Cell Selection Method

Abstract

To provide a cell selection method that avoids a situation in which a terminal device selects a more congested base station as a serving base station and obtains good service quality.SOLUTION: A method includes, while performing a cell selection operation at a plurality of reference base stations, obtaining a signal indicator and a network congestion indicator corresponding to each reference base station, and selecting a serving base station from the reference base stations on the basis of the signal indicator and the network congestion indicator corresponding to each reference base station.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to wireless communication technology, and more particularly to a cell selection method. [Background technology]

[0002] After starting up, a terminal device (e.g., a mobile phone) attempts to connect to a network. During the connection process, the signal information of nearby detectable cells (or base stations) is measured and the more suitable cell is selected for connection. This process is called cell selection.

[0003] After connecting to the network, the terminal device continues to monitor the network conditions so as to perform cell selection again in a timely manner, a process called cell reselection.

[0004] According to relevant communication standards (e.g. 3GPP TS38.304), during cell selection or cell reselection, the terminal device selects a suitable cell for connection based on signal strength (e.g. SrxLev parameter defined in 3GPP TS38.304) and signal quality (e.g. Sqal parameter defined in 3GPP TS38.304), as well as suitable frequency priorities or radio access technologies (RAT_priorities). Summary of the Invention [Problem to be solved by the invention]

[0005] However, although this selection method allows the terminal device to select a serving cell with high signal strength and good signal quality, the terminal device may not obtain good service quality.

[0006] For example, if a cell is experiencing network congestion for some reason (e.g., serving too many terminals), it may slow down the data transfer rates of the terminals it serves despite high signal strength and good signal quality. [Means for solving the problem]

[0007] The present invention provides a cell selection method capable of solving the above technical problems.

[0008] One embodiment of the present invention provides a cell selection method applied to a terminal device, the method including: obtaining a signal indicator and a network congestion indicator corresponding to each reference base station during a cell selection operation in a plurality of reference base stations, and selecting a serving base station from the reference base stations based on the signal indicator and the network congestion indicator corresponding to each reference base station.

[0009] One embodiment of the present invention provides a cell selection method applied to a base station, the method including: providing a signal indicator and a network congestion indicator corresponding to the base station to a terminal device, the signal indicator and the network congestion indicator corresponding to the base station enabling the terminal device to perform a cell selection operation. Effect of the Invention

[0010] Therefore, it is possible to avoid a situation in which the terminal device selects a more congested base station as the serving base station.

[0011] In order to make the above easier to understand, several embodiments are described in detail below in conjunction with the drawings. [Brief description of the drawings]

[0012] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0013] [Figure 1] 1 is a schematic diagram of a communication system according to one embodiment of the present invention. [Diagram 2] 1 is a flow diagram of a cell selection method according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] 1 is a schematic diagram of a communication system according to one embodiment of the present invention. In FIG. 1, a communication system 10 includes a terminal device 11 and a base station 12.

[0015] In different embodiments, the terminal device 11 may represent a user equipment (UE), a mobile station, an advanced mobile station (AMS), or a wireless terminal communication device. In addition, the terminal device 11 may be a mobile phone, a smartphone, a personal computer (PC), a notebook PC, a netbook PC, a tablet PC, a television, a set-top box, a wireless data modem, a game console, a handheld device, or a portable multimedia player, etc.

[0016] In different embodiments, the base station 12 may be, for example, but not limited to, a wireless network access point, an evolved Node B (eNodeB), an advanced base station (ABS), a macrocell base station, a picocell base station, or a Remote Radio Head (RRH), a gNodeB (gNB), etc.

[0017] 1, terminal device 11 includes communication circuitry 112 and a processor 114. In one embodiment, communication circuitry 112 includes at least a transmitter circuit, a receiver circuit, an analog-to-digital (A / D) converter, a digital-to-analog (D / A) converter, a low noise amplifier (LNA), a mixer, a filter, a matching circuit, a transmission line, a power amplifier (PA), one or more antenna units, and a local storage medium to provide wireless access to terminal device 11.

[0018] In some embodiments, the communication circuitry 112 may be a component such as a protocol unit capable of supporting various wireless network communication protocols such as WiFi HaLow, etc. In other embodiments, the communication circuitry 112 may also support, but is not limited to, global system for mobile communication (GSM), personal handy-phone system (PHS), code division multiple access (CDMA) systems, wireless fidelity (Wi-Fi) systems, or worldwide interoperability for microwave access (WiMAX) signal transmissions.

[0019] Additionally, a processor 114 is coupled to the communications circuitry 112 and may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor, multiple microprocessors, one or more microprocessors incorporating a digital signal processor core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any type of integrated circuit, a state machine, an advanced RISC machine (ARM) based processor, and similar products.

[0020] As shown in FIG. 1, the base station 12 includes communication circuitry 122 and a processor 124, the individual possible implementations of which may refer to the communication circuitry 112 and the processor 114 and will not be specifically described below.

[0021] In an embodiment of the present invention, the terminal device 11 and the base station 12 can cooperate to implement a cell selection method aimed at by the present invention, the details of which are described below.

[0022] Figure 2 is a flow diagram of a cell selection method according to one embodiment of the present invention. The method of this embodiment may be performed by the terminal device 11 and the base station 12 in Figure 1, and the details of the steps in Figure 2 are presented below together with the components shown in Figure 1.

[0023] In step S222, the base station 12 provides the terminal device 11 with a signal indicator and a network congestion indicator corresponding to the base station 12.

[0024] In one embodiment, the signal indicators corresponding to the base station 12 include signal strength (e.g., SrxLev parameter) and signal quality (e.g., Sqal parameter). In addition, the network congestion indicators corresponding to the base station 12 may include user network throughput as determined by the base station 12. In one embodiment, the user network throughput of the base station 12 may be, for example, but not limited to, user-perceived IP throughput as determined by the base station 12.

[0025] In different embodiments, the base station 12 may use, for example but not limited to, a statistic (eg, average) of the IP throughput perceived by users of all the terminal devices it serves as the corresponding user network throughput.

[0026] In the first embodiment, the user network throughput of the base station 12 is, for example, the current user network throughput determined by the base station 12. For example, assume that the user network throughput determined by the base station 12 at time instant t (t is a time index) is a particular value, and the base station 12 refers to this value as the current user network throughput (T t ) and T t may be provided to the terminal device 11.

[0027] In the second embodiment, the user network throughput of the base station 12 is, for example, a future user network throughput predicted by the base station 12. For example, assuming that the current time is time t, the future user network throughput is the user network throughput at a later time. The following assumptions regarding the future user network throughput corresponding to time (t+1) are for illustrative purposes only and are not intended to limit potential implementations of the present invention.

[0028] In a second embodiment, the base station 12 may provide at least one historical user network throughput to a prediction model (denoted as M). The prediction model M predicts a future user network throughput (T' t+1 (denoted as ).

[0029] In a first variant of the second embodiment, the prediction model M may include a long-term and short-term memory model. In this case, the future user network throughput T' t+1 can be expressed as:

number

[0030] From Equation 1, the prediction model M is the L+1 historical user network throughput (i.e., T t-L ,…,T t ) to calculate the corresponding network throughput as the future user network throughput T' t+1 It can be seen that the prediction can be made as, but not limited to,

[0031] In a second variant of the second embodiment, the prediction model M may include a regression model. In this case, the future user network throughput T't+1 can be expressed as:

number

[0032] Accordingly, in step S212, while performing a cell selection operation with a plurality of reference base stations (eg including base station 12), the terminal device 11 obtains a signal indicator and a network congestion indicator corresponding to each reference base station.

[0033] In an embodiment of the present invention, the reference base station is, for example, a base station that manages the cell to which the terminal device 11 currently belongs (e.g., a serving base station for the terminal device 11), or a base station that manages a cell adjacent to the terminal device 11, but is not limited to this.

[0034] In this case, the signal indicator corresponding to each reference base station includes a signal strength (e.g., SrxLev parameter) and a signal quality (e.g., Sqal parameter), and the network congestion indicator corresponding to each reference base station includes a user network throughput determined by each reference base station (e.g., the current user network throughput T t and / or the future user network throughput T' in the second embodiment. t+1 ).

[0035] In one embodiment, a terminal device 11 in an idle state (e.g., an RRC_IDLE state) or a non-operational state (e.g., an RRC_INACTIVE state) may obtain information on same-frequency cells, different-frequency cells, other-RAT cells, etc. from a current serving base station and perform a cell selection operation accordingly.

[0036] In the embodiments of the present invention, the cell selection operation referred to may be broadly understood to include, but is not limited to, a cell reselection operation.

[0037] Next, in step S214, the terminal device 11 selects a serving base station from the reference base stations based on the signal indicator and the network congestion indicator corresponding to each reference base station.

[0038] In one embodiment, the terminal device 11 may find at least one candidate base station from the reference base station based on a signal indicator corresponding to each of the reference base stations, the signal indicator corresponding to each of the candidate base stations satisfying a preset condition.

[0039] In one embodiment, for one of the reference base stations (hereinafter referred to as the first reference base station), the terminal device 11 may determine whether the first reference base station belongs to the candidate base stations by determining whether the signal strength corresponding to the first reference base station is not less than a signal strength threshold (e.g., 0 dB) and whether the signal quality corresponding to the first reference base station is not less than a signal quality threshold (e.g., 0 dB).

[0040] In response to determining that the signal strength corresponding to the first reference base station is not less than the signal strength threshold and that the signal quality corresponding to the first reference base station is not less than the signal quality threshold, the terminal device 11 may determine that the signal indicator corresponding to the first reference base station satisfies the preset condition. Conversely, in response to determining that the signal strength corresponding to the first reference base station is less than the signal strength threshold or that the signal quality corresponding to the first reference base station is less than the signal quality threshold, the terminal device 11 may determine that the signal indicator corresponding to the first reference base station does not satisfy the preset condition, but is not limited to this.

[0041] In brief, the terminal device 11 may find, but is not limited to, one or more reference base stations whose signal strength is not below a signal strength threshold and whose signal quality is not below a signal quality threshold as candidate base stations.

[0042] The terminal device 11 may then select a serving base station from the candidate base stations based on a network congestion indicator corresponding to each candidate base station.

[0043] In one embodiment, the terminal device 11 may use one or more of the candidate base stations having, for example, but not limited to, the highest user network throughput as the serving base station. For example, assuming that the base station 12 is the candidate base station having the highest user network throughput in addition to satisfying the preset condition, the terminal device 11 may select, for example, but not limited to, the base station 12 as the serving base station.

[0044] The terminal device 11 may then correspondingly perform a subsequent connection procedure (e.g., a random access procedure) with the selected serving base station (e.g., base station 12) to connect to the selected serving base station, but this is not limited to this.

[0045] In summary, the proposed method of the present invention enables the terminal device to select a base station with a more favorable signal strength, signal quality, and network congestion indicator (e.g., highest user network throughput) as the serving base station, thereby avoiding selecting a more congested base station as the serving base station, which enables the terminal device to obtain a more favorable data rate after the cell selection operation, thus improving the user experience.

[0046] It will be apparent to one skilled in the art that various modifications and variations can be made to the disclosed embodiments without departing from the scope or spirit of the invention. In view of the above, it is intended that the present invention cover modifications and variations provided they come within the scope of the appended claims and their equivalents. [Industrial Applicability]

[0047] The cell selection method of the present invention is applicable to any communication system. [Explanation of symbols]

[0048] 10:Communication Systems 11: Terminal device 112, 122: communication circuit 114, 124: Processor 12:Base station S212~S214, S222: Step

Claims

1. A cell selection method applied to a terminal device, comprising: While performing a cell selection operation at a plurality of reference base stations, obtaining a signal indicator and a network congestion indicator corresponding to each of the reference base stations; selecting a serving base station from the reference base stations based on the signal indicator and the network congestion indicator corresponding to each of the reference base stations; Including, the signal indicators corresponding to each of the reference base stations include signal strength and signal quality, and the network congestion indicators corresponding to each of the reference base stations include a user network throughput determined by each of the reference base stations; The user network throughput is a statistical value of IP throughput perceived by users of all terminal devices serviced by each of the reference base stations; the user network throughput is a current user network throughput determined by a first reference base station among the plurality of reference base stations, or a future user network throughput predicted by the first reference base station; method.

2. selecting the serving base station from the reference base stations based on the signal indicator and the network congestion indicator corresponding to each of the reference base stations, Finding at least one candidate base station from the reference base station based on the signal indicator corresponding to each of the reference base stations, where the signal indicator corresponding to each of the candidate base stations satisfies a preset condition; selecting the serving base station from the at least one candidate base station based on the network congestion indicator corresponding to each of the candidate base stations; Including, the network congestion indicator corresponding to each of the reference base stations includes a user network throughput determined by each of the reference base stations, the serving base station having the highest user network throughput of the at least one candidate base station; the reference base station includes a first reference base station, and the signal indicators corresponding to the first reference base station include signal strength and signal quality; The method comprises: determining that the signal indicator corresponding to the first reference base station satisfies the preset condition in response to determining that the signal strength corresponding to the first reference base station is not less than a signal strength threshold and that the signal quality corresponding to the first reference base station is not less than a signal quality threshold; determining that the signal indicator corresponding to the first reference base station does not satisfy the preset condition in response to determining that the signal strength corresponding to the first reference base station is less than the signal strength threshold or that the signal quality corresponding to the first reference base station is less than the signal quality threshold; Further comprising: The method of claim 1.

3. A cell selection method applied to a base station, comprising: providing a signal indicator and a network congestion indicator corresponding to the base station to a terminal device, the signal indicator and the network congestion indicator corresponding to the base station enabling the terminal device to perform a cell selection operation; Including, the signal indicators corresponding to the base station include signal strength and signal quality, and the network congestion indicators corresponding to the base station include user network throughput determined by the base station; The user network throughput is a statistical value of IP throughput perceived by users of all terminal devices served by the base station; the user network throughput is a current user network throughput determined by the base station or a future user network throughput predicted by the base station; method.

4. The method comprises: providing at least one historical user network throughput to a prediction model, said prediction model predicting said future user network throughput as a function of said at least one historical user network throughput; Further comprising: In a first case, the forecast model includes a long and short-term memory model, and the future user network throughput is [0010] where T ｔ－Ｌ , …, T ｔ is the at least one historical user network throughput, L is a time window, t is a time index, and f λ () is the long-short-term memory model, In a second case, the prediction model includes a regression model, and the future user network throughput is [0025] where c ｔ is the random error value, and ε ｔ is a constant, and φ ｉ is the regression coefficient, T ｔ－Ｌ , …, T ｔ is the at least one historical user network throughput, L is a time window, and t is a time index. The method according to claim 3.

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