Wireless communication system and terminal switching method thereof

Abstract

The embodiment of the invention discloses a wireless communication system and a terminal switching method thereof, the system comprises UE (User Equipment) and a plurality of base stations, the UE firstly analyzes an SIB1 message broadcasted by a source base station and then reports a selected PLMN ID (Public Land Mobile Network Identity); the PLMN identifier of the source base station stores the PLMN ID; the source base station confirms the PLMN attribution of the initially accessed UE and provides service for the UE; when the UE is switched from a source base station to a target base station, the source base station broadcasts an SIB1 message and a PLMN ID of the UE; the target base station receives and analyzes the SIB1 message of the source base station, extracts a PLMN list of the source base station, and finds a PLMN entry corresponding to the PLMN ID; and the target base station analyzes the SIB1 message of the target base station and updates the PLMN identifier of the target base station. According to the invention, under the switching scene, the target base station can identify the PLMN of the UE, the possible problems of neighbor cell matching failure, switching preparation failure and the like are solved, and the success rate of switching is ensured.

Description

Technical Field

[0001] The present invention relates to the field of 4G communication, and in particular to a wireless communication system and a terminal handover method thereof. Background Art

[0002] In a wireless communication system, when a UE (User Equipment) is in the RRC_IDLE (idle) mode, it receives broadcast messages from a base station and selects a suitable PLMN (Public Land Mobile Network) to camp on. During the RRC (Radio Resource Control) connection establishment process, the UE sends an RRC connection request message to the base station, which contains the PLMN identifier it has selected, and the base station can identify the PLMN of the UE.

[0003] In a shared carrier scenario, when a terminal performs an inter-base station handover service for a 4G base station, the target base station may not be able to correctly identify the PLMN of the UE, which may lead to service anomalies and affect the user experience. For example, neighbor cell matching failure: during the handover preparation phase, the current base station searches for the target base station according to the saved PLMN of the UE. If the PLMN is misconfigured, the current base station may not be able to correctly match the neighbor cell information of the target base station, resulting in no handover or handover preparation failure; handover preparation failure: during the handover preparation phase, due to PLMN mismatch, the core network may not be able to find the target base station, resulting in failure to hand over to the target base station. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide a wireless communication system and a terminal handover method thereof, so as to facilitate the UE to find the corresponding neighbor cell when handing over to other base stations and ensure the handover success rate.

[0005] To solve the above technical problem, an embodiment of the present invention provides a wireless communication system, including a UE and a plurality of base stations. The base stations include PLMN identifiers. Among them, the base station accessed by the UE before handover is denoted as the source base station, and the base station after handover is denoted as the target base station; In the initial access phase, the UE first parses the SIB1 message broadcast by the source base station and selects the corresponding PLMN therefrom; subsequently, during the process of establishing a connection with the source base station, the UE reports the selected PLMN ID; the PLMN identifier of the source base station saves the PLMN ID; the source base station confirms the PLMN affiliation of the initially accessed UE and provides services for the UE; When the UE switches from the source base station to the target base station, the source base station broadcasts the SIB1 message and the PLMN ID of the UE; the target base station receives and parses the SIB1 message of the source base station, extracts the PLMN list of the source base station, finds the PLMN entry corresponding to the PLMN ID, and determines the PLMN affiliation of the UE; The target base station parses its own SIB1 message, extracts the PLMN list of the target base station, traverses the list, finds the entry that matches the PLMN affiliation of the UE determined by the source base station, records the position index of the entry in the PLMN list of the target base station, and updates the PLMN identifier of the target base station; the target base station provides services to the UE.

[0006] Correspondingly, an embodiment of the present invention further provides a terminal handover method for a wireless communication system, the system includes a UE and several base stations, the base stations include a PLMN identifier, wherein, the base station that the UE accesses before handover is denoted as the source base station, and the base station after handover is denoted as the target base station; the handover method includes: In the initial access stage, the UE first parses the SIB1 message broadcast by the source base station, and selects the corresponding PLMN from it; subsequently, during the process of establishing a connection with the source base station, the UE reports the selected PLMN ID; the PLMN identifier of the source base station saves the PLMN ID; the source base station confirms the PLMN affiliation of the UE for initial access and provides services to the UE; When the UE switches from the source base station to the target base station, the source base station broadcasts the SIB1 message and the PLMN ID of the UE; the target base station receives and parses the SIB1 message of the source base station, extracts the PLMN list of the source base station, finds the PLMN entry corresponding to the PLMN ID, and determines the PLMN affiliation of the UE; The target base station parses its own SIB1 message, extracts the PLMN list of the target base station, traverses the list, finds the entry that matches the PLMN affiliation of the UE determined by the source base station, records the position index of the entry in the PLMN list of the target base station, and updates the PLMN identifier of the target base station; the target base station provides services to the UE.

[0007] The beneficial effect of the present invention is that in the handover scenario, the target base station can identify the PLMN of the UE, solve problems such as possible neighbor cell matching failure and handover preparation failure, and ensure the success rate of handover. Description of the Drawings

[0008] Figure 1 is a schematic structural diagram of the wireless communication system according to an embodiment of the present invention.

[0009] Figure 2 is a working flowchart of the wireless communication system according to an embodiment of the present invention.

[0010] Figure 3 It is a schematic flow chart of the terminal handover method of the wireless communication system according to an embodiment of the present invention. Detailed implementation manners

[0011] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0012] In the embodiments of the present invention, if there are directional indications (such as up, down, left, right, front, back,...), they are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0013] In addition, in the present invention, the descriptions such as "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature.

[0014] Please refer to Figure 1 , the wireless communication system according to the embodiment of the present invention includes a UE and several base stations. The base stations include PLMN identifiers.

[0015] The base stations are responsible for broadcasting system messages, such as providing comprehensive service support for the UE (user equipment) through SIB1. The PLMN identifier focuses on recording and real-time updating the PLMN ID fed back by the UE, where PLMN represents the Public Land Mobile Network, which is an important part of the mobile communication network. The base stations and the PLMN identifiers cooperate closely to jointly obtain and confirm the PLMN affiliation of the UE.

[0016] The specific working process of the embodiment of the present invention is as Figure 2 shown. In the initial access stage, the UE first parses the SIB1 message broadcast by the base station and selects the most suitable PLMN for itself. Subsequently, during the process of establishing a connection with the base station, the UE reports the selected PLMN ID. At this time, the PLMN identifier is responsible for saving the PLMN ID and providing it to the base station. The base station combines the relevant parameters in the SIB1 message to further confirm the PLMN affiliation of the UE accessing initially, ensuring to provide accurate services for the UE.

[0017] During the process of UE handover between base stations, the present invention introduces a more refined processing mechanism. When the UE hands over from the source base station to the target base station, the source base station not only provides its SIB1 broadcast message, but also works with the PLMN identifier to provide the UE's PLMN ID. These two key pieces of information are transmitted to the target base station together, helping the target base station quickly identify and admit the UE.

[0018] On the target base station side, the present invention designs an efficient processing algorithm for confirming the PLMN affiliation of the UE. It mainly consists of the following two parts: 1. Acquisition of source base station PLMN information and determination of UE affiliation.

[0019] In a mobile communication network, when a user equipment (UE) hands over from one base station (source base station) to another base station (target base station), the target base station first needs to obtain the System Information Block 1 (SIB1) message of the source base station. This message contains the list of Public Land Mobile Networks (PLMNs) served by the source base station, and this list is the key information for identifying the network operator.

[0020] The processing flow is as follows: 1) The target base station receives and parses the SIB1 message of the source base station, and extracts the PLMN list therein.

[0021] 2) Traverse this PLMN list, using the PLMN ID provided by the source base station as an index. This PLMN ID is the unique identifier of the network to which the UE currently belongs.

[0022] 3) Through index matching, find the PLMN entry corresponding to the PLMN ID. This entry contains the Mobile Country Code (MCC) and the Mobile Network Code (MNC), which jointly determine the PLMN affiliation of the UE.

[0023] 2. Synchronization and update of target base station PLMN information.

[0024] After determining the PLMN affiliation of the UE, the target base station needs to ensure that the PLMN information stored internally is synchronized with the current network environment. This is because the PLMN list in the SIB1 message of the target base station may be different from that of the source base station, and continuing to use the PLMN ID of the source base station may lead to incorrect PLMN affiliation identification.

[0025] The synchronization and update process is as follows: 1) The target base station parses its own SIB1 message and extracts the current PLMN list.

[0026] 2) Traverse this list, and compare each PLMN entry one by one for the MCC and MNC. This step is to find the entry that matches the UE PLMN affiliation determined by the source base station.

[0027] 3) Once a match is found, record the position index of the entry in the target base station's PLMN list. This position index will be used as the updated value of the UE's PLMN ID in the current network environment.

[0028] 4) Update the stored information in the PLMN identifier to ensure that the UE's PLMN ID is synchronized with the current network environment. This step is crucial as it ensures that the PLMN affiliation of the UE can be correctly identified regardless of which base station the UE is under.

[0029] Through the above process, the target base station can accurately and efficiently determine and update the UE's PLMN affiliation information, thus providing users with a seamless and stable network service experience.

[0030] In addition, the function of the PLMN identifier is far more than just recording and updating the PLMN ID fed back by the UE. It further improves the accuracy and real-time performance of PLMN identification through a dynamic update mechanism.

[0031] On the one hand, adopt a timing update mechanism: the PLMN identifier can send update requests to the UE at regular intervals to obtain the latest PLMN ID. The update frequency can be dynamically adjusted according to the actual situation of the network environment. For example, when the network load is heavy or the UE's moving speed is fast, the update frequency can be appropriately increased.

[0032] On the other hand, implement an event-triggered update mechanism: when the UE's location changes, network handover occurs, or the PLMN ID changes, the PLMN identifier can immediately trigger an update request, send a request to the UE through the base station, and quickly obtain the latest PLMN ID. This mechanism ensures that the PLMN identifier always has the latest PLMN information, effectively avoiding handover failures or service interruptions caused by information lag.

[0033] The terminal handover method of the wireless communication system according to the embodiment of the present invention includes: In the initial access stage, the UE first parses the SIB1 message broadcast by the source base station, selects the corresponding PLMN therefrom; subsequently, during the process of establishing a connection with the source base station, the UE reports the selected PLMN ID; the PLMN identifier of the source base station saves this PLMN ID; the source base station confirms the PLMN affiliation of the initially accessed UE and provides services for the UE; When the UE switches from the source base station to the target base station, the source base station broadcasts the SIB1 message and the UE's PLMN ID; the target base station receives and parses the SIB1 message of the source base station, extracts the PLMN list of the source base station, finds the PLMN entry corresponding to the PLMN ID, and determines the PLMN affiliation of the UE; The target base station parses its own SIB1 message, extracts the PLMN list of the target base station, traverses the list, finds the entry that matches the PLMN affiliation of the UE determined by the source base station, records the position index of the entry in the target base station's PLMN list, and updates the PLMN identifier of the target base station; the target base station provides services to the UE.

[0034] When the user equipment powers on or enters a new area, it scans the available PLMN list and selects the home public land mobile network (HPLMN) or visited public land mobile network (VPLMN) according to the PLMN identifier. When the user equipment powers on or enters a new area, it first reads the SIB1 message to determine whether it can access the current network. The user equipment decides whether to select the cell for residence according to the PLMN identification and cell access parameters in SIB1.

[0035] As an implementation, the PLMN identifier of the base station periodically sends an update request to the accessed UE, obtains the latest PLMN ID of the UE and updates the saved one.

[0036] As an implementation, when the UE undergoes a location change, network handover, or PLMN ID change, the PLMN identifier of the base station accessing the UE immediately triggers an update request, sends a request to the UE through the base station, quickly obtains the latest PLMN ID of the UE and updates the saved one.

[0037] Embodiment: As Figure 1 , the UE first accesses base station A, then switches to base station B, and finally switches to base station C, and each base station is associated with one PLMN identifier.

[0038] As Figure 3 , the UE initiates an RRC connection establishment request. After the RRC connection establishment is completed, the UE reports the selected PLMN ID, and the PLMN identifier A' obtains the PLMN ID. The base station confirms the PLMN of the UE according to the PLMN ID and the broadcast SIB1 message.

[0039] When the UE initiates a handover after the access is completed, the current base station serves as the source base station. When making a handover decision, it will provide the SIB1 broadcast message of this base station, and at the same time, the PLMN identifier A' will provide the previously saved PLMN ID, which is jointly forwarded by the source base station.

[0040] After receiving the SIB1 broadcast message of the source base station and the PLMN ID of the PLMN identifier A' associated with the source base station, the target base station obtains the PLMN value corresponding to the UE.

[0041] After obtaining the PLMN value, since the SIB1 broadcast message content of the two base stations may be different, the PLMN identifier B' associated with the target base station cannot directly use the PLMN ID value recorded by the PLMN identifier A'. Instead, it is necessary to inversely deduce a new PLMN ID based on the current base station's SIB1 broadcast message and the obtained PLMN value.

[0042] Then, the new PLMN ID is sent to the PLMN identifier B', and the PLMN identifier B' saves this PLMN ID. Subsequently, if the UE cuts over from the current base station to other base stations, it can ensure that other base stations obtain the correct PLMN of the UE. In summary, in the scenario of cutting into a base station, the base station can correctly identify the PLMN of the cutting-in UE according to this method.

[0043] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalent scope.

Claims

1. A wireless communication system, comprising a UE and several base stations, characterized in that: The base station includes a PLMN identifier, wherein the base station to which the UE is connected before the handover is recorded as a source base station, and the base station after the handover is recorded as a target base station; In the initial access phase, the UE first parses the SIB1 message broadcast by the source base station and selects the corresponding PLMN from it; then, in the process of establishing a connection with the source base station, the UE reports the selected PLMN ID; the PLMN identifier of the source base station saves the PLMN ID; the source base station confirms the PLMN affiliation of the UE that initially accesses and provides services to the UE; When the UE switches from the source base station to the target base station, the source base station broadcasts the SIB1 message and the PLMN ID of the UE; the target base station receives and parses the SIB1 message of the source base station, extracts the PLMN list of the source base station, finds the PLMN entry corresponding to the PLMN ID, and determines the PLMN affiliation of the UE; The target base station parses its own SIB1 message, extracts the PLMN list of the target base station, traverses the list, finds the entry that matches the PLMN affiliation of the UE determined by the source base station, records the position index of the entry in the PLMN list of the target base station, and updates the PLMN identifier of the target base station; the target base station provides service for the UE.

2. The wireless communication system according to claim 1, wherein: The PLMN identifier of the base station periodically sends an update request to the connected UE to obtain the latest PLMN ID of the UE and update and save it.

3. The wireless communication system according to claim 1, wherein: When the UE changes its location, network switching or PLMN ID, the PLMN identifier of the base station connected to the UE immediately triggers an update request, sends a request to the UE through the base station, quickly obtains the latest PLMN ID of the UE and updates and saves it.

4. A terminal switching method of a wireless communication system, the system comprising a UE and several base stations, characterized in that: The base station includes a PLMN identifier, wherein the base station accessed by the UE before the handover is recorded as a source base station, and the base station after the handover is recorded as a target base station; the handover method includes: In the initial access phase, the UE first parses the SIB1 message broadcast by the source base station and selects the corresponding PLMN from it; then, in the process of establishing a connection with the source base station, the UE reports the selected PLMN ID; the PLMN identifier of the source base station saves the PLMN ID; the source base station confirms the PLMN affiliation of the UE that initially accesses and provides services to the UE; When the UE switches from the source base station to the target base station, the source base station broadcasts the SIB1 message and the PLMN ID of the UE; the target base station receives and parses the SIB1 message of the source base station, extracts the PLMN list of the source base station, finds the PLMN entry corresponding to the PLMN ID, and determines the PLMN affiliation of the UE; The target base station parses its own SIB1 message, extracts the PLMN list of the target base station, traverses the list, finds the entry that matches the PLMN affiliation of the UE determined by the source base station, records the position index of the entry in the PLMN list of the target base station, and updates the PLMN identifier of the target base station; the target base station provides service for the UE.

5. The terminal switching method of the wireless communication system according to claim 4, characterized in that: The PLMN identifier of the base station periodically sends an update request to the connected UE to obtain the latest PLMN ID of the UE and update and save it.

6. The terminal switching method of the wireless communication system according to claim 4, characterized in that: When the UE changes its location, network switching or PLMN ID, the PLMN identifier of the base station connected to the UE immediately triggers an update request, sends a request to the UE through the base station, quickly obtains the latest PLMN ID of the UE and updates and saves it.

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