CN109495890B

CN109495890B - Access method and terminal

Info

Publication number: CN109495890B
Application number: CN201710813359.4A
Authority: CN
Inventors: 王曦泽; 阮航; 王小旭
Original assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Current assignee: China Mobile Communications Group Co Ltd; China Mobile Communications Ltd Research Institute
Priority date: 2017-09-11
Filing date: 2017-09-11
Publication date: 2021-11-19
Anticipated expiration: 2037-09-11
Also published as: CN109495890A

Abstract

The embodiment of the invention relates to an access method and a terminal, wherein the method is applied to the terminal which can be accessed into a first network and a second network, the access priority of the first network is higher than the access priority of the second network, and the method comprises the following steps: receiving a Radio Resource Control (RRC) connection rejection instruction sent by a base station, wherein the RRC connection rejection instruction comprises an indication field; determining the time when the base station sends the RRC connection rejection instruction and the information indicated by an indication field in the RRC connection rejection instruction; if the time and the information indicated by the indication field meet the preset conditions, the indication of the indication field is accepted but the adjustment of the second network access priority is not accepted, the terminal can be prevented from being continuously influenced by the 4G pseudo base station and being accessed to the GSM pseudo base station according to the first network access priority searching signal, the situation that the GSM pseudo base station is accessed due to the fact that the 4G access priority is reduced under certain scenes is prevented, and meanwhile the fact that the flow of the existing network is not interfered is guaranteed.

Description

Access method and terminal

Technical Field

The embodiment of the invention relates to the technical field of communication, in particular to an access method and a terminal.

Background

According to the Long Term Evolution (LTE) protocol, before safety activation, part of NAS (non-access stratum) signaling does not need integrity protection, and an opportunity is provided for development of a 4G (fourth generation mobile communication technology) pseudo base station.

The existing 4G + GSM pseudo base station works as follows:

1) the 4G pseudo base station sets the same CI (cell identification) as the adjacent cell of the cell where the user is located, different TAIs (tracking area identification codes) and larger transmission power to cause the terminal to reselect and request TAUs (tracking area update);

2) establishing RRC (radio resource control) Connection, initiating an RRC Connection establishment request (RRC Connection request) by a terminal, replying RRC Connection request (refusal) by a pseudo base station, wherein the RRC Connection request comprises a priority request IE, and indicating that the GSM access priority is higher than that of LTE;

3) starting a GSM pseudo base station, simulating a current network cell CI, starting high power and setting a large reselection parameter CRO (cell reselection bias);

4) the terminal accesses the GSM pseudo base station, and the pseudo base station sends a short message.

The priority req IE carried in the RRC Connection Reject message is optional, and can indicate an access priority, so that the terminal searches for a network according to the IE, and prioritizes other networks, such as GSM.

Common causes of RRC Connection Reject are:

insufficient code channel resources of the cell, and insufficient code channels are allocated to the UE (terminal);

interference or power limited, soft resource admission failure;

transmission resource application or bandwidth admission failure.

The multi-user cell admission control situation will issue the instruction.

Other common schemes for accessing the GSM pseudo base station by the 4G terminal include that a TAU Reject message or an RRC Connection Release (RRC Connection Release) includes a GSM redirection indication, and related prevention schemes are discussed in organizations such as 3GPP at present, for example, GSM frequency points are not indicated in the RRC Connection Release after the TAU Reject, but the above-mentioned method of accessing the GSM pseudo base station by the RRC Connection rejection Release is not covered yet, so that the terminal may still be induced by the 4G pseudo base station to access the GSM pseudo base station.

Disclosure of Invention

An object of the embodiments of the present invention is to provide an access method and a terminal, which solve the problem that the terminal is affected by a pseudo base station.

In a first aspect, an access method is provided, which is applied to a terminal capable of accessing a first network and a second network, where the first network access priority is higher than the second network access priority, and the method includes:

receiving a Radio Resource Control (RRC) connection rejection instruction sent by a base station, wherein the RRC connection rejection instruction comprises an indication field;

determining the time when the base station sends the RRC connection rejection instruction and information indicated by an indication field in the RRC connection rejection instruction;

and if the time and the information indicated by the indication field meet the preset condition, accepting the indication of the indication field but not accepting to adjust the second network access priority, and searching signals according to the first network access priority.

Optionally, the method further comprises:

and if the time and the information indicated by the indication field do not meet the preset condition, receiving the indication of the indication field, improving the second network access priority, and searching signals according to the second network access priority.

Optionally, the predetermined condition comprises:

the RRC connection rejection instruction is issued after a non-access stratum (NAS) request; and is

And an indication field in the RRC connection rejection instruction indicates that the second network access priority is improved.

Optionally, the indication field is a depriorityReq IE.

Optionally, the first network is a fourth generation mobile communication technology 4G network, and the second network is a global system for mobile communications GSM network.

In a second aspect, a terminal is provided, which is capable of accessing a first network and a second network, the first network access priority being higher than the second network access priority, and includes:

a network interface, configured to receive a radio resource control RRC connection rejection instruction sent by a base station, where the RRC connection rejection instruction includes an indication field;

a processor, configured to determine a time when the base station sends the RRC connection rejection instruction and information indicated by an indication field in the RRC connection rejection instruction; and if the time and the information indicated by the indication field meet a predetermined condition, accepting the indication of the indication field but not accepting adjustment of a second network access priority, and instructing the network interface to search for a signal according to the first network access priority.

Optionally, the processor is further configured to:

and if the time and the information indicated by the indication field do not meet the preset condition, receiving the indication of the indication field, improving the second network access priority, and indicating the network interface to search signals according to the second network access priority.

Optionally, the predetermined condition comprises:

In a third aspect, a terminal is further provided, including: a processor, a memory and an access program stored on the memory and executable on the processor, the access program, when executed by the processor, implementing the steps of the access method according to the first aspect.

In a fourth aspect, there is also provided a computer readable storage medium having stored thereon an access program which, when executed by a processor, implements the steps of the access method according to the first aspect.

In the prior art, the 4G pseudo base station can be controlled by various means to access the terminal reselecting the 4G pseudo base station to the GSM pseudo base station, and the access method of the embodiment of the invention can avoid the situation that the terminal is continuously influenced by the 4G pseudo base station and is accessed to the GSM pseudo base station, thereby preventing the terminal from being accessed to the GSM pseudo base station due to the fact that the 4G access priority is reduced in certain scenes, simultaneously ensuring that the current network flow is not interfered, and preventing the problem of the normal flow caused by RRC Connetion Reject message.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a hardware diagram of a mobile phone according to an embodiment of the present invention;

fig. 2 is a flowchart of an access method according to an embodiment of the present invention;

FIG. 3 is a timing diagram of an access method according to an embodiment of the present invention;

fig. 4 is one of the structural block diagrams of the terminal according to the embodiment of the present invention;

fig. 5 is a second block diagram of the terminal according to the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "comprises," "comprising," and "having," and any variations thereof, in the description and claims of this invention, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The terms "first" and "second," and the like, in the description and in the claims of embodiments of the present invention are used for distinguishing between different objects and not for describing a particular order of the objects. For example, the first data and the second data are for distinguishing different data, not for describing a specific order of data.

In the embodiments of the present invention, words such as "exemplary" or "for example" are used to mean serving as examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "e.g.," an embodiment of the present invention is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

The terminal provided by the embodiment of the invention can be a mobile phone, a tablet computer, a notebook computer, an ultra-mobile personal computer (UMPC), a netbook or a Personal Digital Assistant (PDA), and the like.

Illustratively, in the embodiment of the present invention, a terminal is taken as a mobile phone as an example, and a hardware structure of the terminal is introduced. The following describes each component of the mobile phone provided by the embodiment of the present invention with reference to fig. 1.

As shown in fig. 1, a mobile phone provided in an embodiment of the present invention includes: a processor 10, a Radio Frequency (RF) circuit 11, a power supply 12, a memory 13, an input unit 14, a display unit 15, and an audio circuit 16. Those skilled in the art will appreciate that the configuration of the handset shown in fig. 1 does not constitute a limitation of the handset, and may include more or fewer components than those shown in fig. 1, or may combine some of the components shown in fig. 1, or may be arranged differently than those shown in fig. 1.

The processor 10 is the control center of the handset and connects the various parts of the entire handset using various interfaces and lines. The overall monitoring of the mobile phone is performed by executing or executing software programs and/or modules stored in the memory 13 and calling data stored in the memory 13 to perform various functions of the mobile phone and process the data. Alternatively, processor 10 may include one or more processing units. Optionally, the processor 10 may integrate an application processor and a modem processor, wherein the application processor mainly processes an operating system, a user interface, an application program, and the like; the modem processor handles primarily wireless communications. It will be appreciated that the modem processor described above may also be a processor separate from the processor 10.

The RF circuit 11 may be used to receive and transmit signals during the transmission and reception of information or during a call. For example, the downlink information of the base station is received and then processed by the processor 10; in addition, the uplink data is transmitted to the base station. Typically, the RF circuit includes, but is not limited to, an antenna, at least one amplifier, a transceiver, a coupler, a Low Noise Amplifier (LNA), and a duplexer. In addition, the handset can also communicate wirelessly with other devices in the network via the RF circuit 11. The wireless communication may use any communication standard or protocol, including but not limited to global system for mobile communications (GSM), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Wideband Code Division Multiple Access (WCDMA), LTE, email, and Short Messaging Service (SMS), among others.

The power supply 12 may be used to power various components of the handset, and the power supply 12 may be a battery. Optionally, the power supply may be logically connected to the processor 10 through a power management system, so as to implement functions of managing charging, discharging, power consumption management, and the like through the power management system.

The memory 13 may be used to store software programs and/or modules, and the processor 10 executes various functional applications and data processing of the mobile phone by operating the software programs and/or modules stored in the memory 13. The memory 13 may mainly include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data (such as audio data, image data, a phonebook, etc.) created according to the use of the cellular phone, and the like. Further, the memory 13 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device.

The input unit 14 may be used to receive input numeric or character information and generate key signal inputs related to user settings and function control of the cellular phone. Specifically, the input unit 14 may include a touch screen 141 and other input devices 142. The touch screen 141, also referred to as a touch panel, may collect touch operations of a user (e.g., operations of the user on or near the touch screen 141 using any suitable object or accessory such as a finger, a stylus, etc.) thereon or nearby, and drive the corresponding connection device according to a preset program. Alternatively, the touch screen 141 may include two parts of a touch detection device and a touch controller. The touch detection device detects the touch direction of a user, detects a signal brought by touch operation and transmits the signal to the touch controller; the touch controller receives touch information from the touch sensing device, converts the touch information into touch point coordinates, sends the touch point coordinates to the processor 10, and can receive and execute commands sent by the processor 10. In addition, the touch screen 141 may be implemented in various types, such as a resistive type, a capacitive type, an infrared ray, and a surface acoustic wave. Other input devices 142 may include, but are not limited to, one or more of a physical keyboard, function keys (such as volume control keys, power switch keys, etc.), a trackball, a mouse, and a joystick.

The display unit 15 may be used to display information input by the user or information provided to the user and various menus of the mobile phone. The display unit 15 may include a display panel 151. Alternatively, the display panel 151 may be configured in the form of a Liquid Crystal Display (LCD), an organic light-emitting diode (OLED), or the like. Further, the touch screen 141 may cover the display panel 151, and when the touch screen 141 detects a touch operation thereon or nearby, it is transmitted to the processor 10 to determine the type of the touch event, and then the processor 10 provides a corresponding visual output on the display panel 151 according to the type of the touch event. Although the touch screen 141 and the display panel 151 are shown as two separate components in fig. 1 to implement the input and output functions of the mobile phone, in some embodiments, the touch screen 141 and the display panel 151 may be integrated to implement the input and output functions of the mobile phone.

Audio circuitry 16, a speaker 161 and a microphone 162 to provide an audio interface between the user and the handset. In one aspect, the audio circuit 16 may transmit the converted electrical signal of the received audio data to the speaker 161, and convert the electrical signal into an audio signal for output by the speaker 161. On the other hand, the microphone 162 converts the collected sound signal into an electrical signal, converts the electrical signal into audio data after being received by the audio circuit 16, and outputs the audio data to the RF circuit 11 through the processor 10 to be transmitted to, for example, another cellular phone, or outputs the audio data to the memory 13 through the processor 10 for further processing.

Optionally, the handset as shown in fig. 1 may also include various sensors. Such as gyroscope sensors, hygrometer sensors, infrared sensors, magnetometer sensors, etc., and will not be described in detail herein.

Optionally, the mobile phone shown in fig. 1 may further include a Wi-Fi module, a bluetooth module, and the like, which are not described herein again.

Referring to fig. 2, a flow of an access method is shown, where the method is applied to a terminal capable of accessing a first network and a second network, and an access priority of the first network is higher than an access priority of the second network, and the method includes the following specific steps:

step 201, receiving an RRC (radio resource control) connection rejection command sent by a base station, where the RRC connection rejection command includes an indication field;

step 202, determining the time when the base station sends the RRC connection rejection command and information indicated by an indication field in the RRC connection rejection command;

and step 203, if the time and the information indicated by the indication field meet the preset conditions, receiving the indication of the indication field but not receiving the adjustment of the second network access priority, and searching the signal according to the first network access priority.

The signal is searched according to the first network access priority, that is, the first network is accessed preferentially.

In an alternative embodiment, the predetermined conditions include: the RRC connection rejection instruction is issued after the non-access stratum NAS request; and an indication field in the RRC connection rejection instruction indicates that the second network access priority is raised.

Alternatively, the NAS request may be: TAU Request (tracking area update Request) or Attch Request (attach Request).

Optionally, the indication field is a depriorityReq IE.

In an alternative embodiment, the first network is a 4G network and the second network is a GSM network, but the invention is not limited thereto.

In the embodiment of the present invention, optionally, the method further includes step 204.

And 204, if the time and the information indicated by the indication field do not meet the preset condition, receiving the indication of the indication field, improving the second network access priority, and searching signals according to the second network access priority.

The signal is searched according to the second network access priority, namely, the second network is accessed preferentially.

Referring to fig. 3, a terminal sends a TAU Request to a base station, the base station sends the TAU Request to an MME (mobility management entity), the terminal sends an RRC Connection establishment Request to the base station, and the base station replies an RRC Connection establishment Request, which includes a priority req IE. If the priority req IE indicates to raise the GSM access priority, the terminal replies the terminal accept message to the base station, but does not adjust the GSM priority according to the priority req IE indication.

Referring to fig. 4, there is shown a structure of a terminal capable of accessing a first network and a second network, the first network access priority being higher than the second network access priority, the terminal comprising:

a network interface 401, configured to receive a radio resource control RRC connection rejection instruction sent by a base station, where the RRC connection rejection instruction includes an indication field;

a processor 402, configured to determine a time when the base station sends the RRC connection rejection instruction and information indicated by an indication field in the RRC connection rejection instruction; and if the time and the information indicated by the indication field meet a predetermined condition, accepting the indication of the indication field but not accepting adjustment of a second network access priority, and instructing the network interface to search for a signal according to the first network access priority.

In this embodiment of the present invention, optionally, the processor 402 is further configured to:

In an embodiment of the present invention, the predetermined condition includes:

The terminal provided in this embodiment may execute the method embodiments described above, and the implementation principle and technical effect are similar, which are not described herein again.

Fig. 5 is a schematic structural diagram of a terminal according to another embodiment of the present invention. As shown in fig. 5, the terminal 500 shown in fig. 5 includes: at least one processor 501, memory 502, at least one network interface 504, and a user interface 503. The various components in terminal 500 are coupled together by a bus system 505. It is understood that the bus system 505 is used to enable connection communications between these components. The bus system 505 includes a power bus, a control bus, and a status signal bus in addition to a data bus. For clarity of illustration, however, the various buses are labeled as bus system 505 in FIG. 5.

The user interface 503 may include, among other things, a display, a keyboard, or a pointing device (e.g., a mouse, trackball, touch pad, or touch screen, among others.

It is to be understood that the memory 502 in embodiments of the present invention may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile Memory may be a Read-Only Memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash Memory. Volatile Memory can be Random Access Memory (RAM), which acts as external cache Memory. By way of illustration and not limitation, many forms of RAM are available, such as Static random access memory (Static RAM, SRAM), Dynamic Random Access Memory (DRAM), Synchronous Dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic random access memory (ddr Data Rate SDRAM, ddr SDRAM), Enhanced Synchronous SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 502 of the subject systems and methods described in connection with the embodiments of the invention is intended to comprise, without being limited to, these and any other suitable types of memory.

In some embodiments, memory 502 holds the following elements, executable modules or data structures, or a subset thereof, or an expanded set thereof: an operating system 5021 and application programs 5022.

The operating system 5021 includes various system programs, such as a framework layer, a core library layer, a driver layer, and the like, and is used for implementing various basic services and processing hardware-based tasks. The application 5022 includes various applications, such as a Media Player (Media Player), a Browser (Browser), and the like, for implementing various application services. The program for implementing the method according to the embodiment of the present invention may be included in the application program 5022.

In the embodiment of the present invention, by calling the program or the instruction stored in the memory 502, specifically, the program or the instruction stored in the application 5022, the following steps are implemented when the program or the instruction is executed: receiving a Radio Resource Control (RRC) connection rejection instruction sent by a base station, wherein the RRC connection rejection instruction comprises an indication field; determining the time when the base station sends the RRC connection rejection instruction and information indicated by an indication field in the RRC connection rejection instruction; and if the time and the information indicated by the indication field meet the preset condition, accepting the indication of the indication field but not accepting to adjust the second network access priority, and searching signals according to the first network access priority.

The method disclosed by the above-mentioned embodiments of the present invention may be applied to the processor 501, or implemented by the processor 501. The processor 501 may be an integrated circuit chip having signal processing capabilities. In implementation, the steps of the above method may be performed by integrated logic circuits of hardware or instructions in the form of software in the processor 501. The Processor 501 may be a general-purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, or discrete hardware components. The various methods, steps and logic blocks disclosed in the embodiments of the present invention may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present invention may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules may be located in ram, flash memory, rom, prom, or eprom, registers, or other storage media as is known in the art. The storage medium is located in the memory 502, and the processor 501 reads the information in the memory 502 and completes the steps of the method in combination with the hardware.

It is to be understood that the embodiments described herein may be implemented in hardware, software, firmware, middleware, microcode, or any combination thereof. For a hardware implementation, the Processing units may be implemented in one or at least two Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), general purpose processors, controllers, micro-controllers, microprocessors, other electronic units configured to perform the functions described herein, or a combination thereof.

For a software implementation, the techniques described in this disclosure may be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described in this disclosure. The software codes may be stored in a memory and executed by a processor. The memory may be implemented within the processor or external to the processor.

An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored, where the computer program, when executed by a processor, implements the steps in the method for applying automatic update.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to perform all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned preservation medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. An access method applied to a terminal capable of accessing a first network and a second network, the first network access priority being higher than the second network access priority, the method comprising:

if the time and the information indicated by the indication field meet the preset condition, accepting the indication of the indication field but not accepting to adjust the second network access priority, and searching signals according to the first network access priority;

the predetermined conditions include:

2. The method of claim 1, further comprising:

3. The method of claim 1, wherein the indication field is a depriorityReq IE.

4. The method of claim 1, wherein the first network is a fourth generation mobile communication technology 4G network and the second network is a Global System for Mobile communications (GSM) network.

5. A terminal capable of accessing a first network and a second network, the first network access priority being higher than the second network access priority, comprising:

a processor, configured to determine a time when the base station sends the RRC connection rejection instruction and information indicated by an indication field in the RRC connection rejection instruction; and if the time and the information indicated by the indication field meet a predetermined condition, accepting the indication of the indication field but not accepting adjustment of a second network access priority, and instructing the network interface to search for a signal according to the first network access priority;

the predetermined conditions include:

6. The terminal of claim 5, wherein the processor is further configured to:

7. A terminal, comprising: processor, memory and an access program stored on the memory and executable on the processor, the access program, when executed by the processor, implementing the steps of the access method according to any one of claims 1 to 4.

8. A computer-readable storage medium, characterized in that the computer-readable storage medium has stored thereon an access program which, when executed by a processor, carries out the steps of the access method according to any one of claims 1 to 4.