Scanning and decoding methods and apparatus for mobile communication devices

• US 20070111740A1
• Filed: 11/16/2005
• Published: 05/17/2007
• Est. Priority Date: 11/16/2005
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Wandel, Matthias
• Granted Patent: US 7,689,216 B2
• Time in Patent Office: Days
• US Class Current: 455/513
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/542 using measured or perceived quality

Abstract

In one illustrative scanning and decoding method, a signal strength level of an RF signal on an RF channel is measured for a plurality of RF channels of an RF band. The act of measuring a signal strength level is repeated at least one time to obtain at least one other signal strength level of the RF signal. Subsequently, an averaging function is completed with use of the signal strength level and the at least one other signal strength level for identifying an averaged signal strength level of the RF signal. At least one optimal RF signal is then identified based on the averaged signal strength levels of the RF signals on the RF channels. In between the repeated acts of measuring signal strength levels of the RF signals, and prior to identifying the averaged signal strength levels, control information is decoded on at least one of the RF channels and stored in memory. A wireless communication network is selected for communication with use of the control information stored in the memory which corresponds to one of the at least one optimal RF signal. In this manner, the mobile station expeditiously obtains the control information for network selection or other purposes prior to completing the averaging of the signal strength levels.

Claims

1. A method for use in scanning a radio frequency (RF) band having a plurality of RF channels in a scanning procedure, the method comprising the acts of:

for at least some of the plurality of RF channels of the RF band;

measuring a signal strength level of an RF signal of a wireless communication network on an RF channel;

repeating the act of measuring at least one time so that at least one other signal strength level of the RF signal is identified;

completing an averaging function with the signal strength level and the at least one other signal strength level for identifying an averaged signal strength level for the RF signal on the RF channel; and

in between at least some of the acts of measuring signal strength levels of the RF signal, decoding control information on at least one of the RF channels of the RF band and storing the control information in memory.

2. The method of claim 1, further comprising:

identifying at least one optimal RF signal based on the averaged signal strength levels of the RF signals on the at least some RF channels; and

selecting a wireless communication network for communication with use of the control information stored in the memory which corresponds to one of the at least one optimal RF signal.

3. The method of claim 1, further comprising:

after identifying the averaged signal strength level for the RF signal on the RF channel, reading the control information associated with the RF channel from memory for use in selecting a wireless communication network for communication.

4. The method of claim 1, further comprising:

identifying at least one optimal RF signal based on the signal strength level of the RF signal on the RF channel; and

wherein the act of decoding comprises the further act of decoding the control information in response to identifying that the RF signal comprises one of the at least one optimal RF signal.

5. The method of claim 1, wherein the act of decoding comprises decoding control information on two or more of the RF channels of the RF band simultaneously and storing the control information in memory.

6. The method of claim 1, further comprising:

wherein in a first repetition of signal strength measurements taken for the RF channels of the RF band, the method further comprises;

identifying a first signal strength level of a first RF signal on a first RF channel;

identifying that the first RF signal is an optimal RF signal based at least on the first signal strength level;

decoding first control information on the first RF channel and storing the first control information in memory based on identifying that the first RF signal is an optimal RF signal;

wherein in a subsequent repetition of signal strength measurements taken for the RF channels of the RF band, the method further comprises;

identifying a second signal strength level of a second RF signal on a second RF channel which is different from the first RF channel;

identifying that the second RF signal is an optimal RF signal based at least on the second signal strength level; and

decoding second control information on the second RF channel and storing the second control information in memory based on identifying that the second RF signal is an optimal RF signal.

7. The method of claim 1, wherein the control information comprises a network identification associated with the wireless communication network.

8. The method of claim 1, wherein the method is performed by a mobile station, the wireless communication network comprises a Global Systems for Mobile communications (GSM) network, and the act of identifying is performed five times for each RF signal on each RF channel over a time period of about five seconds.

9. A communication device, comprising;

a radio frequency (RF) transceiver;

an antenna means coupled to the RF transceiver;

one or more processors coupled to the RF transceiver;

the one or more processors being adapted to, for at least some of a plurality of RF channels of an RF band;

measuring a signal strength level of an RF signal of a wireless communication network on an RF channel;

repeat the act of measuring at least one time so that at least one other signal strength level of the RF signal is identified;

complete an averaging function with the signal strength level and the at least one other signal strength level for identifying an averaged signal strength level for the RF signal on the RF channel; and

in between at least some of the acts of measuring signal strength levels of the RF signal, decode control information on at least one of the RF channels of the RF band and storing the control information in memory.

10. The communication device of claim 9, wherein the one or more processors are further adapted to:

identify at least one optimal RF signal based on the averaged signal strength levels of the RF signals on the at least some RF channels; and

select a wireless communication network for communication with use of the control information stored in the memory which corresponds to one of the at least one optimal RF signal.

11. The communication device of claim 9, wherein the one or more processors are further adapted to:

after identifying the averaged signal strength level for the RF signal on the RF channel, read the control information associated with the RF channel from the memory for use in selecting a wireless communication network for communication.

12. The communication device of claim 9, wherein the one or more processors are further adapted to identify at least one optimal RF signal based on the signal strength level of the RF signal on the RF channel, and wherein the one or more processors are further adapted to decode the control information by decoding the control information in response to identifying that the RF signal comprises one of the at least one optimal RF signal.

13. The communication device of claim 9, wherein the one or more processors are further operative to decode the control information by decoding control information on two or more of the RF channels of the RF band simultaneously and storing the control information in memory.

14. The communication device of claim 9, wherein the one or more processors are further adapted to decode by assigning two or more contexts for decoding control information on two or more of the RF channels of the RF band simultaneously.

15. The communication device of claim 9, further comprising:

wherein the one or more processors are further adapted to, in a first repetition of signal strength measurements taken for the RF channels of the RF band;

identify a first signal strength level of a first RF signal on a first RF channel;

identify that the first RF signal is an optimal RF signal based at least on the first signal strength level;

decode first control information on the first RF channel and storing the first control information in memory based on identifying that the first RF signal is an optimal RF signal;

wherein the one or more processors are further adapted to, in a subsequent repetition of signal strength measurements taken for the RF channels of the RF band;

identify a second signal strength level of a second RF signal on a second RF channel which is different from the first RF channel;

identify that the second RF signal is an optimal RF signal based at least on the second signal strength level; and

decode second control information on the second RF channel and storing the second control information in memory based on identifying that the second RF signal is an optimal RF signal.

16. A computer program product, comprising:

a storage medium;

computer program instructions stored in the storage medium;

the computer program instructions being executable by one or more processors for scanning a radio frequency (RF) band having a plurality of RF channels by;

for at least some of the plurality of RF channels of the RF band;

identifying a signal strength level of an RF signal of a wireless communication network on an RF channel;

repeating the act of identifying at least one time so that at least one other signal strength level of the RF signal is identified;

completing an averaging function with the signal strength level and the at least one other signal strength level for identifying an averaged signal strength level for the RF signal on the RF channel; and

in between at least some of the acts of identifying signal strength levels of the RF signal;

decoding control information on at least one of the RF channels of the RF band and storing the control information in memory.

17. The computer program product of claim 16, wherein the computer program instructions are further executable for:

identifying at least one optimal RF signal based on the averaged signal strength levels of the RF signals on the at least some RF channels; and

selecting a wireless communication network for communication with use of the control information stored in the memory which corresponds to one of the at least one optimal RF signal.

18. The computer program product of claim 16, wherein the computer program instructions are further executable for:

after identifying the averaged signal strength level for the RF signal on the RF channel, reading the control information associated with the RF channel from the memory for selecting a wireless communication network for communication.

19. The computer program product of claim 16, wherein the computer program instructions are further executable for:

identifying at least one optimal RF signal based on the signal strength level of the RF signal on the RF channel; and

decoding the control information in response to identifying that the RF signal comprises one of the at least one optimal RF signal.

20. The computer program product of claim 16, wherein the computer program instructions are further executable for decoding by decoding control information on two or more of the RF channels of the RF band simultaneously and storing the control information in memory.

21. The computer program product of claim 16, further comprising:

wherein the computer instructions are further executable for, in a first repetition of signal strength measurements taken for the RF channels of the RF band;

identifying a first signal strength level of a first RF signal on a first RF channel;

identifying that the first RF signal is an optimal RF signal based at least on the first signal strength level;

decoding first control information on the first RF channel and storing the first control information in memory based on identifying that the first RF signal is an optimal RF signal;

wherein the computer instructions are further executable for, in a subsequent repetition of signal strength measurements taken for the RF channels of the RF band;

identifying a second signal strength level of a second RF signal on a second RF channel which is different from the first RF channel;

identifying that the second RF signal is an optimal RF signal based at least on the second signal strength level; and

decoding second control information on the second RF channel and storing the second control information in memory based on identifying that the second RF signal is an optimal RF signal.