CN108093448B - Cell switching method, terminal and storage medium - Google Patents
Cell switching method, terminal and storage medium Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/0005—Control or signalling for completing the hand-off
- H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W56/00—Synchronisation arrangements
- H04W56/0035—Synchronisation arrangements detecting errors in frequency or phase
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W36/00—Hand-off or reselection arrangements
- H04W36/08—Reselecting an access point
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W74/00—Wireless channel access
- H04W74/002—Transmission of channel access control information
- H04W74/004—Transmission of channel access control information in the uplink, i.e. towards network
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
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Abstract
The embodiment of the invention discloses a cell switching method, which comprises the following steps: detecting whether an access failure condition is met or not when a random access process of a first target cell is carried out based on a switching instruction; when the access failure condition is met, searching a second target cell to acquire first frequency point information of the second target cell; acquiring local frequency point information of the user, and acquiring a frequency offset value according to the local frequency point information and the first frequency point information; and adjusting the local frequency point information in the switching process according to the frequency offset value, and restarting the random access process. The embodiment of the invention also discloses a terminal and a storage medium.
Description
Technical Field
The present invention relates to wireless communication technologies in the field of communications, and in particular, to a cell switching method, a terminal, and a storage medium.
Background
In a wireless communication system, when a terminal, that is, a User Equipment (UE), moves from a current cell (source cell) to another cell (target cell), and the target cell exceeds a wireless coverage of the current cell, in order to ensure normal communication of the UE, a network side needs to initiate inter-cell handover to handover current normal communication from the source cell to the target cell, so that the UE can perform seamless communication between the cells.
However, in the existing (LTE) network, when a plurality of base stations cooperatively cover the UE, a large frequency offset may occur between the plurality of base stations, and when the terminal moves between cells in which the base stations are located, cell handover may occur.
Disclosure of Invention
In order to solve the foregoing technical problems, embodiments of the present invention are directed to providing a cell handover method, a terminal, and a storage medium, which can improve a success rate of cell handover.
The technical scheme of the invention is realized as follows:
the embodiment of the invention provides a cell switching method, which comprises the following steps:
detecting whether an access failure condition is met or not when a random access process of a first target cell is carried out based on a switching instruction;
when the access failure condition is met, searching a second target cell to acquire first frequency point information of the second target cell;
acquiring local frequency point information of the user, and acquiring a frequency offset value according to the local frequency point information and the first frequency point information;
and adjusting the local frequency point information in the switching process according to the frequency offset value, and restarting the random access process.
In the above method, the searching for the second target cell to obtain the first frequency point information of the second target cell includes:
carrying out cell search to search second frequency point information of at least one target cell;
and acquiring the first frequency point information with a synchronous signal from the second frequency point information, wherein the first frequency point information corresponds to the second target cell in the at least one target cell.
In the above method, after the first frequency point information with a synchronization signal is acquired from the second frequency point information, the method further includes:
and detecting the target cell identification of the second target cell from the synchronization signal.
In the above method, the adjusting the local frequency point information in the handover process according to the frequency offset value and re-initiating the random access process includes:
according to the frequency offset value, the local frequency point information in the switching process is adjusted;
and initiating a random access process to the second target cell by adopting the adjusted local frequency point information according to the target cell identification.
In the above method, before the detecting whether the access failure condition is satisfied, the method further includes:
measuring adjacent cells to obtain a measurement report;
reporting the measurement report to the source base station;
receiving the switching instruction sent by the source base station based on the measurement report;
and performing a random access process of the first target cell according to the switching instruction.
In the above method, the performing, according to the handover command, a random access procedure of the first target cell includes:
and sending a random access preamble request to a first target base station corresponding to the first target cell according to the switching instruction, and entering a random access process.
In the above method, the detecting whether the access failure condition is satisfied includes:
receiving a random access response message responding to the random access preamble request;
counting the access times of the random access response message representing access failure;
detecting the access times and a preset threshold value to realize the detection of the access failure condition;
and when the access times exceed the preset threshold value, detecting that the access failure condition is met.
An embodiment of the present invention provides a terminal, including:
a detection unit, configured to detect whether an access failure condition is satisfied when a random access procedure of a first target cell is performed based on a handover instruction;
a searching unit for searching for a second target cell when the access failure condition is satisfied,
an obtaining unit, configured to obtain first frequency point information of the second target cell; acquiring local frequency point information of the user, and acquiring a frequency offset value according to the local frequency point information and the first frequency point information;
an adjusting unit, configured to adjust the local frequency point information in the handover process according to the frequency offset value,
and the access unit is used for reinitiating the random access process.
An embodiment of the present invention further provides a terminal, including:
a receiver, a transmitter, a processor and a storage medium having stored thereon processor-executable instructions, received data of the receiver and transmitted data of the transmitter, the receiver, the transmitter and the storage medium operating over a communication bus in dependence of the processor, the instructions when executed by the processor performing the above-mentioned cell handover method.
Embodiments of the present invention provide a computer storage medium storing a machine instruction, where when the machine instruction is executed by one or more processors, the processors execute the cell handover method.
The embodiment of the invention provides a cell switching method, a terminal and a storage medium, which are used for detecting whether an access failure condition is met or not when a random access process of a first target cell is carried out based on a switching instruction; when the access failure condition is met, searching a second target cell to acquire first frequency point information of the second target cell; acquiring local frequency point information of the user, and acquiring a frequency offset value according to the local frequency point information and the first frequency point information; and adjusting the local frequency point information in the switching process according to the frequency offset value, and restarting the random access process. By adopting the technical scheme, when the terminal performs cell switching, aiming at the condition of access failure caused by frequency deviation, the random access initiated by the cell switching is realized after the adjustment of the advanced frequency deviation, so that the condition of the switching failure caused by the frequency deviation can be eliminated, and the success rate of the cell switching is improved.
Drawings
Fig. 1 is a first flowchart of a cell handover method according to an embodiment of the present invention;
fig. 2 is a schematic diagram of information interaction between an exemplary terminal and a base station according to an embodiment of the present invention;
fig. 3 is a second flowchart of a cell handover method according to an embodiment of the present invention;
fig. 4 is a third flowchart of a cell switching method according to an embodiment of the present invention;
fig. 5 is a first schematic structural diagram of a terminal according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a terminal according to an embodiment of the present invention.
Detailed Description
The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
Example one
An embodiment of the present invention provides a cell handover method, as shown in fig. 1, the method may include:
s101, detecting whether an access failure condition is met or not when a random access process of a first target cell is carried out based on a switching instruction;
an application scenario of the cell switching method provided by the embodiment of the present invention may be as follows: when a terminal (i.e., UE) moves from a current cell (source cell) where the terminal is located to another cell (target cell) in the moving process, cell switching is performed.
It should be noted that the network environment implemented by the embodiment of the present invention is an LTE network.
Optionally, the terminal in the embodiment of the present invention may be an electronic device with a wireless communication function, for example, a mobile phone, a tablet, and the like, which is not limited in the embodiment of the present invention.
In the embodiment of the present invention, a serving cell of a terminal needs to be handed over from a source cell to a target cell due to movement of the terminal, at this time, a source base station (corresponding to the source cell) of the serving terminal informs the terminal that a handover of a first target cell (i.e., the target cell described above, corresponding to the first target base station) is to be performed, so that the terminal may perform a random access procedure on the first target cell, and at this time, an access failure may be caused by frequency offset of a transmission or reception signal when the terminal and the first target base station transmit and receive a signal.
Before this, it should be noted that, in the embodiment of the present invention, the specific implementation of the switching process may be: a terminal receives a measurement configuration message sent by a source base station; the terminal carries out measurement of adjacent cells based on the measurement configuration message to obtain a measurement report; the terminal reports the measurement report to the source base station; the terminal receives a switching instruction sent by a source base station based on a measurement report; and the terminal performs a random access process of the first target cell according to the switching instruction.
In the embodiment of the present invention, LTE handover requires UE to report a measurement result (i.e. measurement report), and reporting can be divided into periodic reporting and event-triggered reporting, where the periodic reporting is configured by a base station, and the UE can directly report the measurement result. The event-triggered reporting is divided into events of the same-frequency system, events of the different-frequency system and events of different systems.
The types of false triggers that are commonly used in the following are presented here.
A1: the source cell is better than a certain threshold; this event can be used to turn off measurements for certain cells;
a2: the source cell is worse than a certain threshold; this event may be used to start measurements for certain cells, since a handover or the like may occur after this event;
a3: the neighbor cell is better than the source cell by a certain threshold;
a4: the neighbor cell is better than a certain threshold;
a5: the source cell is worse than a certain threshold and the neighbor cell is better than a certain threshold;
b1: the quality of the adjacent area of the different system is higher than a certain threshold;
b2: the quality of the source cell is lower than a certain threshold and the quality of the adjacent cell of the different system is higher than a certain threshold.
In the embodiment of the present invention, the event trigger triggering the terminal to perform measurement may be an A3 event, an a4 event, or an a5 event, where the common intra-frequency handover is an A3 event, and the inter-frequency handover is an a4 event or an a5 event.
It should be noted that, in the embodiment of the present invention, switching, starting or stopping threshold of inter-frequency measurement, and transmission mode switching in the LTE system are all performed by depending on information in RRC Connection Reconfiguration signaling, and the UE performs decision by testing levels of the source cell and the neighboring cell, and sends a measurement report after meeting the condition. Different measurement reports are sent on different events, each measurement report has one and only one MeasId, and one MeasId corresponds to one event. For example, MeasId1 corresponds to co-frequency A3, MeasId14 corresponds to 4-3 redirection, MeasId15 corresponds to inter-frequency a1 event, MeasId7 corresponds to inter-frequency a2 event, MeasId14 corresponds to inter-frequency A3 event, MeasId13 corresponds to inter-frequency a5 event, and MeasId9 corresponds to inter-frequency MR strong neighbor reporting, etc. Here, after obtaining the measurement report and reporting the measurement report, the terminal may obtain a handover command RRCConnection Reconfiguration (handover command) for issuing a handover command, where the handover command carries a Physical Cell Identifier (PCI) of the first target Cell.
Then, the terminal may send a random access preamble request to the first target base station corresponding to the first target cell according to the handover instruction, and enter a random access process. In detail, the terminal sends a random access preamble request to the first target base station according to the PCI of the first target cell, and enters a random access process.
It should be noted that, in the embodiment of the present invention, the implementation of the random access procedure starts from sending a random access preamble request, and the random access is implemented by interacting with the first target base station.
For example, as shown in fig. 2, in a handover scenario, a UE sends a random access preamble request to an eNB1 (a first target base station), an eNB1 sends a random access response message to the UE in response to the random access preamble request to inform the UE of uplink resource information that can be used by the UE, when the UE receives a representation permission of the random access response message, the UE sends a scheduling message in uplink resources carried in the random access response message to implement access of the UE, and sends a handover completion message to the eNB1 after the access is completed.
It should be noted that, in the embodiment of the present invention, the random access response message may represent that uplink resource information is allowed to be used, or may represent that uplink resource information is not allowed to be used, and when frequency point information (frequency, that is, a transceiving frequency of a signal) of the first target base station and local frequency point information (that is, a local frequency) of the terminal occur in a frequency offset outside an adjustable range, the random access response message may represent that random access is not allowed, thereby causing a random access failure.
Based on the foregoing implementation, as shown in fig. 3, in the embodiment of the present invention, the detecting, by the terminal, whether the access failure condition is satisfied may include: S1011-S1014. The following were used:
s1011, receiving a random access response message responding to the random access preamble request;
s1012, counting the access times of the random access response message representation access failure;
s1013, detecting the access times and a preset threshold value to realize detection of an access failure condition;
and S1014, when the access times exceed a preset threshold value, detecting that an access failure condition is met.
In the embodiment of the invention, when the random access preamble request fails, namely the random access response message represents the access failure, the random access preamble request can be retransmitted. Therefore, the number of times that the terminal receives the random access response message may be multiple times, that is, the terminal needs to count the access number of times that the random access response message represents the access failure, so that the terminal can detect the access failure condition according to the detected access number and the preset threshold; when the access times exceed a preset threshold value, detecting that an access failure condition is met; and when the access times do not exceed the preset threshold value, detecting that the access failure condition is not met, and continuing to perform retransmission attempt.
In the embodiment of the invention, the random access preamble is considered to be access failure caused by frequency offset only when the number of times of requesting retransmission reaches a certain number, and then the random access is carried out after the frequency offset is eliminated.
Optionally, the preset threshold in the embodiment of the present invention may be 5, and the data of the specific preset threshold may be obtained through actual experiments or calculations, which is not limited in the embodiment of the present invention.
In the embodiment of the invention, the access failure condition is used for representing the judgment of the access failure caused by frequency offset.
S102, when the access failure condition is met, searching a second target cell to acquire first frequency point information of the second target cell;
after the terminal detects whether the access failure condition is met, one of the detection results of the terminal is two, and the other detection result can be used for detecting that the access failure condition is met for the terminal; another method may be that the terminal detects that the terminal meets the access failure condition. Therefore, when the terminal detects that the access failure condition is met, the terminal can search the target cell again to search out a second target cell and obtain the first frequency point information of the second target cell, so that the frequency offset can be eliminated according to the first frequency point information.
In the embodiment of the present invention, the process of the terminal acquiring the first frequency point information may be: the terminal firstly searches a cell and searches second frequency point information of at least one target cell; and acquiring first frequency point information with a synchronous signal from the second frequency point information, wherein the first frequency point information corresponds to a second target cell in at least one target cell. Thus, the first frequency point information of the second target cell is found.
That is, when the terminal satisfies the access failure condition, the terminal needs to start cell search in order to find an available second target cell.
Here, the process of the terminal performing cell search may be: the terminal receives data on several central frequency points where LTE cells may exist and calculates the bandwidth RSSI, and judges whether appropriate target cells may exist around the several central frequency points according to the received signal strength. If no prior information exists, the terminal is likely to search in the full frequency band and find a target cell corresponding to the frequency point with the stronger signal. Therefore, the terminal can search at least one target cell and second frequency point information corresponding to the at least one target cell (because the terminal knows which frequency points the terminal searches on), but because the second frequency point information may have frequency points at which the terminal cannot receive the synchronization signal, the terminal also needs to acquire the first frequency point information having the synchronization signal from the second frequency point information, so that the first frequency point information having the synchronization signal and the corresponding second target cell can be found from the at least one target cell.
In the embodiment of the present invention, the Synchronization Signal may be a Primary Synchronization Signal (PSS) or a Secondary Synchronization Signal (SSS). When a terminal searches a frequency point, the terminal tries to decode PSS by using a designated root index u, the decoded PSS is the primary synchronization signal, so that the information of a first frequency point with the synchronization signal can be found, and then the position of SSS can be determined based on the decoded PSS, namely the SSS is decoded.
S103, local frequency point information of the user is obtained, and a frequency offset value is obtained according to the local frequency point information and the first frequency point information;
after the terminal searches for the second target cell and acquires the first frequency point information of the second target cell, the terminal can acquire the frequency of the receiving and transmitting signal of the terminal (namely, the local frequency point information), so that the terminal can perform frequency offset elimination on the frequency of the receiving and transmitting signal of the second target base station corresponding to the second target cell to which the terminal is to be accessed. Therefore, the terminal can obtain the frequency offset value between the local frequency point information and the first frequency point information after obtaining the local frequency point information and the first frequency point information.
For example, if the local frequency point information is F and the first frequency point information is F + H, the terminal acquires that the frequency offset value at this time is H.
Further, the terminal may estimate, according to the synchronization signal sent by the second target cell, a frequency offset value of the frequency of the locally received signal relative to the local frequency in the handover process, or may estimate, every time a synchronization signal is received in the handover process, a frequency offset value of the frequency of the locally received signal relative to the local frequency in the current handover process according to the currently received signal.
Since there may be a plurality of second target base stations determined in the embodiment of the present invention, there are a plurality of ways for the terminal to estimate the frequency offset value of the frequency of the locally received signal relative to the local frequency during the handover according to all the synchronization signals transmitted by the second target base station in the initial stage of the handover, preferably, there are a plurality of ways to estimate the frequency offset value of the locally received signal relative to the local frequency of the corresponding synchronization signal during the handover according to each synchronization signal in the initial stage of the handover, and then obtain the frequency offset value of the frequency of the locally received signal relative to the local frequency during the handover by performing a weighting operation on all the obtained single estimated frequency offset values, wherein there are a plurality of ways to calculate the weight value corresponding to each single estimated frequency offset value, and preferably, the weight value corresponding to each single estimated frequency offset value can be calculated by an averaging method (i.e. the weight value corresponding to each single estimated frequency offset value is a proportion of one divided by the total number of times, the forgetting factor method may also be used for calculation (that is, as the number of times of transmission increases, the weight value increases), and the embodiment of the present invention is not limited.
And S104, adjusting the local frequency point information in the switching process according to the frequency offset value, and restarting the random access process.
After the terminal acquires the local frequency point information of the terminal, and the frequency offset value is acquired according to the local frequency point information and the first frequency point information, the terminal can adjust the local frequency point information of the terminal according to the acquired frequency offset value, namely, the frequency of a transmitting and receiving signal, and finally, the adjusted local frequency point information is adopted to initiate random access to the second target base station, so that the switching of cells is completed.
The process of the terminal performing the random access again is consistent with the foregoing random access process, and is not described herein again.
It can be understood that, when the terminal performs cell handover, after adjusting the frequency offset for the situation of access failure caused by the frequency offset, the random access initiated by the cell handover is implemented, so that the situation of handover failure caused by the frequency offset can be eliminated, thereby improving the success rate of cell handover.
Example two
An embodiment of the present invention provides a cell handover method, as shown in fig. 4, the method may include:
s201, detecting whether an access failure condition is met or not when a random access process of a first target cell is carried out based on a switching instruction;
in the embodiment of the present invention, a process of the terminal implementing "whether the access failure condition is met when the terminal performs the random access process of the first target cell based on the handover instruction" is consistent with the description of S101 in the first embodiment, and is not described herein again.
S202, when the access failure condition is met, cell searching is carried out, and second frequency point information of at least one target cell is searched;
s203, acquiring first frequency point information with a synchronous signal from the second frequency point information, wherein the first frequency point information corresponds to a second target cell in at least one target cell;
in the embodiment of the present invention, the process of implementing S202-S203 by the terminal is consistent with the description of S102 in the first embodiment, and is not described herein again.
S204, detecting a target cell identifier of a second target cell from the synchronous signal;
after the terminal determines the second target cell, the terminal can decode the PSS and the SSS, that is, the terminal can obtain values of the PSS and the SSS, and then the target cell identifier of the second target cell can be obtained by detecting the PSS value and the SSS value.
In the embodiment of the present invention, the target cell identity of the second target cell is PCI (physical cell identity).
It should be noted that the physical layer divides the cells into 504 cells, which are divided into 168 groups, denoted as N1, and each group is further divided into 3 labels, denoted as N2, so that the physical cell ID is 3 × N1+ N2, N1 belongs to 0 to 167, and N2 belongs to 0 to 2. From the physical layer, the PCI is composed of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS), and can be obtained by a simple operation of formula (1). Equation (1) is as follows:
PCI＝PSS+3*SSS(1)
wherein, PSS is 0.. 2 (actually 3 different PSS sequences), SSS is 0.. 167 (actually 168 different SSS sequences), and the range of PCI obtained by using the above formula (1) is from 0.. 503, so there are 504 PCIs in the physical layer.
It is understood that ci (cellidentity) uniquely identifies a cell from the network operation maintenance level and cannot be repeated in the network. PCI is repeatable because there are only 504 combinations of PSS + SSS. For example, when there are 1000 cells in the network, there are only 504 PCIs, and at this time, the PCI needs to be multiplexed, and in general, the PCI planning principle is to allocate a specific PSS sequence (0.. 2) value to each sector and allocate a specific SSS sequence (0.. 167) value to each base station, so as to avoid the problem of the same PCI between adjacent base stations.
It should be noted that, in the embodiment of the present invention, the PSS and the SSS are mapped to 6 RBs in the middle of the whole bandwidth, and since the PSS and the SSS are both sequences of 62 points, both synchronization signals are mapped to 62 subcarriers (or 62 REs) in the middle of the whole bandwidth (whether the bandwidth is 1.4M or 20M), that is, each point of the sequence corresponds to an RE. There are 5 sub-carriers on either side of the 62 sub-carriers and no further data is mapped. Furthermore, since decoding the SSS signal requires the N (2) _ ID in the PSS signal, the UE must decode the PSS signal first and then the SSS signal. Since the relative time domain positions of PSS and SSS are fixed, once the PSS is blindly detected, the UE can decode the SSS from a specific position, and then determine the current subframe instant (because the SSS sequences of subframes 0, 5 are different).
In the embodiment of the invention, the UE does not know the size of the system bandwidth when being powered on, but knows the frequency band (local frequency point information) and the bandwidth supported by the UE (see 36.101). In order to enable the UE to detect the frequency and symbol synchronization information of the system as soon as possible, regardless of the system bandwidth, the PSS and SSS are located on the central 72 subcarriers (i.e. on the central 6 RBs, which does not contain DC-only 62 subcarriers around the frequency center DC are actually used, leaving 5 subcarriers on each side for the guard band). The UE may attempt to receive PSS and SSS around the center frequency of the LTE frequencies it supports.
S205, obtaining local frequency point information of the user, and obtaining a frequency offset value according to the local frequency point information and the first frequency point information;
in the embodiment of the present invention, the process of "obtaining local frequency point information of the terminal and obtaining a frequency offset value according to the local frequency point information and the first frequency point information" of the terminal is consistent with the description of S205 in the first embodiment, and details are not repeated here.
S206, according to the frequency offset value, adjusting local frequency point information in the switching process;
and S207, initiating a random access process to a second target cell by adopting the adjusted local frequency point information according to the target cell identification.
After the terminal obtains the frequency offset value according to the local frequency point information and the first frequency point information, the terminal obtains the frequency offset value between the terminal and the second target base station, so the terminal can adjust the local frequency point information of the terminal according to the obtained frequency offset value, namely, the frequency of a transmitting and receiving signal, and finally, the terminal detects the target cell identification of the second target cell, so the terminal can initiate a random access process to the second target cell according to the target cell identification by adopting the adjusted local frequency point information, thereby completing the switching of the cells.
The process of the terminal performing the random access again is consistent with the random access process described in the first embodiment, and is not described here again.
It can be understood that, when the terminal performs cell handover, after adjusting the frequency offset for the situation of access failure caused by the frequency offset, the random access initiated by the cell handover is implemented, so that the situation of handover failure caused by the frequency offset can be eliminated, thereby improving the success rate of cell handover.
EXAMPLE III
As shown in fig. 5, an embodiment of the present invention provides a terminal 1, where the terminal 1 may include:
a detecting unit 10, configured to detect whether an access failure condition is satisfied when a random access procedure of a first target cell is performed based on a handover instruction;
a searching unit 11, configured to perform a search for a second target cell when the access failure condition is satisfied,
an obtaining unit 12, configured to obtain first frequency point information of the second target cell; acquiring local frequency point information of the user, and acquiring a frequency offset value according to the local frequency point information and the first frequency point information;
an adjusting unit 13, configured to adjust the local frequency point information in the handover process according to the frequency offset value,
and an access unit 14, configured to reinitiate the random access procedure.
Optionally, the searching unit 11 is specifically configured to perform cell search to search for second frequency point information of at least one target cell;
the obtaining unit 12 is specifically configured to obtain the first frequency point information with a synchronization signal from the second frequency point information, where the first frequency point information corresponds to the second target cell in the at least one target cell.
Optionally, the detecting unit 10 is further configured to detect a target cell identifier of the second target cell from the synchronization signal after acquiring the first frequency point information with the synchronization signal from the second frequency point information.
Optionally, the adjusting unit 13 is specifically configured to adjust the local frequency point information in the handover process according to the frequency offset value;
the access unit 14 is specifically configured to initiate a random access process to the second target cell by using the adjusted local frequency point information according to the target cell identifier.
Optionally, the terminal 1 further includes: a receiving unit 15, a measuring unit 16 and a transmitting unit 17.
The measurement unit 16 is configured to perform measurement on neighboring cells to obtain a measurement report;
the sending unit 17 is configured to report the measurement report to the source base station;
the receiving unit 15 is configured to receive the handover instruction sent by the source base station based on the measurement report;
the access unit 14 is further configured to perform a random access procedure of the first target cell according to the handover instruction.
Optionally, the access unit 14 is specifically configured to send a random access preamble request to the first target base station corresponding to the first target cell according to the handover instruction, and enter a random access process.
Optionally, the receiving unit 15 is further configured to receive a random access response message responding to the random access preamble request;
the obtaining unit 12 is further configured to count access times of the random access response message indicating access failure;
the detecting unit 10 is specifically configured to detect the access times and a preset threshold, so as to implement detection of the access failure condition; and when the access times exceed the preset threshold value, detecting that the access failure condition is met.
In practical applications, the detecting Unit 10, the obtaining Unit 11, the searching Unit 12, the adjusting Unit 13, and the measuring Unit 16 may be implemented by a processor 18 located on the server 1, specifically, implemented by a Central Processing Unit (CPU), a Microprocessor Unit (MPU), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA), or the like, the sending Unit 17 may be implemented by a transmitter 19, the receiving Unit 15 may be implemented by a receiver 110, and the accessing process of the accessing Unit 14 may involve interaction of information to implement the accessing process, so that the accessing Unit 14 may be implemented by the transmitter 19 and the receiver 110 acting together.
As shown in fig. 6, an embodiment of the present invention further provides a terminal, including:
a receiver 110, a transmitter 19, a processor 18, and a storage medium 111 storing instructions executable by the processor 18, data received by the receiver 110, and data transmitted by the transmitter 19, wherein the receiver 110, the transmitter 19, and the storage medium 111 rely on the processor 18 to perform operations via a communication bus 112, and when the instructions are executed by the processor 18, the cell handover methods described in the first and second embodiments are performed.
It should be noted that, in practical applications, the various components in the terminal are coupled together by a communication bus 112. It is understood that the communication bus 112 is used to enable connection communication between these components. The communication bus 112 includes a power bus, a control bus, and a status signal bus in addition to a data bus. But for clarity of illustration the various busses are labeled in figure 6 as communication bus 112.
It can be understood that, when the terminal performs cell handover, after adjusting the frequency offset for the situation of access failure caused by the frequency offset, the random access initiated by the cell handover is implemented, so that the situation of handover failure caused by the frequency offset can be eliminated, thereby improving the success rate of cell handover.
Embodiments of the present invention provide a computer-readable storage medium, which stores machine instructions, and when the machine instructions are executed by one or more processors, the processors execute the cell handover methods described in the first and second embodiments.
The computer-readable storage medium may be a magnetic random access Memory (FRAM), a Read Only Memory (ROM), a Programmable Read Only Memory (PROM), an Erasable Programmable Read Only Memory (EPROM), an Electrically Erasable Programmable Read Only Memory (EEPROM), a Flash Memory (Flash Memory), a magnetic surface Memory, an optical Disc, or a Compact Disc Read-Only Memory (CD-ROM), among others.
As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.
The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (10)
1. A method of cell handover, comprising:
detecting whether an access failure condition is met or not when a random access process of a first target cell is carried out based on a switching instruction; the access failure condition is used for representing judgment of access failure caused by frequency offset;
when the access failure condition is met, searching a second target cell to acquire first frequency point information of the second target cell; the second target cell is a cell which is found from at least one target cell and corresponds to the first frequency point information with the synchronous signal;
acquiring local frequency point information of the user, and acquiring a frequency offset value according to the local frequency point information and the first frequency point information;
and adjusting the local frequency point information in the switching process according to the frequency offset value, and restarting the random access process.
2. The method according to claim 1, wherein the searching for the second target cell to obtain the first frequency point information of the second target cell comprises:
carrying out cell search to search second frequency point information of at least one target cell;
and acquiring the first frequency point information with a synchronous signal from the second frequency point information, wherein the first frequency point information corresponds to the second target cell in the at least one target cell.
3. The method according to claim 2, wherein after the obtaining the first frequency point information with synchronization signals from the second frequency point information, the method further comprises:
and detecting the target cell identification of the second target cell from the synchronization signal.
4. The method of claim 3, wherein the adjusting the local frequency point information in the handover process according to the frequency offset value and reinitiating the random access process comprises:
according to the frequency offset value, the local frequency point information in the switching process is adjusted;
and initiating a random access process to the second target cell by adopting the adjusted local frequency point information according to the target cell identification.
5. The method of claim 1, wherein before the detecting whether the access failure condition is satisfied, the method further comprises:
measuring adjacent cells to obtain a measurement report;
reporting the measurement report to a source base station;
receiving the switching instruction sent by the source base station based on the measurement report;
and performing a random access process of the first target cell according to the switching instruction.
6. The method of claim 5, wherein the performing the random access procedure of the first target cell according to the handover command comprises:
and sending a random access preamble request to a first target base station corresponding to the first target cell according to the switching instruction, and entering a random access process.
7. The method of claim 6, wherein the detecting whether the access failure condition is met comprises:
receiving a random access response message responding to the random access preamble request;
counting the access times of the random access response message representing access failure;
detecting the access times and a preset threshold value to realize the detection of the access failure condition;
and when the access times exceed the preset threshold value, detecting that the access failure condition is met.
8. A terminal, comprising:
a detection unit, configured to detect whether an access failure condition is satisfied when a random access procedure of a first target cell is performed based on a handover instruction; the access failure condition is used for representing judgment of access failure caused by frequency offset;
a searching unit, configured to search a second target cell when the access failure condition is met, where the second target cell is a cell corresponding to first frequency point information with a synchronization signal, which is found from at least one target cell;
an obtaining unit, configured to obtain first frequency point information of the second target cell; acquiring local frequency point information of the user, and acquiring a frequency offset value according to the local frequency point information and the first frequency point information;
an adjusting unit, configured to adjust the local frequency point information in the handover process according to the frequency offset value,
and the access unit is used for reinitiating the random access process.
9. A terminal, comprising:
a receiver, a transmitter, a processor and a storage medium having stored thereon processor-executable instructions, received data of the receiver and transmitted data of the transmitter, the receiver, the transmitter and the storage medium operating over a communication bus in dependence of the processor, the instructions, when executed by the processor, performing the cell handover method of any of the preceding claims 1 to 7.
10. A computer storage medium having stored thereon machine instructions which, when executed by one or more processors, perform the cell handover method of any one of claims 1 to 7.
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| CN113115386B (en) * | 2018-09-18 | 2022-12-20 | Oppo广东移动通信有限公司 | Switching processing method, terminal equipment and network equipment |
| CN109089297B (en) * | 2018-10-30 | 2021-01-08 | 维沃移动通信有限公司 | Network searching method and terminal |
| EP3927020A4 (en) * | 2019-02-13 | 2022-03-02 | Guangdong Oppo Mobile Telecommunications Corp., Ltd. | Method for cell handover, and devices |
| CN111756559B (en) * | 2019-03-26 | 2021-10-15 | 华为技术有限公司 | Method and device for acquiring tracking information |
| CN112929899A (en) * | 2019-12-06 | 2021-06-08 | 华为技术有限公司 | Method and apparatus for access |
| CN111726846B (en) * | 2020-06-08 | 2023-03-24 | 南京酷派软件技术有限公司 | Network cell switching method and device, storage medium and electronic equipment |
| CN111966776B (en) * | 2020-08-27 | 2024-05-03 | Oppo广东移动通信有限公司 | Map construction method, map construction device, electronic equipment and storage medium |
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| WO2011006352A1 (en) * | 2009-07-13 | 2011-01-20 | 大唐移动通信设备有限公司 | Method and device for frequency deviation pre-correction |
| CN104125601A (en) * | 2013-04-23 | 2014-10-29 | 成都鼎桥通信技术有限公司 | Use method of frequency band numbers and frequency point numbers of UDD cells |
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| CN101883408A (en) * | 2009-05-07 | 2010-11-10 | 中国移动通信集团公司 | Location updating method and user terminal |
| WO2011006352A1 (en) * | 2009-07-13 | 2011-01-20 | 大唐移动通信设备有限公司 | Method and device for frequency deviation pre-correction |
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