Network search optimization method for inter-system redirection of user terminal

Abstract

The invention relates to the technical field of network communication, in particular to a network searching optimization method for inter-system redirection of a user terminal. Comprising the following steps: user equipment searches a network according to a second network frequency point specified by a network control message, judges whether a resident second network cell is searched or not, resides in the searched second network cell if the resident second network cell is searched, searches the resident second network cell under historical frequency point information of the user equipment if the resident second network cell is not searched, judges whether the resident second network cell is searched or not, and resides in the resident second network cell if the resident second network cell is searched; if so, residing in the searched second network cell; if the second network cell is not searched, detecting whether the second network cell of the signed operator is searched in the network searching process, and if the second network cell of the signed operator is searched, carrying out full-band network searching; if not, stopping network searching, and returning to the first network for residence; according to the invention, only redirection specified frequency point search and historical frequency point search are carried out, full-band search is skipped, the network search time in different networks is shortened, and the situation of missing search of different network cells is compensated.

Description

Technical Field

[0001] The present invention relates to the technical field of network communication, and in particular to a network search optimization method. Background Art

[0002] Redcap UE (Reduced Capability User Equipment) is a low-complexity lightweight user equipment introduced by 3GPP in R17. In the early stage of Redcap application, lightweight user equipment is generally dual-mode, that is, it supports access to 4G LTE and 5G NR networks at the same time. However, the existing 4G LTE base stations have not been upgraded on a large scale, and the existing 5G NR base stations have not been upgraded on a large scale to support Redcap. The current existing LTE base stations may redirect Redcap UE to a foreign network NR frequency point where a Redcap cell is not deployed, which will cause the redirected frequency point network search to fail.

[0003] Although the redirected frequency may fail to search for a network, the user device is allowed to continue searching for a network in the NR standard of the heterogeneous network. Therefore, after the redirected frequency fails to search for a network, the user device may perform a full-band search (full-band search). Once the full-band search is performed, the network search time may be too long in the heterogeneous network, resulting in a long service interruption. Summary of the invention

[0004] The purpose of the present invention is to provide a method for optimizing network search by redirecting user terminals in different systems to solve the above technical problems;

[0005] The technical problem solved by the present invention can be achieved by adopting the following technical solutions:

[0006] A network search optimization method for redirecting a user terminal in a different system, comprising:

[0007] Step S1, a user equipment residing in a first network receives a network control message for redirecting to a second network, and the user equipment searches for a network according to a second network frequency specified by the network control message, and determines whether a second network cell that can be resident is found. If so, the user equipment resides in the second network cell that is found. If not, step S2 is executed;

[0008] Step S2, searching for the second network cell that can be resident under the historical frequency point information of the user equipment, and determining whether it is found, if so, resident in the searched second network cell; if not, executing step S3;

[0009] Step S3, detecting whether the second network cell of the contracted operator is found in the network search process of step S1 and step S2, if so, executing step S4; if not, stopping the network search and returning to the first network for residence;

[0010] Step S4, perform a full-band network search to determine whether the second network cell that can be resided is found. If so, reside in the second network cell that is found; if not, stop searching and return to the first network cell.

[0011] Preferably, the user equipment is a lightweight terminal that supports some 5G functions.

[0012] Preferably, the first network is a 4G LTE network and the second network is a 5G NR network.

[0013] Preferably, step S1 comprises:

[0014] Step S11, the user equipment receives the network control message from the first network, and switches from the first network to the second network for redirection based on the network control message;

[0015] Step S12, the user equipment performs a network search according to the second network frequency specified by the network control message, and detects the second network frequency specified by the network control message in sequence starting from the first second network frequency;

[0016] Step S13, determining whether the second network frequency point currently detected meets the access requirement of the user equipment. If so, the user equipment selects to reside on the second network frequency point currently detected, and the redirection is completed; if not, executing step S14;

[0017] Step S14, determine whether all the second network frequency points specified by the network control message have been detected. If not, perform detection on the next second network frequency point and return to step S13; if all the detections are completed, determine that the user equipment has not found the second network cell in which it can reside at the second network frequency point specified by the network control message, and execute step S2.

[0018] Preferably, step S2 comprises,

[0019] Step S21, determining whether the historical frequency point information exists, if yes, executing step S22, if no, executing step S3;

[0020] Step S22, searching for the second network cell that can be resided in under the historical frequency point information, and determining whether it is found. If so, reside in the searched second network cell; if not, executing step S3.

[0021] Preferably, in step S2, the historical frequency point information is the saved frequency point information to which the user equipment has successfully connected in the past.

[0022] Preferably, in step S3, during the network search process of steps S1 and S2, it is detected whether there is the second network cell of the contracted operator where the user equipment cannot reside due to the network usage standards or restriction standards. If not, the network search is stopped and the user equipment returns to the first network to reside. If so, step S4 is executed.

[0023] Preferably, in step S3, the contracted operator is the operator bound to the SIM card of the user equipment.

[0024] Preferably, in the process of searching the second network cell that can be resided in step S1, step S2 and step S4, it is also determined whether the network search time exceeds the service interruption tolerance time. If so, the network search is interrupted and returns to the first network for residency; if not, the network search is continued.

[0025] Preferably, in step S1, step S2 and step S4, the time of the network search process is sensed by a terminal module of the user equipment, and the terminal module is composed of at least one of an application processing unit, a non-access layer unit of the control plane and a wireless resource control unit.

[0026] Beneficial effects of the present invention: Due to the adoption of the above technical scheme, the user equipment of the present invention can reduce the network search time in a foreign network by only redirecting the designated frequency search and the historical frequency search and skipping the full-band search during the redirection to the foreign network. In addition, during the redirection of the designated frequency search or the historical frequency search, the user equipment decides to further search the full-band search based on the situation of searching the cell of the contracted operator, which can make up for the situation of missing the search of the foreign network cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the steps of a network search optimization method according to an embodiment of the present invention;

[0028] Figure 2 Flow chart of the network search optimization method in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of step S1 in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of step S2 in an embodiment of the present invention;

[0031] Figure 5 Schematic diagram of terminal module duration perception in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0034] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0035] A method for optimizing network search by redirecting user terminals in different systems, such as Figure 1 , Figure 2 As shown, including

[0036] Step S1, a user equipment residing in a first network receives a network control message for redirecting to a second network, and the user equipment searches for a network according to the second network frequency specified in the network control message, and determines whether a second network cell that can be resident is found. If so, the user equipment resides in the found second network cell; if not, step S2 is executed;

[0037] Step S2, searching for a second network cell that can be resident in the historical frequency point information of the user equipment, and determining whether it is found. If it is found, resident in the searched second network cell; if not found, executing step S3;

[0038] Step S3, detecting whether the second network cell of the contracted operator is found in the network search process of step S1 and step S2, if so, executing step S4; if not, stopping the network search and returning to the first network;

[0039] Step S4, perform full-band network search to determine whether a second network cell that can be resident is found. If so, reside in the second network cell; if not, stop searching and return to the first network cell.

[0040] In a preferred embodiment, the user equipment is a lightweight terminal that supports some 5G functions, namely, a Redcap terminal.

[0041] In a preferred embodiment, the first network is a 4G LTE network, the second network is a 5G NR network, and the second network cell is a Redcap cell that supports Redcap terminal access.

[0042] The present invention is directed to a Redcap terminal that receives a signal from LTE and redirects the signal to NR. The first step is to perform a redirected frequency search. However, if the redirected frequency search fails, continue to try to use the historical frequency search. If the historical frequency search fails, but there is a Redcap cell of the contracted operator during the redirected frequency search and the historical frequency search, a full-band search is performed again, with the goal of trying to find a suitable NR Redcap cell to reside in. Otherwise, after the historical frequency search fails, it returns to the cell of the LTE standard.

[0043] The present invention solves the problem of the Redcap terminal in the network search process when the 4G LTE network is redirected to the 5G NR network, reduces the excessively long network search time and the resulting service interruption during the redirection process, and meets the requirements of the 3GPP protocol.

[0044] When a Redcap terminal is redirected from an LTE network to an NR network, it first searches for a network on the redirected frequency point. The redirected frequency point uses the frequency band specified by the network control message to enable access to the NR network as quickly as possible, ensuring that the user equipment can smoothly transition to the new network.

[0045] If the user equipment fails to successfully connect to the NR network at the redirected frequency, the present invention starts to execute step S2 and searches the network using the historical frequency, where the historical frequency refers to the frequency to which the user equipment has been connected before.

[0046] When neither the redirected frequency nor the historical frequency finds a suitable NR cell, a full-band network search is further performed to find a qualified Redcap cell by extensively searching more frequency bands. A Redcap cell refers to a cell that complies with the Redcap protocol, which is a low-complexity, low-power 5G access point that supports Redcap terminal access.

[0047] During the search process of redirected frequencies and historical frequencies, it is first determined whether there is a Redcap cell provided by the contracted operator. If so, it indicates that the contracted operator is likely to deploy Redcap cells at other frequencies. Therefore, the success rate of successfully joining the NR network by performing a full-band search is relatively high. Therefore, the present invention performs a full-band search after determining whether there is a Redcap cell provided by the contracted operator to improve the access success rate.

[0048] If the full-band network search still fails, the final fallback action is to return to the 4G LTE cell, and the user device will reconnect to the LTE network, thus avoiding long-term network search failures and service interruptions.

[0049] In the present invention, NR refers to New Radio, i.e., the wireless access technology of 5G. During the redirection process, the user equipment needs to reside in a network environment that supports the NR standard, i.e., communicate in a 5G network. If the user equipment successfully searches for a suitable NR cell, it resides in the NR cell and uses the 5G network for communication.

[0050] NR Redcap cell refers to a special type of cell in the 5G network, which is used to support lightweight terminals with some 5G functions, namely Redcap terminal access.

[0051] In a preferred embodiment, Figure 3 As shown, step S1 includes,

[0052] Step S11, the user equipment receives a network control message from the first network, and switches from the first network to the second network for redirection based on the network control message;

[0053] Step S12, the user equipment performs a network search according to the second network frequency point specified by the network control message, and detects the second network frequency points specified by the network control message in sequence starting from the first second network frequency point;

[0054] Step S13, determining whether the second network frequency point currently detected meets the access requirement of the user equipment. If so, the user equipment selects to reside on the second network frequency point currently detected, and the redirection is completed; if not, executing step S14;

[0055] Step S14, determine whether all detections of the second network frequency points specified by the network control message have been completed. If not, perform detection of the next second network frequency point and return to step S13; if all detections are completed, it is determined that the user equipment has not found a second network cell in which it can reside at the second network frequency point specified by the network control message, and execute step S2.

[0056] Specifically, under the LTE standard, the user equipment receives a network control message redirected to the NR frequency point, and the user equipment searches the network according to the NR frequency point specified by the redirection. If a cell that can be resident is found under this frequency point, it stays under the NR standard and the redirection process ends. However, if no NR Redcap cell that can be resident is found under the NR frequency point, step S2 is executed to determine whether there is historical frequency point information of the Redcap cell.

[0057] Specifically, under the LTE standard, the user equipment receives a network control message redirecting to the NR frequency point. Based on the redirection message, the user equipment switches from the current LTE network to the 5G NR frequency point, and the user equipment performs a "network search" operation according to the NR frequency point provided in the redirection message. Specifically, it will try to search for available cells on the specified NR frequency point.

[0058] If the user equipment successfully finds a cell that can be resident at the redirected frequency, it switches to the NR network and the redirection process ends. If the user equipment does not find an available cell at the specified NR frequency, the present invention enters step S2 to search the Redcap cell frequency recorded in the historical frequency information.

[0059] In a preferred embodiment, Figure 4 As shown, step S2 includes,

[0060] Step S21, determine whether there is historical frequency point information, if yes, execute step S22, if no, execute step S3;

[0061] Step S22, searching for a second network cell that can be resided in under the historical frequency information, and determining whether it is found. If it is found, reside in the searched second network cell; if not found, executing step S3.

[0062] Specifically, the present invention first determines whether there is historical frequency information of the NR Redcap cell, that is, whether there is a previously connected and known NR cell frequency. If so, the user equipment will search and access on the historical frequency. If the user equipment has no historical frequency information, that is, there is no known available NR frequency, then execute step S3 and perform subsequent network search steps.

[0063] In a preferred embodiment, in step S2, the historical frequency point information is the saved frequency point information to which the user equipment has successfully connected in the past.

[0064] In a preferred embodiment, in step S3, it is detected during the network search process of steps S1 and S2 whether there is a second network cell of the contracted operator where the user equipment cannot reside due to the network usage standards or restriction standards. If not, the network search is stopped and the user equipment returns to the first network for residence; if so, step S4 is executed.

[0065] Specifically, if the user device fails to search for the Redcap cell of the contracted operator (i.e. the 5G cell deployed by the current operator) during the network search at the designated frequency point and the network search at the historical frequency point, the device will return to the LTE standard to reside, interrupt the switch to the 5G network, and the network search process will end, thereby preventing service termination caused by a long network search process.

[0066] In a preferred embodiment, in step S3, the contracted operator is the operator bound to the SIM card of the user equipment.

[0067] Specifically, the contracted operator is the same operator as the SIM card. If the user equipment searches for the Redcap cell of the same operator as the SIM card during the designated frequency search or the historical frequency search, but cannot reside due to the S criterion or bar indication, it indicates that the contracted operator is likely to deploy Redcap cells at other frequencies. Therefore, the success rate of successfully joining the NR network by performing a full-band network search is relatively high. Therefore, the present invention performs a full-band network search after determining whether there is a Redcap cell provided by the contracted operator, thereby improving the access success rate.

[0068] The S criterion refers to a standard used in the network, such as a signal quality standard or a cell selection standard. For example, the user equipment finds a Redcap cell during search, but cannot successfully connect to the cell because the signal strength does not meet the requirements.

[0069] The Bar indication refers to network restrictions, for example, the user equipment cannot access the Redcap cell due to network resource issues, network policies, or operator restrictions.

[0070] If the user equipment cannot reside on the Redcap cell found above, the present invention will continue to perform a full-band search, that is, search in multiple frequency bands to identify whether the current operator has upgraded the Redcap cell in the NR network. Through the full-band search, the present invention can search in a wider frequency range. After the user equipment has found the Redcap cell, it indicates that the contracted operator has a high probability of upgrading other Redcap cells. If it is unable to access due to the S criterion and Bar indication, a full-band search is performed, and there is a high probability of finding a Redcap cell that can be resided.

[0071] If an NR Redcap cell is searched, that is, when the user equipment finds a Redcap cell that can be camped, it stops searching the network and chooses to camp under the NR standard to complete the redirection process.

[0072] If no NR Redcap cell is found in the full-band search, the user equipment will give up 5G access and return to the LTE standard, ending the redirection.

[0073] In a preferred embodiment, during the process of searching for the second network cell in which the cell can reside in step S1, step S2 and step S4, it is also determined whether the network search time exceeds the service interruption tolerance time. If so, the network search is interrupted and the cell returns to the first network for residency; if not, the network search is continued.

[0074] Specifically, Figure 5As shown, during the redirection of the designated frequency search in step S1, the historical frequency search in step S2, or the full-band network search in step S4, the terminal module 1 senses that the current release redirection to the NR network search time exceeds the service interruption tolerance time. The network search can be terminated by triggering the action of interrupting the network search, returning to the LTE standard, and the process of releasing the redirection to the NR ends.

[0075] The terminal module 1 senses the redirection network search duration. Once the network search tolerance duration is exceeded, the network search interruption action can be triggered to return to the LTE standard, thereby further reducing the impact of service interruption.

[0076] In a preferred embodiment, in step S1, step S2 and step S4, the time of the network search process is sensed by the terminal module 1 of the user equipment, and the terminal module 1 is composed of at least one of an application processing unit, a non-access layer unit of the control plane and a wireless resource control unit.

[0077] Specifically, the terminal module 1 is composed of one or more of an application processing (AP) unit, a non-access stratum (NAS) unit in a control plane (CP), and a radio resource control (RRC) unit.

[0078] The application processing unit is used to process network communication at the application layer, NAS is used for user session management and connection management, and the radio resource control unit is used to control the process of network switching. The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be realized that all solutions obtained by equivalent substitution and obvious changes made by using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing network search by redirecting user terminals in different systems, characterized in that: include, Step S1, a user equipment residing in a first network receives a network control message for redirecting to a second network, and the user equipment searches for a network according to a second network frequency specified by the network control message, and determines whether a second network cell that can be resident is found. If so, the user equipment resides in the second network cell that is found. If not, step S2 is executed; Step S2, searching for the second network cell that can be resident under the historical frequency point information of the user equipment, and determining whether it is found, if so, resident in the searched second network cell; if not, executing step S3; Step S3, detecting whether the second network cell of the contracted operator is found in the network search process of step S1 and step S2, if so, executing step S4; if not, stopping the network search and returning to the first network for residence; Step S4, perform a full-band network search to determine whether the second network cell that can be resided is found. If so, reside in the second network cell that is found; if not, stop searching and return to the first network cell.

2. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: The user equipment is a lightweight terminal that supports some 5G functions.

3. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: The first network is a 4G LTE network, and the second network is a 5G NR network.

4. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: Step S1 comprises, Step S11, the user equipment receives the network control message from the first network, and switches from the first network to the second network for redirection based on the network control message; Step S12, the user equipment performs a network search according to the second network frequency specified by the network control message, and detects the second network frequency specified by the network control message in sequence starting from the first second network frequency; Step S13, determining whether the second network frequency point currently detected meets the access requirement of the user equipment. If so, the user equipment selects to reside on the second network frequency point currently detected, and the redirection is completed; if not, executing step S14; Step S14, determining whether all the second network frequency points specified by the network control message have been detected. If not, detecting the next second network frequency point is performed, and returning to step S13; If all detections are completed and it is determined that the user equipment has not found the second network cell in which it can reside at the second network frequency specified by the network control message, step S2 is executed.

5. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: Step S2 comprises, Step S21, determining whether the historical frequency point information exists, if yes, executing step S22, if no, executing step S3; Step S22, searching for the second network cell that can be resided in under the historical frequency point information, and determining whether it is found. If so, reside in the searched second network cell; if not, executing step S3.

6. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: In step S2, the historical frequency point information is the saved frequency point information to which the user equipment has successfully connected in the past.

7. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: In step S3, during the network search process of steps S1 and S2, it is detected whether there is the second network cell of the contracted operator where the user equipment cannot reside due to the network usage standards or restriction standards. If not, the network search is stopped and the user equipment returns to the first network to reside. If so, step S4 is executed.

8. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: In step S3, the contracted operator is the operator bound to the SIM card of the user equipment.

9. The method for optimizing network search by redirecting user terminals in different systems according to claim 1, characterized in that: In the process of searching the second network cell that can be resided in step S1, step S2 and step S4, it is also determined whether the network search time exceeds the service interruption tolerance time. If so, the network search is interrupted and the first network is returned to reside; if not, the network search is continued.

10. The method for optimizing network search by redirecting user terminals in different systems according to claim 9, characterized in that: In step S1, step S2 and step S4, the time of the network search process is sensed by the terminal module of the user equipment, and the terminal module is composed of at least one of an application processing unit, a non-access layer unit of the control plane and a radio resource control unit.

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