# US 2014/0155061 A1 · Enhanced Higher Priority Public Land Mobile Network (HPPLMN) Search > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0155061 A1 - Document ID: US20140155061A1 - Status: Published application - Kind: A1 - Application number: 13/706,009 - Filed: 2012-12-05 - Published: 2014-06-05 - Earliest claimed: 2012-12-05 - Assignees: Broadcom Corporation - Applicants: Broadcom Corporation - Inventors: Arzad KHERANI; Anand Devidas Kashikar - Web page: https://patentgrep.com/patent/US20140155061A1 ## CPC - H04W 48/16: Discovering, processing access restriction or access information - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Embodiments provide an enhanced approach for Higher Priority Public Land Mobile Network (HPPLMN) search. In one embodiment, information acquired during a search (for each detected cell per frequency channel) is saved in a database and persisted in the database based on a validity time. An idle mode-to-connected mode transition by the UE, rather than aborting the search, only suspends the search for it to be resumed at a later time upon a connected mode-to-idle mode transition by the UE. Saved search data that is valid at the time of the transition is maintained and the frequency channel(s) associated with it is not re-searched in the current search. In an embodiment, the search is resumed based on weights that are associated with frequency channels, where a weight indicates a priority for visiting the frequency channel. ## Claims ### Claim 1 A method for performing a search over a plurality of frequency channels in a device, comprising: selecting a frequency channel from the plurality of frequency channels based on respective weights associated with the plurality of frequency channels; searching the frequency channel for detectable cells; and updating a respective weight associated with the frequency channel in response to said searching. ### Claim 2 (depends on 1) The method of claim 1, wherein the respective weight is responsive to a respective last visit time associated with the frequency channel. ### Claim 3 (depends on 2) The method of claim 2, wherein the respective weight is based on a difference between the respective last visit time associated with the frequency channel and a respective threshold associated with the frequency channel. ### Claim 4 (depends on 3) The method of claim 3, wherein the difference corresponding to the selected frequency channel is most negative among the plurality of frequency channels. ### Claim 5 (depends on 3) The method of claim 3, wherein updating the respective weight associated with the frequency channel comprises updating the respective last visit time and the respective threshold associated with the frequency channel. ### Claim 6 (depends on 1) The method of claim 1, further comprising: detecting a cell on the frequency channel; decoding a system information block associated with the detected cell to determine one or more Public Land Mobile Networks (PLMNs) associated with the detected cell; and storing the determined PLMNs associated with the cell in a database. ### Claim 7 (depends on 1) The method of claim 1, further comprising: detecting an idle mode-to-connected mode transition with the device; and suspending the search over the plurality of frequency channels in response to said idle mode-to-connected mode transition. ### Claim 8 (depends on 7) The method of claim 7, further comprising: detecting a connected mode-to-idle mode transition within the device; and resuming the search over the plurality of frequency channels in response to said connected mode-to-idle mode transition. ### Claim 9 (depends on 8) The method of claim 8, wherein resuming the search comprises: comparing a first cell with a second cell, the first cell being a cell camped on by the device after the connected mode-to-idle mode transition and the second cell being a cell camped on by the device before the idle mode-to-connected mode transition; and resuming the search over the plurality of frequency channels without re-searching the selected frequency channel if the first cell and the second cell are the same. ### Claim 10 (depends on 8) The method of claim 8, further comprising: updating the respective weight associated with the frequency channel based on a connected mode duration between the idle mode-to-connected mode transition and the connected mode-to-idle mode transition. ### Claim 11 (depends on 8) The method of claim 8, wherein resuming the search comprises: comparing a validity time associated with data obtained by searching the frequency channel with a current time; and resuming the search over the plurality of frequency channels without researching the frequency channel if validity time is later than the current time. ### Claim 12 (depends on 11) The method of claim 11, wherein the validity time is based on a mobility state of the device, further comprising: updating the respective weight associated with the frequency channel based on the mobility state of the device. ### Claim 13 (depends on 1) The method of claim 1, further comprising: determining a number of past searches of the frequency channel; and updating a search depth associated with the frequency channel based on the number of past searches, wherein the search depth indicates a maximum number of cells to decode from cells detected on the frequency cell. ### Claim 14 (depends on 13) The method of claim 13, further comprising: increasing the search depth associated with the frequency channel if a number of detected cells in a previous search of the frequency channel is greater than the search depth currently associated with the frequency channel; and decreasing the search depth associated with the frequency channel if the number of detected cells in the previous search of the frequency channel is lower than the search depth current associated with the frequency channel. ### Claim 15 A method for performing a search over a plurality of frequency channels in a device, comprising: sequentially searching frequency channels of the plurality of frequency channels according to an order determined by respective weights associated with the plurality of frequency channels; detecting an idle mode-to-connected mode transition within the device; suspending the search over the plurality of frequency channels in response to the idle mode-to-connected mode transition within the device. ### Claim 16 (depends on 15) The method of claim 15, further comprising: resuming the search over the plurality of frequency channels in response to a connected mode-to-idle mode transition within the device without re-searching a frequency channel searched before the idle mode-to-connected mode transition within the device. ### Claim 17 (depends on 16) The method of claim 16, wherein a cell camped on by the device after the connected mode-to-idle mode transition is the same as a cell camped on by the device before the idle mode-to-connected mode transition. ### Claim 18 (depends on 16) The method of claim 16, wherein a validity time associated with data obtained by searching the frequency channel before the idle mode-to-connected mode transition is later than a current time. ### Claim 19 A device, comprising: a non-access stratum (NAS) layer module configured to detect an expiration of a Higher Priority Public Land Mobile Network (HPPLMN) search timer and to send a command to an access stratum (AS) layer in response to the expiration of the HPPLMN search timer; a radio resource control (RRC) module of the AS layer configured to initiate a HPPLMN search in response to the command and to save Public Land Mobile Networks (PLMNs) identified on a searched cell during the HPPLMN search, the RRC module further configured to: suspend the HPPLMN search upon a connected mode-to-idle mode transition, and resume the HPPLMN search upon a connected mode-to-idle mode transition without discarding the PLMNs identified on the searched cell, wherein a cell camped on by the device after the connected mode-to-idle mode transition is the same as a cell camped on by the device before the idle mode-to-connected mode transition. ### Claim 20 (depends on 19) The device of claim 19, wherein a validity time associated with the PLMNs identified on the searched cell is later than a current time.