Method and device for managing handover in wireless communication system

Abstract

The present invention provides a method for controlling and managing handovers between base stations of adjacent cells in a wireless communication system, the method comprising: a user device reports a bit error rate to a base station communicating with the user device; the base station determines whether the bit error rate is greater than a predetermined threshold, if the bit error rate is greater than the predetermined threshold, the base station further determines whether the user device meets a handover condition within a period of time; if the user device meets the handover condition within the period of time and the target base station is not yet fully loaded, the user device is handed over to the target base station. The present invention also provides a device for implementing the method. The present invention can manage handovers in a wireless communication network.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communications, and more particularly to a method and device for managing handover. Background Art

[0002] In the fourth generation (4G) wireless communication system, the evolved Node B (eNB) uses adaptive modulation and coding (AMC) technology to determine the modulation suitable for the user equipment and the number of available resource blocks to communicate with the user equipment. If the 4G signal quality is still poor after using AMC technology, it will switch to the 3G network or handover to other base stations (eNB). Although this method is used in the fifth generation of wireless communication, it also leads to other problems.

[0003] The advent of the Internet of Things era will lead to a shortage of 4G resource blocks. If the system triggers the user equipment to switch from the next-generation base station (gNB) to the eNB based solely on the received power level, the handover will lead to a decline in the overall network performance when there are still sufficient fifth-generation resource blocks. Therefore, this method is not suitable for fifth-generation wireless communications. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a method and device for managing handover in a wireless communication system, which can manage handover in a 4G / 5G wireless network.

[0005] An embodiment of the present invention provides a method for managing handover in a wireless communication system, the method comprising the following steps: a serving base station receives a measurement report from a user equipment, wherein the measurement report includes a channel quality indicator and a bit error rate; the serving base station determines whether the bit error rate is greater than a preset bit error rate threshold; when it is determined that the bit error rate is greater than the preset bit error rate threshold, the serving base station determines whether the user equipment meets a handover condition; when it is determined that the user equipment meets the handover condition, the serving base station determines whether the user equipment continues to meet the handover condition within a preset time period; when it is determined that the user equipment continues to meet the handover condition within the preset time period, the serving base station determines whether the current load of the target base station is overloaded; and when it is determined that the current load of the target base station is not overloaded, the serving base station hands over the user equipment to the target base station.

[0006] An embodiment of the present invention further provides an apparatus for managing handover in a wireless communication system, wherein the apparatus comprises: a processor; and a memory for storing at least one computer program, wherein the computer program comprises instructions executed by the processor, so that the processor performs the following steps: a serving base station receives a measurement report from a user equipment, wherein the measurement report comprises a channel quality indicator and a bit error rate; the serving base station determines whether the bit error rate is greater than a preset bit error rate threshold; when it is determined that the bit error rate is greater than the preset bit error rate threshold, the serving base station determines whether the user equipment meets a handover condition; when it is determined that the user equipment meets the handover condition, the serving base station determines whether the user equipment continuously meets the handover condition within a preset time period; when it is determined that the user equipment continuously meets the handover condition within the preset time period, the serving base station determines whether a current load of a target base station is overloaded; and when it is determined that the current load of the target base station is not overloaded, the serving base station hands over the user equipment to the target base station.

[0007] Compared with the prior art, the method and device for managing handover in a wireless communication system provided by the present invention can provide handover management in a 4G / 5G wireless network environment. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0009] Figure 2 FIG. 4 is a flow chart of a method for managing handover according to an embodiment of the present invention.

[0010] Figure 3 FIG. 4 is a block diagram of a device for managing handover according to an embodiment of the present invention.

[0011] Main component symbols

[0012]

[0013]

[0014] The following specific implementation manner will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0015] In order to facilitate the understanding and implementation of the present invention by those skilled in the art of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the present invention provides many applicable inventive concepts, which can be implemented in a variety of specific forms. Those skilled in the art of the present invention can use the details described in these embodiments or other embodiments and other available structural, logical and electrical changes to implement the invention without departing from the spirit and scope of the present invention.

[0016] The present invention specification provides different embodiments to illustrate the technical features of different implementations of the present invention. Among them, the configuration of each component in the embodiment is for illustrative purposes and is not intended to limit the present invention. And the partial repetition of the figure numbers in the embodiment is to simplify the description and does not mean the correlation between different embodiments. Among them, the same component numbers used in the drawings and the description represent the same or similar components. The drawings in this specification are simplified and are not drawn to exact proportions.

[0017] Furthermore, in describing some embodiments of the present invention, the specification describes the method and (or) program of the present invention in a specific order of steps. However, since the method and program are not necessarily implemented according to the specific order of steps described, they are not limited to the specific order of steps described. A person skilled in the art of the present invention will know that other orders are also possible implementation methods. Therefore, the specific order of steps described in the specification is not used to limit the scope of the patent application. Furthermore, the scope of the patent application for the method and (or) program of the present invention is not limited to the order of execution steps written therein, and a person skilled in the art of the present invention will understand that adjusting the order of execution steps does not deviate from the spirit and scope of the present invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0019] See also Figure 1, which is a schematic diagram of a wireless communication system 100 for wireless communication according to an embodiment of the present invention. The wireless communication system 100 includes a user equipment 102, a first cell 104, a second cell 106, a first base station 108 for managing the first cell 104, and a second base station 110 for managing the second cell 106. The wireless communication system 100 also includes a core network 112 that communicates with the first base station 108 and the second base station 110. In one embodiment, the first cell 104 includes a New Radio (NR) cell, the first base station 108 is a serving base station (gNB) of the user equipment 102, the second cell 106 includes a fourth generation long term evolution (4G / LTE) cell, and the second base station 110 is an target base station (eNB) located near the user equipment 102. In the wireless communication system 100, the user equipment 102 may perform a handover between the first base station 108 and the second base station 110, and both the first base station 108 and the second base station 110 may become the serving base stations of the user equipment 102.

[0020] See also Figure 2 , which is a flow chart of a method for managing handover in a wireless communication system 100 according to an embodiment of the present invention. It should be noted that even if one or more blocks (or steps) are added to or removed from the process 200, the basic logic flow of the present embodiment will not change; as long as there is no contradiction, the order of the blocks (or steps) of the present embodiment can also be changed, and is not limited to Figure 2 The specific order shown.

[0021] Step S202, the serving base station (for example, Figure 1 The first base station 108 in the embodiment receives a signal from a user equipment (eg, Figure 1 The measurement report of the user equipment 102 in the embodiment of the present invention is a measurement report of the user equipment 102 in the embodiment of the present invention. The measurement report includes a channel quality indicator (Channel Quality Indicator, CQI) and a bit error rate (Bit Error Rate, BER). In one embodiment, the user equipment calculates the BER by dividing the number of error bits received in a certain time period by the total number of bits received. In one embodiment, the user equipment may send the measurement report in a periodic reporting mode and an aperiodic reporting mode. In the periodic reporting mode, the user equipment periodically sends the measurement report according to the time period set by the serving base station. In the aperiodic reporting mode, the user equipment is triggered to send the measurement report via the trigger signaling of the serving base station. In another embodiment, the measurement report only includes the BER. The user equipment sends the measurement report and the CQI report simultaneously in the periodic reporting mode and the aperiodic reporting mode.

[0022] In step S204, the serving base station obtains a modulation and coding scheme (MCS) value according to the received CQI value. In one embodiment, a formula may be used to calculate or a mapping table may be preset to obtain the MCS value according to the received CQI value.

[0023] In step S206, the serving base station receives a reference signal received power (RSRP) report from the user equipment. The RSRP report includes the RSRP of the serving base station and the RSRP of the target base station (eg, Figure 1 RSRP of the second base station 110) in.

[0024] In step S208, the serving base station determines whether the received BER is greater than a preset BER threshold. If the serving base station determines that the received BER is greater than the preset BER threshold, step S210 is executed; otherwise, step S218 is executed. In one embodiment, the BER of any user equipment should be maintained below the preset BER threshold. In this embodiment, the preset BER threshold can be set to, for example, 10%, i.e., 0.1.

[0025] Step S210, the serving base station determines whether the user equipment meets the handover condition. In one embodiment, the serving base station determines whether the user equipment meets the handover condition based on the received RSRP report, wherein the handover condition is that the RSRP of the target base station is greater than the RSRP of the serving base station plus the handover threshold. In one embodiment, when the user equipment meets the handover condition, the user equipment sends the RSRP report to the serving base station. In one embodiment, the serving base station uses the following formula to determine whether the user equipment meets the handover condition:

[0026] RSRP T >(RSRP S +HO TH ), where RSRP T RSRP and RSRP for the target base station S RSRP and HO serving base stations TH is the turnover threshold.

[0027] If the serving base station determines that the user equipment meets the handover condition, step S212 is executed; otherwise, step S218 is executed.

[0028] In step S212, the service base station determines whether the user equipment continues to meet the handover condition within a preset time period. In one embodiment, the preset time period is set as a trigger time (Time-TO-Trigger, TTT) value. If the service base station determines that the user equipment continues to meet the handover condition within the preset time period, step S214 is executed; otherwise, step S218 is executed. In one embodiment, when the user equipment meets the handover condition for the first time, the service base station starts a timer to count the TTT value, and when the timer expires, it determines whether the user equipment still meets the handover condition. In a specific application environment, this step can avoid the ping-pong effect during the handover process.

[0029] In one embodiment, the handover threshold and TTT value may be set based on empirical data. For example, an operator may test the wireless communication system and set the handover threshold and TTT value based on specific situations / operating conditions.

[0030] In step S214, the serving base station determines whether the current load of the target base station is overloaded. In one embodiment, the serving base station determines whether the current load of the target base station is overloaded based on the load message reported by the target base station. The load message includes the radio resource occupancy status of the target base station. In one embodiment, the load message also includes spectrum occupancy, the number of user devices served, resource idle rate, and the capacity corresponding to the reserved resources. If the serving base station determines that the current load of the target base station is overloaded, execute step S216; otherwise, execute step S220.

[0031] In step S216, the serving base station reduces the MCS value.

[0032] Step S218, the serving base station allocates resource blocks to the user equipment according to the MCS value. In one embodiment, the serving base station searches one or more tables according to the MCS value to determine the size of the transport block and the number of resource blocks. In practice, the one or more tables may be set according to one or other LTE standards.

[0033] Step S220: The serving base station performs a handover of the user equipment with the target base station. Specifically, the serving base station hands over the user equipment to the target base station.

[0034] See also Figure 3 , which is a block diagram of a device 300 for managing handover in an embodiment of the present invention. It should be noted that the device 300 is only an example, and other existing or future products that can be adapted to the present application should also be included in the protection scope of the present application and included here by reference.

[0035] The device 300 includes a processor 302, a memory 304, and a transceiver 306. The processor 302 includes a microcontroller, a microprocessor, a complex instruction set computing microprocessor, a reduced instruction set computing microprocessor, a very long instruction set computing microprocessor, a super parallel instruction set computing microprocessor, and any digital signal processor or other circuit with computing processing capabilities. The processor 302 is used to implement the method disclosed in the present invention. The memory 304 includes a read-only memory, a random access memory, a magnetic storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other computer-readable storage medium, including a physical / tangible and non-temporary device. The memory 304 is coupled to the processor 302 to store one or more computer programs that control the operation of the device 300 and is executed by the processor 302. The transceiver 306 is coupled to the processor 302 to send and / or receive radio signals.

[0036] In summary, the method and device for managing handovers, which add BER as a handover condition for signal quality, can allow the service base station to more accurately determine whether the user equipment needs to handover. At the same time, the service base station will consider the load status of the target base station. If the target base station is in an overloaded state, the service base station will first maintain the throughput by reducing the MCS value, making it difficult for the user equipment to compete for the resources of the target base station, thereby improving the overall throughput in the wireless communication system.

[0037] It is worth noting that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for managing handover in a wireless communication system, characterized in that: The method comprises the following steps: The serving base station receives a measurement report from the user equipment, wherein the measurement report includes a channel quality indicator and a bit error rate; The serving base station determines whether the bit error rate is greater than a preset bit error rate threshold; When it is determined that the bit error rate is greater than the preset bit error rate threshold, the serving base station determines whether the user equipment meets a handover condition; When it is determined that the user equipment meets the handover condition, the serving base station determines whether the user equipment continuously meets the handover condition within a preset time period; When it is determined that the user equipment continuously satisfies the handover condition within the preset time period, the serving base station determines whether a current load of the target base station is overloaded; When it is determined that the current load of the target base station is not overloaded, the serving base station hands over the user equipment to the target base station; The serving base station determines and obtains a modulation and coding scheme (MCS) value according to the channel quality indicator; and When it is determined that the current load of the target base station is overloaded, the serving base station reduces the MCS value.

2. The method according to claim 1, characterized in that The method further comprises the following steps: When it is determined that the current load of the target base station is overloaded, the serving base station allocates resource blocks to the user equipment according to the MCS value.

3. The method according to claim 1, characterized in that The method further comprises the following steps: The serving base station receives a Reference Signal Received Power (RSRP) report from the user equipment, wherein the RSRP report includes the RSRP of the serving base station and the RSRP of the target base station.

4. The method according to claim 3, characterized in that The handover condition includes that the RSRP of the target base station is greater than the RSRP of the serving base station plus a handover threshold.

5. A device for managing handover in a wireless communication system, characterized in that: The device comprises: Processor; and A memory for storing at least one computer program, wherein the computer program comprises instructions executed by the processor, causing the processor to perform the following steps: The serving base station receives a measurement report from the user equipment, wherein the measurement report includes a channel quality indicator and a bit error rate; The serving base station determines whether the bit error rate is greater than a preset bit error rate threshold; When it is determined that the bit error rate is greater than the preset bit error rate threshold, the serving base station determines whether the user equipment meets a handover condition; When it is determined that the user equipment meets the handover condition, the serving base station determines whether the user equipment continuously meets the handover condition within a preset time period; When it is determined that the user equipment continuously satisfies the handover condition within the preset time period, the serving base station determines whether a current load of the target base station is overloaded; When it is determined that the current load of the target base station is not overloaded, the serving base station hands over the user equipment to the target base station; The serving base station determines and obtains a modulation and coding scheme (MCS) value according to the channel quality indicator; and When it is determined that the current load of the target base station is overloaded, the serving base station reduces the MCS value.

6. The device according to claim 5, characterized in that The processor also performs the following steps: When it is determined that the current load of the target base station is overloaded, the serving base station allocates resource blocks to the user equipment according to the MCS value.

7. The device according to claim 5, characterized in that The processor also performs the following steps: The serving base station receives a Reference Signal Received Power (RSRP) report from the user equipment, wherein the RSRP report includes the RSRP of the serving base station and the RSRP of the target base station.

8. The device according to claim 7, characterized in that The handover condition includes that the RSRP of the target base station is greater than the RSRP of the serving base station plus a handover threshold.

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