WO2013060146A1

WO2013060146A1 - Csg cell searching method and device

Info

Publication number: WO2013060146A1
Application number: PCT/CN2012/076939
Authority: WO
Inventors: 方百里
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-10-25
Filing date: 2012-06-14
Publication date: 2013-05-02
Also published as: CN102395165A; CN102395165B

Abstract

The present invention relates to the field of communications. Provided is a CSG cell searching method. The method includes: when the exiting CSG information of a terminal changes or a user requests to perform CSG cell searching, the terminal performing frequency scanning in the capability range thereof to find out a specific CSG cell at each frequency point; reading system information SIB1 about the CSG cell to acquire public land mobile network PLMN and CSG ID information about said cell; and if the cell PLMN and CSG ID are in a CSG whitelist of the terminal, recording the information about the CSG cell into the residence history of the CSG cell. Also provided is a CSG cell searching device and a cell reselection judgment method in an idle state. The technical solution in the present invention is employed to enable a terminal to enlarge the cell measurement range in case of meeting electricity-saving requirements to realize CSG cell reselection and handover.

Description

Search method and device for CSG cell

The present invention relates to mobile communication technologies, and in particular, to a CSG (Closed Subscriber Group) cell search method and apparatus. Background technique

In an LTE system, a cell can be divided into a normal cell (also referred to as a non-CSG cell) and a CSG cell. The CSG cell is part of a PLMN (Public Land Mobile Network) and is served by a HNB/HeNB (Home NodeB/Home eNodeB, Home Node B/Home Evolved Node B). Compared with a normal cell, the CSG cell is a CSG cell. Generally, it has the advantages of cheap billing, flexible service selection, higher download rate, more stable signal, etc., but the camping is limited, only when the CSG ID of the user card exists and the ID of the CSG cell to be camped on. The match can successfully reside. There may be one or more CSG IDs in the user card. The set of these CSG IDs is called "CSG Whitelist".

According to 3GPP TS 36.304 and 36.331, as long as the CSG white list of the terminal is not empty, the terminal needs to support the automatic search function of the CSG cell in order to implement reselection and handover to the CSG cell. In the normal working mode, the reselection of the terminal is to generate a measurement task for the adjacent frequency point according to the list of adjacent frequency points in the system information, and then generate a reselection target cell by the evaluation of the measurement result to implement cell reselection; According to the measurement object list in the measurement configuration, a measurement task for the specified frequency point is generated, and then the measurement report criterion and the evaluation of the measurement result are used to generate a measurement report, and according to the received measurement report, whether to initiate the reselection is determined. The information about the frequency of the CSG cell is not necessarily included in the list of neighboring frequency points of the system information or in the measurement object list of the measurement configuration. Therefore, if the terminal uses the measurement task generation mode in the normal working mode, the vicinity may not be detected. The existence of the CSG cell makes it impossible to reselect and switch to the CSG cell. Summary of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a CSG cell search method and device, so as to solve the problem that the prior art cannot perform reselection and handover to the CSG cell.

An embodiment of the present invention provides a method for searching for a CSG cell, where the method includes: when the existing CSG information of the terminal changes or the user requests to perform a CSG cell search, the terminal performs frequency sweeping within the capability range thereof to find out a specific CSG cell under each frequency point; reading system information SIB1 of the CSG cell, acquiring public land mobile network PLMN and CSG ID information of the CSG cell;

If the cell PLMN and the CSG ID are in the CSG white list of the terminal, the information of the CSG cell is recorded in the CSG cell resident history.

In the above method, the existing CSG information of the terminal is changed to: the terminal detects that the CSG whitelist has new content, or the terminal is successfully camped on, or the CSG whitelist is not empty but has no CSG cell. Resident record.

In the above method, the information of the CSG cell is recorded in the CSG cell resident history:

Obtaining the CSG cell information of the current selection;

Before the CSG cell information is selected, if the terminal does not have a serving cell, it is checked whether the currently selected CSG cell is in the CSG cell resident history list, and the currently selected CSG cell is not in the CSG cell resident history list, then in the CSG A new record is added to the cell resident history list, and the CSG cell information selected this time is recorded in the newly added record entry.

Further, the method further includes:

Before the CSG cell is selected, if the terminal already has a serving cell, the information of the serving cell where the terminal is located before the CSG cell selection is obtained;

If the CSG cell selected this time is in the CSG cell resident history list, the serving cell information of the terminal before the CSG cell selection does not exist in the environment column of the selected CSG cell history record. In the table, the serving cell environment information is added to the CSG cell environment information list; or, if the currently selected CSG cell is not in the CSG cell resident history list, a new record is added in the CSG cell resident history list. The CSG cell information selected this time is recorded into the newly added record entry, and the serving cell environment information is added to the CSG cell environment information list.

In the above method, further, the method further includes:

When the terminal is in the idle state, whenever the serving cell change occurs, the terminal starts the measurement task and the additional CSG automatic search judgment, which is specifically:

The terminal obtains basic measurement information from the system information, and generates a basic measurement task according to the basic measurement information, and the terminal sets the CSG cell automatic search task information set to all records in the CSG cell resident history list;

For each record in the automatic search information set of the CSG cell, if it is checked that the cell frequency point in the current CSG cell record exists in the basic measurement task, the physical cell ID of the CSG cell is added to the specified cell list of the corresponding frequency of the basic measurement task. Delete this record in the CSG cell automatic search task information set.

Further, the method further includes:

For each record in the CSG cell automatic search information set, if it is checked that the cell frequency point in the current CSG cell record does not exist in the basic measurement task, then:

If the CSG cell automatic search information set has been traversed, and the CSG cell automatic search information set is not empty at this time, the location information of the current serving cell is obtained, and the filtered CSG automatic search information set does not belong to or does not belong to the current serving cell location. Record

If the CSG cell automatic search information set at this time is not empty, the CSG cell is traversed to automatically search each record in the information set.

If it is determined that the environmental information of the CSG history record meets any one of the measurement objects in the basic measurement task, and the CSG cell automatic search information set has been traversed, the additional CSG cell search target is set to the CSG automatic search information set record, and the additional CSG is started. Cell search process; or,

If it is determined that the environmental information of the CSG history record does not meet any of the measurement objects in the basic measurement task, the frequency of the CSG cell is added within the capability range of the terminal for measurement, and the record is deleted in the CSG cell automatic search information set.

In the above method, the initiating additional CSG cell search process is:

In a period of 5 minutes, the filtered CSG automatically searches for cells in the information set, and selects a cell whose measurement result is better than the high quality standard in the PLMN search;

If it is determined that a cell satisfies the high-quality condition, the cell that meets the high-quality standard is measured, and the frequency of the cell is measured. After determining the frequency point measurement, whether the highest-ranked cell is a CSG cell that the terminal can camp on, after the frequency point measurement, the highest The ranked cell is a CSG cell that the terminal can camp on, and the terminal performs reselection to the selected CSG cell; after the frequency point measurement, the highest ranked cell is not a CSG cell that the terminal can camp on, or no cell satisfies high quality condition Then, for the best cell at each frequency point of the normal measurement task, the SIB1 of the cell is read, and the cell is determined to be a CSG cell whose terminal meets the camping condition, and the terminal performs reselection to the selected CSG cell.

Further, the method further includes

When the terminal is in the connected state, whenever a switch occurs or a new measurement configuration is received, then:

The terminal generates a normal measurement task according to the measurement configuration message, and obtains basic information of the current serving cell, where the location of the CSG cell in the historical camping information of the CSG cell belongs to or is close to the serving cell;

The CSG historical camped cell whose location information is close to the current serving cell is collected from the CSG cell historical camping information, and is set as the CSG automatic search cell set; in the CSG automatic search cell set, the filtered frequency point already exists in the normal measurement task. If there is no remaining record in the CSG automatic search cell set after filtering, the terminal only performs normal measurement tasks; if the CSG automatically searches for the remaining set of cells in the CSG after filtering, the CSG automatically searches for the cell set, the CSG cell history record. The environment information, checking the frequency and location information of the current serving cell, if the environment information of the specific CSG cell camping history includes the serving cell, or the environment information of the specific CSG cell camping history does not include the serving cell, but the terminal measurement After the CSG automatically searches for the signal strength of all the historical CSG cells in the cell set, it is determined that the signal strength of the historical CSG cell is better than the standard of the high-quality cell, and the terminal initiates the Proximity Indication process for the frequency of the CSG cell that meets the condition. The presence of a network side CSG cell.

The embodiment of the present invention further provides a method for determining a cell reselection in an idle state, including: determining whether a current serving cell of the terminal is a CSG cell, and if yes, considering a reselection priority of the serving cell frequency point in reselection Perform normal cell reselection evaluation; otherwise, sort the cell measurement results under the frequency point for each frequency point measurement result; determine whether the best cell under the frequency point is a historically resident CSG cell, if yes , select to this CSG cell; otherwise, after all frequency points are traversed, normal cell reselection evaluation is performed.

An embodiment of the present invention further provides a CSG cell search apparatus, including

The frequency sweeping module is configured to perform frequency sweeping within the capability range when the existing CSG information of the terminal changes or the user requests to perform CSG cell search, and find a specific CSG cell under each frequency point;

Obtaining a module, configured to read system information SIB1 of the CSG cell, and obtain PLMN and CSG ID information of the public land mobile network of the cell;

The recording module is configured to record the information of the CSG cell into the CSG cell resident history when the cell PLMN and the CSG ID are in the CSG white list of the terminal.

The technical solution described in the embodiment of the present invention enables the terminal to increase the cell measurement range and achieve reselection and handover to the CSG cell when the terminal meets the power saving requirement. DRAWINGS

Figure 1 is a flow chart of a first embodiment of the present invention;

Figure 2 is a flow chart of a second embodiment of the present invention; Figure 3 is a flow chart of a third embodiment of the present invention;

Figure 4 is a flow chart of a fourth embodiment of the present invention;

Figure 5 is a flow chart of a fifth embodiment of the present invention;

Figure 6 is a flow chart of a sixth embodiment of the present invention. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments in order to make the present invention. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In order to support reselection and handover to the CSG cell, the terminal may need to initiate a search for the CSG cell in addition to the content of the existing measurement task. Specifically, the frequency of the cell can be obtained by frequent frequency point scanning, and then the system is read. The information determines whether a suitable CSG cell can reside, however, in this way, the terminal consumes more power. The solution provided by the embodiment of the present invention enables the terminal to increase the cell measurement range and achieve reselection and handover to the CSG cell when the terminal meets the power saving requirement.

The first embodiment of the present invention provides a CSG cell search method, when the user instructs the terminal to perform a CSG cell search by using an instruction, or when the terminal detects that the CSG white list has new content; or, the terminal is successfully camped on. When the CSG whitelist is found to be empty but there is no resident record of the CSG cell, the CGS cell is searched. FIG. 1 is a flowchart of the first embodiment of the present invention. As shown in FIG. 1, the first embodiment of the present invention specifically includes :

Step S101: The terminal performs frequency sweeping within its capability range to find two best CSG cells under each frequency point;

Step S102: Read system information SIB1 (System Information Blocks) of the CSG cell, and obtain PLMN and CSG ID information of the cell.

Step S103, determining whether the cell PLMN and CSG ID are in the CSG white list of the terminal, if yes, go to step S105, if not, go to step S104; Step S104, determining whether there are other frequency points in the frequency sweeping result, if yes, go to step 101, and if not, end;

Step S105, the information of the CSG cell is recorded in the CSG cell resident history, and the process goes to step S104.

The second embodiment of the present invention provides a method for recording CSG cell resident history information when a terminal selects or reselects to a CSG cell, or when the terminal switches to a CSG cell, and FIG. 2 is a second embodiment of the present invention. Flowchart, as shown in FIG. 2, the method specifically includes:

Step S201: Obtain the CSG cell information that is selected this time, including a PLMN, a CSG ID, a cell PhysCdlld (physical cell address), a cell frequency point, and a cell location information of the cell;

Step S202, determining whether the terminal has a serving cell before the current CSG cell selection, that is, whether the terminal successfully camps on a serving cell or establishes a connection with a cell, and if yes, go to step 205, if not, turn Go to step S203;

Step 203, check whether the CSG cell selected this time is in the CSG cell resident history list, and if yes, then, otherwise, go to step S204;

Step S204, adding a record in the CSG cell resident history list, which will be selected this time.

The CSG cell information is recorded in the newly added record entry, and ends;

Step S205: Obtain information about the serving cell where the terminal is located before the CSG cell is selected, including the PLMN, the cell frequency, and the cell location information of the cell.

Step S206, it is checked whether the CSG cell selected this time is in the CSG cell resident history list, if yes, go to step S208, otherwise, go to step S207;

Step S207, adding a record in the CSG cell resident history list, recording the currently selected CSG cell information into the newly added record entry, and proceeding to step S209;

Step S208, determining whether the serving cell information of the terminal before the CSG cell selection exists in the environment list of the selected CSG cell history record, if not, going to step S209, otherwise ending; Step S209, adding the serving cell environment information to the CSG cell environment information list, and ending.

The second embodiment of the present invention provides a method for determining that a terminal initiates a measurement task and an additional CSG automatic search every time a serving cell change occurs when the terminal is in an idle state, and FIG. 3 is a flowchart of the third embodiment of the present invention. Figure, as shown in Figure 3, the process includes:

Step S301: The terminal acquires basic measurement information from the system information; the terminal generates a basic measurement task according to the basic measurement information; and the terminal sets the CSG cell automatic search task information set to all records in the CSG cell resident history list;

Step S302, the CSG cell automatically searches for each record in the information set: check whether the cell frequency point in the current CSG cell record exists in the basic measurement task, and if yes, go to step S303, otherwise, go to step S304;

Step S303: Add the PhysCdlld of the CSG cell to the specified cell list corresponding to the corresponding frequency of the basic measurement task, and delete the record in the CSG cell automatic search task information set;

Step S304, determining whether the CSG cell automatic search information set has been traversed, if yes, proceeding to step 305, otherwise, returning to step S302;

Step S305, determining whether the automatic search information set of the CSG cell at this time is empty, if it is empty, stopping the additional CSG cell search process, and ending; otherwise, going to step S306;

Step S306: Acquire location information of the current serving cell, and filter records in the CSG automatic search information set that are not or not close to the current serving cell location.

Step S307, determining whether the CSG cell automatic search information set at this time is empty, if it is empty, stopping the additional CSG cell search process, ending; otherwise, going to step S308;

Step S308, traversing the CSG cell to automatically search each record in the information set: determining that the environmental information of the CSG history record meets any one of the basic measurement tasks, and if yes, go to step S309, otherwise, add the CSG within the terminal capability range. The frequency of the cell is measured; the record is deleted in the CSG cell automatic search information set; Step S309, determining whether the CSG cell automatic search information set has been traversed, and if so, setting an additional CSG cell search target to the CSG automatic search information set record; initiating an additional CSG cell search process, ending; otherwise, returning to step S308.

The fourth embodiment of the present invention provides a method for determining cell reselection in an idle state, and FIG. 4 is a flowchart of a fourth embodiment of the present invention. As shown in FIG. 4, the process specifically includes:

Step S401, determining whether the current serving cell is a CSG cell, if yes, go to step S402, otherwise, go to step S403;

Step S402: Considering that the reselection priority of the serving cell frequency point is the highest in the reselection, performing normal cell reselection evaluation, and ending;

Step S403: Sort the cell measurement results under the frequency point for the measurement result of each frequency point; determine whether the best cell under the frequency point is a historically camped CSG cell, and if yes, select the CSG cell, End; otherwise, go to the next step;

Step S404, it is judged whether all the frequency points are traversed, and if yes, the normal cell reselection evaluation is performed, and the process ends; otherwise, the process goes to step S403.

A fifth embodiment of the present invention provides a method for searching for an additional CSG cell in an idle state. FIG. 5 is a flowchart of a fifth embodiment of the present invention. As shown in FIG. 5, the terminal starts a 5-minute periodic timer. When it times out, it specifically includes:

Step S501: The filtered CSG automatically searches for a cell in the information set; the selected measurement result is better than the high quality standard in the PLMN search (ie, the RSRP (reference signal received power) measurement value of the cell is higher than -110 dBm) Community

Step S502, it is determined whether a cell meets the high quality condition, if yes, go to step S503, otherwise, go to step S504;

Step S503: Measure the frequency point of the cell that meets the high quality standard. After determining the frequency point measurement, whether the highest ranked cell is a CSG cell that the terminal can camp on, and if yes, the terminal performs heavy to the selected CSG cell. Select, end; otherwise, go to step S504; Step S504: For the best cell at each frequency point of the normal measurement task, read the SIB1 of the cell, determine whether the cell is a CSG cell that the terminal can camp on, and if yes, the terminal performs reselection to the selected CSG cell, End; otherwise, go to step S505;

Step S505: Determine whether the best cells of all normal measurement frequency points are traversed, and if yes, end, otherwise, return to step S504.

A sixth embodiment of the present invention provides an automatic CSG cell automatic search process in a connected state, and FIG. 6 is a flowchart of a sixth embodiment of the present invention. As shown in FIG. 6, the terminal is in a connected state, whenever it occurs. When switching, or when a new measurement configuration is received, B'J:

Step S601: The terminal generates a normal measurement task according to the measurement configuration message, and obtains basic information of the current serving cell, including a serving cell frequency point, a location information of the serving cell, and the like; and determining whether the CSG cell history resident information has a historical resident The location of the CSG cell belongs to or is close to the serving cell. If yes, go to step S602. Otherwise, the terminal only performs normal measurement tasks and ends.

Step S602, collecting a CSG historical resident cell whose location information is close to the current serving cell from the CSG cell history camping information, and setting it as a CSG automatic search cell set; in the CSG automatic search cell set, the filtered frequency point already exists in the normal The cell in the task is measured; after the filtering is determined, the CSG automatically searches whether the cell set has remaining records, and if so, goes to step S603; otherwise, the terminal only performs a normal measurement task, and ends;

Step S603, obtaining CGW automatically searches for the environment information of the CSG cell history record in the cell set; checking the frequency and location information of the current serving cell, determining whether the environment information of the camping history of a certain CSG cell includes the serving cell, and if so, Go to step S605, otherwise, go to step S604;

The following steps, in a 5 minute cycle, are repeated:

Step S604: The terminal measures, by the CSG, the signal strength of all historical CSG cells in the cell set automatically, and determines whether the signal strength of the historical CSG cell is better than the PLMN search. The criteria of the zone, if yes, go to step S605, otherwise, wait for the next five-minute period to arrive; step S605, the terminal initiates Proximity for the frequency point of the CSG cell that satisfies the condition

Indication (ie, "proximity indication message", used to notify the network side UE to enter the coverage of a certain CSG cell), notifying the presence of the network side CSG cell.

Sweep module, set to change when the existing CSG information of the terminal changes or the user requests

When searching for a CSG cell, perform frequency sweeping within its capability to find a specific CSG cell at each frequency point;

In the apparatus, the above method flow is specifically performed such that the apparatus has functional modules corresponding to the method flow.

The technical solution in the embodiment of the present invention solves the problem that the common reselection procedure is not applicable to the cell reselection problem with the CSG cell, and increases the number of measurements in the idle state, and improves the CSG cell reselection of the existing resident history. Search for a new CSG cell under possible conditions; in the connected state, provide the function of the terminal to switch to a part of the CSG cell while ensuring the quality of the service.

The above description shows and describes a preferred embodiment of the present invention, but as described above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be construed as being Other combinations, modifications, and environments are possible and can be modified by the teachings of the above teachings or related art within the scope of the inventive concept described herein. All changes and modifications made by those skilled in the art are intended to be within the scope of the appended claims.

Claims

Claim

A search method for a CSG cell, where the method includes:

When the existing CSG information of the terminal changes or the user requests to perform CSG cell search, the terminal performs frequency sweeping within its capability range to find a specific CSG cell under each frequency point; and reads the system of the CSG cell. Information SIB1, acquiring public land mobile network PLMN and CSG ID information of the CSG cell;

2. The method according to claim 1, wherein the existing CSG information of the terminal changes to: the terminal detects that the CSG whitelist has new content, or the terminal is successfully camped on, or the CSG whitelist is not Empty but no resident record of the CSG cell.

3. The method according to claim 2, wherein the recording of the information of the CSG cell into the CSG cell resident history is:

Obtaining the CSG cell information of the current selection;

4. The method according to claim 3, wherein the method further comprises:

If the CSG cell selected this time is in the CSG cell resident history list, and the serving cell information of the terminal before the CSG cell selection does not exist in the environment list of the selected CSG cell history record, the serving cell environment information is added to the CSG. In the cell environment information list; or, if the CSG cell selected this time is not in the CSG cell resident history list, it is small in the CSG A new record is added to the area resident history list, and the selected CSG cell information is recorded in the newly added record entry, and the serving cell environment information is added to the CSG cell environment information list.

The method according to any one of claims 1 to 4, wherein the method further comprises: when the terminal is in an idle state, the terminal initiates a measurement task and an additional CSG automatic search whenever a serving cell change occurs. Judgment, specifically:

6. The method of claim 5, wherein the method further comprises

If it is judged that the environmental information of this CSG history record does not meet any of the basic measurement tasks For the measurement object, the frequency of the CSG cell is added within the capability range of the terminal for measurement, and the record is deleted in the CSG cell automatic search information set.

7. The method according to claim 6, wherein the initiating additional CSG cell search process is:

The CSG automatically filters the cells in the information set by the timing measurement, and selects a cell whose measurement result is better than the high quality standard in the PLMN search;

If it is determined that a cell satisfies the high-quality condition, the cell that meets the high-quality standard is measured, and the frequency of the cell is measured. After determining the frequency point measurement, whether the highest-ranked cell is a CSG cell that the terminal can camp on, after the frequency point measurement, the highest The ranked cell is a CSG cell that the terminal can camp on, and the terminal performs reselection to the selected CSG cell; after the frequency point measurement, the highest ranked cell is not a CSG cell that the terminal can camp on, or no cell satisfies high quality condition Then, for the best cell at each frequency point of the normal measurement task, the SIB1 of the cell is read, the cell is determined to be a CSG cell whose terminal meets the camping condition, and the terminal performs reselection to the selected CSG cell.

The method according to any one of claims 1 to 4, wherein the method further comprises: when the terminal is in the connected state, whenever a handover occurs, or a new measurement configuration is received, then:

The CSG historical camped cell whose location information is close to the current serving cell is collected from the CSG cell historical camping information, and is set as the CSG automatic search cell set; in the CSG automatic search cell set, the filtered frequency point already exists in the normal measurement task. If the CSG automatically searches for the cell set and has no remaining records after filtering, the terminal only performs the normal measurement task; if the CSG automatically searches for the remaining set of the cell set after filtering, the CSG automatically searches for the cell concentration, and the CSG cell history record environment. Information, check the frequency and location information of the current serving cell, if a specific CSG cell resides The historical environment information includes the serving cell, or the environmental information of the specific CSG cell resident history does not include the serving cell, but the terminal measures the signal strength of all the historical CSG cells in the cell set after the CSG automatically searches for the signal, and determines the signal of the historical CSG cell. The strength is better than the PLMN search is a standard of the high-quality cell, and the terminal initiates a Proximity Indication process for the frequency of the CSG cell that satisfies the condition, and notifies the presence of the CSG cell on the network side.

9. A method for judging cell reselection in an idle state, wherein the method includes:

Determining whether the current serving cell of the terminal is a CSG cell, and if yes, considering the reselection priority of the serving cell frequency point in the reselection, performing normal cell reselection evaluation; otherwise, for each frequency point measurement result, Sorting the cell measurement results at the frequency point; determining whether the best cell under the frequency point is a historically resident CSG cell, and if so, selecting to the CSG cell; otherwise, after all frequency points are traversed, normal operation is performed. Cell re-election assessment.

10. A CSG cell search device, where the device includes: