CN110475307B

CN110475307B - Communication method, user equipment and device with storage function

Info

Publication number: CN110475307B
Application number: CN201810451025.1A
Authority: CN
Inventors: 邬月萍; 陈翔; 杨璐; 招溢利
Original assignee: Huizhou TCL Mobile Communication Co Ltd
Current assignee: Huizhou TCL Mobile Communication Co Ltd
Priority date: 2018-05-11
Filing date: 2018-05-11
Publication date: 2022-01-25
Anticipated expiration: 2038-05-11
Also published as: CN110475307A; WO2019214203A1

Abstract

The invention discloses a communication method, user equipment and a device with a storage function. The communication method comprises the following steps: searching at least one first optimal cell in the wireless access network notification area, wherein the communication quality of the first optimal cell meets the requirement, and the absolute priority of all cells with the communication quality meeting the requirement in the wireless access network notification area is the highest; if the first best cell is found, the first best cell is used as a reselection cell, if the first best cell is not found, a second best cell is found in all available cells, the communication quality of the second best cell meets the requirement, and the absolute priority is highest in all the cells with the communication quality meeting the requirement in all the available cells; and if the second best cell is found, the second best cell is taken as the reselection cell. By the mode, unnecessary signaling overhead and power consumption can be avoided, and resources are saved.

Description

Communication method, user equipment and device with storage function

Technical Field

The present invention relates to the field of communications, and in particular, to a communication method, a user equipment, and a device having a storage function.

Background

In an NR (New Radio) network, in order to reduce signaling overhead and power consumption and latency, it is necessary to keep a ue in a connectable state, and therefore, an RRC _ INACTIVE state (RRC _ INACTIVE) for Radio resource control is introduced. When the user equipment is in a Radio resource control standby state, it maintains a connection of CN (Core Network) -RAN (Radio Access Network), but disconnects the RAN. When the ue is in the radio resource control dormant state, since the ue may be kept in the mobile state all the time and may move out of the range of the currently camped cell, at this time, cell reselection may be performed to select at least one suitable cell as a reselected cell, which may be a new camped cell of the ue.

In the process of selecting at least one suitable cell as the reselection cell, if the selected at least one cell includes a cell outside the radio access network notification area, the user equipment needs to perform RLAU (RAN-based location update) operation, which results in higher signaling overhead and power consumption. Furthermore, it is not possible to determine that all cells support the dormant state of radio resource control, and therefore if at least one selected cell includes a cell in the dormant state that does not support radio resource control, the ue needs to first transition to the idle state of radio resource control to complete cell reselection when connecting with the cell. This state transition will also result in higher additional power consumption.

Disclosure of Invention

The technical problem mainly solved by the invention is to provide a communication method, user equipment and a device with a storage function, which can reduce signaling overhead and power consumption required by communication of the user equipment and save resources.

In order to solve the technical problems, the invention adopts a technical scheme that: there is provided a communication method including: searching at least one first best cell within the range of a wireless access network notification area, wherein the communication quality of the first best cell meets requirements, and the absolute priority of all the cells with the communication quality meeting the requirements in the wireless access network notification area is the highest; if the first best cell is found, the first best cell is used as a reselection cell, if the first best cell is not found within the range of the wireless access network notification area, a second best cell is found in all available cells, the communication quality of the second best cell meets the requirement, and the absolute priority is highest in all the cells with the qualified communication quality; if the second best cell is found, the second best cell is taken as the reselection cell.

In order to solve the technical problem, the invention adopts another technical scheme that: there is provided a user equipment comprising a processor, a communication circuit and a memory coupled to each other, the processor being coupled to the communication circuit and the memory for implementing the method as described above.

In order to solve the technical problem, the invention adopts another technical scheme that: there is provided an apparatus having a storage function, storing program data executable to implement the steps in the method as described above.

The invention has the beneficial effects that: different from the situation of the prior art, the invention firstly searches at least one suitable cell as a reselected cell in the range of the Radio Access Network notification area of the user equipment, and if the cell which can avoid selecting the cell out of the range of the Radio Access Network notification area of the user equipment is successfully found, RLAU (Radio-based location update) operation is carried out based on the location update of RAN (Radio Access Network); when no suitable cell exists within the range of the notification area of the radio access network of the user equipment as the reselection cell, a cell in a dormant state supporting radio resource control is selected as the reselection cell from all the selectable cells, and if the cell in the dormant state not supporting radio resource control is successfully found, the user equipment needs to be converted into a signaling resource spent in an idle state of radio resource control. In the cell reselection process, the priority of a cell is also considered in addition to the signal quality of the cell. The whole cell in the wireless access network notification area range has the highest priority, and the standby cell supporting the wireless resource control reduces signaling overhead and power consumption brought by the RLAU and the user equipment for RRC _ IDLE, thereby saving resources.

Drawings

Fig. 1 is a schematic flow chart of a first embodiment of a communication method provided by the present invention;

fig. 2 is a flowchart illustrating a first embodiment of a method for finding a first best cell according to the present invention;

fig. 3 is a flowchart illustrating a first embodiment of a method for determining whether a first best cell can be used as a reselecting cell according to the present invention;

fig. 4 is a flowchart illustrating a second embodiment of a method for finding a first best cell according to the present invention;

fig. 5 is a flowchart illustrating a second embodiment of the communication method provided by the present invention;

fig. 6 is a flowchart illustrating an embodiment of a method for finding a second best cell according to the present invention;

fig. 7 is a flowchart illustrating a first embodiment of a method for determining whether a second best cell can be used as a reselecting cell according to the present invention;

fig. 8 is a flowchart illustrating a third embodiment of the communication method provided by the present invention;

fig. 9 is a schematic structural diagram of an embodiment of a user equipment provided in the present invention;

fig. 10 is a schematic structural diagram of an embodiment of the apparatus with a storage function according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Referring to fig. 1, fig. 1 is a flowchart illustrating a communication method according to a first embodiment of the present invention. As shown in fig. 1, the communication method provided by the present invention comprises the following steps:

s101: at least one first best cell is searched within the range of the wireless access network notification area, the communication quality of the first best cell meets the requirement, and the absolute priority is highest in all the cells with the qualified communication quality in the wireless access network notification area.

In an NR (New Radio) network, in order to reduce signaling overhead and power consumption and delay, it is necessary to keep a ue in a connectable state, and thus a Radio resource control standby state is introduced. In the NR network, all ues in the Radio Resource Control standby state are configured with an RNA (Radio access network notification area) range, and when the ue moves away from the current RNA range, the ue needs to perform an RLAU (RAN-based location update) operation, which requires the ue to send and/or receive some RRC (Radio Resource Control) signaling information, which results in higher signaling overhead and power consumption, thereby resulting in Resource waste. Therefore, if the reselected cell selected by the user equipment is a cell outside the radio access network notification area, the RLAU operation needs to be performed. In order to reduce signaling overhead and power consumption during communication of user equipment and avoid unnecessary resource waste, in the invention, a suitable cell is preferentially searched in a current wireless access network notification area range of the user equipment as a reselection cell.

In one particular implementation scenario, each frequency is assigned an absolute priority. The absolute priorities of the different frequencies may be transmitted to the user equipment in advance through one or more of 1) system information broadcast by a cell, 2) an RRCConnectionRelease message transmitted by a current base station, and 3) inheritance from a previous RAT when a RAT (Radio Access Technology) cell is selected or (re-selected). In other implementation scenarios, the priority of each frequency may be sent to the user equipment by other methods, for example, by pre-defining the priority of each frequency in the user equipment, and the like.

The radio access network announcement zone frequency list comprises all frequencies and their absolute priorities within the radio access network announcement zone of the user equipment. And the current base station connected with the user equipment sends the radio access network notification area frequency list to the user equipment through RRCConnectionRelease.

Specifically, please refer to fig. 2, wherein fig. 2 is a flowchart illustrating a method for finding a first best cell according to a first embodiment of the present invention. The method for searching the first best cell provided by the invention comprises the following steps:

s1011: and checking the radio access network notification area frequency list, and sequencing and storing all frequencies in the radio access network notification area frequency list according to the absolute priority level of the frequencies from high to low to form a candidate radio access network notification area frequency set.

In a specific implementation scenario, the ue checks the received radio access network notification area frequency list sent by the current base station, and obtains all frequencies in the radio access network notification area of the ue. The user equipment sorts the frequencies from high to low according to the absolute priorities of the different frequencies received in advance, and stores the frequencies according to the sorting to form a candidate wireless access network notification area frequency set.

In other implementation scenarios, in order to facilitate subsequent searching of an absolute priority of a certain frequency or a frequency corresponding to a certain priority, all frequencies in the radio access network notification area of the user equipment and their corresponding absolute priorities may be stored in pairs, or stored in pairs and sequentially stored from high to low or from low to high according to the level of their absolute priorities, so as to form a frequency set of the notification area of the candidate radio access network.

S1012: and checking the candidate wireless access network notification area frequency set to acquire one or more frequencies with the highest absolute priority.

In a specific implementation scenario, the user equipment checks one or more frequencies in the candidate radio access network announcement area frequency set with the highest absolute priority. It is noted that a plurality of different frequencies may also have the same absolute priority. And the user equipment finds the grade of the absolute priority of the one or more frequencies according to the received absolute priorities corresponding to the different frequencies. In other implementation scenarios, since all frequencies and their corresponding absolute priorities within the radio access network notification area of the user equipment are stored in pairs, the frequency with the highest absolute priority is found and the level of the absolute priority it has been assigned is already obtained. In other implementation scenarios, in step S1011, when all the frequencies in the notification area of the radio access network of the ue are sorted from high to low according to the absolute priority level, the ue may record the highest absolute priority of all the absolute priorities.

S1013: comparing the absolute priority that the frequency of the current cell has with the highest absolute priority.

In a specific implementation scenario, the ue checks the level of absolute priority of the frequency of the current cell, and compares the level with the highest absolute priority level of the absolute priority levels of all frequencies in the radio access network notification area of the ue. It should be noted that the user equipment may have multiple current cells (including a primary cell, a secondary cell, etc.), and the user equipment needs to acquire the absolute priority of the frequencies in which all the current cells are located. The user equipment compares the one or more absolute priority levels with the highest absolute priority level of the absolute priority levels of all frequencies within the user equipment radio access network announcement zone.

S1014: detecting all cells at the frequency with the highest absolute priority if the frequency with which the current cell is located has the absolute priority lower than the highest absolute priority.

In other implementations, since the highest absolute priority of the absolute priorities of all frequencies in the radio access network notification area of the user equipment may correspond to more than one frequency, it may be necessary to detect all cells on the frequencies with the highest absolute priority.

In other implementation scenarios, when the ue has multiple current cells, the ue compares the highest absolute priority level of the absolute priorities of the frequencies of the current cells with the highest absolute priority level of the absolute priorities of all frequencies in the radio access network notification area of the ue. If all frequencies within the user equipment radio access network announcement zone have a higher level of absolute priority than the highest of the absolute priorities of the frequencies of the current cell, then all cells on that frequency are detected.

In other implementation scenarios, when the ue has multiple current cells, the ue compares the absolute priority levels of all frequencies of the current cells with the highest absolute priority level of all frequencies of the frequencies in the radio access network notification area of the ue. If the highest absolute priority among the absolute priorities of all the frequencies in the radio access network notification area of the user equipment is higher than the level of any one of the absolute priorities of the frequencies in which the current cell is located, all the cells in the frequency are detected.

S1015: selecting a cell in a radio access network announcement area among all cells at the frequency having the highest absolute priority, and measuring communication quality of the cell in the radio access network announcement area.

In a specific implementation scenario, after the communication quality of the cells having the frequency with the highest absolute priority in the radio access network notification area of the user equipment is measured, the user equipment determines whether the cells are the cells in the radio access network notification area. Although some cells are located in the radio access network notification area, since a plurality of cells may be located in the same frequency, it cannot be determined that all cells corresponding to frequencies located in the radio access network notification area are located in the radio access network notification area.

The user equipment may receive the radio access network notification area configuration sent by the current base station, and obtain the explicit cell list contained therein. If the cell is in the explicit cell list, the cell is in the radio access network notification area. The user equipment can thus pick out the cells that are within the radio access network announcement area from all the cells that are at the frequency with the highest absolute priority.

In another specific implementation scenario, the system information broadcasted by the cell includes an ID (identification) of the radio access network/tracking area, the identification is compared with the identification of the cell in the radio access network notification area configuration, and if the two identifications are the same or match, the cell is within the radio access network notification area.

In a specific implementation scenario, the measuring of the communication Quality of a cell is to measure at least one of a Reference Signal Received Power (RSRP) and a Reference Signal Received Quality (RSRQ) of the cell, and in other implementation scenarios, at least one of a Received Signal Strength Indicator (RSSI) or a Signal to Interference Noise Ratio (RS-SINR) of the cell may be measured.

S1016: deleting the cells which cannot be used as candidate cells for reselecting the cells in the wireless access network notification area, sorting the rest cells in the wireless access network notification area according to R standard, and selecting the first cell arranged in the sorting as the first best cell.

In one particular implementation scenario, if a cell is a candidate cell that cannot be a reselection cell, the cell may not be a reselection cell, and the cells may be deleted before being sorted in a prescribed order of priority to reduce the workload of subsequent sorting. Cells that are not candidates for reselection cells include one or more of cells indicated as "reserved for other use", cells indicated as "forbidden to use", and cells indicated as "reserved for operator use".

In this implementation scenario, the list of cells that cannot be used as candidate cells for the reselection cell may be stored in the user equipment in advance, and if the list of cells that cannot be used as candidate cells for the reselection cell does not store the cell or the identifier of the cell, the cell is not a cell that cannot be used as a candidate cell for the reselection cell. In another implementation scenario, the determination criteria of the cell that cannot be used as the candidate cell of the reselection cell may be stored in the user equipment in advance, and the user equipment determines whether the cell is the cell that cannot be used as the candidate cell of the reselection cell according to the determination criteria. Or a special identifier may be added to a cell belonging to a candidate cell that cannot be used as a reselected cell, and the user equipment determines whether the first best cell is a cell that cannot be used as a candidate cell of the reselected cell according to whether the first best cell carries the special identifier.

In a specific implementation scenario, the ue ranks the remaining cells according to the R-standard [ TS38.304], that is, ranks each remaining cell according to a specified priority, specifically according to:

Rs＝Qmeas,s+Qhyst

Rn＝Qmeas,n+Qoffset

the two equations may be sorted first by Rs and then by Rn if Rs is equal, or may be sorted conversely first by Rn and then by Rs if Rn is equal. The cell in the first place after sorting is the first best cell. In other implementation scenarios, the ordering may also be according to one of Rs or Rn.

Where Qmeas, s is the RSRP measurement used in cell reselection. Qoffset for intra-frequency: qoffsets, n equals Qoffsets, n if valid, otherwise it equals zero. For the frequency interval: if Qoffset, n is valid, equal to Qoffset, n plus Qoffset frequency, otherwise equal to Qoffset frequency. Qoffset, n specifies the offset between two cells, Qoffset frequency is the frequency specific offset of the same priority E-UTRAN frequency. Qhyst specifies a hysteresis value for the ranking criteria.

In other embodiments, the steps may not be performed in the order of the present embodiment. For example, the user equipment may first select cells within the radio access network notification area from all the cells in the frequency with the highest absolute priority, and then measure the communication quality of these cells. This may reduce the number of cells that need to be measured. Or the user equipment may first select the cells within the notification area of the radio access network from all the cells in the frequency with the highest absolute priority, and after sorting the cells according to the R standard, select one or more cells sorted in the front to measure the communication quality thereof, thereby further reducing the number of cells to be measured.

And S102, if the first best cell is found, the first best cell is used as a reselecting cell.

After the first best cell is found, a further decision on the cell is needed to determine whether it can be used as a reselection cell. Specifically, referring to fig. 3, fig. 3 is a flowchart illustrating a method for determining whether a first best cell can be used as a reselecting cell according to a first embodiment of the present invention. The method for judging whether the first best cell can be used as the reselecting cell comprises the following steps:

s1021: and judging whether the communication quality of the first best cell meets the requirement.

In a specific implementation scenario, the ue compares the previously measured communication Quality of the cell with a preset threshold, in this implementation scenario, the RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) of the cell are measured, and if both the RSRP and the RSRQ of the cell are higher than the preset threshold, the communication Quality of the cell meets the requirement. In other implementation scenarios, if one of RSRP and RSRQ of the cell is higher than a preset threshold, the communication quality of the cell is satisfactory. In another specific implementation scenario, at least one of a Received Signal Strength Indicator (RSSI) or a Signal to Interference Noise Ratio (RS-SINR) of the cell is also measured, and when the RSSI or the RS-SINR is higher than a preset threshold, the communication quality of the cell meets the requirement.

S1022: if the communication quality of the first best cell meets the requirement, determining whether the first best cell belongs to a part of a 'tracking area list prohibited from roaming' and/or a public land mobile network not indicated as being identical to a registered public land mobile network, and if the first best cell does not belong to a part of the 'tracking area list prohibited from roaming' or a public land mobile network not indicated as being identical to the registered public land mobile network, regarding the first best cell as a reselecting cell.

In a specific implementation scenario, if the first best cell belongs to a part of the "roaming forbidden tracking area list" or to a PLMN that is not indicated as identical to a registered PLMN (public land Mobile Network), the first best cell cannot be used as a reselection cell either.

In other implementation scenarios, the step of interrupting whether the first best cell belongs to a part of the "list of tracking areas forbidden to roam" and/or belongs to a public land mobile network that is not indicated as identical to the registered public land mobile network may also be performed in step S1016 to further reduce the workload of ranking.

In other implementation scenarios, the order of the parts in steps S1021 and S1022 may be reversed, that is, it may be determined whether the cell belongs to the "list of tracking areas forbidden to roam" and/or belongs to the plmn that is not indicated as being identical to the registered plmn, and then it is determined whether the communication quality of the cell meets the requirement.

If a suitable cell is found as the reselection cell in step S1022, the method proceeds to step S1023 if a suitable cell is not found.

S1023: if the communication quality of the remaining cells in the one or more frequencies with the highest absolute priority are not satisfactory or belong to a part of a "list of tracking areas forbidden to roam" and/or belong to a public land mobile network that is not indicated as being identical to a registered public land mobile network, the one or more frequencies with the highest absolute priority are deleted in the set of candidate radio access network notification area frequencies and the method of selecting the first best cell is performed as described above.

In a specific implementation scenario, when the first best cell is not suitable as the reselection cell, steps S1021 to S1022 are performed for each cell in turn according to the sorting order in step S1016. Until a suitable cell is found as a reselection cell among the remaining cells in the one or more frequencies having the highest absolute priority. If the communication quality of the remaining cells in the one or more frequencies with the highest absolute priority is not satisfactory, the remaining cells are the first best cells which are not found in the one or more frequencies with the highest absolute priority. The user equipment will delete the frequency or frequencies with the highest absolute priority currently within the radio access network announcement zone of the user equipment in the set of candidate radio access network announcement zone frequencies. And informing the area frequency set of the candidate wireless access network that the absolute priority is next to the highest absolute priority as the current highest absolute priority. Step S1012 to step S1016 are performed again to find the first best cell, and then step S1021 to step S1022/step S1023 are performed again until the first best cell that can be a reselection cell is found.

It can be known from the above description that the present invention preferentially selects a suitable cell within the radio access network notification area of the user equipment as the reselected cell, and if the cell can be successfully found, the RLAU operation performed by selecting a cell outside the radio access network notification area can be avoided, so that the signaling overhead and power consumption can be reduced, and the resources can be saved.

Referring to fig. 4, fig. 4 is a flowchart illustrating a method for finding a first best cell according to a second embodiment of the present invention. The method for searching the first best cell provided by the invention comprises the following steps:

s2011: and checking the radio access network notification area frequency list, and sequencing and storing all frequencies in the radio access network notification area frequency list according to the absolute priority level of the frequencies from high to low to form a candidate radio access network notification area frequency set.

S2012: and checking the candidate wireless access network notification area frequency set to acquire one or more frequencies with the highest absolute priority.

S2013: comparing the absolute priority that the frequency of the current cell has with the highest absolute priority.

Step S2011 to step S2013 are substantially the same as step S1011 to step S1013 in the first embodiment of the method for finding the first best cell, and are not described herein again.

S2014: and if the absolute priority of the frequency of the current cell is higher than or equal to the highest absolute priority, measuring the communication quality of the current cell, and if the communication quality of the current cell meets the requirement, taking the current cell as a reselected cell.

If the level of the highest absolute priority among the absolute priorities of all the frequencies in the notification area of the user equipment radio access network is lower than or equal to the level of the absolute priority of the frequency of the current cell, the user equipment measures the communication Quality of the current cell, in this implementation scenario, at least one of the RSRP (Reference Signal Received Power) and the RSRQ (Reference Signal Received Quality) of the current cell is measured, and in other implementation scenarios, at least one of the RSSI (Received Signal Strength Indicator) or the RS-SINR (Signal to Interference Noise Ratio) of the current cell may be measured.

And if the communication quality of the current cell meets the requirement, the current cell is taken as a reselecting cell. In this implementation scenario, the RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) of the current cell are measured, and if both the RSRP and the RSRQ of the current cell are higher than a preset threshold, the communication Quality of the current cell meets the requirement. In other implementation scenarios, it may also be that one of RSRP and RSRQ of the current cell is higher than a preset threshold, and then the communication quality of the current cell meets the requirement. In another specific implementation scenario, at least one of a Received Signal Strength Indicator (RSSI) or a Signal to Interference Noise Ratio (RS-SINR) of the current cell is also measured, and when the RSSI or the RS-SINR is higher than a preset threshold, the communication quality of the current cell meets the requirement.

In another implementation scenario, if the communication quality of the current cell is not satisfactory, the candidate radio access network is measured to notify frequencies in the area frequency list with an absolute priority lower than that of the frequency of the current cell. The specific measurement steps and the measurement contents are as described in steps S1014 to S1016 and S102, and are not described herein again.

In this implementation scenario, a cell that is suitable for being found from the cell at the frequency with the highest absolute priority is selected as the reselection cell, and in other implementation scenarios, since the candidate radio access network notifies that the absolute priority of all frequencies in the regional frequency set is lower than the absolute priority of the frequency at which the current cell is located, a cell at any one or more frequencies can be selected for measurement.

As can be seen from the above description, in this embodiment, when a cell that is not suitable for selection within the radio access network notification area of the user equipment is selected as a reselected cell, the current cell is preferentially considered to be used for continuing communication, so that signaling overhead and power consumption caused by re-expanding the selection range are avoided.

Referring to fig. 5, fig. 5 is a flowchart illustrating a communication method according to a second embodiment of the present invention. As shown in fig. 5, the communication method provided by the present invention includes the following steps:

s301: at least one first best cell is searched within the range of the wireless access network notification area, the communication quality of the first best cell meets the requirement, and the absolute priority is highest in all the cells with the qualified communication quality in the wireless access network notification area.

Step S301 is substantially the same as step S101 in the first embodiment of the communication method provided by the present invention, and is not described herein again.

S302: if the first best cell is found, the first best cell is taken as a reselection cell, if the first best cell is not found, a second best cell is found among all available cells, the communication quality of the second best cell is satisfactory, and the absolute priority is highest among all the cells in which the communication quality is satisfactory.

When all the cells in the radio access network notification area range of the user equipment are cells with unsatisfactory communication quality or candidate cells which cannot be used as reselected cells, the method is that a suitable cell cannot be found in the radio access network notification area range of the user equipment to be used as a reselected cell. In addition, the communication quality of the current cell is not satisfactory, and the current cell cannot be used continuously. Therefore, the user equipment needs to find a suitable cell among cells corresponding to all available frequencies outside the notification area of the radio access network as a reselection cell.

Referring to fig. 6, fig. 6 is a flowchart illustrating an embodiment of a method for searching a second best cell according to the present invention, wherein the method for searching a second best cell includes the following steps:

s3021: all available frequencies are examined, sorted from high to low according to their level of absolute priority and stored to form a set of candidate frequencies.

In a specific implementation scenario, the ue checks all available frequencies, ranks the available frequencies from high to low according to the absolute priorities of different frequencies obtained in advance, and stores the frequencies in the rank to form a candidate frequency set. In other implementation scenarios, in order to facilitate subsequent searching of an absolute priority of a certain frequency or a frequency corresponding to a certain priority, all available frequencies and their corresponding absolute priorities may be stored in pairs, or stored in pairs and ordered from high to low or from low to high according to the level of their absolute priorities, so as to form a candidate frequency set.

In another specific implementation scenario, since no suitable cell is found in the cells corresponding to the frequencies in the candidate radio access network notification area frequency set as the reselection cell, the frequencies may be directly excluded to reduce the workload of the user equipment.

S3022: and checking the candidate frequency set to acquire the frequency with the highest absolute priority.

In a specific implementation scenario, the user equipment checks one or more frequencies in the candidate set of frequencies with the highest absolute priority. It is noted that a plurality of different frequencies may also have the same absolute priority. And the user equipment finds the grade of the absolute priority of the one or more frequencies according to the received absolute priorities corresponding to the different frequencies. In other implementation scenarios, since all available frequencies and their corresponding absolute priorities are stored in pairs, the frequency with the highest absolute priority is found with the level of the absolute priority it has obtained. In other implementation scenarios, the ue may record the highest absolute priority of all the absolute priorities when all the available frequencies are ranked from high to low in step S3021.

S3023: deleting cells belonging to the candidate cell that cannot be a reselection cell among all cells at the frequency having the highest absolute priority; and/or deleting the cells within the radio access network notification area among all cells at the frequency having the highest absolute priority.

In a specific implementation scenario, if a cell is a candidate cell that cannot be used as a reselection cell, that is, the cell is not possible to be used as a reselection cell, the cells may be deleted before the cells are sorted according to the specified priority order, so as to reduce the workload of subsequent sorting. Cells that are not candidates for reselection cells include one or more of cells indicated as "reserved for other use", cells indicated as "forbidden to use", and cells indicated as "reserved for operator use".

In another specific implementation scenario, since all cells within the notification area range of the candidate radio access network are not suitable for being used as reselected cells, all cells within the notification area range of the candidate radio access network can be directly excluded as reselected cells during measurement, so as to save workload of the user equipment and save resources.

S3024: and sequencing the cells according to advanced R standard, and selecting the first cell arranged in the sequencing as the second best cell.

In a specific implementation scenario, the ue ranks the remaining cells at the frequency with the highest absolute priority according to an advanced R standard, that is, all cells are ranked according to a defined priority, which is specifically to be according to:

Rs＝Qmeas,s+Qhyst+QINACTIVE

Rn＝Qmeas,n+Qoffset+QINACTIVE

the two equations may be sorted first by Rs and then by Rn if Rs is equal, or may be sorted conversely first by Rn and then by Rs if Rn is equal. The cell in the first place after sorting is the second best cell. In other implementation scenarios, the ordering may also be according to one of Rs or Rn. Where Qmeas, s is the RSRP measurement used in cell reselection. Qoffset for intra-frequency: qoffsets, n equals Qoffsets, n if valid, otherwise it equals zero. For the frequency interval: if Qoffset, n is valid, equal to Qoffset, n plus Qoffset frequency, otherwise equal to Qoffset frequency. Qoffset, n specifies the offset between two cells, Qoffset frequency is the frequency specific offset of the same priority E-UTRAN frequency. Qhyst specifies a hysteresis value for the ranking criteria. QINACTIVE is an additional offset.

The dormant state of whether the cell has certain radio resource control is not defined in NR 2-1803978 and R2-1802931, so if at least one selected cell includes a cell in the dormant state that does not support radio resource control, the user equipment needs to first transition to the idle state of radio resource control when connecting with the cell. This in turn will lead to higher additional power consumption.

The additional offset is for enabling the user equipment to select a cell supporting a dormant state of radio resource control when selecting the cell. Each cell includes information on whether it supports a dormant state of radio resource control in system information, which is transmitted to a user equipment through broadcasting. The additional offset may be either cell-specific or user equipment-specific. In this implementation scenario, if the additional offset is specified by a cell, the system information broadcast by each cell includes the additional offset QINACTIVE. In this implementation scenario, the offset of each cell is not the same. In other implementation scenarios, the additional offset may also be specified by the ue, so that the offsets of each cell are the same and are a common offset. And the current base station sends the common offset to the user equipment through RRCConnectionRelease. So that the additional offsets of all cells supporting the dormant state of radio resource control are equal. In the NR network, there is no explicit provision as to whether or not the cell needs to support the dormant state of radio resource control, and it is highly likely that the user equipment will select a cell in the dormant state that does not support radio resource control when selecting a reselection cell. Thus, when the user equipment receives an equal or unequal additional offset from different cells, the user equipment can increase the probability of selecting a cell supporting a dormant state of radio resource control according to the additional offset.

In this implementation scenario, the priority of the cell is ordered taking into account its additional offset QINACTIVE, i.e., the dormant state of whether the cell supports radio resource control is taken into account. The probability that the selected second best cell supports the dormant state of radio resource control is high.

S303: if the second best cell is found, the second best cell is taken as the reselection cell.

After the second best cell is found, a further decision on the cell is needed to determine whether it can be used as a reselection cell. Specifically, referring to fig. 7, fig. 7 is a flowchart illustrating a method for determining whether a second best cell can be used as a reselecting cell according to a first embodiment of the present invention. The method for judging whether the second best cell can be used as the reselected cell comprises the following steps:

s3031: and judging whether the communication quality of the second best cell meets the requirement.

S3032: if the communication quality of the second best cell meets the requirement, determining whether the second best cell belongs to a part of a 'tracking area list forbidden to roam' and/or a public land mobile network which is not indicated to be identical to a registered public land mobile network, and if the second best cell does not belong to a part of the 'tracking area list forbidden to roam' or a public land mobile network which is not indicated to be identical to the registered public land mobile network, taking the second best cell as a reselecting cell.

In a specific implementation scenario, if the second best cell belongs to a part of the "roaming forbidden tracking area list" or to a PLMN that is not indicated as identical to the registered PLMN (public land Mobile Network), the second best cell cannot be used as the reselection cell.

In other implementation scenarios, the order of the steps S3021 and S3022 may be exchanged, that is, it may be determined whether the cell belongs to the "list of tracking areas where roaming is prohibited" and/or belongs to a public land mobile network that is not indicated as being identical to the registered public land mobile network, and then whether the communication quality of the cell meets the requirement.

If a suitable cell is found as the reselection cell in step S3032, the method terminates, if not found, step S3033 is performed.

S3033: if the communication quality of the remaining cells in the one or more frequencies with the highest absolute priority are not satisfactory or belong to a part of a "list of tracking areas forbidden to roam" and/or belong to a public land mobile network that is not indicated as being identical to a registered public land mobile network, deleting the one or more frequencies with the highest absolute priority in the candidate frequency set, treating the deleted candidate frequency set as a new candidate frequency set, examining the new candidate frequency set, acquiring the one or more frequencies with the highest absolute priority in the new candidate frequency set, and then performing the method for selecting a second best cell as described above

In a specific implementation scenario, when the second best cell is not suitable as the reselection cell, steps S3031 to S3032 are performed for each cell in turn according to the sequence sorted in step S3024. Until a suitable cell is found as a reselection cell among the remaining cells in the one or more frequencies having the highest absolute priority. If the communication quality of the remaining cells in the one or more frequencies with the highest absolute priority is not satisfactory, the remaining cells are the second best cells which are not found in the one or more frequencies with the highest absolute priority. The user equipment will delete the frequency or frequencies currently in the candidate set of frequencies with the highest absolute priority. And taking the absolute priority in the new candidate frequency set next to the highest absolute priority as the current highest absolute priority. Step S3022 to step S3023 are performed again to find the second best cell, and then step S3031 to step S3032/step S3033 are performed again until the second best cell that can be the reselection cell is found.

As can be seen from the above description, the present invention preferentially selects a suitable cell within the radio access network notification area of the user equipment as the reselection cell, and can avoid the RLAU operation performed by selecting a cell outside the radio access network notification area. When the suitable cell is not searched in the wireless access network notification area range of the user equipment to be used as the reselection cell, the cell in the standby state supporting the wireless resource control is selected from the selectable cells, thereby avoiding the state transition required by selecting the cell in the standby state not supporting the wireless resource control. Therefore, signaling overhead and power consumption can be reduced, and resources are saved.

Referring to fig. 8, fig. 8 is a flowchart illustrating a communication method according to a third embodiment of the present invention. The communication method provided by the invention comprises the following steps:

s401: and starting.

The user equipment receives and stores parameters and lists required for performing the communication method, such as absolute priority of frequencies, radio access network notification area frequency list and additional offset, before or just at the start of the communication method.

S402: and checking the radio access network notification area frequency list, and sequencing and storing all frequencies in the radio access network notification area frequency list according to the absolute priority level of the frequencies from high to low to form a candidate radio access network notification area frequency set.

S403: and checking the candidate wireless access network notification area frequency set to acquire one or more frequencies with the highest absolute priority.

S404: and judging whether the highest absolute priority is higher than the absolute priority of the frequency of the current cell.

In other implementation scenarios, when the ue has multiple current cells, the ue compares the highest absolute priority level of the absolute priorities of the frequencies of the current cells with the highest absolute priority level of the absolute priorities of all frequencies in the radio access network notification area of the ue. If the highest absolute priority among the absolute priorities of all the frequencies in the radio access network notification area of the user equipment is higher than the highest absolute priority among the absolute priorities of the frequencies of the current cell, the communication quality of the frequency is measured.

In other implementation scenarios, when the ue has multiple current cells, the ue compares the absolute priority levels of all frequencies of the current cells with the highest absolute priority level of all frequencies of the frequencies in the radio access network notification area of the ue. If the highest absolute priority among the absolute priorities of all the frequencies in the radio access network notification area of the user equipment is higher than the highest absolute priority among the absolute priorities of the frequencies of the current cell, the communication quality of the frequency is measured.

Step S405 is performed if the highest absolute priority is higher than the absolute priority that the frequency of the current cell is on, and step S406 is performed otherwise.

S405: all cells at the frequency with the highest absolute priority are detected.

If the highest absolute priority is higher than the absolute priority of the frequency on which the current cell is located, all cells on the frequency with the highest absolute priority are measured.

In other implementation scenarios, since the highest absolute priority of the absolute priorities of all frequencies in the radio access network notification area of the ue may correspond to more than one frequency, the communication quality of all cells in all frequencies with the highest absolute priority needs to be detected.

S406: and judging whether the communication quality of the current cell meets the requirement.

In a specific implementation scenario, if a level of a highest absolute priority among absolute priorities of all frequencies in the radio access network notification area of the ue is lower than or equal to a level of an absolute priority of a frequency in which the current cell is located, the ue measures the communication Quality of the current cell, in the implementation scenario, at least one of a Reference Signal Received Power (RSRP) and a Reference Signal Received Quality (RSRQ) of the current cell is measured, and in other implementation scenarios, at least one of a Received Signal Strength Indicator (RSSI) or a Signal Interference Noise Ratio (RS-SINR) of the current cell may be measured.

If the communication quality of the current cell meets the requirement, step S407 is executed, otherwise, step S408 is executed.

S407: stopping the measurement and continuing to use the current cell as the reselected cell.

In a specific implementation scenario, the current cell is used as the reselection cell, and since a suitable cell has been found to continue communication, there is no need to measure other cells, and thus the measurement process may be stopped. In this implementation scenario, the RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) of the current cell are measured, and if both the RSRP and the RSRQ of the current cell are higher than a preset threshold, the communication Quality of the current cell meets the requirement. In other implementation scenarios, it may also be that one of RSRP and RSRQ of the current cell is higher than a preset threshold, and then the communication quality of the current cell meets the requirement. In another specific implementation scenario, at least one of a Received Signal Strength Indicator (RSSI) or a Signal to Interference Noise Ratio (RS-SINR) of the current cell is also measured, and when the RSSI or the RS-SINR is higher than a preset threshold, the communication quality of the current cell meets the requirement.

S408: the communication quality of all cells at frequencies having said absolute priority lower than the current cell is measured.

In one implementation scenario, if the communication quality of the current cell is not satisfactory, the candidate radio access network is measured to notify frequencies in the area frequency list, which have an absolute priority lower than that of the frequency of the current cell. The communication quality at the frequency with the highest absolute priority may be measured as described in step 405. Since the absolute priority of all frequencies is lower than that of the current cell, the communication quality of any frequency with absolute priority can be measured at will.

S409: selecting a cell in a radio access network announcement area among all cells at the frequency having the highest absolute priority, and measuring communication quality of the cell in the radio access network announcement area.

S410: deleting the cells which cannot be used as candidate cells for reselecting the cells in the wireless access network notification area, sorting the rest cells in the wireless access network notification area according to R standard, and selecting the first cell arranged in the sorting as the first best cell.

In one particular implementation scenario, if a cell is a candidate cell that cannot be a reselection cell, the cell may not be a reselection cell, and the cells may be deleted before being sorted in a prescribed order of priority to reduce the workload of subsequent sorting. Cells that are not candidates for reselection cells include one or more of cells indicated as "reserved" for other purposes, cells indicated as "forbidden" for operator use, and cells indicated as "unreserved" for operator use.

In a specific implementation scenario, the ue ranks the remaining cells according to the R-criteria [ TS38.304], specifically according to:

Rs＝Qmeas,s+Qhyst

Rn＝Qmeas,n+Qoffset

the two equations may be sorted first by Rs and then by Rn if Rs is equal, or may be sorted conversely first by Rn and then by Rs if Rn is equal. The cell in the first place after sorting is the first best cell. In other implementation scenarios, the ordering may also be according to one of Rs or Rn. Where Qmeas, s is the RSRP measurement used in cell reselection. Qoffset for intra-frequency: qoffsets, n equals Qoffsets, n if valid, otherwise it equals zero. For the frequency interval: if Qoffset, n is valid, equal to Qoffset, n plus Qoffset frequency, otherwise equal to Qoffset frequency. Qoffset, n specifies the offset between two cells, Qoffset frequency is the frequency specific offset of the same priority E-UTRAN frequency. Qhyst specifies a hysteresis value for the ranking criteria.

S411: determining whether a communication quality of a first best cell is above a threshold, and determining whether the first best cell belongs to a part of a "list of tracking areas forbidden to roam" and/or belongs to a public land mobile network that is not indicated as being identical to a registered public land mobile network.

If the communication quality of the cell is satisfactory and does not belong to a part of the "tracking area list prohibited from roaming" and does not belong to a PLMN which is not indicated as being identical to the registered PLMN (Public land mobile Network), step S412 is performed to regard the first best cell as the reselecting cell, and the process ends. If the communication quality of the cell is not satisfactory or the cell belongs to a part of the "tracking area list prohibited from roaming" or to a PLMN which is not indicated as being identical to a registered PLMN (Public Land Mobile Network), step S413 is performed.

S413: and deleting the frequency of the first best cell in the candidate wireless access network notification area frequency set.

In a specific implementation scenario, the ue deletes the frequency of the first best cell in the candidate radio access network notification area frequency set. In another implementation scenario, the user equipment may delete the frequency or frequencies with the highest absolute priority currently within the radio access network notification area of the user equipment.

S414: the candidate radio access network informs whether the regional frequency set is empty.

After deleting the frequency of the first best cell, determining whether the candidate radio access network notification area frequency set has any remaining frequency, if yes, executing step S403, selecting a suitable cell from the cells corresponding to the remaining frequency as a reselection cell, and if not, executing step S415.

S415: a baseline cell reselection is performed based on the absolute priority and an advanced R criterion.

Step S415 is similar to steps S302 to S303 of the communication method provided by the present invention, and is not described herein again.

Referring to fig. 9, fig. 9 is a schematic structural diagram of a testing device according to an embodiment of the invention. As shown in fig. 9, the user equipment 10 includes a processor 11, a communication circuit 12, and a storage circuit 13. Processor 11 is coupled to communication circuit 12 and storage circuit 13.

In one implementation scenario, the storage circuit 13 is configured to store parameters and lists required for performing the communication method, such as absolute priority of frequencies, radio access network notification area frequency list and additional offsets.

The processor 11 controls the communication circuit 12 to enable selection of a suitable cell as a reselection cell within the radio access network notification area of the user equipment 10. If all cells within the radio access network notification area are not suitable as reselection cells and the communication quality of the current cell is not satisfactory, the processor 11 controls the communication circuit 12 to preferentially select a cell in a dormant state supporting radio resource control among the useful cells as a reselection cell.

The specific process of the processor 11 for implementing the above functions may refer to the above method embodiments.

As can be seen from the above description, in this embodiment, the processor is coupled to the communication circuit and the storage circuit to preferentially select a suitable cell within the notification area of the radio access network as the reselected cell, so that signaling overhead and power consumption can be reduced. In addition, when the cell outside the notification area range of the radio access network is selected as the reselected cell, the cell in the standby state supporting the radio resource control is preferentially selected as the reselected cell, so that the signaling overhead and the power consumption brought by state transition can be further reduced, and the resources are saved.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a device with a memory function according to the present invention. The device 20 with storage function has stored therein at least one program data 21, the program data 21 being used for performing the method of automatic testing as shown in any one of fig. 1 to 8. In one embodiment, the apparatus with storage function may be a storage chip in a terminal, a hard disk, or a removable hard disk or other readable and writable storage tool such as a flash disk, an optical disk, or the like, and may also be a server or the like.

As can be seen from the above description, the program data stored in the embodiment of the apparatus with storage function in this embodiment may be used to select a suitable cell as a reselected cell, so that resources may be saved.

Different from the prior art, the invention selects a proper cell as the reselected cell from the cells within the radio access network notification area range of the user equipment preferentially, thereby avoiding signaling overhead and power consumption caused by RLAU operation performed by selecting the cells outside the radio access network notification area range, and saving resources. When the cells in the wireless access network notification area range are not suitable to be used as reselected cells and the communication quality of the current cell is not in line with the requirement and can not be used continuously, the cell in the standby state supporting the wireless resource control is preferentially selected to be used as the reselected cell, so that the signaling overhead and power consumption caused by the fact that the user equipment needs to be converted into the idle state of the wireless resource control when the cell in the standby state not supporting the wireless resource control is selected can be avoided, and the resources are further saved.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A method of communication, comprising:

searching at least one first best cell within the range of a wireless access network notification area, wherein the communication quality of the first best cell meets requirements, and the absolute priority of all the cells with the communication quality meeting the requirements in the wireless access network notification area is the highest;

if the first best cell is found, the first best cell is used as a reselection cell, if the first best cell is not found within the range of the wireless access network notification area, a second best cell is found in all available cells, the communication quality of the second best cell meets the requirement, and the absolute priority is highest in all the cells with the qualified communication quality;

if the second best cell is found, treating the second best cell as the reselection cell, wherein,

the finding of at least one first best cell within the radio access network notification area comprises:

receiving a radio access network notification area frequency list sent by a current base station, and acquiring absolute priorities corresponding to all frequencies; the acquiring absolute priorities corresponding to all frequencies includes:

receiving system information broadcasted by a cell, wherein the system information comprises absolute priorities corresponding to all frequencies, and/or;

receiving a radio resource control connection release message sent by the current base station, wherein the radio resource control connection release message comprises absolute priorities corresponding to all frequencies and/or;

inheriting absolute priorities corresponding to all frequencies included in the last wireless access technology;

if the first best cell is not found, finding a second best cell in the candidate cell set, comprising:

checking all available frequencies, and sorting and storing all available frequencies from high to low according to the grades of the absolute priorities of the available frequencies to form a candidate frequency set;

checking the candidate frequency set to obtain the frequency with the highest absolute priority;

selecting at least one cell among all cells having the highest absolute priority as the at least one second best cell;

said selecting at least one cell among all cells having the highest absolute priority as the at least one second best cell comprises:

deleting cells belonging to candidate cells that cannot be reselected cells among all cells at the frequency having the highest absolute priority; and/or

Deleting the cells within the radio access network notification area from all cells at the frequency having the highest absolute priority;

said selecting at least one cell among all cells having the highest absolute priority as the at least one second best cell further comprises: sorting the deleted cells at the frequency with the highest absolute priority according to a progressive R standard, and selecting a first cell arranged in the sorting as the second best cell;

the sorting the deleted cells at the frequency with the highest absolute priority according to an advanced R standard includes: acquiring an additional offset of each cell supporting the standby state of the radio resource control;

the additional offset is specified by the cell, and the obtaining of the additional offset for each cell supporting a dormant state of radio resource control comprises: receiving system information broadcast by the cell, the system information including the additional offset.

2. The method of claim 1, wherein the finding at least one first best cell within the radio access network notification area comprises:

checking the radio access network notification area frequency list, and sequencing and storing all frequencies in the radio access network notification area frequency list according to the absolute priority level of the frequencies from high to low to form a candidate radio access network notification area frequency set;

checking the candidate radio access network announcement area frequency set, acquiring one or more frequencies with the highest absolute priority in the candidate radio access network announcement area frequency set, and selecting at least one suitable cell from the cells in the one or more frequencies with the highest absolute priority as the first best cell.

3. The method of claim 2, wherein the selecting at least one suitable cell from the cells in the one or more frequencies with the highest absolute priority as the first best cell comprises:

comparing the absolute priority that the frequency of the current cell has with the highest absolute priority;

if the frequency of the current cell has the absolute priority lower than the highest absolute priority, all cells at the frequency having the highest absolute priority are detected, and at least one suitable cell is selected as the first best cell from all cells at the frequency having the highest absolute priority.

4. The method of claim 3, wherein the selecting at least one suitable cell from the cells in the one or more frequencies with the highest absolute priority as the first best cell comprises:

selecting a cell in a radio access network announcement area among all cells at the frequency having the highest absolute priority, and measuring communication quality of the cell in the radio access network announcement area;

deleting cells which cannot be used as candidate cells of a reselected cell in the cells in the wireless access network notification area, sorting the rest cells in the wireless access network notification area according to the communication quality according to an R standard, and selecting the first cell arranged in the sorting as the first best cell;

wherein the cell that cannot be a candidate cell for the reselection cell comprises:

a cell indicated as "reserved for other use"; and/or

A cell indicated as "forbidden to use"; and/or

A cell indicated as "reserved for operator use".

5. The method of claim 2, wherein selecting at least one suitable cell from the cells in the one or more frequencies with the highest absolute priority as the first best cell further comprises:

and if the absolute priority of the frequency of the current cell is higher than or equal to the highest absolute priority, measuring the communication quality of the current cell, and if the communication quality of the current cell meets the requirement, taking the current cell as a reselected cell.

6. The method of claim 5, wherein selecting at least one suitable cell from the cells in the one or more frequencies with the highest absolute priority as the first best cell further comprises:

if the communication quality of the current cell is not satisfactory, the method of claim 4 is performed to find the first best cell.

7. The method of claim 1, wherein if the first best cell is found, using the first best cell as a reselection cell comprises:

judging whether the communication quality of the first best cell meets the requirement or not;

if the communication quality of the first best cell meets the requirement, judging whether the first best cell belongs to a part of a 'tracking area list forbidden to roam' and/or belongs to a public land mobile network which is not indicated to be identical to a registered public land mobile network;

if the first best cell does not belong to either part of the "roaming forbidden tracking area list" or to a public land mobile network that is not indicated as identical to the registered public land mobile network, then the first best cell is taken as the reselection cell.

8. The method of claim 7, wherein if the first best cell is found, the first best cell is used as a reselection cell, further comprising:

deleting the one or more frequencies with the highest absolute priority in a candidate radio access network notification area frequency set if the communication quality of the remaining cells in the one or more frequencies with the highest absolute priority are not satisfactory;

taking the deleted candidate radio access network announcement area frequency set as a new candidate radio access network announcement area frequency set, checking the new candidate radio access network announcement area frequency set, obtaining one or more frequencies in the new candidate radio access network announcement area frequency set with the highest absolute priority, and then performing the method of any one of claims 3-7.

9. The method of claim 1,

the cells that cannot be candidates for the reselection cell include:

a cell indicated as "reserved for other use"; and/or

A cell indicated as "forbidden to use"; and/or

A cell indicated as "reserved for operator use".

10. The method of claim 1, wherein the additional offset is specified by the current base station, and wherein obtaining the additional offset for each cell supporting radio resource control dormant state comprises:

and receiving a radio resource control connection release message sent by the current base station, wherein the radio resource control connection release message comprises the additional offset.

11. The method of claim 10, wherein the additional offset is specified by the current base station, and wherein obtaining the additional offset for each cell supporting radio resource control dormant state further comprises:

disregarding the additional offset included by the system information when the additional offset included by the system information is different from the additional offset included by the radio resource control connection release message.

12. The method of claim 1, wherein if the second best cell is found, using the second best cell as a reselection cell comprises:

judging whether the communication quality of the second best cell meets the requirement,

if the communication quality of the second best cell meets the requirement, determining whether the second best cell belongs to a part of a 'tracking area list forbidden to roam' and/or a public land mobile network which is not indicated to be identical to a registered public land mobile network, and if the second best cell does not belong to a part of the 'tracking area list forbidden to roam' or a public land mobile network which is not indicated to be identical to the registered public land mobile network, taking the second best cell as a reselecting cell.

13. The method of claim 12, wherein if the second best cell is found, using the second best cell as a reselection cell comprises:

if the communication quality of the remaining cells in the one or more frequencies with the highest absolute priority are not satisfactory or belong to a "list of tracking areas forbidden to roam" and/or belong to a public land mobile network that is not indicated as being identical to a registered public land mobile network, deleting the one or more frequencies with the highest absolute priority in the candidate frequency set, treating the deleted candidate frequency set as a new candidate frequency set, examining the new candidate frequency set, acquiring the one or more frequencies with the highest absolute priority in the new candidate frequency set, and then performing the method of any one of claims 9-12.

14. The method according to any one of claims 1 to 13,

the communication quality includes: at least one of a reference signal received power and a reference signal received quality of the cell;

the communication quality meets the requirements, including:

at least one of the reference signal received power and the reference signal received quality of the cell is higher than a preset threshold;

the communication quality is not satisfactory, and comprises the following steps:

at least one of the reference signal received power and the reference signal received quality of the cell is lower than or equal to a preset threshold.

15. A user equipment comprising a processor, a communication circuit and a memory coupled to each other, the processor coupling the communication circuit and the memory for implementing the method of any one of claims 1-13.

16. An apparatus having a memory function, characterized in that program data are stored, which program data can be executed to implement the steps in the method according to any of claims 1-13.