# US 9,883,476 B2 · Regulating IMS use with non-VoLTE cellular communications systems

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,883,476 B2
- Document ID: US9883476B2
- Status: Granted
- Kind: B2
- Application number: 14/702,418
- Filed: 2015-05-01
- Published: 2016-11-03
- Granted: 2018-01-30
- Earliest claimed: 2015-05-01
- Assignees: General Motors Corporation
- Applicants: General Motors LLC
- Inventors: Mohammad Ishfaq; David George
- Web page: https://patentgrep.com/patent/US9883476B2

## CPC

- H04W 60/04: using triggered events
- H04L 65/1016: IP multimedia subsystem [IMS]
- H04L 65/1104: Session initiation protocol [SIP]
- H04W 48/18: Selecting a network or a communication service
- H04W 48/16: Discovering, processing access restriction or access information
- H04W 76/16: Involving different core network technologies, e.g. a packet-switched [PS] bearer in combination with a circuit-switched [CS] bearer
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A system and method of registering a voice over LTE (VoLTE) capable vehicle telematics unit with a wireless carrier system includes: detecting at the vehicle telematics unit a wireless signal broadcast by a cell tower; determining from the wireless signal whether the cell tower provides cellular service using a VoLTE cellular protocol; and when it is determined that the cell tower does not provide cellular service using the VoLTE protocol, then preventing the VoLTE-capable vehicle telematics unit from attempting to wirelessly connect with the cell tower using an IP multimedia subsystem (IMS) protocol.

## Claims

### Claim 1

A method of registering a voice over long-term evolution (VoLTE) capable vehicle telematics unit with a wireless carrier system, comprising the steps of:
(a) detecting at the vehicle telematics unit a wireless signal broadcast by a cell tower;
(b) determining from the wireless signal whether the cell tower provides cellular service using a VoLTE cellular protocol; and
(c) when it is determined in step (b) that the cell tower does not provide cellular service using the VoLTE protocol, then preventing the VoLTE-capable vehicle telematics unit from attempting to wirelessly connect with the cell tower using an IP multimedia subsystem (IMS) protocol;
wherein step (c) further comprises communicating an instruction not use the IMS protocol from a processor of the vehicle telematics unit to a cellular chipset of the vehicle telematics unit.

### Claim 2 (depends on 1)

The method of claim 1, wherein the VoLTE cellular protocol is LTE or LTE Advanced.

### Claim 3 (depends on 1)

The method of claim 1, further comprising:
(d) wirelessly connecting to the cell tower using the IMS protocol when it is determined in step (b) that the cell tower provides cellular service using the VoLTE cellular protocol.

### Claim 4

A method of registering a voice over long-term evolution (VoLTE) capable vehicle telematics unit with a wireless carrier system, comprising the steps of:
(a) detecting at the vehicle telematics unit a wireless signal broadcast by a first cell tower;
(b) determining from the wireless signal broadcast by a first cell tower that the first cell tower provides cellular service using a VoLTE cellular protocol;
(c) directing the VoLTE-capable vehicle telematics unit to wirelessly connect with the first cell tower using an IP multimedia subsystem (IMS) framework;
(d) detecting at the vehicle telematics unit a wireless signal broadcast by a second cell tower;
(e) determining from the wireless signal broadcast by a second cell tower that the second cell tower provides cellular service using a non-VoLTE cellular protocol; and
(f) establishing cellular communications with the second cell tower while maintaining the previously-established IMS connection.

### Claim 5 (depends on 4)

The method of claim 4, wherein the VoLTE cellular protocol is LTE or LTE Advanced.