SYSTEM SUPPORT FOR ACCESSING AND SWITCHING AMONG MULTIPLE WIRELESS INTERFACES ON MOBILE DEVICES

• US 20120140651A1
• Filed: 09/21/2011
• Published: 06/07/2012
• Est. Priority Date: 12/01/2010
• Status: Active Grant

• Current Assignee: Deutsche Telekom AG
• Original Assignee: Deutsche Telekom AG
• Inventors: Nicoara, Angela, Singh, Jatinder Pal, Nirjon, S.M. Shahriar
• Granted Patent: US 8,750,188 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 52/02 Power saving arrangements in wired systems H04L12/12; signaling of mobile application services, e.g. low battery notifications H04W4/20
• 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: Y02D 30/70 in wireless communication networks

Abstract

A client-based system for use in a mobile client device in communication with a remote server device provides for dynamically switching among multiple wireless interfaces on the mobile client device. The system includes a first interface for communicating over a cellular network, a second interface for communicating over a WiFi network, and a computer-readable medium within the mobile client device, having thereon computer-executable instructions for switching one or more connection-oriented sessions from one of the first and second interfaces to the other based on a selection policy selected from an energy saving selection policy, an offload selection policy, and a performance selection policy.

Claims

1. A client-based system for use in a mobile client device in communication with a remote server device for dynamically switching among multiple wireless interfaces on the mobile client device, the system comprising:

a first interface for communicating over a cellular network;

a second interface for communicating over a WiFi network; and

a computer-readable medium within the mobile client device, having thereon computer-executable instructions for switching one or more connection-oriented sessions from one of the first and second interfaces to the other of the first and second interfaces based on a selection policy selected from an energy saving selection policy, an offload selection policy, and a performance selection policy.

2. The client-based system according to claim 1, wherein the energy saving selection policy specifies that the device use the first network interface while idle and use the second network interface when an application running on the device is sending and receiving mobile data and a predetermined threshold condition is met.

3. The client-based system according to claim 2, wherein the predetermined threshold condition specifies availability of WiFi and that a total amount of data sent over the first network interface by the application exceeds a predetermined data threshold.

4. The client-based system according to claim 2, wherein the energy saving selection policy further specifies that after using the second network interface, the device return to using only the first network interface when data activity over the second network interface falls below a utilization threshold for a predetermined period of time.

5. The client-based system according to claim 1, wherein the offload selection policy specifies that the device use the second interface when the device is sending or receiving data and WiFi connectivity is available.

6. The client-based system according to claim 5, wherein the offload selection policy further specifies that after using the second network interface, the device will again use only the first network interface when WiFi connectivity becomes unavailable.

7. The client-based system according to claim 5, wherein the offload selection policy further specifies that after using the second network interface, the device will again use the first network interface when a WiFi signal strength falls below a predetermined WiFi threshold.

8. The client-based system according to claim 1, wherein the performance selection policy is adapted to maximize available data throughput without regard to energy usage.

9. The client-based system according to claim 8, wherein maximizing available data throughput comprises reading a cellular signal strength and a WiFi signal strength, inferring an achievable bandwidth based on the measured signal strengths, determining which of the first and second interface is associated with the higher bandwidth, and using the interface associated with the higher bandwidth.

10. The client-based system according to claim 1, wherein the computer-executable instructions for switching one or more connection-oriented sessions from one of the first and second interfaces to the other comprises instructions for:

counting existing TCP connections on the current interface;

adding new routing table entries for the counted connections specifying the destination address, gateway and mask for the current interface if the count is non zero so that existing TCP flows remain in the current interface;

activating the other of the first and second network interfaces;

adding routing table entries for the other network interface including a default route;

removing a default route of the routing table of the current interface;

awaiting expiration of a predefined timeout period; and

deactivating the current interface so that the device uses the other interface.

11. The client-based system according to claim 10, wherein sessions that have gone past the established state are disregarded while counting existing TCP connections on the current interface.

12. A method for allowing a mobile client device to dynamically switch among multiple wireless interfaces to respective multiple wireless networks, the method comprising:

using a first one of the multiple wireless interfaces to execute one or more connection-oriented sessions;

accessing a selection policy;

determining while using the first one of the multiple wireless interfaces that the selection policy specifies switching to a second one of the multiple wireless interfaces; and

switching the one or more connection-oriented sessions from the first wireless interface to the second wireless interface.

13. The method according to claim 12, wherein the selection policy is selected from an energy saving selection policy, an offload selection policy, and a performance selection policy.

14. The method according to claim 13, wherein the energy saving selection policy specifies that the device use the first network interface while idle and use the second network interface when an application running on the device is sending and receiving mobile data and a predetermined threshold condition is met.

15. The client-based system according to claim 14, wherein the predetermined threshold condition specifies availability of WiFi and that a total amount of data sent over the first network interface by the application exceeds a predetermined data threshold.

16. The method according to claim 13, wherein the energy saving selection policy further specifies that after using the second network interface, the device return to using the first network interface when data activity over the second network interface falls below a utilization threshold for a predetermined period of time.

17. The method according to claim 13, wherein the offload selection policy specifies that the device use the second interface whenever the device is sending or receiving data and WiFi connectivity is available.

18. The method according to claim 13, wherein the performance selection policy is adapted to maximize available data throughput without regard to energy usage by reading a cellular signal strength and a WiFi signal strength, inferring an achievable bandwidth based on the measured signal strengths, determining which of the first and second interface is associated with the higher bandwidth, and utilizing the interface associated with the higher bandwidth.

19. A method for switching wireless connection-oriented sessions in a mobile wireless device from a current one of a cellular interface and a WiFi interface to the other of the cellular interface and the WiFi interface, the method comprising:

counting existing TCP connections on the current interface;

adding new routing table entries for the counted connections specifying the destination address, gateway and mask for the current interface if the count is non zero so that existing TCP flows remain in the current interface;

activating the other of the interfaces;

adding routing table entries for the other interface including a default route;

removing a default route of the routing table of the current interface;

awaiting expiration of a predefined timeout period; and

deactivating the current interface so that the device uses the other interface.

20. The method according to claim 19, wherein sessions that have gone past the established state are disregarded while counting existing TCP connections on the current interface.