# US 8,787,913 B2 · Primary connection strategy for vehicle originated cellular communication to a call center

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- Number: US 8,787,913 B2
- Document ID: US8787913B2
- Status: Granted
- Kind: B2
- Application number: 13/285,674
- Filed: 2011-10-31
- Published: 2012-02-23
- Granted: 2014-07-22
- Earliest claimed: 2008-12-29
- Assignees: General Motors Corporation
- Applicants: Sethu K. Madhavan; Ki Hak Yi
- Inventors: Sethu K. Madhavan; Ki Hak Yi
- Web page: https://patentgrep.com/patent/US8787913B2

## CPC

- H04W 76/18: Management of setup rejection or failure
- H04M 1/6075: {adapted for handsfree use in a vehicle (H04M1/6058 takes precedence; arrangements for holding telephones in a vehicle B60R11/0241)}
- H04M 1/72418: for supporting emergency services
- H04M 2250/12: including a sensor for measuring a physical value, e.g. temperature or motion
- H04W 88/06: adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08)

## Abstract

A system and method for making vehicle originated calls to a telematics service provider or other call center. The method includes identifying a call type associated with a desired wireless communication of speech or data to the call center, and then carrying out one of a number of different call connection processes depending on the call type. For voice channel cellular connections, an in-band modem cellular connection is preferably established in most instances using a connection retry strategy that includes primary, secondary, and possibly tertiary connection attempts. The system and method can be carried out in connection with various cellular system technologies, but is especially suited for use with GSM systems.

## Claims

### Claim 1

A connection method for use by a vehicle telematics unit to establish a wireless telephone connection between the telematics unit and a call center over a GSM cellular system, comprising the steps of:
(a) determining if the telematics unit is currently attached to a base station of a registered public land mobile network (PLMN) and, if not, executing an idle mode process involving cell reselection and attempting to attach to a base station following cell reselection;
(b) attempting origination of an in-band modem cellular call if the telematics unit is attached to a base station; and
(c) if the origination attempt fails, then carrying out steps (a) and (b) for one or more neighboring base stations using a broadcast control channel (BCCH) Allocation list.

### Claim 2 (depends on 1)

A connection method as defined in claim 1, wherein step (b) further comprises attempting to originate the call as a voice channel data connection.

### Claim 3 (depends on 1)

A connection method as defined in claim 1, wherein, if the origination attempts carried out in step (c) fail, then the method further comprises attempting to originate the connection with the call center using an alternative connection strategy.

### Claim 4 (depends on 1)

A connection method as defined in claim 1, wherein the alternative connection strategy includes the step of establishing a packet switched data connection.

### Claim 5 (depends on 1)

A connection method as defined in claim 1, wherein step (c) further comprises receiving and decoding base station information via the BCCH and attempting to originate the connection using the decoded information.

### Claim 6 (depends on 5)

A connection method as defined in claim 5, wherein step (c) further comprises obtaining the BCCH Allocation (BA) list and identifying the neighboring base station from the BA list.

### Claim 7 (depends on 5)

A connection method as defined in claim 5, wherein step (c) further comprises obtaining connection information for the neighboring base station from the BA list.

### Claim 8 (depends on 1)

A connection method as defined in claim 1, wherein step (c) comprises, for at least one iteration of steps (a) and (b) using a neighboring base station, the steps of:
receiving a PLMN change event interrupt;
carrying out a PLMN reselection process based on the interrupt; and
attaching to a base station following PLMN reselection.

### Claim 9 (depends on 8)

A connection method as defined in claim 8, wherein the step of carrying out a PLMN reselection process further comprises the step of executing an idle mode process involving PLMN reselection.