VOICE AND DATA CONTINUITY BETWEEN WIRELESS DEVICES

• US 20170094597A1
• Filed: 09/23/2016
• Published: 03/30/2017
• Est. Priority Date: 09/30/2015
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: SU, Li, SHAMIM, Tahir, SHI, Jianxiong, ZHANG, Wanping
• Granted Patent: US 10,015,740 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 65/1016 IP multimedia subsystem [IMS]
• CPC Class Codes: H04L 9/0861 Generation of secret information including derivation or calculation of cryptographic keys or passwords
• CPC Class Codes: H04L 9/14 using a plurality of keys or algorithms
• CPC Class Codes: H04W 12/033 of the user plane, e.g. user's traffic
• CPC Class Codes: H04W 12/037 of the control plane, e.g. signalling traffic
• CPC Class Codes: H04W 12/041 Key generation or derivation
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 52/0209 in terminal devices terminal devices per se H04W88/02
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 76/15 Setup of multiple wireless link connections
• CPC Class Codes: H04W 76/25 Maintenance of established connections
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/04 adapted for relaying to or from another terminal or user
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

An accessory wireless device partakes in a data session with a remote device. The data session may be a voice call or other service. To preserve the battery power of the accessory wireless device, the accessory wireless device opportunistically offloads medium-to-long range radio transmission and reception tasks to the companion wireless device while maintaining call continuity. The accessory wireless device and the companion wireless device communicate through a local connection. In one embodiment, the accessory wireless device pushes a wireless wide area network (WWAN) connection to the companion device by sharing selected security and network information with the companion wireless device. When the accessory device and/or the companion device determine that the local connection may not be sustainable, the accessory device pulls the WWAN connection of the companion device back to itself.

Claims

1. A method of maintaining call continuity at a first wireless device, the method comprising:

at the first wireless device;

establishing a radio resource control (RRC) connection to a base station of a wireless wide area network (WWAN);

receiving, from the base station, first data encrypted based on a Cipher Key (CK), wherein a portion of the first data is generated by a remote device;

establishing a local connection to a second wireless device;

sending a signaling message comprising key data to the second wireless device, wherein the key data is based on the CK; and

receiving, from the second wireless device, second data encrypted based on the CK via the local connection.

2. The method of claim 1, wherein the key data comprises one or more of a network access stratum (NAS) encryption key, a NAS integrity key, a user plane integrity key, a user plane encryption key, an RRC integrity key, or an RRC encryption key.

3. The method of claim 1, further comprising:

releasing, subsequent to sending the signaling message to the second wireless device, the RRC connection to the base station.

4. The method of claim 1, further comprising:

receiving, from the base station, a temporary mobile station identifier (TMSI).

5. The method of claim 1, further comprising:

generating a first key based on the CK, an integrity key (IK), and a subscriber key (K); and

generating a second key based on the CK, the IK, and the K.

6. The method of claim 5, wherein the signaling message further comprises the IK, the first key, the second key, and the TMSI.

7. The method of claim 6, wherein:

i) the first key comprises a radio resource control (RRC) encryption key, and ii) the second key comprises a network access stratum (NAS) encryption key.

8. A method of relaying data to a first wireless device from a second wireless device, the method comprising:

at the second wireless device;

receiving a signaling message from the first wireless device over a local connection, wherein the signaling message comprises;

a request to receive data via the local connection, and

a base station identifier identifying a base station of a wireless wide area network (WWAN);

receiving key data from the first wireless device, wherein the key data comprises a first key;

establishing, using the first key, a radio resource control (RRC) connection with a base station identified by the base station identifier;

receiving, from the base station subsequent to the establishing, data originating from a remote device; and

transmitting the data to the first wireless device via the local connection.

9. The method of claim 8, further comprising:

at the second wireless device;

receiving a request from the first wireless device to establish the local connection; and

establishing the local connection with the first wireless device.

10. The method of claim 8, further comprising:

receiving key data from the first wireless device, wherein the key data comprises a second key, an integrity key (IK), and a cipher key (CK).

11. The method of claim 8, further comprising:

receiving a temporary mobile station identifier (TMSI) from the first wireless device.

12. The method of claim 8, further comprising:

establishing, using the second key and the TMSI, a Non-Access Stratum (NAS) connection to a Mobility Management Entity (MME) of the WWAN.

13. A wireless device comprising:

a processor; and

a memory coupled to the processor, wherein the memory comprises instructions that when executed by the processor cause the wireless device to perform steps comprising;

receiving first data originating from a remote device, wherein the first data is relayed by a second wireless device to the wireless device over a local connection;

detecting that performance of the local connection is deteriorating; and

transmitting a signaling message to the second wireless device, wherein;

i) the signaling message comprises a request to receive subsequent data over a wireless wide area network (WWAN), ii) the second wireless device has a radio resource control (RRC) connection to a base station of the WWAN and iii) the second wireless device has a non-access stratum (NAS) connection to a mobility management entity (MME) of the WWAN.

14. The wireless device of claim 13, wherein the steps further comprise:

receiving key data from the second wireless device, wherein the key data comprises a first key, a second key, an integrity key (IK), and a cipher key (CK).

15. The wireless device of claim 14, wherein the steps further comprise:

receiving a temporary mobile station identifier (TMSI) from the second wireless device.

16. The wireless device of claim 15, wherein the steps further comprise:

establishing, using the first key, a radio resource control (RRC) connection to the base station.

17. The wireless device of claim 16, wherein the steps further comprise:

establishing, using the second key and the TMSI, a non-access stratum (NAS) connection to the mobility management entity (MME).

18. The wireless device of claim 17, wherein the steps further comprise:

receiving, subsequent to establishing the RRC connection and the NAS connection, second data originating from the remote device.

19. The wireless device of claim 18, wherein the second data is encrypted based on the CK.

20. The wireless device of claim 19, wherein CK conforms with a MILENAGE algorithm.