VEHICLE TELEMATICS SCAN RATE CONTROL

• US 20150223151A1
• Filed: 01/31/2014
• Published: 08/06/2015
• Est. Priority Date: 01/31/2014
• Status: Active Grant

• Current Assignee: General Motors LLC (General Motors Company)
• Original Assignee: General Motors LLC (General Motors Company)
• Inventors: Lei, Yao Hui, Macdonald, Andrew J.
• Granted Patent: US 9,357,475 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 36/0094 Definition of hand-off measurement parameters
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 48/10 using broadcasted information
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 52/0209 in terminal devices terminal devices per se H04W88/02
• CPC Class Codes: H04W 72/30 Resource management for broadcast services
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 8/24 Transfer of terminal data
• 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 method and a system of controlling a PLMN scan rate (PCR) in a vehicle telematics unit. The method carried out by the system includes the steps of: (a) determining a power condition that includes a powered mode, an unpowered mode, and a DRx mode; (b) determining whether the telematics unit is scanning one or more home networks or one or more visitor networks; and (c) setting the PCR based on the determined power condition and the determined network, including: (c1) when in the powered mode and scanning a visitor network, the PCR is set to a first scan rate; (c2) when in the powered mode and scanning a home network, the PCR is set to a second scan rate that is slower than the first rate; and (c3) when in the DRx mode, the PCR is set to a third scan rate that is slower than the second rate.

Claims

1. A method of controlling a public land mobile network (PLMN) scan rate in a vehicle telematics unit, comprising the steps of:

(a) determining at the telematics unit a power condition that includes a powered mode, an unpowered mode, and a discontinuous reception (DRx) mode;

(b) determining at the telematics unit whether the telematics unit is scanning one or more home networks or one or more visitor networks; and

(c) setting the PLMN scan rate for the telematics unit based on the determined power condition and the determined network, wherein;

(c1) when the telematics unit is in the powered mode and when the telematics unit is scanning a visitor network, the PLMN scan rate is set to a first scan rate;

(c2) when the telematics unit is in the powered mode and when the telematics unit is scanning a home network, the PLMN scan rate is set to a second scan rate that is slower than the first rate; and

(c3) when the telematics unit is in the DRx mode, the PLMN scan rate is set to a third scan rate that is slower than the second rate.

2. The method of claim 1, wherein the second rate is a NORMAL scan rate associated with a subscriber identity module (SIM) of the telematics unit.

3. The method of claim 1, wherein the one or more home networks includes at least one of a primary home network and an equivalent home network.

4. The method of claim 1, wherein a list of the one or more visitor networks is stored in the telematics unit.

5. The method of claim 4, further comprising receiving at the telematics unit an updated list of visitor networks to replace the previous list from one of a call center, remote computer, or service center.

6. The method of claim 5, wherein the updated list further comprises a value of the first scan rate and a value of the third scan rate.

7. The method of claim 6, wherein the value of the first scan rate or the value of the third scan rate is associated with a multiplier.

8. The method of claim 5, further comprising when the updated list received at the telematics unit is corrupted, performing at the telematics unit the following steps:

ignoring the updated list;

setting the first and third scan rates to be equal with the second scan rate; and

removing any of the one or more visitor networks on the previous list.

9. The method of claim 4, wherein the list includes zero to twenty visitor networks.

10. The method of claim 1, further comprising repeating step (c) when the telematics unit is determined to be scanning a different home or visitor network.

11. The method of claim 1, further comprising repeating steps (a), (b), and (c) after the telematics unit exits the DRx mode or after the telematics unit exits the unpowered mode.

12. A method of controlling a public land mobile network (PLMN) scan rate in a vehicle telematics unit, comprising the steps of:

(a) determining a PLMN scanned by the telematics unit;

(b) setting a PLMN scan rate of the telematics unit, wherein;

(b1) when the scanned PLMN is included in a predetermined PLMN list, the scan rate is set to a first scan rate; and

(b2) when the PLMN is not included in the predetermined PLMN list, the scan rate is set to a second scan rate that is slower than the first scan rate;

(c) after setting the first scan rate or the second scan rate, determining whether the PLMN being scanned has changed, wherein;

(c1) when the scanned PLMN has changed, repeating step (b) for the currently scanned PLMN; and

(c2) when the scanned PLMN has not changed, determining whether the telematics unit is in a powered mode, an unpowered mode, or in a discontinuous reception (DRx) mode, wherein;

(c2.1) when the telematics unit is in a powered mode, repeating step (c);

(c2.2) when the telematics unit is in the unpowered mode, repeating steps (a), (b), and (c) when the telematics unit is powered again; and

(c2.3) when the telematics unit is in the DRx mode, setting the scan rate to a third scan rate that is slower than the second scan rate.

13. The method of claim 12, wherein the second scan rate is a NORMAL scan rate associated with a subscriber identity module (SIM) of the telematics unit.

14. The method of claim 12, wherein the predetermined PLMN list is stored in the telematics unit and replaced with an updated PLMN list from time to time.

15. The method of claim 14, wherein the updated PLMN list includes zero or more new PLMNs, an updated value of the first scan rate, and an updated value of the third scan rate.

16. The method of claim 15, further comprising performing at the telematics unit the following steps when the updated PLMN list is corrupted:

ignoring the updated PLMN list;

setting the first and third scan rates to be equal with the second scan rate; and

removing any of the one or more PLMNs on the predetermined PLMN list.

17. A method of updating public land mobile network (PLMN) scan rate data for a vehicle telematics unit, comprising the steps of:

(a) receiving scan rate data at a vehicle telematics unit having a first scan rate and a second, slower scan rate, wherein the second scan rate is associated with a cellular chipset of the telematics unit, wherein the scan rate data comprises an updated first scan rate;

(b) determining whether the scan rate data is corrupt;

(c) when step (b) determines the scan rate data not to be corrupt, replacing the first scan rate with the updated first scan rate; and

(d) when step (b) determines the scan rate data to be corrupt, setting the value of the first scan rate to the second scan rate.

18. The method of claim 17, wherein the telematics unit further has a third scan rate that is slower than the second scan rate and a fast list of visitor PLMNs, wherein the scan rate data further comprises an updated third scan rate and an updated fast list.

19. The method of claim 18, wherein step (c) further comprises replacing the third scan rate with the updated third scan rate, and replacing the fast list with an updated fast list.

20. The method of claim 18, wherein step (d) further comprises setting the value of the third scan rate to the second scan rate, and setting the quantity of PLMNs on the fast list to zero.