Method and apparatus for performing a handoff of a data communication session from one network to another network

• US 8,918,051 B1
• Filed: 02/03/2010
• Issued: 12/23/2014
• Est. Priority Date: 06/18/2007
• Status: Expired due to Fees

• Current Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Original Assignee: Marvell International Limited (Marvell Technology Group Limited)
• Inventors: Chang, Lu, Lambert, Paul A.
• Primary Examiner(s): HUANG, WEN WU
• Application Number:
  US12/699,416
• Time in Patent Office: 1,784 Days
• Field of Search: 455/41.1, 455/41.2, 455/41.3, 455/59, 455/142, 455/143
• US Class Current: 455/41.2
• CPC Class Codes: H04W 36/1446 wherein at least one of the networks is unlicensed
• CPC Class Codes: H04W 36/304 due to measured or perceived resources with higher communication quality

Abstract

A mobile device includes a first interface module, a second interface module, and a control module. The first interface module is configured to interface the mobile device to a first wireless network and to receive data from a transmitting device via the first wireless network. The second interface module is configured to interface the mobile device to a second wireless network. The control module is configured to determine based on the data received when to switch a link to the transmitting device from the first wireless network to the second wireless network. The control module is further configured to transmit a message that informs the transmitting device not to transmit the data to the mobile device via the first wireless network in response to the link being switched to the second wireless network.

Claims

1. A mobile device, comprising:

a first interface module configured to

interface the mobile device to a cellular network, and

receive, from a transmitting device, data transmitted over the cellular network to the mobile device, wherein the data originates at the transmitting device;

a second interface module configured to

interface the mobile device to a wireless local area network, and

receive, from the transmitting device, data transmitted over the wireless local area network to the mobile device, wherein the data transmitted over the wireless local area network corresponds to the data transmitted over the cellular network; and

a control module configured to

compare (i) a first time stamp associated with the data received from the transmitting device over the cellular network to (ii) a second time stamp associated with the data received from the transmitting device over the wireless local area network,

determine, based on the comparison of the first time stamp to the second time stamp, when the first time stamp matches the second time stamp,

in response to a determination that the first time stamp matches the second time, switch a communication link to the transmitting device from the cellular network to the wireless local area network, and

in response to, and subsequent to, the communication link to the transmitting device being switched from the cellular network to the wireless local area network, transmit a message to the transmitting device, wherein the message informs the transmitting device not to transmit the data to the mobile device over the network.

2. The mobile device of claim 1, wherein the data comprises at least one of voice, video, or text data.

3. The mobile device of claim 1, further comprising a time stamp detection module configured to:

detect the first time stamp in a first packet received over the cellular network, wherein the data transmitted over the cellular network to the mobile device comprises the first packet; and

detect the second time stamp in a second packet received over the wireless local area network, wherein the data transmitted over the wireless local area network to the mobile device comprises the second packet.

4. The mobile device of claim 3, further comprising:

a time stamp detection module configured to

detect the first time stamp in the first packet received over the cellular network, wherein the data transmitted over the cellular network to the mobile device comprises the first packet, and

detect the second time stamp in the second packet received over the wireless local area network, wherein the data transmitted over the wireless local area network to the mobile device comprises the second packet;

a latency measuring module configured to respectively measure a first latency and a second latency of the cellular network and the wireless local area network based on the first time stamp and the second time stamp; and

a jitter buffer module including a first jitter buffer and a second jitter buffer respectively associated with the cellular network and the wireless local area network, wherein the jitter buffer module is configured to adjust a size of at least one of the first jitter buffer and the second jitter buffer based on the first time stamp and the second time stamp, respectively, so that the first latency matches the second latency,

wherein the control module switches the communication link to the transmitting device from the cellular network to the wireless local area network in response to the first latency matching the second latency.

5. The mobile device of claim 1, further comprising a packet number detection module configured to:

detect first packet numbers of a first set of packets received over the cellular network, wherein the data transmitted over the cellular network to the mobile device comprises the first set of packets, and

detect second packet numbers of a second set of packets received over the wireless local area network, wherein the data transmitted over the wireless local area network to the mobile device comprises the second set of packets,

wherein the control module switches the communication link to the transmitting device from the cellular network to the wireless local area network in response to the first packet numbers matching the second packet numbers.

6. The mobile device of claim 1, further comprising:

a packet detection module configured to

detect first packets missing in the data received over the cellular network, and

detect second packets present in the data received over the wireless local area network, wherein the second packets include information contained in the first packets missing in the data received over the cellular network; and

a combining module configured to combine the information from the second packets with the data received over the cellular network.

7. The mobile device of claim 6, wherein the control module is configured to not switch the communication link to the transmitting device from the cellular network to the wireless local area network in response to the combining module combining the second packets with the data received via the cellular network.

8. The mobile device of claim 1, further comprising:

a jitter buffer module configured to determine network jitter based on the data received over the cellular network; and

a packet detection module configured to determine packet loss based on the data received over the cellular network,

wherein the control module does not switch the communication link to the transmitting device from the cellular network to the wireless local area network in response to (i) the network jitter being even and (ii) the packet loss being less than or equal to a predetermined threshold.

9. The mobile device of claim 1, further comprising:

a jitter buffer module configured to

determine a first network jitter based on the data received over the cellular network, and

determine a second network jitter based on the data received over the wireless local area network; and

a packet detection module configured to

determine a first packet loss based on the data received over the cellular network,

determine a second packet loss based on the data received over the wireless local area network,

wherein the control module switches the communication link to the transmitting device from the cellular network to the wireless local area network in response to (i) the first network jitter being uneven, (ii) the first packet loss being greater than a predetermined threshold, (iii) the second network jitter being even, and (iv) the second packet loss being less than or equal to the predetermined threshold.

10. The mobile device of claim 1, further comprising:

a logging module configured to log network jitter and packet loss rate based on the data received over the cellular network; and

a timing window module configured to generate a timing window,

wherein the control module scans entries of the network jitter and the packet loss logged over a predetermined time period using the timing window, and decides, based on the entries, whether to switch the communication link to the transmitting device from the cellular network to the wireless local area network.

11. The mobile device of claim 10, wherein the control module does not switch the communication link to the transmitting device from the cellular network to the wireless local area network in response to (i) the network jitter of the cellular network being even and (ii) the packet loss of the cellular network being less than or equal to a predetermined threshold.

12. The mobile device of claim 10, wherein the control module switches the communication link to the transmitting device from the cellular network to the wireless local area network in response to:

(i) the network jitter of the cellular network being uneven, (ii) the packet loss of the cellular network being greater than a predetermined threshold, (iii) the network jitter of the wireless local area network being even, and (iv) the packet loss of the wireless local area network being less than or equal to the predetermined threshold.