Adaptive cell search
Systems, methods, and circuitries are provided for performing adaptive cell searching. In one example, a method for a user equipment (UE) includes determining that the UE has entered an out of coverage (OOC) status and, in response, configuring a cell search pattern that defines a series of scheduled search instances for each of one or more frequency sets. A timing of the series of scheduled search instances is based on a time at which the UE entered OOC status and the cell search pattern is configured to cause performance of a respective minimum search rate of respective frequency sets. The frequency sets are searched based on the configured cell search pattern.
1 . A user equipment (UE) comprising a memory and a baseband processor configured to, when executing instructions stored in the memory, in response to entering out of coverage (OOC) status, cause the UE to
configure a cell search pattern that defines a series of scheduled search instances for at least one frequency set, wherein a timing of the series of scheduled search instances is based on a time at which the UE entered OOC status, further wherein the cell search pattern is configured to cause performance of a minimum search rate of the frequency set,
wherein the cell search pattern includes more than one time phase, wherein during each time phase the cell search pattern includes search instances of the frequency set according to a different pattern as compared to a pattern in other time phases, further wherein respective lengths of the more than one time phase are based on a configurable wait time; and
perform a search of the frequency set based on the configured cell search pattern.
2 . The UE of claim 1 , wherein a cell search pattern configuration includes respective pattern parameters for the frequency set indicating one or more of an initial gap time between scheduled search instances, a maximum gap time between scheduled search instances that is based on the minimum search rate of the frequency set, an increment of gap increase between scheduled search instances, or a multiplier to be applied to the increment for each successive scheduled search instance.
3 . The UE of claim 1 , wherein the baseband processor is configured to, when executing instructions stored in the memory, configure the cell search pattern based on a power state of the UE.
4 . The UE of claim 1 , wherein the baseband processor is configured to, when executing instructions stored in the memory, configure a different cell search pattern for a static UE state and a motion UE state.
5 . The UE of claim 1 , wherein the baseband processor is configured to adjust the cell search pattern in response to detecting a WiFi connection for the UE, detecting that the UE is operating in low power mode, or detecting that a rate of motion of the UE has increased.
6 . The UE of claim 1 , wherein the baseband processor is configured to cause the UE to, in response to a trigger event associated with the frequency set occurring at an offset time prior to a scheduled search instance,
determine whether a previous trigger event occurred within a trigger interval and, if not,
perform a search of the frequency set; and
adjust a timing of the scheduled search instances for the frequency set based on the offset time, while preserving an original interval between scheduled search instances for another frequency set.
7 . The UE of claim 6 , wherein the trigger event comprises a screen unlock, a transition from screen sleep to screen awake, a transition from a UE sleep state to a wake state, detection of an unknown band, or detection of a proximate geographic border.
8 . The UE of claim 1 , wherein the baseband processor is configured to modify frequencies included in the frequency set based on information received from an application processor database that stores operating frequency information mapped to location information for in-coverage UEs.
9 . The UE of claim 1 , wherein the baseband processor is configured to, when executing instructions stored in the memory, cause the UE to
receive an indication of frequencies supported in one or more cells proximate to the UE or frequencies supported in a larger set of cells proximate to the UE; and
modify frequencies included in the frequency set based on the indication of frequencies.
10 . A method for a user equipment (UE) comprising:
determining that the UE has entered out of coverage (OOC) status;
in response, configuring a cell search pattern that defines a series of scheduled search instances for at least one frequency set, wherein a timing of the series of scheduled search instances is based on a time at which the UE entered OOC status, further wherein the cell search pattern is configured to cause performance of a minimum search rate of the frequency set;
in response to a trigger event associated with the frequency set occurring at an offset time prior to a scheduled search instance,
determining whether a previous trigger event occurred within a trigger interval and, if not,
performing a search of the frequency set; and
adjusting a timing of the scheduled search instances for the frequency set based on the offset time, while preserving an original interval between scheduled search instances for another frequency set; and
searching the frequency set and the other frequency set based on the configured cell search pattern and the adjusted timing of the scheduled search instances.
11 . The method of claim 10 , wherein a cell search pattern configuration includes respective pattern parameters for the frequency set indicating one or more of an initial gap time between scheduled search instances, a maximum gap time between scheduled search instances that is based on the minimum search rate of the frequency set, an increment of gap increase between scheduled search instances, or a multiplier to be applied to the increment for each successive scheduled search instance.
12 . The method of claim 10 , comprising configuring the cell search pattern based on a power state of the UE.
13 . The method of claim 10 , comprising configuring a different cell search pattern for a static UE state and a motion UE state.
14 . The method of claim 10 , comprising adjusting the cell search pattern in response to detecting a WiFi connection for the UE, detecting that the UE is operating in low power mode, or detecting that a rate of motion of the UE has increased.
15 . The method of claim 10 , wherein the cell search pattern includes more than one time phase, wherein during each time phase the cell search pattern schedules search instances of the frequency set according to a different pattern as compared to a pattern in other time phases, wherein the method comprises controlling respective lengths of the more than one time phase by configuring a wait time associated with the cell search pattern.
16 . The method of claim 10 , wherein the trigger event comprises a screen unlock, a transition from screen sleep to screen awake, a transition from a UE sleep state to a wake state, detection of an unknown band, or detection of a proximate geographic border.
17 . The method of claim 10 , comprising modifying frequencies included in the frequency set based on information received from an application processor database that stores operating frequency information mapped to location information for in-coverage UEs.
18 . The method of claim 10 , comprising
receiving an indication of frequencies supported in one or more cells proximate to the UE or frequencies supported in a larger set of cells proximate to the UE; and
modifying frequencies included in the frequency set based on the indication of frequencies.
19 . A user equipment (UE) comprising a memory and a baseband processor configured to, when executing instructions stored in the memory, in response to entering out of coverage (OOC) status, cause the UE to
perform searches of at least one frequency set based on a cell search pattern that defines a series of scheduled search instances for the frequency set; and
modify frequencies included in the frequency set based on information received from an application processor database that stores operating frequency information mapped to location information for in-coverage UEs.
20 . The UE of claim 19 , wherein the baseband processor is configured to, when executing instructions stored in the memory, cause the UE to
receive indication of a set of frequencies supported in one or more cells proximate to the UE or frequencies supported in a larger set of cells proximate to the UE; and
modify the frequencies included in the frequency set based on the set of frequencies.
21 . The UE of claim 20 , wherein the baseband processor is configured to, when executing instructions stored in the memory, cause the UE to include a subset of the set of frequencies in successive searches of the frequency set.
22 . The UE of claim 19 , wherein the baseband processor is configured to, when executing instructions stored in the memory, cause the UE to
fetch, from the application processor database, cell level frequency information when the UE acquires a new cell, is switched out of airplane mode, or connects with a different SIM card; and
modify the frequencies included in the frequency set on the fetched cell level frequency information.
23 . The UE of claim 19 , wherein the baseband processor is configured to, when executing instructions stored in the memory, cause the UE to
fetch, from the application processor database, frequencies mapped to mobile country codes of countries proximate the UE; and
modify the frequencies included in the frequency set based on the fetched frequencies.