阅读说明：本技术 一种基于云卡的数字对讲系统及方法 (Digital intercom system and method based on cloud card ) 是由 姚忠邦 卢浩杰 何达峰 郑志伟 卢宏游 付文良 于 2020-05-27 设计创作，主要内容包括：本发明提供了一种基于云卡的数字对讲系统及方法,包括云卡平台、PoC对讲平台和PoC数字对讲机；云卡平台对接全球多个运营商网络形成共享的数据流量池,且云卡平台通过公网网络分别与PoC对讲平台和PoC数字对讲机建立连接,通过云服务的方式为PoC对讲业务提供数据流量,PoC数字对讲机与PoC对讲平台连接以实现PoC对讲业务；云卡平台具有服务器、SIM卡库和云卡软件。本发明基于云卡平台使得PoC对讲机可根据其所处位置的多个运营商之PLMN、信号强度等参数选择最优的本地移动运营商网络,从而既可以实现更大范围的覆盖,又可以选择信号最优的运营商网络,并且各个PoC数字对讲机可实现数据流量的共享。(The invention provides a cloud card-based digital intercom system and a cloud card-based digital intercom method, which comprise a cloud card platform, a PoC intercom platform and PoC digital interphones, wherein the cloud card platform is connected with a plurality of global operator networks to form a shared data flow pool, the cloud card platform is respectively connected with the PoC intercom platform and the PoC digital interphones through a public network, data flow is provided for PoC intercom service in a cloud service mode, the PoC digital interphones are connected with the PoC intercom platform to realize the PoC intercom service, the cloud card platform is provided with a server, an SIM card library and cloud card software, the PoC interphones can select the optimal local mobile operator network according to parameters such as P L MN, signal strength and the like of the plurality of operators at the positions of the PoC interphones based on the cloud card platform, so that the coverage of a larger range can be realized, the PoC operator network with the optimal signal can be selected, and the PoC digital interphones can realize the sharing of the data flow.)

1. A PoC digital intercom system based on a cloud card is characterized by comprising a cloud card platform (1), a PoC intercom platform (2) and a PoC digital interphone (3); wherein the content of the first and second substances,

the cloud card platform (1) is in butt joint with a plurality of global operator networks (4) to form a shared data flow pool, the cloud card platform (1) is respectively connected with the PoC intercommunication platform (2) and the PoC digital interphone (3) through a public network, and the PoC digital interphone (3) is connected with the PoC intercommunication platform (2) to realize PoC service;

the cloud card platform (1) is provided with a server, an SIM card library and cloud card software, the server and the SIM card library are placed in a machine room of a cloud service provider, the cloud card software is embedded into a PoC digital interphone (3), the PoC digital interphone (3) realizes communication of all global operator networks in butt joint with the cloud card platform (1) based on the cloud card software, and is connected with the PoC talkback platform (2) so as to realize talkback communication based on cloud card data flow;

the PoC digital interphone (3) is internally provided with a hardware platform and cloud card software, and the PoC digital interphone (3) is in butt joint with the cloud card platform (1) by running an operating system software, a driving software and the cloud card software on the hardware platform; the PoC digital interphone (3) realizes the butt joint with the PoC talkback platform (2) and a man-machine interface by running PoC application software on a hardware platform.

2. The cloud card-based digital intercom system according to claim 1, wherein the cloud card is an SIM card mirror image file corresponding to an entity SIM card in an SIM card library of the cloud card platform (1), and user identification in the process of using operator network communication is realized through cloud card software built in the PoC digital intercom (3); when the PoC digital interphone (3) is a single-card interphone, the single-card interphone has a unique IMEI/MEID identification code, and the IMEI/MEID identification code can correspond to a plurality of cloud cards.

3. The digital intercom system based on the cloud card as claimed in claim 1, wherein the PoC intercom platform (2) is a service platform built in a public network for realizing voice or short message intercom, and comprises a network management system, a PoC server system and a scheduling system which are connected in pairs; the network management system, the PoC server system and the dispatching system realize public network talkback services through communication protocols and signaling exchange, and the public network talkback services comprise digital signaling services in conventional talkback for realizing multiple talkback calls of group call, individual call, full call and broadcast call of voice/short messages, and alarming, telepronous shooting, telephoning, remote monitoring, environment monitoring and forced disconnection and forced insertion;

the network management system is used for authentication management, configuration management and grouping management of the PoC digital interphone (3) and providing basic data of the PoC digital interphone (3) for the PoC server system;

the PoC server system is used for signaling control of the PoC digital interphone (3) and realizing the voice soft switching talkback service;

the dispatching system is used for commanding a dispatching client user of a dispatching center to acquire the equipment data of the PoC digital interphone (3) in real time on a computer host, comprises the information of position information, online state, electric quantity and signal strength, and can initiate calling and control on the PoC digital interphone (3).

4. A cloud card based digital intercom system as in claim 1 wherein the running platform of PoC digital intercom (3) is mobile intelligent operating system or any embedded operating system using 2G/3G/4G/5G public network hardware platform.

5. A cloud card based digital intercom system as in claim 1 wherein the hardware platform of the PoC digital intercom (3) is capable of directly controlling access to the 2G/3G/4G/5G public network.

6. A cloud card based digital intercom system as in claim 1 wherein PoC digital intercom (3) is automatically switched to the operator network with the best signal quality.

7. A digital intercom method using the cloud card-based digital intercom system according to any one of claims 1 to 6, characterized in that said digital intercom method comprises the steps of:

step S1): the PoC digital interphone (3) judges whether an entity SIM card exists;

if there is a physical SIM card, go to step S2); if there is no physical SIM card, go to step S5);

step S2): judging whether the preset of the PoC digital interphone (3) is that the entity SIM takes precedence or the cloud card takes precedence;

if the preset is entity SIM priority, then go to step S3);

if the preset is the cloud card priority, the step S5 is carried out);

step S3): if the entity SIM card priority is preset, the entity SIM card is directly used for logging in an operator network, and the cloud card service is not used;

step S4): the PoC digital interphone (3) uses the SIM card to access the operator network and judges whether the PoC digital interphone (3) arrears the flow;

if the flow rate is owed, the flow proceeds to step S8); otherwise, go to step S9);

step S5): the cloud card priority is preset, and no matter whether an entity SIM card exists or not, the locally stored seed SIM card is directly used for logging in a cloud card platform (1);

step S6), the cloud card platform (1) determines the optimal operator that should be selected by the PoC digital interphone (3) according to the received P L MN of each operator and the signal strength information parameter provided by the PoC digital interphone (3), and provides the SIM card mirror image file of the operator to the PoC digital interphone (3);

step S7): the PoC digital interphone (3) uses the cloud card to log in and access the operator network, and judges whether the PoC digital interphone (3) arrears the flow;

if the flow rate is owed, the flow proceeds to step S8); otherwise, go to step S9);

step S8): the PoC digital interphone (3) is in flow arrearage, prompts arrearage information, reminds a user to pay and finishes;

step S9): the PoC digital interphone (3) directly logs in the PoC intercommunication platform (2);

step S10): the PoC digital interphone (3) judges whether the ID of the interphone is in PoC service arrearage or not through the feedback information when the PoC talkback platform (2) logs in;

if the PoC service arrears, prompting arrearage information, reminding the user to pay and ending; otherwise, go to step S11);

step S11): the PoC digital interphone (3) downloads the talkback information of the local machine to the local machine from the PoC talkback platform (2);

step S12): the PoC digital interphone (3) runs the PoC talkback service;

step S13), the PoC digital interphone (3) judges whether the power is low; if yes, ending the PoC service software, and shutting down the power supply; otherwise, returning to step S12) to continue running the PoC talk service.

Technical Field

The invention belongs to the technical field of digital talkback, and particularly relates to a digital talkback system and a digital talkback method based on a cloud card.

Background

The existing digital intercom system mainly has two modes of realizing intercom based on a wireless private network standard and based on public network data traffic.

The problems of the wireless private network intercom system mainly include: 1) the talkback range is limited, no matter a direct mode without a transfer platform and a private network base station or a transfer and cluster mode with the transfer platform and the private network base station is adopted, the reliable talkback range between the digital interphones is limited, and the talkback service cannot be realized in places which cannot be covered; 2) professional terminals are high in price, and especially private network cluster digital interphones are high in price, so that many common users have to consider the public network digital interphones with lower cost; 3) the infrastructure maintenance cost is high, and because the number of actual interphone users is poor compared with the number of public network mobile phones and the users are used by themselves, under the condition of adopting private network infrastructures such as a transfer platform and a base station, the users have to spend a large amount of cost and expense on maintaining the network.

Obviously, the public network digital interphone has obvious advantages compared with the private network digital interphone, such as: the cost is low, the coverage is wide (as long as there is public network basic station of operator can realize normal talkback), but this type digital intercom also has obvious shortcoming, mainly includes: 1) the digital interphone terminal is complex in setting, such as: different operators in different countries need to set different APNs, and particularly, the simple digital interphone without the display screen and the digital keyboard is more complex without intelligent operating systems such as Android and the like and display screens; 2) the problem of charge renewal in this mode is caused by the problems related to the operator traffic charge and the use charge of the PoC talkback platform, which is completely different from the use mode of the private network digital interphone; 3) once an operator is selected, the problem of poor coverage of the base stations of the individual operators in some places is still encountered; 4) if the public network interphone simultaneously uses 2 SIM cards to select 2 public network operators, the problems of high data flow charge and manual selection of different SIM cards for talkback are involved; 5) when the ordinary PoC public network digital intercom system is adopted, the transaction mode between an intercom system manufacturer and a client becomes more complex, and the two-party transaction (intercom system manufacturer and client) becomes three-party or four-party transaction (intercom system manufacturer, client, public network operator and PoC intercom platform operator), so that the client is daunting on the transaction mode, and the development of the PoC public network intercom industry is hindered to a certain extent.

Disclosure of Invention

In order to solve the defects of the prior art, the invention aims to provide a digital intercom system and method based on a cloud card to overcome the defects in the prior art.

In order to achieve the above object, the present invention provides a cloud card based digital intercom system, comprising a cloud card platform, a PoC intercom platform and a PoC digital intercom; the cloud card platform is connected with a plurality of global operator networks in an interfacing manner to form a shared data flow pool, the cloud card platform is respectively connected with the PoC talkback platform and the PoC digital interphone through a public network, and the PoC digital interphone is connected with the PoC talkback platform to realize PoC talkback service; the cloud card platform is provided with a server, an SIM card library and cloud card software, the server and the SIM card library are placed in a machine room of a cloud service provider, the cloud card software is embedded into a PoC digital interphone, the PoC digital interphone realizes communication of all global operator networks in butt joint with the cloud card platform based on the cloud card software, and is connected with the PoC talkback platform so as to realize talkback communication based on cloud card data flow; the PoC digital interphone is internally provided with a hardware platform and cloud card software, realizes the butt joint with the cloud card platform by running an operating system software, a driving software and the cloud card software on the hardware platform of the PoC digital interphone, and realizes the butt joint with the PoC talkback platform and a man-machine interface by running a PoC application software on the hardware platform of the PoC digital interphone.

Through the technical scheme, the cloud card platform unifies various SIM cards from various operators all over the world into the cloud card by utilizing the virtualization technology of the SIM cards and the Internet and the cloud computing technology to form a shared data traffic pool, provides data traffic for the PoC talkback service in a cloud service mode, and adopts the shared data traffic of the cloud card platform, so that the PoC digital interphone can use the shared data traffic of a plurality of operators to realize the sharing of the data traffic, and can avoid the situation that the traffic of some users is excessive to cause waste and the traffic of other users is insufficient, thereby further saving traffic cost; the coverage of a larger range can be realized, and the coverage range of the base stations of all operators docked by the cloud card platform can be expanded; and complex operations such as SIM card purchase, APN setting and the like are not required to be carried out with operators, so that the 'instant use when starting up' is realized, and the use and maintenance cost of the PoC public network interphone is simplified.

As a further description of the cloud card-based digital intercom system of the present invention, preferably, the cloud card is an SIM card mirror image file corresponding to an entity SIM card in an SIM card library of a cloud card platform, and the cloud card software built in the PoC digital intercom realizes the user identity identification in the process of using the operator network for communication. For a single card PoC digital interphone, the PoC digital interphone has a unique IMEI/MEID identification code which can correspond to a plurality of cloud cards.

Through the technical scheme, the PoC digital interphone does not need to install an entity SIM card, set APN and other complex operations, and the use of the PoC digital interphone is greatly simplified.

As a further explanation of the cloud card-based digital intercom system of the present invention, preferably, the PoC intercom platform is a service platform that is built in a public network and implements voice/short message intercom, and includes a network management system, a PoC server system and a scheduling system that are connected in pairs, where the network management system, the PoC server system and the scheduling system implement public network intercom services through a set of complete communication protocol and signaling exchange, including implementing multiple intercom calls such as voice/short message group call, individual call, full call, broadcast call, and digital signaling services in conventional intercom such as alarm, telephotography, remote kill, wakeup, remote monitor, environmental monitor, forced release and forced insertion; the network management system is used for authentication management, configuration management and grouping management of the PoC digital interphone and providing basic data of the PoC digital interphone for the PoC server system; the PoC server system is used for realizing the signaling control and the voice soft switching talkback service of the PoC digital interphone; the dispatching system is used for commanding a dispatching client user of the control center to acquire equipment data of the PoC digital interphone in real time on a computer host, wherein the equipment data comprises information such as position information, online state, electric quantity, signal strength and the like, and can initiate calling and control on the PoC digital interphone.

Through the technical scheme, the PoC intercommunication platform can realize PoC intercommunication service of the PoC digital interphone and realize the function of recording PoC digital interphone intercommunication information.

As a further description of the cloud card-based digital intercom system of the present invention, preferably, the running platform of the PoC digital intercom is a mobile intelligent operating system or any embedded operating system that employs a 2G/3G/4G/5G public network hardware platform.

By the technical scheme, the butt joint of the PoC digital interphone, the PoC talkback platform and the cloud card platform can be realized.

As a further description of the cloud card-based digital intercom system of the present invention, preferably, the running platform of the PoC digital intercom is a 2G/3G/4G/5G public network hardware platform, and the hardware platform can run an intelligent operating system or any embedded operating system. In some practical implementations of the PoC digital walkie-talkie, the hardware platform may also be additionally added with an MCU hardware platform, and the MCU hardware platform runs an intelligent operating system or any embedded operating system.

By the technical scheme, the butt joint of the PoC digital interphone, the PoC talkback platform and the cloud card platform can be realized.

As a further description of the cloud card based digital intercom system of the present invention, preferably, the hardware platform of the PoC digital intercom is capable of directly controlling access to the 2G/3G/4G/5G public network.

Through the technical scheme, the direct access to the 2G/3G/4G/5G public network enables the PoC digital interphone using the cloud card platform without SIM card to work normally.

As a further description of the cloud card based digital intercom system of the present invention, preferably, the PoC digital intercom may automatically switch to the operator network with the best signal quality.

In order to achieve another object of the present invention, the present invention also provides a digital intercom method using the cloud card-based digital intercom system, the digital intercom method comprising the steps of:

step S1), the PoC digital interphone judges whether an entity SIM card exists; if there is a physical SIM card, go to step S2); if there is no physical SIM card, go to step S5);

step S2), judging whether the preset of the PoC digital interphone is that the entity SIM takes precedence or the cloud card takes precedence; if the preset is entity SIM priority, then go to step S3); if the preset is the cloud card priority, the step S5 is carried out);

step S3), if the entity SIM card priority is preset, the entity SIM card is directly used for logging in the operator network, and the cloud card service is not used any more;

step S4), the PoC digital interphone uses the SIM card to access the operator network and judges whether the PoC digital interphone arrears the flow; if the flow rate is owed, the flow proceeds to step S8); otherwise, go to step S9);

step S5), the cloud card priority is preset, and no matter whether a solid SIM card exists or not, the locally stored seed SIM card is directly used for logging in the cloud card platform;

step S6), the cloud card platform determines the optimal operator that the PoC digital interphone should select according to the received P L MN of each operator and the signal strength information parameter provided by the PoC digital interphone, and provides the SIM card image file (namely cloud card) of the operator to the PoC digital interphone;

step S7), the PoC digital interphone uses the cloud card to log in and access the operator network, and judges whether the PoC digital interphone arrears the flow; if the flow rate is owed, the flow proceeds to step S8); otherwise, go to step S9);

step S8), the PoC digital interphone flow arrears, prompts arrearage information, reminds the user to pay and ends;

step S9), the PoC digital interphone directly logs in the PoC intercommunication platform;

step S10), the PoC digital interphone judges whether the ID of the local machine is in PoC service arrearage through the feedback information when the PoC intercommunication platform logs in; if the PoC service arrears, prompting arrearage information, reminding the user to pay and ending; otherwise, go to step S11);

step S11), the PoC digital interphone downloads the talkback information of the local machine to the local machine from the PoC talkback platform;

step S12), the PoC digital interphone runs the PoC intercommunication service;

step S13), the PoC digital interphone judges whether the power is low; if yes, ending the PoC service software, and shutting down the power supply; otherwise, returning to step S12) to continue running the PoC talk service.

The invention has the beneficial effects that:

1. the invention adopts the 'shared data flow' of the cloud card platform, thereby enabling the PoC intercom system to use the 'shared data flow' of a plurality of operators, realizing the sharing of the 'data flow', avoiding the situation that 'the flow of some users is excessive to cause waste and the flow of other users is insufficient', and further saving the flow cost.

2. The PoC digital interphone can use networks of multiple operators through a cloud card platform, thereby realizing wider coverage without complex operations such as SIM card installation, APN setting and the like, and can automatically switch to the operator network with the best signal quality when the signal quality is poor.

3. The PoC public network digital intercommunication product transaction mode of the invention can directly realize the transaction between a manufacturer and a client, and the client does not need to purchase SIM cards, purchase data traffic and other transactions with an operator.

Drawings

Fig. 1 is a schematic structural diagram of a cloud card-based digital intercom system of the present invention.

Fig. 2 is a block diagram of the PoC digital interphone of the present invention.

Fig. 3 is a flowchart of a cloud card-based digital intercom method of the present invention.

Detailed Description

To further understand the structure, characteristics and other objects of the present invention, the following detailed description is given with reference to the accompanying preferred embodiments, which are only used to illustrate the technical solutions of the present invention and are not to limit the present invention.

First, referring to fig. 1, fig. 1 is a schematic structural diagram of a cloud card-based digital intercom system of the present invention. As shown in fig. 1, the digital intercom system based on the cloud card of the present invention includes a cloud card platform 1, a PoC intercom platform 2 and a PoC digital intercom 3; the cloud card platform 1 is connected with a plurality of global operator networks in a butt joint mode to form a shared data flow pool, the cloud card platform 1 is connected with the PoC talkback platform 2 and the PoC digital interphone 3 through a public network, and the PoC digital interphone 3 is connected with the PoC talkback platform 2 to achieve PoC service.

The cloud card platform 1 is provided with a server, an SIM card library and cloud card software, the server and the SIM card library are placed in a machine room of a cloud service provider, the cloud card software is embedded into the PoC digital interphone 3, and the PoC digital interphone 3 can realize communication of all global operator networks in butt joint with the cloud card platform based on the cloud card software and is connected with the PoC talkback platform so as to realize talkback communication based on cloud card data flow. The cloud card platform 1 is generally responsible for research, development, operation and maintenance by a special cloud card operator, and the organization will purchase enough SIM cards and traffic from various mobile public network operators all over the world to form a common cloud card traffic pool. The cloud card platform operator generally sells a self-owned terminal or a flow package of the cloud card to the customer for use. The cloud card platform 1 unifies various SIM cards originated from various operators all over the world into a cloud card by using the virtualization technology of the SIM card and utilizing the Internet and the cloud computing technology to form a shared data flow pool and provide data flow for the PoC intercommunication service in a cloud service mode, wherein the cloud card is an SIM card mirror image file corresponding to an entity SIM card in an SIM card library of the cloud card platform 1, and the user identity identification in the network communication process of the operators is realized by cloud card software built in the PoC digital interphone 3. For a single card PoC digital interphone, the PoC digital interphone has a unique IMEI/MEID identification code which can correspond to a plurality of cloud cards.

The PoC intercommunication platform 2 is a service platform which is built in a public network and realizes voice/short message intercommunication, and comprises a network management system and a dispatching system of a PoC server system which are connected in pairs, the network management system, the PoC server system and the dispatching system realize the public network intercommunication service through a set of complete communication protocol and signaling exchange, can realize various intercommunication calls such as voice/short message group calling, individual calling, total calling and broadcast calling, and digital signaling services in conventional intercommunication such as alarming, telephonism, remote killing, awakening, remote monitoring, environment monitoring, forced dismantling and forced plugging. The network management system is used for authentication management, configuration management and grouping management of the PoC digital interphone 3 and provides basic data of the PoC digital interphone 3 for the PoC server system; the PoC server system is used for the signaling control of the PoC digital interphone 3 and the realization of the voice soft switching talkback service; the scheduling system is used for the end user to obtain the equipment data of the PoC digital interphone 3 in real time on the computer host, including position information, online state, electric quantity and signal strength, and can initiate calling and control on the PoC digital interphone 3.

The PoC digital interphone 3 is a handheld, vehicle-mounted or other PoC public network interphone used by an end user, and is internally provided with a hardware platform and cloud card software, wherein the hardware platform mainly has three modes, one mode is a mobile intelligent operating system adopting a 2G/3G/4G/5G public network hardware platform, such as a hardware platform capable of running an Android operating system, the other mode is an embedded operating system adopting the 2G/3G/4G/5G public network hardware platform, such as a hardware platform capable of running an L inux operating system, the other mode is a hardware platform adopting the 2G/3G/4G/5G public network hardware platform and an MCU, the MCU can run a L inux operating system or any other embedded operating system similar to uCos, and the like.

As shown in FIG. 2, the PoC digital interphone 3 can automatically switch to the operator network with the best signal quality by running operating system software and driving software such as Android/L inux/uCos on a hardware platform of the PoC digital interphone 3 and cloud card software to realize the docking with the cloud card platform 1. the PoC digital interphone 3 can realize the docking with the PoC intercom platform 2 and a man-machine interface such as an embedded L inux program, Android APK software and the like by running PoC application software on the hardware platform of the PoC digital interphone 3.

As shown in fig. 3, fig. 3 is a flowchart of the cloud card based digital intercom method of the present invention. A digital intercom method using the cloud card-based digital intercom system, the digital intercom method comprising the steps of:

step S1), the PoC digital interphone 3 judges whether there is an entity SIM card; if there is a physical SIM card, go to step S2); if there is no physical SIM card, step S5 is entered).

Step S2), judging whether the preset of the PoC digital interphone 3 is entity SIM-first or cloud card-first; if the preset is entity SIM priority, then go to step S3); if the preset is the cloud card priority, step S5 is entered).

Step S3), if the entity SIM card priority is preset, the entity SIM card is directly used for logging in the operator network, and the cloud card service is not used any more.

Step S4), the PoC digital interphone 3 uses the SIM card to access the operator network and judges whether the PoC digital interphone 3 has the flow arrearage; if the flow rate is owed, the flow proceeds to step S8); otherwise, proceed to step S9).

Step S5), the cloud card priority is preset, and the locally stored seed SIM card is directly used to log in the cloud card platform 1 regardless of whether there is a solid SIM card.

Step S6), the cloud card platform 1 determines the optimal operator that the PoC digital interphone 3 should select according to the received P L MN and signal strength information parameters of each operator provided by the PoC digital interphone 3, and provides the SIM card image file of the operator, i.e., the cloud card, to the PoC digital interphone 3.

Step S7), the PoC digital interphone 3 logs in and accesses the operator network using the cloud card, and judges whether the PoC digital interphone 3 is in traffic arrearage; if the flow rate is owed, the flow proceeds to step S8); otherwise, proceed to step S9).

Step S8), the PoC digital interphone 3 flow arrears, prompts arrears information, reminds the user to pay and ends.

Step S9), the PoC digital interphone 3 directly logs in to the PoC intercom platform 2.

Step S10), the PoC digital interphone 3 judges whether the ID of the local machine is in PoC service arrearage through the feedback information when the PoC intercommunication platform 2 logs in; if the PoC service arrears, prompting arrearage information, reminding the user to pay and ending; otherwise, proceed to step S11).

Step 11), the PoC digital interphone 3 downloads the intercom information of the local machine to the local machine from the PoC intercom platform 2.

Step S12), the PoC digital interphone 3 runs the PoC talkback service.

Step S13), the PoC digital interphone 3 judges whether or not the power is low; if yes, ending the PoC service software, and shutting down the power supply; otherwise, returning to step S12) to continue running the PoC talk service.

The invention discloses a digital intercom system and method based on cloud card, which overcomes the defects of special network digital intercom system and conventional public network PoC digital intercom system, and after the system is adopted: 1) the coverage mode of the interphone is greatly expanded, so that the coverage range of the base station of a certain operator can be expanded, and the coverage range of the base stations of all operators butted by the cloud card platform can be expanded; 2) the use of the PoC public network interphone is simplified, such as: APN (access point name) does not need to be set, and the 'instant use after starting up' is realized; 3) if a third-party cloud card platform is adopted, the maintenance cost of the PoC public network digital system is greatly reduced, and the cloud card platform can realize the functions of data flow purchase, SIM card purchase, automatic renewal and the like with an operator; 4) the transaction mode of the private network product manufacturer and the private network client simplifies the three-party or four-party transaction of the traditional PoC talkback service into two-party transaction, and the private network client does not need to transact with an operator; 5) the PoC digital interphone adopting the cloud card can be automatically switched to an operator network with good signal quality when meeting the place with poor signal quality of the current operator; 6) the digital interphones of each PoC public network adopting the method can share the data flow, thereby avoiding the problem that the flow of some users is excessive to cause waste and the flow of other users is insufficient, which is encountered by the common PoC digital interphones system.

It should be noted that the above summary and the detailed description are intended to demonstrate the practical application of the technical solutions provided by the present invention, and should not be construed as limiting the scope of the present invention. Various modifications, equivalent substitutions, or improvements may be made by those skilled in the art within the spirit and principles of the invention. The scope of the invention is to be determined by the appended claims.