CN101984711A - Method for controlling cell reselection and wireless communication terminal - Google Patents

Abstract

The present invention proposes a method for controlling cell reselection and a wireless communication terminal, a method for controlling cell reselection, judging whether frequent reselection occurs by recording the number of cell camps per unit time, and starting frequent reselection protection if frequent reselection occurs The strategy is to record the sub-priority cell in the cell reselection forbidden list, so that the terminal can try to camp in the cell with higher service quality or relatively stable signal level. The above-mentioned method of controlling cell reselection prevents the mobile terminal from decoding BCCH information because the target cell is prohibited or inaccessible, reduces standby energy consumption, improves the operating efficiency of the protocol stack, and dynamically adjusts according to the wireless environment The reselection parameter avoids the frequent reselection problem that occurs when the cell level fluctuates frequently, and improves the wireless communication service quality and user experience.

Description

Method for controlling cell reselection and wireless communication terminal

technical field

The present invention relates to the field of mobile communication, more specifically, to a method for controlling cell reselection and a wireless communication terminal.

Background technique

With the development of mobile communication technology, most mainstream mobile communication network systems provide comprehensive network coverage in the form of cellular, and according to the 3GPP specification TS23.122, when the terminal is turned on, it will first select the registered public land mobile communication network (Registered Public Land Mobile Network, RPLMN), RPLMN is the network successfully registered by the terminal last time, if there is no RPLMN in the mobile phone or RPLMN is unavailable, the terminal will find an available public land mobile network (Public Land Mobile Network, PLMN) according to the specified order After finding the PLMN, the terminal will initiate a cell selection process. Once the terminal selects a "suitable" cell to reside in, the terminal will generate a list of candidate cells, which includes information about the selected cell and neighboring cells. This information can be obtained from the SIB11 message of the camped cell. After the mobile terminal selects a certain cell as the current serving cell, the mobile terminal will stay in the selected cell when the cell level signal changes little. After that, in order to ensure continuous and high-quality service, the mobile device will measure the current network environment, including the current serving cell of the mobile device and surrounding neighbor cells, and under the control conditions of the measurement parameters, the mobile device will reselect to a network with a higher quality of service or signal strength. nice neighborhood.

For example, in the GSM/WCDMA system, the mobile device can decode various system messages broadcast periodically on the BCCH (Broadcast Control Channel), which contains the frequency point configuration of neighboring cells required for cell reselection, and the mobile terminal will Monitor the BCCH carriers of the frequency points of the adjacent cells, and obtain the parameters of the current cell reselection by decoding the six strongest BCCH carrier information, and in the process of continuous measurement and decoding, if it is found condition, the mobile device will initiate a cell reselection process.

If this approach is followed, when the mobile device is currently in an environment with frequent level fluctuations and high interference, the level of the serving cell fluctuates greatly, and the adjacent cells in the monitoring set must constantly change and adjust, such as monitoring set cells The number of cells, the order of cell priority, etc., then the operations of measuring, synchronizing, and decoding BCCH channels for changing cells will be greatly increased, and at the same time, the energy consumption of mobile devices will also be greatly increased. Reduce standby time.

Secondly, this approach does not consider other conditions in the cell reselection process, such as whether the measurement cell is accessible, whether the measurement cell belongs to the PLMN to which it belongs, and if the reselected target cell is set to prohibit access by the operator (or the location area cell Forbidden access) or the cell does not belong to its home network, when the terminal continuously tries to access, it needs to perform cell selection process every time, perform frame synchronization, decode BCCH broadcast information and other operations, frequent synchronous decoding operations will inevitably bring At the same time, the existing implementation methods face the problem of single measurement quality evaluation (either Ec/No or RSCP), and the hysteresis parameter (delivered by the network side) is not flexible.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings in the prior art, provide a method and terminal capable of performing cell reselection operations more effectively, provide better user experience, and reduce energy consumption of cell reselection.

In order to achieve the above object, the present invention proposes a method for controlling cell reselection, judging whether frequent reselection occurs by recording the number of times the cell is stationed in a unit time, if frequent reselection occurs, then start the frequent reselection protection strategy, and set the sub-priority cell The cell reselection prohibited list is recorded, so that the terminal tries to camp in a cell with high service quality or relatively stable signal level.

Further, said starting the frequent reselection protection strategy includes increasing the reselection hysteresis parameter.

Further, the recording the sub-priority cell into the cell reselection prohibition list includes: moving the neighbor cell with the most camping times into the reselection prohibition cell list, and reordering the neighbor cell list.

Further, the reordering rule of the neighbor cell list is performed according to Ec/No or RSCP or RSSI, and the priority factor Pr is added for the 3G cell, and the calculation method of the priority factor Pr is as follows:

Pr＝k+1/(|Ec/No*RSCP|)

K is a constant and defaults to 1.

Further, before judging whether frequent reselection occurs, the method further includes: reading configuration information, and initializing a list of prohibited reselection cells and a list of successful reselection cells; the configuration information includes a reselection granularity threshold.

Further, before starting the frequent reselection protection strategy, it also includes:

Judging whether the reselected cell is in the list of prohibited reselected cells;

If the reselected cell is not in the prohibited reselected cell list, then further judge whether the target cell is in the successful reselected cell list;

If the target cell is not in the list of successfully reselected cells, it is further judged whether the reselection granularity threshold of the cell is greater than a preset value, and if so, the frequent reselection protection strategy is started.

The present invention also proposes a wireless communication terminal, which includes: a measurement module, an adaptive module and a judgment module, wherein,

The measurement module measures adjacent cells, obtains network parameters of adjacent cells, and sorts the measured cells according to the measurement results;

The self-adapting module collects measurement parameters issued by the network side, and dynamically adjusts the measurement parameters according to the state of the terminal;

The judgment module executes a cell reselection process according to the protocol.

Further, performing the cell reselection process according to the protocol includes: if frequent reselection occurs, start the frequent reselection protection strategy, and record the sub-priority cell into the list of prohibited reselection cells, so that the terminal can try to camp on a cell with higher service quality or signal power. Flat and relatively stable neighborhood.

Further, the network parameters include one or more of the following: Ec/Io or RSCP parameters of FDD or TDD cells, and RSSI parameters of GSM cells.

Further, the sorting the measurement cells according to the measurement results includes: sorting the neighboring cells according to the 3GPP protocol TS25.304, sorting the FDD or TDD cells according to Ec/Io or RSCP, and sorting the cells according to RSSI for the GSM cells.

To sum up, by adopting the technical solution of the present invention, the mobile terminal records the access information of adjacent cells, so that the mobile terminal can know whether the target cell is accessible before initiating cell reselection, and avoids Prohibit or disable access to decode BCCH information, reduce standby energy consumption, improve the operating efficiency of the protocol stack, and dynamically adjust reselection parameters according to the wireless environment, avoiding frequent reselection problems caused by frequent fluctuations in cell levels , improving the wireless communication service quality and user experience.

Description of drawings

Fig. 1 is the prohibited reselection cell list structure in the embodiment of the present invention;

Fig. 2 is the successful reselection cell list structure in the embodiment of the present invention;

FIG. 3 is a schematic diagram of a terminal module for controlling cell reselection according to an embodiment of the present invention;

FIG. 4 is a schematic flow diagram of a method for controlling cell reselection according to an embodiment of the present invention;

Fig. 5 is a schematic diagram of the steps of the frequent reselection protection strategy in the embodiment of the present invention.

Detailed ways

This implementation provides a method and terminal for controlling cell reselection. It judges whether frequent reselection occurs by recording the number of cell camps per unit time. If frequent reselection occurs, the frequent reselection protection strategy is started, and the reselection hysteresis parameter is appropriately adjusted. And the secondary priority cell is recorded in the cell reselection prohibited list, so that the terminal tries to camp in a cell with higher service quality or relatively stable signal level.

The implementation of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

The present invention provides a terminal and method for controlling cell reselection, which can effectively avoid frequent reselection by recording cell reselection information on the terminal side and dynamically adjusting reselection parameters according to network environment.

As shown in Figure 1, it is the prohibited reselection cell list structure in the embodiment of the present invention:

Field S101 is the primary scrambling code of the cell.

Field S102 is the PLMN to which the cell belongs.

Field S103 is the frequency point to which the cell belongs.

Field S104 is the frequency band group to which the cell belongs.

Field S105 is the ID of the location area to which the cell belongs.

Field S106 is the reason for cell access prohibition.

Field S107 is the last modification time stamp.

As shown in Figure 2, it is the successful reselection cell list structure in the embodiment of the present invention:

Field S201 is the primary scrambling code of the cell.

Field S202 is the PLMN to which the cell belongs.

Field S203 is the frequency point to which the cell belongs.

Field S204 is the frequency band group to which the cell belongs.

Field S205 is the ID of the location area to which the cell belongs.

Field S206 is the cell reselection camping count.

Field S207 is the last modification time stamp.

As shown in FIG. 3 , it is a schematic diagram of a terminal module for controlling cell reselection according to an embodiment of the present invention. The terminal includes: a measurement module, an adaptive module, and a judgment module.

The measurement module is responsible for initiating the measurement of the adjacent cells in the monitoring set, obtaining the network parameters of the adjacent cells, and sorting the measured cells according to the measurement results. The network parameters include Ec/Io or RSCP parameters of FDD or TDD cells, and RSSI parameters of GSM cells.

After obtaining the measurement results of neighboring cells, the neighboring cells can be sorted according to the 3GPP protocol TS25.304. For FDD or TDD cells, they can be sorted according to Ec/Io or RSCP, and for GSM cells, they can be sorted according to RSSI.

The self-adaptation module is responsible for collecting the measurement parameters issued by the network side, and dynamically adjusts the measurement parameters according to the state of the terminal, for example, avoiding frequent reselection as much as possible.

The judgment module is responsible for executing the cell reselection process according to the protocol. When the frequent reselection protection strategy is activated, the sub-priority cell is recorded in the cell reselection prohibited list, so that the terminal tries to camp in a cell with high service quality or relatively stable signal level.

As shown in Figure 4, it is a schematic flow chart of the method for controlling cell reselection according to the embodiment of the present invention, including the following steps:

Step S401: The mobile terminal starts up, reads the EFS file or NV configuration information, initializes the list of prohibited reselection cells and the list of successful reselection cells;

The configuration information includes reselection granularity threshold N, time interval T, reselection times N, hysteresis increment parameter RSTEP, and high-quality cell signal strength threshold PREF_SELECTION_THRESHOLD. Clear the list of prohibited reselection cells and the list of successful reselection cells.

Step S402: The mobile terminal performs normal network registration, PLMN selection, cell selection, location update, and route update operations;

Step S403: measure the neighboring cells, and sort the neighboring cells according to the network side configuration;

Neighboring cells are sorted according to the 3GPP protocol TS25.304. FDD or TDD cells can be sorted according to Ec/Io or RSCP, and GSM cells can be sorted according to RSSI. At the same time, in the case of coexistence of 2G and 3G, this implementation always considers the 3G cell as the priority cell, that is, the priority factor Pr is added to the 3G cell for sorting, instead of only considering the signal or interference of the cell, this can prevent continuous 3G coverage Under certain circumstances, the terminal reselects to the 2G network, which can effectively improve user experience.

Step S404: judging whether the reselected cell is in the list of prohibited reselected cells;

Carry out reselection, judge whether the reselected cell is in the cell list forbidding reselection, if it is in the cell list forbidding reselection, then stop the reselection operation, and execute step S411; otherwise, execute step S405;

Step S405: Determine whether the target cell is successfully reselected from the cell list, if yes, enter step S406, otherwise execute step S407;

Step S406: Check whether the reselection granularity threshold of the cell is greater than the preset value, if so, execute step S407, otherwise continue the reselection camping process and execute step S408;

Step S407: Start reselecting the protection strategy;

If the frequent cell reselection protection strategy is enabled, the adaptive reselection parameters Qhyst1s or Qhyst2s are dynamically adjusted according to the network status, and RSTEP is incremented each time to increase the reselection hysteresis and reorder neighboring cells to keep the UE at the current service quality as much as possible For cells with higher or more stable signal levels, neighbor cells with the second lowest number of reselections are added to the list of prohibited reselection cells to prevent terminals from frequently reselecting to the second priority.

Step S408: normal camping;

Step S409: Check whether the camping is successful, if the camping is successful, go to step S410; otherwise go to step S411.

Step S410: Record the cell to the list of successfully reselected cells, record the cell information including the primary scrambling code, frequency point, and camping time, and add 1 to the camping times, and then execute step S412;

Record the successful reselection cell information, including camping time, frequency information, cell ID, scrambling code information, etc., and add one to the number of camping times; if reselection fails, you need to check whether the cell is bar or prohibited from accessing, and whether the country code and network code are Consistent with the network to which it belongs, if the cell is banned or the network code is inconsistent, the cell will be added to the list of prohibited reselection cells to prevent reselection to the cell next time.

Step S411: If camping fails, check whether the cell is reserved by the operator or whether the cell is forbidden to access (it is issued in the system message) and whether the country code and network code of the cell are the same as the country code and network code in SIM/USIM , if different, the cell will be added to the list of prohibited reselection cells, and reselection will not be initiated to the cell next time;

Step S412: end.

The configuration information: the reselection granularity refers to the number of reselections N within a unit time T, the time interval T, and the number of reselections N; the adaptive parameter RSTEP is an adjustment parameter used to dynamically adjust hysteresis parameters, and these parameters are stored in Terminal non-volatile memory (NV) or EFS file, and can be set or adjusted.

For the calculation of the priority of the neighbor cell list, according to the 3GPP protocol TS25.304, the FDD or TDD cells can be sorted according to Ec/Io or RSCP, and the GSM cells can be sorted according to RSSI.

The target cell refers to a cell that is in the neighbor cell list and whose calculated R value (priority) is higher than the current serving cell.

The parameter Qhyst1s or Qhyst2s is issued by the network side and is used for the hysteresis value of cell reselection. When the cell reselection indicator is set to CPICH RSCP, Qhyst1s is used, and when CPICH EC/NO is used, Qhyst2s is used. The hysteresis increment parameter RSTEP is an increment stored in an EFS file or a non-volatile memory on the terminal side and used to adjust the hysteresis difference.

As shown in Figure 5, it is a schematic diagram of the frequent reselection protection strategy steps in the embodiment of the present invention, mainly including the following steps:

Step S501: Increase the reselection hysteresis parameter, and increase RSTEP step by step.

The reselection hysteresis parameter is a parameter sent to the terminal by the network side. The RSTEP parameter is an adjustment parameter used to dynamically adjust the hysteresis parameter, which is stored in the terminal non-volatile memory (NV) or EFS file, and can be Set to empirical value or dynamic adjustment. The reselection hysteresis parameter is a deviation value added to the signal quality of the current serving cell when the terminal performs cell reselection to sort neighboring cells, and the adjacent cell subtracts the same deviation value, in order to properly separate the current cell from the neighboring cells The signal quality of the neighbor cell will not be reselected when the level of the neighbor cell is within a reasonable range of variation, which can effectively suppress the ping-pong effect and avoid frequent reselection.

Step S502: Move the neighbor cell with the most camping times into the list of prohibited reselection cells, and reorder the list of neighbor cells;

The sorting rules are based on Ec/No or RSCP or RSSI, and at the same time, the priority factor Pr is added for 3G cells. The calculation method of the priority factor Pr is as follows:

Pr＝k+1/(|Ec/No*RSCP|)

K is a constant, and the default is 1. When the product of Ec/No and RSCP is smaller and Pr is larger, the priority coefficient of the cell is higher. That is, the better the signal strength and signal quality are, the smaller the absolute value is, and the smaller the product is, the more preferential the cell is, and the more likely it is to reselect to the 3G cell. The purpose of this is to keep the dual-mode terminal in the 3G cell as much as possible, even if the 2G signal is better than the 3G signal, it can keep the UE in the 3G cell as much as possible, so as to improve user experience.

Step S503: Execute the cell reselection camping process.

The purpose of the present invention is to overcome the shortcomings in the prior art, provide a method and terminal capable of performing cell reselection operations more effectively, provide better user experience, and reduce energy consumption of cell reselection.

To sum up, the above-mentioned method of controlling cell reselection is adopted, and the mobile terminal records the access information of adjacent cells, so that the mobile terminal can know whether the target cell is accessible before initiating cell reselection, which avoids the need for the mobile terminal to Decoding BCCH information because the target cell is prohibited or inaccessible reduces standby energy consumption and improves the operating efficiency of the protocol stack. At the same time, the reselection parameters are dynamically adjusted according to the wireless environment to avoid frequent fluctuations in the cell level. The problem of frequent reselection improves the service quality and user experience of wireless communication.

Certainly, the present invention can also have multiple implementation modes, without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes or changes according to the present invention, but all Any modifications, equivalent replacements, and improvements made within the spirit and principles shall be included within the protection scope of the present invention.

Claims (10)

1. A method for controlling cell reselection, characterized in that, judge whether frequent reselection occurs by recording the number of times that the cell is stationed in the unit time, if frequent reselection occurs, then start the frequent reselection protection strategy, and record the sub-priority cell to It is forbidden to reselect the cell list, so that the terminal can try to camp in a cell with high service quality or relatively stable signal level. 2. The method according to claim 1, wherein said starting the frequent reselection protection strategy comprises increasing a reselection hysteresis parameter. 3. The method according to claim 1, wherein the recording the sub-priority cell into the list of prohibited reselection cells comprises: moving the neighbor cell with the largest number of camping times into the list of prohibited reselection cells, and registering the neighbor cell list Reorder. 4. The method according to claim 3, wherein the reordering rule of the adjacent cell list is carried out according to Ec/No or RSCP or RSSI, and the priority factor Pr is increased for the 3G cell, and the calculation method of the priority factor Pr is as follows: Pr＝k+1/(|Ec/No*RSCP|) K is a constant and defaults to 1. 5. The method according to claim 1, further comprising: before judging whether frequent reselection occurs: reading configuration information, and initializing a list of prohibited reselection cells and a list of successful reselection cells; the configuration information includes Reselect the granularity threshold. 6. The method according to claim 5, further comprising: before starting the frequent reselection protection strategy: Judging whether the reselected cell is in the list of prohibited reselected cells; If the reselected cell is not in the prohibited reselected cell list, then further judge whether the target cell is in the successful reselected cell list; If the target cell is not in the list of successfully reselected cells, it is further judged whether the reselection granularity threshold of the cell is greater than a preset value, and if so, the frequent reselection protection strategy is started. 7. A wireless communication terminal, characterized in that, the wireless communication terminal comprises: a measurement module, an adaptive module and a judgment module, wherein, The measurement module measures adjacent cells, obtains network parameters of adjacent cells, and sorts the measured cells according to the measurement results; The self-adapting module collects measurement parameters issued by the network side, and dynamically adjusts the measurement parameters according to the state of the terminal; The judgment module executes a cell reselection process according to the protocol. 8. The terminal according to claim 7, wherein performing the cell reselection process according to the protocol comprises: if frequent reselection occurs, then start a frequent reselection protection strategy, and record the sub-priority cell into the list of prohibited reselection cells, thereby Make the terminal try to camp in a cell with high service quality or relatively stable signal level. 9. The terminal according to claim 7, wherein the network parameters include one or more of the following: Ec/Io or RSCP parameters of FDD or TDD cells, and RSSI parameters of GSM cells. 10. The terminal according to claim 7, wherein the sorting the measured cells according to the measurement results comprises: sorting the neighboring cells according to the 3GPP protocol TS25.304, and sorting the FDD or TDD cells according to Ec/Io or RSCP , for GSM cells, perform cell sorting according to RSSI.

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