Global virtual local area network for voice communication sessions in a wireless local area network

• US 8,194,605 B2
• Filed: 12/22/2006
• Issued: 06/05/2012
• Est. Priority Date: 12/22/2006
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Kezys, Vytautas Robertas
• Primary Examiner(s): Lee, Jae Y
• Application Number:
  US11/615,284
• Publication Number:
  US 20080151868A1
• Time in Patent Office: 1,992 Days
• Field of Search: None
• US Class Current: 370/331
• CPC Class Codes: H04L 12/4641 Virtual LANs, VLANs, e.g. virtual private networks [VPN] LAN interconnection over a bridge based backbone H04L12/462; encapsulation techniques H04L12/4633; routing of packets H04L45/00; packet switches H04L49/00; virtual private networks for security H04L63/0272
• CPC Class Codes: H04L 65/1083 In-session procedures
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 8/087 for preserving data network PoA address despite hand-offs
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A first wireless AP of a WLAN in a first subnet segment of a network has both a local ESSID and a global ESSID for mobile devices to associate with it. Similarly, a second wireless AP of the WLAN in a second subnet segment of the network has both a local ESSID and the global ESSID for mobile devices to associate with it. The global ESSID is used for accessing a global VLAN which spans across the first and the second subnet segments. Initially, a mobile device associates with the first wireless AP using the local ESSID. Just prior to a VoIP session, the mobile device reassociates with the first wireless AP using the global ESSID. If a handoff to the second wireless AP is made during the VoIP session, the mobile device associates with the second wireless AP using the global ESSID.

Claims

1. A method for facilitating voice communication sessions for a mobile communication device in a communication network, the communication network having at least first and second subnet segments and a router coupled between the first and the second subnet segments, the first subnet segment having a first IP subnet address range and the second subnet segment having a second IP subnet address range different from the first IP subnet address range, the communication network including a wireless network having at least a first wireless access point and a second wireless access point, the first wireless access point being in the first subnet segment and having a local extended service set identifier (ESSID) and a global ESSID for mobile communication devices to associate with the first wireless access point, the second wireless access point being in the second subnet segment and having a local ESSID and the global ESSID for mobile communication devices to associate with the second wireless access point, the global ESSID being used for accessing a global virtual local area network (VLAN) of the communication network which spans the first and the second subnet segments, the method comprising:

causing an association to be made between the mobile communication device and the first wireless access point in the first subnet segment with use of the local ESSID of the first wireless access point;

in response to a request to establish a voice communication session involving the mobile communication device;

causing an association to be made between the mobile communication device and the first wireless access point of the first subnet segment with use of the global ESSID associated with the global VLAN;

establishing and maintaining the voice communication session for the mobile communication device in the global VLAN after the association is made using the global ESSID; and

if a handoff to the second wireless access point of the second subnet segment is made during the voice communication session, then causing an association to be made between the mobile communication device and the second wireless access point with use of the global ESSID associated with the global VLAN.

2. The method of claim 1, further comprising:

upon termination of the voice communication session, causing an association to be made between the mobile communication device and the first or the second wireless access point with use of the local ESSID corresponding to the first or the second wireless access point with which association is being made.

3. The method of claim 1, further comprising:

prior to the voice communication session being established, receiving an assignment of an IP address of the first subnet segment; and

after causing an association to be made with use of the global ESSID of the global VLAN, receiving an assignment of an IP address in the global VLAN.

4. The method of claim 1, further comprising:

if the handoff to the second wireless access point of the second subnet segment is made during the voice communication session, then refraining from requesting an assignment of an IP address of the second subnet segment during the voice communication session for the mobile communication device.

5. The method of claim 1, further comprising:

upon termination of the voice communication session;

causing an association to be made between the mobile communication device and the second wireless access point of the second subnet segment with use of the local ESSID of the second wireless access point; and

receiving an assignment of an IP address of the second subnet segment.

6. The method of claim 1, further comprising:

prior to the voice communication session being established, identifying whether there is a likelihood of the handoff to occur during the voice communication session; and

in response to identifying that there is the likelihood of the handoff to occur during the voice communication session, using the global ESSID and the global VLAN for a Voice-over-IP (VoIP) communication session.

7. The method of claim 1, wherein all of the acts of the method are performed by the communication network.

8. The method of claim 1, wherein all of the acts of the method are performed by the mobile communication device.

9. The method of claim 1, which is embodied in a computer program product which comprises a non-transitory computer readable medium and computer instructions stored in the non-transitory computer readable medium which are executable by one or more processors for performing the method.

10. A communication network having a wireless network configured to provide wireless communications for a plurality of mobile communication devices, the communication network comprising:

at least first and second subnet segments;

the first subnet segment having a first IP subnet address range;

the second subnet segment having a second IP subnet address range different from the first IP subnet address range;

a router for coupling between the first and the second subnet segments;

a session server which is accessible in a global virtual local area network (VLAN) which spans the first and the second subnet segments;

a first wireless access point for coupling in the first subnet segment;

the first wireless access point having both a local extended service set identifier (ESSID) and a global ESSID which is associated with the global VLAN;

the first wireless access point being configured to allow a mobile communication device to associate with the first wireless access point with use of the local ESSID prior to establishment of a voice communication session involving the mobile communication device;

the first wireless access point being further configured to allow the mobile communication device to associate with the first wireless access point with use of the global ESSID associated with the global VLAN in response to a request to establish a voice communication session for the mobile communication device, and to maintain such association with the mobile communication device during the voice communication session;

a second wireless access point for coupling in the second subnet segment;

the second wireless access point having both a local ESSID and the global ESSID which is associated with the global VLAN; and

the second wireless access point being configured to allow the mobile communication device to associate with the second wireless access point with use of the global ESSID associated with the global VLAN, and to maintain such association with the mobile communication device during the voice communication session.

11. The communication network of claim 10, further comprising:

the first wireless access point being further configured to associate with the mobile communication device with use of the local ESSID of the first wireless access point outside of any voice communication session; and

the second wireless access point being further configured to associate with the mobile communication device with use of the local ESSID of the second wireless access point outside of any voice communication session.

12. The communication network of claim 10, further comprising:

at least one VLAN switch which is configured to provide the global VLAN in the communication network.

13. The communication network of claim 10, further comprising:

the mobile communication device being configured to, upon termination of the voice communication session, cause an association to be made with the first or the second wireless access point using the local ESSID corresponding to the first or the second wireless access point with which association is being made.

14. The communication network of claim 10, further comprising:

the mobile communication device being configured to identify whether there is a likelihood of a handoff during the voice communication session, and use the global ESSID and the global VLAN for the voice communication session in response to identifying that the mobile communication device is likely to require the handoff during the voice communication session.

15. A mobile communication device which is configured to operate in a wireless network which is part of a communication network, the communication network having at least first and second subnet segments and a router coupled between the first and the second subnet segments, the first subnet segment having a first IP subnet address range and the second subnet segment having a second IP subnet address range different from the first IP subnet address range, the wireless network including at least a first wireless access point and a second wireless access point, the first wireless access point being in the first subnet segment and having a local extended service set identifier (ESSID) and a global ESSID for mobile communication devices to associate with the first wireless access point, the second wireless access point being in the second subnet segment and having a local ESSID and the global ESSID for mobile communication device to associate with the second wireless access point, the global ESSID being used for accessing a global virtual local area network (VLAN) of the communication network which spans the first and the second subnet segments, the mobile communication device comprising:

one or more processors;

a wireless transceiver coupled to the one or more processors;

the one or more processors being operative to;

associate with the first wireless access point, with use of the wireless transceiver, using the local ESSID of the first wireless access point;

in response to detecting a request to establish a voice communication session;

associate with the first wireless access point, with use of the wireless transceiver, using the global ESSID associated with the global VLAN;

establish and maintain the voice communication session in the global VLAN with use of the wireless transceiver after associating with use of the global ESSID; and

if a handoff to the second wireless access point of the second subnet segment is made during the voice communication session, then associate with the second wireless access point, with use of the wireless transceiver, using the global ESSID associated with the global VLAN.

16. The mobile communication device of claim 15, wherein the one or more processors are further operative to:

upon termination of the voice communication session, associate with the first or the second wireless access point with use of the wireless transceiver, using the local ESSID of the corresponding first or the second wireless access point with which association is being made.

17. The mobile communication device of claim 15, wherein the one or more processors are further operative to:

prior to the voice communication session being established, receive an assignment of an IP address of the first subnet segment; and

after associating with use of the global ESSID of the global VLAN, request an assignment of an IP address of the global VLAN.

18. The mobile communication device of claim 15, wherein the one or more processors are further operative to:

if the handoff to the second wireless access point of the second subnet segment is made during the voice communication session, then refrain from requesting an assignment of an IP address of the second subnet segment during the voice communication session for the mobile communication device.

19. The mobile communication device of claim 15, wherein the one or more processors are further operative to:

upon termination of the voice communication session;

associate with the second wireless access point, with use of the wireless transceiver, using the local ESSID; and

receive an assignment of an IP address of the second subnet segment.

20. The mobile communication device of claim 15, wherein the one or more processors are further operative to:

prior to the voice communication session being established, identify whether there is a likelihood of the handoff to occur during the voice communication session; and

in response to identifying that there is a likelihood of the handoff to occur during the voice communication session, use the global ESSID and the global VLAN for the voice communication session.