Cell selection method and equipment
Technical Field
The present invention relates to the field of communications technologies, and in particular, to a cell selection method and device.
Background
In an LTE (Long Term evolution ) system, RRC (Radio Resource Control) states of a UE (User Equipment) are divided into an RRC IDLE state (RRC _ IDLE) and an RRC CONNECTED state (RRC _ CONNECTED); the RRC idle state refers to a state that the UE does not establish connection with any base station and the core network entity stores the context of the UE; the RRC connected state is a state in which the UE establishes connection with a specific base station, and the UE can perform data transmission in the RRC connected state.
The process of selecting a resident cell such as cell selection, cell reselection and the like is defined in the LTE system; in order to ensure the fast network attachment, once the UE selects a proper cell, the UE dwells and selects a better cell through a cell reselection process, the subsequent RRC connection establishment process is carried out in the resident cell, if the connection is established to a cell, the UE detects that the channel quality of the cell is not optimal, and the cell can be switched to a better cell through a cell switching process; a cell selection procedure and a cell reselection procedure are explained below.
(1) The cell selection process refers to that the UE selects a cell to reside by means of initial cell selection or stored information cell selection and the like. In the initial cell selection method, the UE does not have prior carrier information, the UE performs frequency scanning according to its own capability, the UE only needs to search a strongest cell on a certain carrier frequency, the UE selects a cell to camp on once finding a suitable cell, the suitable cell refers to a cell where the UE can camp to obtain normal service, the suitable cell has capability and resources to serve the UE, a channel condition between the cell and the UE needs to satisfy a cell selection channel Quality standard (referred to as an S criterion in an LTE system), and the S criterion refers to RSRP (Reference Signal Received Power) and RSRQ (Reference Signal Received Quality) measured by the UE and is greater than a preset threshold. In the cell selection mode of the stored information, the UE stores information such as carrier waves and the like, and can perform cell detection according to the prior information; similar to the initial cell selection approach, the UE only needs to search for a suitable cell to select and camp on.
(2) A cell reselection process, which refers to a process of continuing to search a better cell after the UE selects the cell; in a cell reselection process, a UE first needs to determine priorities between different E-UTRAN (Evolved universal terrestrial Radio Access Network) frequency points and different RATs according to a system message, an RRC connection release message, or other RAT (Radio Access technology) reselection messages, and the like; in the cell reselection process, the UE needs to consider the frequency point priority and the RAT priority, the UE moving state, the time when the UE resides in the current cell, the cell reselection condition meeting the time period and other factors; and the cell reselection follows the principles of optimizing higher priority frequency points and RATs, not starting the cell reselection too frequently after the UE resides, and ensuring that the channel quality of the cell to be selected is good enough in a certain time.
In the prior art, in order to meet the increasing data service requirement, a base station local IP access system based on an LTE system is developed. As shown in fig. 1, which is a schematic diagram of a base station local IP access system, the base station local IP access system provides network coverage and wireless access service for a user by a base station (also referred to as an access point AP) by constructing a local wireless network; the local IP access system of the base station adopts a flat network architecture, so that the access of the UE to an external network can be simply realized at low cost, the architecture is completely based on the architecture of an access network, a core network of an LTE system is cancelled, and a data transmission path and network complexity are simplified.
In a local IP access system of a base station, UE is generally in a relatively static state, and no core network entity stores the context of the UE, so that the local IP access system of the base station has no RRC idle state, and the UE directly enters an RRC connection state after being accessed into a network and is always connected with a selected base station; further, in the local IP access system of the base station, since the core network is cancelled, the handover signaling transmission which is completed by the core network and the data forwarding process between different base stations cannot be realized, and therefore, the handover process of the LTE system is cancelled, and if the original serving cell cannot serve the UE any more (including RRC connection release or serving cell channel quality degradation, etc.), the UE starts the cell selection process to additionally select a cell and initiate RRC connection establishment.
It should be noted that according to the cell selection method of the LTE system, after the UE selects a suitable cell, the UE shall camp on the cell, and if the RRC connection needs to be established, the UE shall immediately perform the RRC connection establishment procedure with the selected cell; however, in the local IP access system of the base station, after the UE establishes connection with any selected suitable cell, the UE is always in the RRC connected state, and as long as the UE does not move out of the cell or become unavailable due to cell failure, the UE cannot select another cell.
In the process of implementing the invention, the inventor finds that at least the following problems exist in the prior art:
since the UE can no longer select to other cells, the UE is likely to be unable to operate in the cell with the best channel quality; and if all the UEs in the similar geographic positions carry out cell search according to the same frequency point sequence, the same cell is likely to be selected to establish connection, and further the load among the cells is unbalanced.
Disclosure of Invention
The embodiment of the invention provides a cell selection method and equipment, so that UE (user equipment) works in a cell with the best channel quality and the load balance among the cells is ensured.
In order to achieve the above object, an embodiment of the present invention provides a cell selection method, including:
user Equipment (UE) acquires priority information of frequency points;
the UE carries out cell channel quality evaluation on each cell of the frequency point with the highest priority level to obtain channel quality evaluation values respectively corresponding to each cell of the frequency point with the highest priority level;
and the UE selects a cell with the largest channel quality evaluation value from the cells meeting the cell selection channel quality standard to establish connection.
The embodiment of the invention provides a cell selection method, which comprises the following steps:
the base station equipment determines the priority information of the frequency points;
and the base station equipment informs User Equipment (UE) of the priority information of the frequency points, and the UE performs cell selection by using the priority information of the frequency points.
An embodiment of the present invention provides a user equipment UE, including:
the acquisition module is used for acquiring the priority information of the frequency points;
the calculating module is used for carrying out cell channel quality evaluation on each cell of the frequency point with the highest priority level to obtain channel quality evaluation values respectively corresponding to each cell of the frequency point with the highest priority level;
and the selection module is used for selecting the cell with the largest channel quality evaluation value from the cells meeting the cell selection channel quality standard to establish connection.
An embodiment of the present invention provides a base station device, including:
the determining module is used for determining the priority information of the frequency points;
and the sending module is used for notifying the priority information of the frequency point to User Equipment (UE), and the UE utilizes the priority information of the frequency point to select the cell.
Compared with the prior art, the embodiment of the invention at least has the following advantages: in the embodiment of the invention, the selection of the cells is carried out through the priority information of the frequency points, so that the UE can work in the cell with the best channel quality, and the load balance among the cells can be ensured.
Drawings
In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.
FIG. 1 is a schematic diagram of a prior art base station local IP access system;
fig. 2 is a flowchart illustrating a cell selection method according to an embodiment of the present invention;
fig. 3 is a flowchart illustrating a cell selection method according to a second embodiment of the present invention;
fig. 4 is a flowchart illustrating a cell selection method according to a third embodiment of the present invention;
fig. 5 is a flowchart illustrating a cell selection method according to a fourth embodiment of the present invention;
fig. 6 is a flowchart illustrating a cell selection method according to a fifth embodiment of the present invention;
fig. 7 is a schematic structural diagram of a user equipment according to a sixth embodiment of the present invention;
fig. 8 is a schematic structural diagram of a base station device according to a seventh embodiment of the present invention.
Detailed Description
The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example one
The embodiment of the invention provides a cell selection method, which provides a mode of selecting an optimal cell for a mode that UE is always in a connected state after accessing a network, and can be applied to a local IP access system of a base station; certainly, the application scenario of the method is not limited to this, for example, if the UE establishes a connection with the base station device after initial access in the LTE system and keeps the connection all the time, the technical solution provided in the embodiment of the present invention is also applicable; as shown in fig. 2, the method comprises the steps of:
step 201, the UE obtains priority information of the frequency point.
In the embodiment of the present invention, the manner for the UE to obtain the priority information of the frequency point includes, but is not limited to:
(1) the UE obtains the priority information of the frequency points through the subscription data; in this manner, priority information of the frequency point needs to be recorded in advance in the subscription data of the UE.
(2) The UE obtains the priority information of the frequency points through the information built in the equipment capacity limit; in this manner, priority information of the frequency point needs to be built in the UE.
(3) The UE obtains the priority information of the frequency point through the information indicated by the base station equipment in the connection establishment release message, and the information indicated by the base station equipment in the connection establishment release message is specifically the frequency point priority when the UE performs cell selection next time; in this way, the base station device needs to determine the priority information of the frequency point and notify the priority information of the frequency point to the UE, and the base station device notifies the UE of the priority information of the frequency point when the UE performs cell selection next time through the connection establishment release message.
(4) The UE sets the current working frequency point as the priority of the designated level in the connection establishment and release process to obtain the priority information of the frequency point; for example, in the connection establishment and release process, the UE sets the current working frequency point to the highest priority, and then may determine that the priority information of the working frequency point is the highest priority.
(5) The UE obtains the priority information of the frequency points by storing the priority information of each frequency point in the system message of the current service cell and storing for a period of designated time (such as several hours) after the connection is established and released.
It should be noted that, when the UE performs cell selection, the base station local IP access system is taken as the highest priority, and other RATs have lower priorities, so that cell selection of other RATs does not need to be considered in the cell selection process, and only cell selection of the base station local IP access system needs to be considered; based on this, in the embodiment of the present invention, the process of obtaining the priority information of the frequency point by the UE specifically includes: the UE determines a frequency point corresponding to the local IP access system of the base station, and obtains priority information of the frequency point corresponding to the local IP access system of the base station, that is, in step 201, the priority information of the frequency point corresponding to the local IP access system of the base station is obtained.
In the embodiment of the present invention, the method for determining the frequency point corresponding to the local IP access system of the base station by the UE includes, but is not limited to, the following methods:
in the first mode, when the local IP access system of the base station adopts the dedicated frequency band, the UE determines the frequency point in the dedicated frequency band as the frequency point corresponding to the local IP access system of the base station.
Further, since the frequency point in the dedicated frequency band is a frequency point corresponding to the local IP access system of the base station, subsequent processing can be performed based on the frequency point in the dedicated frequency band, that is, the UE takes the frequency point in the dedicated frequency band as a high-priority frequency point and preferentially searches the frequency point in the dedicated frequency band when performing frequency point search.
In a second mode, when the base station local IP access system and other wireless access systems or the traditional LTE system adopt the same frequency band, the base station local IP access system can be identified through the cell type notified by the system message, namely the UE can determine the frequency point corresponding to the base station local IP access system through the cell type notified by the system message; in this way, the base station device needs to broadcast the cell type in the cell system message, that is, the base station device notifies the UE of the cell type through the system message.
In the embodiment of the present invention, for the base station local IP Access system, the system message for notifying the cell type may carry information such as a network identifier of the base station local IP Access system, or a cell name, or an Access Point (AP) name, or an identifier recognizable by other users; further, after receiving the system message for notifying the cell type in the cell, the UE may determine the cell type by reading the system message, and if it is known that the cell is a cell in the base station local IP access system (that is, the system message carries information such as a network identifier, a cell name, or a service AP name of the base station local IP access system), determine the frequency point corresponding to the cell as the frequency point corresponding to the base station local IP access system.
And thirdly, when the local IP access system of the base station and other wireless access systems or the traditional LTE system adopt the same frequency band, the UE can determine the cell type through the physical signal characteristics and determine the frequency point corresponding to the local IP access system of the base station by using the determined cell type.
In the embodiment of the present invention, when the physical Signal characteristic is a location of a PSS (Primary Synchronization Signal)/SSS (Secondary Synchronization Signal), different Synchronization Signal locations are adopted in the radio frame signals sent in the base station local IP access system and the macro network system, and the location may be a time domain location and/or a frequency domain location, so that the UE may determine the cell type according to a difference of the PSS/SSS locations detected during cell search.
For example, the PSS/SSS in the base station local IP access system cell and the macro network system cell have different OFDM (Orthogonal Frequency Division Multiplexing) symbol positions in a radio frame, or have different relative positions between the PSS and the SSS.
In the embodiment of the present invention, when the Physical signal characteristic is a position of a PBCH (Physical broadcast channel), the radio frame signals sent in the local IP access system and the macro network system of the base station will adopt different PBCH positions, where the position may be an absolute position (i.e., a time domain OFDM symbol and a frequency domain subcarrier position of the PBCH in the radio frame) or a relative position (i.e., a difference value of the PBCH in the radio frame with respect to a time domain OFDM symbol or a frequency domain subcarrier position of a synchronization signal PSS or SSS), and therefore, the UE may determine the cell type according to an absolute time frequency domain position of the PBCH detected during cell search or a difference of the PBCH and the PSS/SSS relative positions.
Step 202, the UE performs cell channel quality assessment on each cell with the frequency point having the highest priority level to obtain channel quality assessment values respectively corresponding to each cell with the frequency point having the highest priority level.
For example, when the priority information of the frequency points is a high priority level, a normal priority level and a low priority level, if there is a frequency point with a high priority level, the frequency point with the high priority level is the frequency point with the highest priority level; if no frequency point with high priority level exists and a frequency point with normal priority level exists, the frequency point with normal priority level is the frequency point with the highest priority level; if there is no frequency point with high priority, no frequency point with normal priority and frequency point with low priority, the frequency point with low priority is the frequency point with highest priority.
In step 203, the UE selects a cell with the largest channel quality assessment value among the cells satisfying the cell selection channel quality criteria to establish a connection.
In the embodiment of the present invention, after the UE obtains the channel quality assessment values corresponding to the cells of the frequency points with the highest priority, if any cell meets the cell selection channel quality standard, the UE determines not to perform the cell channel quality assessment process on the cells of the frequency points with the next priority (for example, when the highest priority is the high priority, the next priority is the normal priority, and when the highest priority is the normal priority, the next priority is the low priority).
If no cell meets the cell selection channel quality standard, the UE performs cell channel quality evaluation on each cell of the frequency point with the next priority level to obtain channel quality evaluation values respectively corresponding to each cell of the frequency point with the next priority level; if the cell in each cell of the frequency point with the next priority level meets the cell selection channel quality standard, selecting the cell with the largest channel quality evaluation value from the cells meeting the cell selection channel quality standard to establish connection; and if no cell in each cell of the frequency point with the next priority level meets the cell selection channel quality standard, continuing to evaluate the cell channel quality of each cell of the frequency point with the next priority level, and so on.
In summary, in the embodiments of the present invention, the UE performs cell channel quality evaluation and cell selection according to the frequency point priority order, that is, the UE performs cell channel quality RSRP and RSRQ measurement from the highest priority frequency point, performs channel quality evaluation ranking, selects a cell with the largest channel quality assessment value from the cells meeting the cell selection channel quality standard for connection establishment, and may not perform channel quality measurement of the low priority frequency point after selecting the cell for connection establishment.
Further, the UE needs to perform RSRP and RSRQ measurement on cells at each frequency point under the same frequency point priority, perform channel quality evaluation, and select a cell with the largest channel quality evaluation value from the cells that satisfy the cell selection channel quality standard and allow the UE to access to perform connection establishment, where it is noted that each frequency point only needs to select a cell with the best channel quality to participate in the ranking.
Therefore, in the embodiment of the present invention, selecting, by the UE, a cell with a largest channel quality assessment value among cells that satisfy the cell selection channel quality criterion to establish a connection includes: and the UE determines the cell with the largest channel quality assessment value under each frequency point with the highest priority level, sorts all the cells with the largest channel quality assessment values under the frequency points with the highest priority level, and selects the cell with the largest channel quality assessment value from the cells meeting the cell selection channel quality standard by utilizing the sorting result to establish connection.
It should be noted that the channel quality estimation method may use the S criterion in the LTE system, but the two methods are different, and the difference is specifically expressed as: in order to facilitate channel quality sequencing, the embodiment of the invention introduces offset parameters based on frequency points, and cancels relevant parameters of PLMN (Public Land Mobile Network) in an S criterion of an LTE (long term evolution) system.
Based on this, in the embodiment of the present invention, the cell selection channel quality criteria is: srxlev _ Hi>0 toAnd Squal _ Hi>0; wherein Srxlev _ Hi = Qrxlevmeas–QrxlevminPcompensation Qoffset _ Hi, and Squal _ Hi = Qqualmeas–Qqualmin(ii) a In the above formula, Srxlev denotes a cell selection reception level value (dB), Squal denotes a cell selection quality value (dB), QrxlevmeasRepresenting cell RSRP measurement, QrxlevminIndicates the minimum received level requirement (dBm) of the cell and Pcompensition is max (P)EMAX–PPowerClass0), i.e., Pcompenation is (P)EMAX–PPowerClass) And maximum of 0, and PEMAXMaximum uplink transmission power (dBm) of UE in a cell designated for higher layers, indicated in a base station system message, PPowerClassQoffset _ Hi represents the measurement offset value at different frequency points, Q, for the maximum radio frequency output power (dBm) of the UE determined according to the power class of the UEqualmeasRepresenting cell RSRQ measurement, QqualminRepresenting the minimum received quality requirement (dB) of the cell.
Further, the Qoffse _ Hi obtaining manner includes but is not limited to: the UE obtains Qoffset _ Hi through subscription data; or the UE obtains the Qoffset _ Hi through the built-in information of the equipment capability limit; or, the UE obtains the Qoffse _ Hi through information indicated in the connection setup release message by the base station device, and the information indicated in the connection setup release message by the base station device is specifically the Qoffse _ Hi when the UE performs cell selection next time (in this manner, the base station device needs to notify the UE of the Qoffse _ Hi, which is a measurement offset value at a different frequency point when the UE performs cell selection next time, in the connection setup release message); the UE sets the current Qoffset _ Hi as the Qoffset _ Hi used next time in the connection establishment and release process to obtain the Qoffset _ Hi; or the UE stores the Qoffset _ Hi of each frequency point in the system message of the current service cell and stores the Qoffset _ Hi for a period of designated time after connection establishment and release so as to obtain the Qoffset _ Hi.
It should be noted that, for the notification process of the priority of the frequency point and the notification process of Qoffset _ Hi, the system message of the cell may include the priority of the frequency point and Qoffset _ Hi at the same time; or, the RRC connection release message for releasing the UE may include the priority of the frequency point and Qoffset _ Hi at the same time; further, if the UE obtains a specified value of Qoffset _ Hi, Qoffset = 0.
The following describes embodiments of the present invention in detail with reference to specific application scenarios.
Example two
In the embodiment of the present invention, a cell selection process of UE without frequency point priority information is taken as an example for description, in this embodiment, the UE determines that a base station local IP access system is available for selection, and lists the frequency point as an available frequency point (which has the highest priority), and the determination method of the base station local IP access system includes but is not limited to: based on dedicated frequency points, based on system message notification, or based on physical layer parameters; based on the above process, as shown in fig. 3, the cell selection method includes the following steps:
step 301, UE searches available frequency points and detects available cells; the available cell refers to a cell to which the UE is not barred from accessing.
In the embodiment of the invention, the available frequency point information is stored in the UE, and the UE can also store the available cell information; in a preferred embodiment, the UE stores information { candidate cell id, Srxlev _ Hi _ old } corresponding to the candidate cell, Srxlev _ Hi _ old is a cell channel quality assessment value of a cell with the best channel quality stored by the UE, and the initial value candidate cell id = NULL, and Srxlev _ Hi _ old = 0.
Step 302, the UE judges whether an available cell is detected; if yes, go to step 303, if no, go to step 306.
Step 303, the UE measures the RSRP and the RSRQ of the cell and calculates a channel quality assessment value; the process of calculating the channel quality assessment value specifically includes: srxlev _ Hi and Squal _ Hi are calculated according to the following formulas;
Srxlev_Hi=Qrxlevmeas–Qrxlevmin–Pcompensation–Qoffset_Hi;
Squal_Hi=Qqualmeas–Qqualmin。
step 304, the UE judges whether the conditions Srxlev _ Hi >0, Squal _ Hi >0 and Srxlev _ Hi > Srxlev _ Hi _ old are met; if so, go to step 305; if not, step 306 is performed.
Step 305, the UE updates information { the identifier of the cell to be selected, Srxlev _ Hi _ old } corresponding to the cell to be selected; wherein, the updating process specifically comprises: and setting the identifier of the cell to be selected as the current measuring cell, and setting Srxlev _ Hi _ old as the Srxlev _ Hi of the current measuring cell.
Step 306, the UE judges whether the searching of all frequency points and cells is finished; if yes, go to step 307; if not, go to step 301.
Step 307, the UE selects a cell corresponding to the stored identifier of the cell to be selected to initiate a connection establishment procedure.
It should be noted that the above process of this embodiment does not describe an abnormal flow, that is, the UE does not find a suitable cell after completing the search of all frequency points; in a general scenario, it is considered that the UE can always select one cell to initiate connection establishment, and if not, the UE may trigger a cell selection process of another RAT or LTE system, which is not described in this embodiment of the present invention.
EXAMPLE III
In the embodiment of the present invention, a cell selection process of a UE having frequency point priority information is taken as an example for description, in this embodiment, the UE determines that a base station local IP access system is available for selection, and lists the frequency point as an available frequency point (which has the highest priority), and the determination method of the base station local IP access system includes, but is not limited to: based on dedicated frequency points, based on system message notification, or based on physical layer parameters; based on the above process, as shown in fig. 4, the cell selection method includes the following steps:
step 401, UE searches for a set frequency point, detects an available cell, and initially sets the frequency point as a highest priority frequency point; the available cell refers to a cell to which the UE is not barred from accessing.
In the embodiment of the invention, the priority information of the frequency point is stored in the UE, and the priority information of the frequency point is built in the UE or the UE acquires the priority information of the frequency point in the last RRC connection process; in addition, available cell information may also be stored within the UE; in a preferred embodiment, the UE stores information { candidate cell id, Srxlev _ Hi _ old } corresponding to the candidate cell, Srxlev _ Hi _ old is a cell channel quality assessment value of a cell with the best channel quality stored by the UE, and the initial value candidate cell id = NULL, and Srxlev _ Hi _ old = 0.
Step 402, UE judges whether available cells are detected; if yes, go to step 403, if no, go to step 409.
Step 403, the UE measures the RSRP and the RSRQ of the cell and calculates a channel quality assessment value; the process of calculating the channel quality assessment value specifically includes: srxlev _ Hi and Squal _ Hi are calculated according to the following formulas;
Srxlev_Hi=Qrxlevmeas–Qrxlevmin–Pcompensation–Qoffset_Hi;
Squal_Hi=Qqualmeas–Qqualmin。
step 404, the UE determines whether the condition Srxlev _ Hi >0, Squal _ Hi >0, and Srxlev _ Hi > Srxlev _ Hi _ old is satisfied; if so, go to step 405; if not, step 406 is performed.
Step 405, the UE updates information { the identifier of the cell to be selected, Srxlev _ Hi _ old } corresponding to the cell to be selected; wherein, the updating process specifically comprises: and setting the identifier of the cell to be selected as the current measuring cell, and setting Srxlev _ Hi _ old as the Srxlev _ Hi of the current measuring cell.
Step 406, the UE determines whether the search of all cells of the set frequency point has been completed; if yes, go to step 407; if not, go to step 401.
Step 407, the UE determines whether the identifier of the cell to be selected is not NULL; if so, step 408 is performed, otherwise, step 409 is performed.
In step 408, the UE selects a cell corresponding to the stored identifier of the cell to be selected to initiate a connection establishment procedure.
In step 409, the UE sets the set frequency point to a frequency point one priority lower than the currently set frequency point, and executes step 401.
It should be noted that the above process of this embodiment does not describe an abnormal flow, that is, the UE does not find a suitable cell after completing the search of all frequency points; in a general scenario, it is considered that the UE can always select one cell to initiate connection establishment, and if not, the UE may trigger a cell selection process of another RAT or LTE system, which is not described in this embodiment of the present invention.
Example four
In the embodiment of the present invention, priority information of a frequency point and/or Qoffset _ Hi obtained by a UE through a system message (for example, priority information of a frequency point and Qoffset _ Hi are subsequently used as examples) is taken as an example for explanation, in this embodiment, the UE does not have an actual serving cell during initial access, and therefore, it is not necessary to obtain priority information of a frequency point through a system message of a serving cell as in a cell reselection process of an LTE system.
Processing for the base station apparatus: requiring the base station equipment to contain the priority information of the frequency points and Qoffset _ Hi in the system message of the cell; specifically, parameters cellreselection priority and q-OffsetFreq of inter freqcarrierfreqinfo in an LTE System message SIB15 (System Information Block ) can be multiplexed; or, constructing new system message content dedicated to indicating the priority and Qoffset _ Hi of the frequency points, and putting the message content into SIB2 or constructing a SIB separately.
Based on the above-mentioned correlation processing of the base station apparatus, as shown in fig. 5, for the correlation processing on the UE side, the cell selection method includes the following steps:
step 501, the UE reads the system message of the cell maintaining RRC connection with the UE, and obtains the frequency point priority and Qoffset _ Hi.
Step 502, the UE stores the frequency point priority and Qoffset _ Hi, and performs corresponding update each time the system message is updated.
In step 503, after the UE disconnects from the base station device (for example, the UE is powered off or moves to another RAT), the frequency point priority and Qoffset _ Hi are reserved within a predetermined time (for example, several hours).
Further, after the specified time is overtime, the UE deletes the frequency point priority and Qoffset _ Hi; and if the frequency point priority and the Qoffset _ Hi are deleted by the UE, the UE considers that no frequency point priority and no Qoffset _ Hi =0 exist in the subsequent cell selection process.
It should be noted that the specified time may be set to infinity, i.e. the UE keeps the parameters until new frequency bin priority and Qoffset _ Hi are obtained.
Step 504, when the UE initiates cell selection in the local IP access system of the base station, the UE performs cell selection processing using the stored frequency point priority and Qoffset _ Hi.
EXAMPLE five
In the embodiment of the present invention, a case where a base station device notifies a UE of frequency point priority information and/or Qoffset _ Hi (hereinafter, the priority information and Qoffset _ Hi of the frequency point are taken as examples) when connection is released is described.
Processing for the base station apparatus: the base station equipment can inform the UE of the priority information of the frequency points and Qoffset _ Hi through the dedicated RRC message of the UE; specifically, when releasing the RRC connection of the UE, the base station device may include the frequency point priority information and Qoffset _ Hi in an RRC connection release message RRCConnectionRelease, and send the RRC connection release message to the UE.
Based on the above-mentioned correlation processing of the base station apparatus, as shown in fig. 6, for the correlation processing on the UE side, the cell selection method includes the following steps:
step 601, the UE reads the RRC connection release message and acquires the frequency point priority and Qoffset _ Hi.
Step 602, the UE stores the frequency point priority and Qoffset _ Hi.
Step 603, after the UE disconnects from the base station device (for example, the UE powers off or moves to another RAT), the frequency point priority and Qoffset _ Hi are reserved within a specified time (for example, several hours).
Further, after the specified time is overtime, the UE deletes the frequency point priority and Qoffset _ Hi; and if the frequency point priority and the Qoffset _ Hi are deleted by the UE, the UE considers that no frequency point priority and no Qoffset _ Hi =0 exist in the subsequent cell selection process.
It should be noted that the specified time may be set to infinity, i.e. the UE keeps the parameters until new frequency bin priority and Qoffset _ Hi are obtained.
Step 604, when the UE initiates cell selection in the local IP access system of the base station, the UE performs cell selection processing using the stored frequency point priority and Qoffset _ Hi.
EXAMPLE six
Based on the same inventive concept as the above method, an embodiment of the present invention further provides a user equipment, as shown in fig. 7, where the user equipment includes:
an obtaining module 11, configured to obtain priority information of a frequency point;
a calculating module 12, configured to perform cell channel quality assessment on each cell of the frequency points with the highest priority level to obtain channel quality assessment values respectively corresponding to each cell of the frequency points with the highest priority level;
and a selecting module 13, configured to select a cell with the largest channel quality assessment value among cells that meet the cell selection channel quality criterion for connection establishment.
The calculating module 12 is further configured to perform cell channel quality evaluation on each cell of the frequency points with the next priority level if no cell meets the cell selection channel quality standard, so as to obtain channel quality evaluation values respectively corresponding to each cell of the frequency points with the next priority level; if the cell meets the cell selection channel quality standard, determining not to execute the process of cell channel quality evaluation on each cell of the frequency points with the next priority level;
the selecting module 13 is further configured to select a cell with the largest channel quality assessment value from the cells meeting the cell selection channel quality standard to establish a connection if any cell in each cell of the frequency points with the next priority level meets the cell selection channel quality standard.
The selecting module 13 is specifically configured to determine each cell with the largest channel quality assessment value at the frequency point with the highest priority level, sort all cells with the largest channel quality assessment values at the frequency point with the highest priority level, and select a cell with the largest channel quality assessment value from the cells meeting the cell selection channel quality standard by using the sorting result to establish a connection.
The obtaining module 11 is specifically configured to obtain priority information of the frequency point through the subscription data; or, obtaining the priority information of the frequency point through the information built in the equipment capacity limit; or, obtaining priority information of the frequency point through information indicated in the connection establishment release message by the base station equipment, wherein the information indicated in the connection establishment release message by the base station equipment is specifically the frequency point priority when the UE performs cell selection next time; or, the priority information of the frequency point is obtained by setting the current working frequency point to the priority of the designated level in the connection establishment and release process; or, the priority information of the frequency points is obtained by storing the priority information of each frequency point in the system message of the current service cell and storing for a period of designated time after the connection is established and released.
The obtaining module 11 is specifically configured to determine a frequency point corresponding to the base station local IP access system, and obtain priority information of the frequency point corresponding to the base station local IP access system.
The obtaining module 11 is further configured to determine, when a dedicated frequency band is adopted by a local IP access system of a base station, a frequency point in the dedicated frequency band as a frequency point corresponding to the local IP access system of the base station; or when the local IP access system of the base station and other wireless access systems adopt the same frequency band, determining a frequency point corresponding to the local IP access system of the base station according to the cell type notified by the system message; or when the local IP access system of the base station and other wireless access systems adopt the same frequency band, determining the cell type through the physical signal characteristics, and determining the frequency point corresponding to the local IP access system of the base station by using the determined cell type.
The obtaining module 11 is further configured to, after receiving a system message for notifying a cell type in a cell, determine that a frequency point corresponding to the cell is a frequency point corresponding to a local IP access system of a base station if it is known that the cell is a cell in the local IP access system of the base station; when the system message for notifying the cell type carries the network identifier, the cell name, or the name of the service access point AP of the local IP access system of the base station, the UE knows that the cell is a cell under the local IP access system of the base station.
The obtaining module 11 is further configured to, when the physical signal characteristic is a location of a primary synchronization signal PSS/secondary synchronization signal SSS, determine a cell type according to a difference between the detected PSS/SSS locations during cell search; or, when the physical signal characteristic is the position of the physical broadcast channel PBCH, determining the cell type according to the absolute time-frequency domain position of the PBCH or the difference of the relative positions of the PBCH and the PSS/SSS detected in cell search.
In the embodiment of the invention, the cellThe channel quality criteria are selected as: srxlev _ Hi>0 and Squal _ Hi>0; wherein Srxlev _ Hi = Qrxlevmeas– QrxlevminPcompensation Qoffset _ Hi, and Squal _ Hi = Qqualmeas–Qqualmin(ii) a Srxlev denotes a cell selection reception level value, Squal denotes a cell selection quality value, QrxlevmeasRepresenting cell reference symbol received power, RSRP, measurement, QrxlevminIndicating the minimum received level requirement of the cell, Pcompensition is max (P)EMAX–PPowerClass,0),PEMAXMaximum uplink transmission power, P, of UE in a cell specified for higher layersPowerClassQoffset _ Hi represents the measurement offset value under different frequency points, Q, for the maximum radio frequency output power of the UE determined according to the power level of the UEqualmeasRepresenting cell reference symbol received quality, RSRQ, measurements, QqualminIndicating the minimum reception quality requirement of the cell.
The obtaining module 11 is further configured to obtain the measurement offset value Qoffse _ Hi at the different frequency points in the following manner; obtaining the Qoffset _ Hi through subscription data; or, the Qoffset _ Hi is obtained through information built in the device capability limit; or, obtaining the Qoffse _ Hi through information indicated by the base station equipment in the connection setup release message, where the information indicated by the base station equipment in the connection setup release message is specifically Qoffse _ Hi when the UE performs cell selection next time; or, setting the current Qoffset _ Hi as the next Qoffset _ Hi to obtain the Qoffset _ Hi in the connection establishment and release process; or, the Qoffse _ Hi of each frequency point in the system message of the current serving cell is saved, and the Qoffse _ Hi is obtained after the connection establishment is released and is saved for a period of designated time.
The modules of the device can be integrated into a whole or can be separately deployed. The modules can be combined into one module, and can also be further split into a plurality of sub-modules.
EXAMPLE seven
Based on the same inventive concept as the above method, an embodiment of the present invention further provides a base station apparatus, as shown in fig. 8, where the base station apparatus includes:
a determining module 21, configured to determine priority information of a frequency point;
a sending module 22, configured to notify the priority information of the frequency point to a user equipment UE, where the UE performs cell selection by using the priority information of the frequency point.
The sending module 22 is specifically configured to notify the UE of the frequency point priority information when the UE performs cell selection next time in the connection establishment release message.
The sending module 22 is further configured to notify the UE of the measurement offset value Qoffse _ Hi at different frequency points when the UE performs cell selection next time in the connection setup release message.
The sending module 22 is further configured to notify the UE of the cell type through a system message when the local IP access system of the base station and the other wireless access systems use the same frequency band; the system message for informing the cell type carries the network identifier, the cell name or the name of the service access point AP of the local IP access system of the base station.
The modules of the device can be integrated into a whole or can be separately deployed. The modules can be combined into one module, and can also be further split into a plurality of sub-modules.
Through the above description of the embodiments, those skilled in the art will clearly understand that the present invention may be implemented by software plus a necessary general hardware platform, and certainly may also be implemented by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute the methods according to the embodiments of the present invention.
Those skilled in the art will appreciate that the drawings are merely schematic representations of one preferred embodiment and that the blocks or flow diagrams in the drawings are not necessarily required to practice the present invention.
Those skilled in the art will appreciate that the modules in the devices in the embodiments may be distributed in the devices in the embodiments according to the description of the embodiments, and may be correspondingly changed in one or more devices different from the embodiments. The modules of the above embodiments may be combined into one module, or further split into multiple sub-modules.
The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.
The above disclosure is only for a few specific embodiments of the present invention, but the present invention is not limited thereto, and any variations that can be made by those skilled in the art are intended to fall within the scope of the present invention.