Mobile communication device for weak signal coverage scene

Abstract

The invention provides a mobile communication device for a weak signal coverage scene. The mobile communication device comprises a mobile operation access control device, a penetrating operation coverage device and a handheld terminal, the mobile operation access control device sends a message to the penetrating operation coverage device, the penetrating operation coverage device sends the message to the handheld receiving end, and after the handheld receiving end processes the message, the processed data are sent to the penetrating operation coverage device and finally transmitted back to the mobile operation control device. According to the invention, a modular, integrated and error-proof design is adopted, a collaborative ad hoc network technology and a coverage enhancement technology are applied, 4G signal coverage in a specific scene can be accurately solved, and the requirements of maneuvering deployment, rapid networking, reliable connection, resource collaboration and high destroy resistance of communication networking in complex scene operation are met. A test result shows that the method can provide stable, reliable and composite multimode mobile communication service for operators under the conditions of communication interruption after an earthquake, operation in weak signal scenes such as deserts or valleys and the like.

Description

Technical Field

[0001] The present invention relates to the field of mobile communication technology, and in particular to a mobile communication device for weak signal coverage scenarios. Background Art

[0002] The issue of communication in weak signal coverage scenarios remains a major challenge in mobile network communications. This is particularly true in complex terrains like deserts and valleys, where network signal obstruction can make mobile network quality difficult to guarantee. Furthermore, after natural disasters like earthquakes, damage to base stations and other infrastructure can disrupt communications in the affected area, significantly impacting disaster relief efforts. Therefore, when conducting rescue operations and scientific research in these weak or no signal coverage scenarios, a mobile communication networking device suitable for these complex scenarios is needed to enhance the resilience and survivability of communication networks operating in these complex scenarios and address the challenges of weak signal space operations.

[0003] Among the various wireless communication networks currently available, the 4G private network (B-TrunC standard) is the most mature. B-TrunC, developed by the Broadband Trunking Industry Alliance, is a TD-LTE-based private network broadband trunking system standard featuring "LTE digital transmission + trunking voice communication." In 2015, B-TrunC Release 1 became the first ITU-recommended LTE broadband trunking standard for public safety and disaster reduction applications, supporting point-to-multipoint voice and multimedia trunking dispatch. While maintaining compatibility with LTE data services, B-TrunC Release 1 enhances broadband trunking capabilities, including basic and supplementary voice trunking services and multimedia trunking dispatch. Featuring flexible bandwidth, high spectral efficiency, low latency, and high reliability, B-TrunC meets the needs of professional users for voice trunking, broadband data, and emergency command and dispatch.

[0004] However, the current 4G private network (B-TrunC standard) networking technology still has many flaws:

[0005] First, B-TrunC uses cellular mobile technology, which is suitable for fixed base stations to establish cell coverage. When the base station moves, the cellular cell cannot accurately achieve continuous and seamless connection. Therefore, the base station deployment location must be relatively fixed, which lacks mobility.

[0006] Second, base station signal coverage is significantly affected by the base station antenna's installation height, antenna azimuth, and antenna downtilt angle, making it unable to meet the wireless broadband signal quality requirements required for operations in complex scenarios such as deserts, valleys, and post-earthquake building collapses.

[0007] Third, due to the loss of wireless signals in space and their rapid fading when encountering obstacles, network signal quality cannot meet the requirements of operations over long distances or in closed environments (collapsed buildings, underground spaces), seriously hindering the development of informatization, digitization, and intelligentization, and improving capabilities in complex scenarios.

[0008] Fourth, existing ad hoc networks are mostly based on single-channel TDMA or CSMA, and the entire network operates on a single frequency. When TDMA is used, the more nodes access the network, the fewer resources each node can be allocated, and the traffic volume drops significantly. When CSMA is used, different nodes compete for resources, and as the number of nodes increases, conflicts in the network increase sharply, which also causes a sharp drop in traffic volume. Summary of the Invention

[0009] In response to the problems existing in the existing technology, the present invention proposes a mobile communication device for weak signal coverage scenarios to meet the needs of providing stable, reliable, composite multi-mode mobile communication services to workers in situations such as communication interruption after an earthquake and operations in weak signal scenarios such as deserts or valleys.

[0010] The technical solution of the present invention is:

[0011] The mobile communication device for weak signal coverage scenarios includes a mobile operation access control device, a penetrating operation coverage device, and a handheld terminal;

[0012] The mobile operation access control device sends a message to the penetrating operation coverage device, which then sends the message to the handheld receiving terminal. After the handheld terminal completes the processing, it sends the processed data to the penetrating operation coverage device and finally sends it back to the mobile operation control device.

[0013] The mobile operation access control device includes a service and streaming cluster scheduling service module, a B-TrunC core network processing module, and an ad hoc network backhaul module; the penetration operation coverage device includes a B-TrunC base station processing module and an ad hoc network backhaul module, and adopts collaborative ad hoc networking technology to realize multi-base station networking function;

[0014] The business and streaming cluster scheduling service module implements cluster B-TrunC business communication service scheduling and control, wherein the business module is used for business data interaction and storage, and the streaming cluster scheduling service module supports background streaming services;

[0015] The B-TrunC core network processing module implements mobility management functions, cluster control functions, cluster media functions, integrated gateway functions, and eHSS functions;

[0016] The self-organizing network backhaul module provides a wireless backhaul channel for the B-TrunC processing unit in a mobile state and is mainly composed of a core network processor motherboard, a radio frequency module, and an antenna. The core network processor motherboard is the resident and running platform for system software and networking control protocol software, and provides various internal and external functional interface protocol processing and data forwarding functions. The radio frequency unit is responsible for baseband modulation and radio frequency modulation of the OFDM wireless waveform and completes MAC layer protocol processing.

[0017] When the business and streaming media cluster scheduling service module generates data, the self-organizing network backhaul module in the mobile operation access control device encodes the data into a digital signal, modulates the digital signal and maps it to a carrier, and then converts the digital signal into an analog signal through digital-to-analog conversion, up-converts the analog baseband signal, and finally amplifies the power and filters it to form a self-organizing network signal emitted from the antenna; when the antenna of the penetrating operation coverage device captures the self-organizing network signal, the signal is amplified by LNA, the amplified RF signal is mixed with the local oscillator through a mixer, and down-converted to an intermediate frequency or baseband, and the intermediate frequency or baseband analog signal is transmitted through the ADC The digital signal is converted into a digital signal, which is demodulated by a demodulator to extract the data modulated on the carrier, perform error detection and correction on the data, and decode the data, and send the data to the B-TrunC base station processing module through the interactive machine; the B-TrunC base station processing module is the network coverage access node of the penetration operation coverage device, and provides a data transmission network channel for each terminal device; the B-TrunC base station processing module obtains the data provided by the self-organizing network backhaul module in the penetration operation coverage device through the switch, encodes and modulates it on the digital board, performs up-conversion and power amplification on the power amplifier board, and transmits it from the antenna after filtering through the filter.

[0018] Furthermore, the functions implemented by the B-TrunC core network processing module are as follows:

[0019] The mobility management function is used to manage the location information, security, and business continuity of handheld terminals, so that the connection between the handheld terminal and the network can be optimized, thereby providing guarantees for the application of various network services;

[0020] The cluster control function manages and controls cluster services. By connecting to the eHSS, it implements cluster user authentication, registration, deregistration, and user subscription management. By connecting to the eMME, it implements service scheduling and voice rights management.

[0021] The cluster media function is responsible for the media plane data transmission of cluster services, including cluster user plane resource management, and routing and forwarding of cluster service data.

[0022] The integrated gateway provides bearer management, data routing and forwarding functions, including LTE basic data services and trunking services;

[0023] The eHSS function includes two logical functions: LTE subscription data management HSS and cluster subscription data management THSS.

[0024] Furthermore, the core network processor motherboard implements: running an embedded Linux operating system; running a mobile broadband grid network networking and routing protocol; providing external interfaces, including Ethernet, Wi-Fi, UART and USB interfaces; and providing a MiniPCI-E interface as a radio frequency module interface.

[0025] Furthermore, the radio frequency unit takes the OFDM digital signal processor as the core, realizes the self-organizing network MAC layer protocol processing, OFDM waveform baseband and radio frequency signal processing, and exchanges data with the core network processor motherboard through the MiniPCI-E interface.

[0026] Beneficial effects

[0027] This invention proposes a mobile communication device for weak signal coverage scenarios. This device utilizes a modular, integrated, and error-proof design, along with collaborative ad hoc networking and coverage enhancement technologies. It precisely addresses 4G signal coverage in specific scenarios and meets the requirements for flexible deployment, rapid networking, reliable connectivity, resource coordination, and high resilience for complex communication networking scenarios. Test results demonstrate that this device can provide stable, reliable, and multi-mode mobile communication services to operators in situations such as post-earthquake communication disruptions and in weak signal environments like deserts and valleys.

[0028] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0030] Figure 1 : Connection diagram of mobile operation access control device and penetrating operation coverage device;

[0031] Figure 2 : Block diagram of the overall physical architecture of the ad hoc network backhaul module;

[0032] Figure 3 : Core network processor motherboard principle block diagram;

[0033] Figure 4 : RF module principle block diagram;

[0034] Figure 5 : CFR implementation block diagram;

[0035] Figure 6 : DPD technology principle block diagram;

[0036] Figure 7 : Schematic diagram of DPD principle;

[0037] Figure 8 :Digital predistortion implementation block diagram;

[0038] Figure 9 : Module distribution of mobile command access control device;

[0039] Figure 10 : Portable towing aviation box design;

[0040] Figure 11 : Working mode status diagram of the coverage device in weak signal scenario. DETAILED DESCRIPTION

[0041] The following describes in detail embodiments of the present invention. The embodiments are exemplary and intended to explain the present invention, but are not to be construed as limiting the present invention.

[0042] This embodiment addresses the communication networking requirements in weak signal coverage scenarios and proposes a multi-mode converged mobile communication device and method based on the B_TrunC communication standard. This device utilizes a modular, integrated, and error-proof design, employing collaborative ad hoc networking and coverage enhancement technologies to precisely address 4G signal coverage in specific scenarios. It meets the communication networking requirements for flexible deployment, rapid networking, reliable connectivity, resource coordination, and high resilience in complex scenarios.

[0043] like Figure 1 As shown, the mobile communication device for weak signal coverage scenarios includes a mobile operation access control device, a penetrating operation coverage device and a handheld terminal.

[0044] The mobile operation access control device sends a message to the penetrating operation coverage device, which sends the message to the handheld receiving terminal. After the handheld terminal completes the processing, it sends the processed data to the penetrating operation coverage device and finally sends it back to the mobile operation control device.

[0045] The mobile operation access control device includes a business and streaming cluster scheduling service module, a B-TrunC core network processing module, and an ad hoc network backhaul module; the penetrating operation coverage device includes a B-TrunC base station processing module and an ad hoc network backhaul module, and adopts collaborative ad hoc networking technology to realize multi-base station networking function.

[0046] The service and streaming cluster scheduling service modules implement the scheduling and control of various types of cluster B-TrunC services (voice, video, information, and PTT). The service module is primarily responsible for service data interaction and storage, while the streaming cluster scheduling service module mainly supports background streaming services.

[0047] The B-TrunC core network processing module implements the mobility management function (eMME), trunk control function (TCF), trunk media function (TMF), integrated gateway (xGW) and enhanced home subscriber server (eHSS) functions.

[0048] The eMME manages the location, security, and service continuity of handheld terminals, ensuring optimal connectivity between them and the network, and thus guaranteeing the availability of various network services. The Trunking Control Function (TCF) manages and controls trunking services. Connecting to the eHSS, it implements functions such as authentication, registration, deregistration, and user subscription management for trunking users. Connecting to the eMME, it implements service scheduling and voice management. The Trunking Media Function (TMF) is responsible for media-plane data transmission for trunking services, including trunking user-plane resource management and routing and forwarding of trunking service data. The xGW provides bearer management, data routing, and forwarding, including both LTE basic data services and trunking services. The eHSS serves as the user subscription data management and authentication center, encompassing two logical functions: the LTE subscription data management HSS and the trunking subscription data management THSS.

[0049] The self-organizing network backhaul module provides a wireless backhaul channel for the B-TrunC core network processing module in a mobile state. It is mainly composed of a core network processor motherboard, a radio frequency module and an antenna. Figure 2 As shown. The core network processor motherboard is the resident and operating platform of the system software and networking control protocol software, and provides various internal and external functional interface protocol processing and data forwarding functions. The radio frequency unit is responsible for the baseband modulation and radio frequency modulation of the OFDM wireless waveform, and completes the processing of the MAC layer protocol. The core network processor motherboard is as shown. Figure 3 As shown, the main functions include: running the embedded Linux operating system; running the mobile broadband grid network and routing protocol; providing external interfaces, including Ethernet, Wi-Fi, UART and USB; providing MiniPCI-E interface as the RF module interface. Figure 4 As shown, with the OFDM digital signal processor as the core, it realizes the self-organizing network MAC layer protocol processing, OFDM waveform baseband and RF signal processing, and exchanges data with the core network processor motherboard through the MiniPCI-E interface.

[0050] When the service and streaming cluster scheduling service module generates data, the ad hoc network backhaul module in the mobile operation access control device encodes the data generated by the service and streaming cluster scheduling service module into a digital signal, modulates the digital signal onto a carrier, converts the digital signal into an analog signal through digital-to-analog conversion, up-converts the analog baseband signal through frequency conversion, amplifies the power and filters, forms an ad hoc network signal, and transmits the signal from the antenna.

[0051] The B-TrunC base station processing module is a network coverage access node of the penetration operation coverage device, and provides a data transmission network channel for each terminal device. When the antenna of the penetration operation coverage device captures the ad hoc network signal, the signal is amplified through an LNA, the amplified radio frequency signal is mixed with a local oscillator through a frequency mixer, down-converted to an intermediate frequency or a baseband, the intermediate frequency or baseband analog signal is converted into a digital signal through an ADC, the digital signal is demodulated through a demodulator, the data modulated on the carrier is extracted, the data is error detected and corrected and decoded, and the data is sent to the B-TrunC base station processing module in the penetration operation coverage device through an interactive machine. The B-TrunC base station processing module obtains the data provided by the ad hoc network backhaul module in the penetration operation coverage device through a switch, encodes and modulates the data on a digital board, up-converts and power amplifies the data on a power amplifier board, filters the data through a filter, and transmits the data from an antenna, thereby realizing the functions of an RRU (radio frequency unit) and a BBU (baseband processing unit) of a B-TrunC access network.

[0052] In this embodiment, wireless link coverage analysis is performed by comprehensively considering the wireless signal propagation characteristics, and a cooperative ad hoc network technology and a coverage enhancement technology are adopted.

[0053] 1. Cooperative ad hoc network technology

[0054] The cooperative ad hoc network is a wireless ad hoc network technology improved on the basis of a traditional MESH ad hoc network. The penetration operation coverage device is provided with an ad hoc network backhaul module and a B-TrunC base station processing module, and adopts a cooperative ad hoc network+B-TrunC dual-mode system to realize wideband mobile communication. In addition to the traditional MESH ad hoc network features such as self-organization, self-repeater, and network fault self-recovery, the penetration operation coverage device can realize the transformation of a “communication pipeline” into an “intelligent network” through the introduction of an intelligent spectrum cooperation mechanism, has the characteristics of multi-information concurrent transmission, significantly improves network traffic, realizes high real-time resource cooperation, and continuously maintains multi-hop traffic, and realizes larger-scale networking through autonomous negotiation and multiplexing, and is a flat intelligent wireless broadband communication network facing the future full distribution, self-organization, and strong cooperation.

[0055] The collaborative ad hoc network utilizes intelligent spectrum coordination technology. Based on real-time awareness of the air interface spectrum, it leverages an intelligent distributed learning decision-making algorithm at each node to coordinate the use of time and frequency resources between nodes. Aiming for network optimization rather than single-point optimization, this technology performs real-time optimization and iteration, avoiding resource conflicts between nodes and dynamically selecting the most efficient time and frequency resources. When data is transmitted between nodes, the "optimal" time and frequency resources are dynamically selected in real time. Using "intelligent spectrum coordination multiple access" technology, multiple pairs of data streams can be transmitted simultaneously on the air interface, significantly increasing network throughput. Simultaneously, different data streams are transmitted on different frequencies, enabling multi-hop traffic between different nodes to pass concurrently and without conflict, ensuring continuous throughput. Through real-time perception and negotiation, and inertial hysteresis maintenance, multiple data streams can be transmitted concurrently between air interface nodes, significantly expanding network throughput and significantly increasing maximum network throughput as network scale increases.

[0056] In terms of modulation and coding technology, cooperative ad hoc networks use the same technologies as various wireless communication systems, such as BPSK / QPSK / 16QAM / 64QAM, OFDM, and Turbo coding. Its biggest innovation is the introduction of multiple access technology.

[0057] In terms of network connection, the collaborative ad hoc network uses the ad hoc network as the interconnection link between the base station and the core network, and uses route optimization and cell coverage edge design technology to solve the problem of B-TrunC multi-base station mobile networking. The use of mature B-TrunC terminals and confidentiality systems can achieve reliable high-speed confidential communication.

[0058] 2. Coverage Enhancement Technology

[0059] The B-TrunC base station processing module of the penetrating coverage device effectively solves the network signal quality issues existing in the current B-TrunC network by using coverage enhancement technology, greatly improving the reliability of the network connection. The details are as follows:

[0060] a. Increase terminal transmit power

[0061] The LTE system has severely limited uplink transmission power. Currently, typical terminal transmit power is 23dBm. In this embodiment, based on terminal system design, the B-TrunC base station processing module of the penetration coverage device uses an external power amplifier to increase terminal transmit power to 27-30dBm. Furthermore, EVM is controlled to meet the demodulation signal-to-noise ratio requirements of 64QAM.

[0062] b. Increase downlink power

[0063] The LTE system's physical layer solution uses OFDMA technology for downlink, resulting in a high peak-to-average signal ratio (PAR), typically reaching 10-12dB. To ensure linearity in the transmission system, high-power transistors are required, resulting in low system efficiency. To improve system efficiency, the B-TrunC base station processing module in the penetrating coverage device utilizes digital peak clipping (CFR) and digital predistortion (DPD) technologies.

[0064] Under OFDMA signals, typical power amplifier designs use power back-off technology to ensure linearity, and a power amplifier efficiency of around 8% is generally required to ensure system linearity. Under the same power output and linearity requirements, the use of peak clipping (CFR) and delay predistortion (DPD) technologies can increase power amplifier efficiency to over 30%.

[0065] The digital peak clipping (CFR) algorithm is implemented in the digital intermediate frequency part. The implementation block diagram is shown in the attached figure. Figure 2 The CFR technology reduces the system peak-to-average ratio, reducing the signal peak-to-average ratio of this device from 10-12dB to about 7dB.

[0066] The principle of digital predistortion (DPD) is shown in the attached Figure 3 and Figure 4 The basic principle is to use the power amplifier model to construct a signal that is in phase with the distorted signal through the feedback signal, merge it in the digital part, and send it to the power amplifier to compensate for the distortion of the power amplifier, so that the final signal is linearly corrected and the linearity is improved. The digital predistortion implementation block diagram is shown in the attached figure. Figure 5 As shown in the figure, in its specific implementation, this function is performed by the DSP, CPU, FPGA, and RF link working together. Experimental tests comparing peak clipping and predistortion show that the use of DPD technology improves adjacent channel rejection (ACLR) from -31.83dBC to -46.55dBC.

[0067] c. TTI Bundling

[0068] The B-TrunC base station processing module of the penetrating coverage device uses TTI (subframe bundling) technology. TTI bundling combines four consecutive subframes, transmitting the same data across these four subframes. If data transmitted using TTI bundling requires retransmission, the retransmission is also done using TTI bundling. In this case, the number of HARQ processes per UE is reduced accordingly. In TDD systems, the retransmission interval varies depending on the uplink and downlink ratios.

[0069] When the TTI bundling function is enabled and the UE channel quality is poor and the power is limited, configuring TTI bundling for the UE can obtain more transmission opportunities within the air interface delay budget and improve uplink coverage.

[0070] d. RAKE receiving technology

[0071] The signal receiving unit of the B-TrunC base station processing module of the penetrating coverage device uses RAKE receiving technology, which is a multipath diversity receiving technology. It distinguishes subtle multipath signals in time, and weights and adjusts these distinguished multipath signals separately to composite them into an enhanced signal.

[0072] e. Uplink closed-loop power control

[0073] From the perspective of enhancing coverage, the main consideration is PUSCH closed-loop power control. The purpose of PUSCH power control is to reduce interference to neighboring cells and improve regional throughput, ensuring the speed of users at the edge of the area.

[0074] With PUSCH closed-loop power control enabled, the eNodeB estimates the user's transmit power spectrum and periodically adjusts the PUSCH transmit power based on the difference between the estimated value and the target value to adapt to changes in the channel environment. If the estimated value exceeds the target value, the eNodeB sends a TPC command to the UE to reduce power. If the estimated value falls below the target value, the eNodeB sends a TPC command to increase power.

[0075] In addition, in this embodiment, in order to meet the requirements of mobile deployment and high survivability of mobile communication devices, the device adopts modular design, portable and draggable design, composite multi-mode design, external interface error-proofing enhanced design, and internal AC / DC direct conversion design.

[0076] 1. Modular design

[0077] In order to enhance mobility, improve the interchangeability of the device, and reduce the difficulty of commissioning and maintenance, the mobile operation access control device and the penetrating operation coverage device adopt a modular and integrated design. They are quick to deploy and can be turned on with one button. They can work just by powering on and do not require excessive manual intervention.

[0078] The modules of the device are distributed as follows Figure 6 As previously mentioned, the business server, streaming media server, core network, and ad hoc network are all independent modules, with switch buttons and USB ports provided for external use. This standardized modular design effectively improves the standardization of the equipment and enhances its maintainability and survivability.

[0079] 2. Portable and draggable design

[0080] The outer packaging of the mobile operation access control device and the penetration operation covering device adopts a portable drag aviation box design (the shape is as follows Figure 7 ) stated that the device's housing is constructed of high-strength plastic, combining lightness with a robust structure. The interface utilizes a fast-acting, waterproof aviation socket. An internal heat-conducting air duct is designed to conduct heat to the housing via a built-in fan. The housing features grille-style heat dissipation holes, achieving an integrated internal and external passive heat dissipation system. The entire device casing is constructed of 6063 aluminum alloy. 6063 aluminum alloy, with its high strength, corrosion resistance, and excellent machinability, is widely used in electronic structural materials in the aviation industry. It ensures the device's structural strength, waterproofing, dustproofing, shock resistance, and environmental adaptability, effectively addressing the challenges of mobile deployment.

[0081] 3. Composite multi-mode design

[0082] In the present invention, the B-TrunC base station processing module (penetrating operation coverage device) and the B-TrunC core network processing module (mobile operation access control device) of the penetrating operation coverage device are designed separately, which is an enhanced design to adapt to the operation mobility in complex scenarios.

[0083] like Figure 11 As shown, the complex scene penetration operation coverage device has two operating modes to meet different coverage requirements. Mode 1 is the normal operating mode, in which the complex scene penetration operation coverage device and the mobile operation access control device work together. Mode 2 is the enhanced mode, in which the complex scene penetration operation coverage device accesses the existing 4G-LTE private network.

[0084] Working mode 1:

[0085] The deployment of mobile operation access control devices and penetrating operation coverage devices in complex scenarios achieves reliable wireless transmission through ad hoc networks. Penetrating operation coverage devices can be deployed in multiple units, and the B-TrunC base station utilizes high-gain plate antennas, effectively addressing long-distance coverage issues and adapting to confined environments such as valleys and collapsed areas. For coverage in confined environments such as valleys, buildings, and collapsed areas, where coverage range or distance requirements are lower, omnidirectional antennas are used. Both devices can be deployed in a distributed manner or flexibly in close proximity. This is the standard operating mode, capable of independent operation in mobile situations, effectively addressing the long-distance distribution of operating forces and the difficulty of 4G signal penetration and coverage.

[0086] like Figure 11As shown in working mode 1, the weak signal scene penetration operation coverage device and the mobile operation access control device work in cooperation with each other, the penetration operation coverage device B-TrunC base station processing unit and the self-organizing network backhaul unit are in working state, and the various unit modules of the weak signal scene mobile operation access control device are in working state. In this typical application scenario, multiple penetration operation coverage devices can be deployed to realize the networking function through collaborative self-organizing network technology. Alternatively, the self-organizing network module units of the weak signal scene penetration operation coverage device and the mobile operation access control device can be in non-working state, and the RJ45 Ethernet interface provided by the device can be directly connected to enable the penetration operation coverage device and the mobile operation access control device to work in cooperation with each other to realize mobile operation command and scheduling.

[0087] The aforementioned application scenarios describe how the weak-signal penetration coverage device and the mobile access control device can collaborate via two interoperability modes. This mode enables mobile command of complex operations using dynamic communication. The two devices can be stacked and connected directly via a network cable. The penetration coverage device can be connected to a portable vehicle-mounted suction cup antenna, achieving an effective coverage distance of 2-3 kilometers. Furthermore, for applications such as ultra-short-range operations, the B-TrunC base station power configuration can be adjusted or an attenuator can be connected to the RF external interface to reduce RF power output.

[0088] Working mode 2:

[0089] The B-TrunC base station connects to the existing external B-TrunC core network when a backhaul channel is available, and at this time, it is disconnected from the access control device for mobile operation, thus enhancing mobility.

[0090] like Figure 11 In operating mode 2, the weak-signal penetration coverage device operates independently, while the mobile access control device is inactive. The B-TrunC base station processing unit and ad hoc backhaul unit of the penetration coverage device are operational. The B-TrunC base station is connected to the existing B-TrunC core network using ad hoc backhaul. Backend connections are established through the existing B-TrunC core network with the operation server, the mobile operation command and dispatch system, and the audio and video convergence dispatch server, enabling packet data services and audio and video dispatch services for complex operation scenarios.

[0091] 4. Enhanced design of external interface error prevention

[0092] The mobile operation access control device's external interfaces include an RF antenna port, an Ethernet port, a BeiDou port, and a power supply. To prevent errors, all interfaces are designed with aviation plugs and clearly labeled. Furthermore, to reduce the need for external devices and simplify deployment, the device includes a built-in network switch, providing multiple external interfaces and simplifying deployment.

[0093] 5. AC / DC internal direct conversion design

[0094] The Mobile Access Control Device and Penetrating Coverage Device utilize a 24V DC input and an external 220V AC to 24V DC adapter for AC / DC power supply. This allows for rapid deployment and operation in a variety of conditions.

[0095] Through the above design, the final link budget and wireless link coverage analysis of this embodiment are as follows:

[0096] (1) Link budget:

[0097] Link budget input parameters:

[0098] Technology system: TD-LTE

[0099] Working frequency: 600MHz,

[0100] Carrier bandwidth: 20MHz

[0101] TD-LTE time slot ratio mode: uplink and downlink subframe ratio 2:2

[0102] Uplink edge rate: 512kbps, 1Mbps, 2Mbps

[0103] Base station configuration: 2T2R, transmission power 2×30W

[0104] Base station antenna gain 12dBi

[0105] Terminal configuration: 1T2R, transmit power 200mW

[0106] Communication environment: complex external environment

[0107] Base station antenna hanging height: 40m

[0108] Link budget results:

[0109] Based on the link budget input parameters above, in the first TD-LTE timeslot allocation mode, i.e., a 2:2 uplink and downlink subframe ratio, when the uplink edge rate of the working area is 2 Mbps (considering 720P video upload and pull-down), the working area coverage radius can reach 5.37 km.

[0110] Table 1 Link budget results

[0111]

[0112] For TD-LTE systems, the peak throughput rates of uplink and downlink are not only related to key system technologies, but also to network configuration. Specific parameters that affect the system peak rate are:

[0113] Uplink and downlink subframe ratio: Because uplink transmission time is shared, the peak rates of both directions are closely related to the uplink and downlink subframe ratio. The higher the proportion of either direction, the higher the peak rate. Common uplink and downlink subframe ratios are 3:1, 2:2, and 1:3.

[0114] Carrier bandwidth: LTE supports different carrier bandwidths such as 3 / 5 / 10 / 15 / 20 MHz. The wider the carrier bandwidth, the higher the peak rate.

[0115] Number of carriers: When the number of carriers is higher, the corresponding peak rate of the working area is higher. The improvement of the terminal peak rate needs to rely on the carrier aggregation (CA) function.

[0116] Link MIMO configuration: Based on typical base station and terminal equipment configurations, the uplink MIMO configuration is 1T2R and the downlink is 2T2R. Therefore, the uplink peak rate is single-stream, and the downlink peak rate is dual-stream.

[0117] Terminal Category: Different terminal categories support different modulation coding energies. Category 3 terminals support up to 16QAM modulation, while Category 5 terminals support 64QAM, resulting in higher peak rates.

[0118] Based on the above factors, the reference values ​​of uplink and downlink peak rates in common single-carrier configurations are shown in the following table.

[0119] Table 2. Peak rate reference values ​​for uplink and downlink in common single-carrier configurations

[0120]

[0121] The following table shows the reference values ​​of uplink and downlink peak rates for common dual-carrier configurations.

[0122] Table 3. Peak rate reference values ​​for uplink and downlink in common dual-carrier configurations

[0123]

[0124] (2) Wireless link coverage analysis:

[0125] Wireless signal is closely related to the wireless environment, such as terrain, buildings, trees, etc. when propagating in space. The propagation loss of wireless signal is also related to the propagation medium. The wireless propagation model is a model used to predict the propagation characteristics of radio waves. The prediction of the propagation characteristics is the basis of wireless network planning, and the accurate propagation model is the prerequisite for effective wireless network planning.

[0126] The commonly used propagation model can be divided into the following two types:

[0127] a. Deterministic model: the method of directly applying electromagnetic theory calculation to specific site environment.

[0128] b. Empirical model: the empirical formula fitted based on a large number of field strength test results.

[0129] The commonly used model is: COST 231-Hata, Okumura-Hata, SPM (Standard Propagation model) propagation model, etc.

[0130] The present application adopts the result of the test model correction (K value is obtained by actual measurement correction) of the SPM transmission model as the simulation propagation model. The path loss formula is as follows:

[0131]

[0132] The following are two simulation scenarios:

[0133] a. Building or collapsed area coverage, the building is calculated using the dense urban scenario, and the base station uses a transmission power of 1W, and the terminal uses a transmission power of 200mW.

[0134] b. Building outside backhaul coverage, according to the environment, the environment outside the building is relatively good, and the suburban coverage scenario is used. The self-organizing network equipment outside the building uses a transmission power of 2W, and the equipment is hung at a height of about 5 meters.

[0135] If the 12.2kbps cluster voice service continuous coverage is to be met, the edge signal strength needs to be greater than -108.63dBm; if the 1024kbps video service continuous coverage is to be met, the edge signal strength needs to be greater than -99.28dBm. By using the Matlab tool, the above two different simulation scenarios are simulated and analyzed, and combined with the link budget formula, the following conclusions can be obtained: in the case of ensuring that the SINR is not less than 20, the uplink and downlink rates are both greater than 10Mbps, the coverage radius of scenario a is about 300 meters; in the case of ensuring that the transmission rate is 50Mbps, scenario b can cover about 2000 meters; the mobile communication networking control device meets the wireless coverage requirements of scenarios a and b.

[0136] It can be seen that the present invention can provide stable, reliable, composite multi-mode mobile communication services to operators in situations such as communication interruption after an earthquake or working in weak signal scenes such as deserts or valleys.

[0137] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A mobile communication device for weak signal coverage scenarios, characterized by: Including mobile operation access control device, penetrating operation coverage device and handheld terminal; The mobile operation access control device sends a message to the penetrating operation coverage device, which then sends the message to the handheld receiving terminal. After the handheld terminal completes the processing, it sends the processed data to the penetrating operation coverage device and finally sends it back to the mobile operation control device. The mobile operation access control device includes a service and streaming cluster scheduling service module, a B-TrunC core network processing module, and an ad hoc network backhaul module; the penetration operation coverage device includes a B-TrunC base station processing module and an ad hoc network backhaul module, and adopts collaborative ad hoc networking technology to realize multi-base station networking function; The business and streaming cluster scheduling service module implements cluster B-TrunC business communication service scheduling and control, wherein the business module is used for business data interaction and storage, and the streaming cluster scheduling service module supports background streaming services; The B-TrunC core network processing module implements mobility management functions, cluster control functions, cluster media functions, integrated gateway functions, and eHSS functions; The self-organizing network backhaul module provides a wireless backhaul channel for the B-TrunC processing unit in a mobile state and is composed of a core network processor motherboard, a radio frequency module, and an antenna. The core network processor motherboard is the resident and operating platform for system software and networking control protocol software, and provides various internal and external functional interface protocol processing and data forwarding functions. The radio frequency unit is responsible for baseband modulation and radio frequency modulation of the OFDM wireless waveform and completes MAC layer protocol processing. When the business and streaming media cluster scheduling service module generates data, the self-organizing network backhaul module in the mobile operation access control device encodes the data into a digital signal, modulates the digital signal and maps it to a carrier, and then converts the digital signal into an analog signal through digital-to-analog conversion, up-converts the analog baseband signal, and finally amplifies the power and filters it to form a self-organizing network signal emitted from the antenna; when the antenna of the penetrating operation coverage device captures the self-organizing network signal, the signal is amplified by LNA, the amplified RF signal is mixed with the local oscillator through a mixer, and down-converted to an intermediate frequency or baseband, and the intermediate frequency or baseband analog signal is transmitted through the ADC The digital signal is converted into a digital signal, which is demodulated by a demodulator to extract the data modulated on the carrier, perform error detection and correction on the data, and decode the data, and send the data to the B-TrunC base station processing module through the interactive machine; the B-TrunC base station processing module is the network coverage access node of the penetration operation coverage device, and provides a data transmission network channel for each terminal device; the B-TrunC base station processing module obtains the data provided by the self-organizing network backhaul module in the penetration operation coverage device through the switch, encodes and modulates it on the digital board, performs up-conversion and power amplification on the power amplifier board, and transmits it from the antenna after filtering through the filter.

2. The mobile communication device for weak signal coverage scenarios according to claim 1, characterized in that: The functions implemented by the B-TrunC core network processing module are as follows: The mobility management function is used to manage the location information, security, and business continuity of handheld terminals, so that the connection between the handheld terminal and the network can be optimized, thereby providing guarantees for the application of various network services; The cluster control function manages and controls cluster services. By connecting to the eHSS, it implements cluster user authentication, registration, deregistration, and user subscription management. By connecting to the eMME, it implements service scheduling and voice rights management. The cluster media function is responsible for the media plane data transmission of cluster services, including cluster user plane resource management, and routing and forwarding of cluster service data. The integrated gateway provides bearer management, data routing and forwarding functions, including LTE basic data services and trunking services; The eHSS function includes two logical functions: LTE subscription data management HSS and cluster subscription data management THSS.

3. The mobile communication device for weak signal coverage scenarios according to claim 1, characterized in that: The core network processor motherboard realizes: running an embedded Linux operating system; running a mobile broadband grid network networking and routing protocol; providing external interfaces, including Ethernet, Wi-Fi, UART and USB interfaces; and providing a MiniPCI-E interface as a radio frequency module interface.

4. The mobile communication device for weak signal coverage scenarios according to claim 1, characterized in that: The radio frequency unit is based on the OFDM digital signal processor, realizes the processing of the MAC layer protocol of the self-organizing network, the OFDM waveform baseband and the radio frequency signal, and exchanges data with the core network processor motherboard through the MiniPCI-E interface.

5. The mobile communication device for weak signal coverage scenarios according to claim 1, characterized in that: The collaborative self-organizing network technology adopts intelligent spectrum collaboration technology, based on real-time cognition of the air interface spectrum, using the intelligent distributed learning decision algorithm of each node to coordinate the use strategy of time and frequency resources among nodes, aiming at network optimization rather than single-point optimization, and optimizing and iterating in real time to avoid conflicts between resources among nodes and dynamically select the time and frequency resources with the highest utilization efficiency.

6. The mobile communication device for weak signal coverage scenarios according to claim 1, characterized in that: The B-TrunC base station processing module uses coverage enhancement technology, including: improving terminal transmission power, enhancing downlink power, subframe bundling technology, RAKE receiving technology, and uplink closed-loop power control.

7. The mobile communication device for weak signal coverage scenarios according to claim 1, characterized in that: In response to different coverage requirements, the penetrating operation coverage device has two working modes. Mode 1 is the normal working mode, in which the penetrating operation coverage device and the mobile operation access control device cooperate with each other to complete the work; Mode 2 is the enhanced mode, in which the penetrating operation coverage device accesses the existing 4G-LTE private network to work.

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