are further operative to:

receive at least one of an IP address and a link layer address of the mobile communication device; and

wherein the act of receiving the voice data of the communication session comprises the further act of receiving voice data which is addressed to the at least one of the IP address and the link layer address of the mobile communication device.

16. A communication network, comprising:

a wireless local area network (WLAN) comprising a plurality of wireless access points (APs) through which a mobile communication device may operate in a communication session with another communication device;

a network support node comprising;

one or more processors;

a first communication interface coupled to the one or more processors and adapted to connect to the communication network;

a second communication interface coupled to the one or more processors and comprising a wireless communication interface adapted for communications via a wireless communication link with a base station of a wireless wide area network (WWAN);

the one or more processors being adapted to;

receive, from the communication network via the first communication interface, voice data of the communication session between the mobile communication device and the other communication device; and

communicate, with the mobile communication device, the voice data of the communication session via the WWAN over the wireless communication link with the base station at lest while communication operations for the mobile communication device are being switched from the WLAN to the WWAN.

17. The communication network of claim 16, wherein the WLAN comprises an IEEE 802.11-based network.

18. The communication network of claim 16, wherein the first communication interface comprises a wired communication interface.

19. The communication network of claim 16, wherein the one or more processors of the network support node are further adapted to:

cause, via the second communication interface, a call to be established an maintained with the mobile communication device for communicating the voice data of the communication session.

20. The communication network of claim 16, wherein the one or more processors of the network support node are further operative to:

receive, via the first communication interface, a message which is indicative of a transition of the mobile communication device from the WLAN to the WWAN; and

in response to the message which is indicative of the transition, cause a message to be sent to the router device for receiving the voice data.

21. The communication network of claim 16, wherein the one or more processors of the network support node are further operative to:

receive at least one of an IP address and a link layer address of the mobile communication device; and

wherein the act of receiving the voice data of the communication session comprises the further act of receiving voice data which is addressed to the at least one of the IP address and the link layer address of the mobile communication device.

22. A method for use in switching communication operations between a wireless local area network (WLAN) and a wireless wide area network (WWAN) by a mobile communication device, the method of comprising the acts of:

operating, via the WLAN with the use of a WLAN transceiver portion, in a communication session with another communication device;

during the communication session and at least while communication operations are being switched from the WLAN to the WWAN for the mobile communication device;

communicating, via the WWAN with use of a WWAN transceiver portion, with a network support node connected to a communication network which includes the WLAN; and

receiving, via the WWAN from the network support node, voice data of the communication session with the other communication device.

23. The method of claim 22, wherein the WLAN comprises an IEEE 802.11-based network and the WWAN comprises a cellular telecommunications network.

24. The method of claim 22, further comprising:

prior to receiving the call, causing a message which is indicative of a transition of the mobile communication device from the WLAN to the WWAN to be sent to the network support node.

25. The method of claim 22, further comprising:

requesting and receiving an IP address from the WWAN.

26. The method of claim 22, further comprising:

causing a handover message to be sent so that the communication session is switched to the WWAN.

27. The method of claim 22, further comprising:

requesting and receiving an IP address from the WWAN; and

causing a SIP message with the IP address to be sent so that the communication session is switched to the WWAN.

28. A mobile communication device, comprising:

one or more processor;

a wireless local area network (WLAN) transceiver portion coupled to the one or more processors and adapted for communications with a WLAN;

a wireless wide area network (WWAN) transceiver portion coupled to the one or more processors and adapted for communications with a WWAN;

the one or more processors being adapted to;

operate the WLAN transceiver portion in the WLAN in a communication session with another communication device;

during the communication session and at least while communication operations are being switched from the WLAN to the WWAN for the mobile communication device;

communicate, via the WWAN with use of the WWAN transceiver portion, with a network support node connected to a communication network which includes the WLAN; and

receive, via the WWAN with the network support node, voice data of the communication session between the mobile communication device and the other communication device.

29. The mobile communication device of claim 28, wherein the WLAN transceiver portion comprises an IEEE 802.11-based transceiver portion and the WLAN transceiver portion comprises a cellular transceiver portion.

30. The mobile communication device of claim 28, wherein the one or more processors are further operative to:

prior to the communication session with the network support node, cause a message which is indicative of a transition of the mobile communication device from the WLAN to the WWAN to be sent to the network support node.

31. The mobile communication device of claim 28, wherein the one or more processors are further operative to:

request and receive an IP address from the WWAN.

32. The mobile communication device of claim 28, wherein the one or more processors are further operative to:

cause a handover message to be sent to the WWAN so that the communication session is switched to the WWAN.

33. The mobile communication device of claim 28, wherein the one or more processors are further operative to:

request and receive an IP address from the WWAN; and

cause a SIP message with the IP address to be sent in the WWAN so that the communication session is switched to the WWAN.

34. A method for use in switching communication operations between a wireless local area network (WLAN) and a wireless wide area network (WWAN) for a mobile communication device operating in the WLAN in a communication session with another communication device, the method comprising the acts of:

receiving a message which indicates that the mobile communication device is transitioning from the WLAN to the WWAN;

in response to receiving the message, causing a message to be sent to a router of a communication network which includes the WLAN for instructing the router to communicate voice data of the communication session to it;

in response to sending the message to the router, receiving voice data of the communication session from the router through an interface with the communication network; and

causing the voice data of the communication session to be transmitted over a wireless communication link to a base station of the WWAN for receipt by the mobile communication device in the WWAN.

35. The method of claim 34, wherein the WLAN comprises an IEEE 802.11-based network and the WWAN comprises a cellular telecommunications network.

36. The method of claim 34, wherein the act of causing the message to be sent to the router comprises the further act of causing an Address Resolution Protocol (ARP) message to be sent to the router.

37. The method of claim 34, wherein the act of receiving the voice data of the communication session from the router through the interface comprises the use of an Ethernet interface.

38. The method of claim 34, wherein the act of receiving the message comprises receiving a message having at least one of a link layer address and an IP address of the mobile communication device.

39. The method of claim 34, wherein the act of receiving the message comprises the further act of receiving a message having at least one of a link layer address and an IP address of the mobile communication device, and wherein the act of causing the message to be sent to the router comprises the further act of causing a Address Resolution Protocol (ARP) message having the at least one of the link layer address and the IP address to be sent to the router.