mesh_project/White Paper on Decentralized Mesh Communication Structure Based on Wireless Mesh.md

White Paper on Decentralized Mesh Communication Structure Based on Wireless Mesh

Preface

1.1 Background and Significance

With the rapid rise of demands for the Internet of Things (IoT), mobile Internet, and emergency communications, the drawbacks of the traditional centralized communication network architecture relying on core base stations and gateways have become increasingly prominent—single-point failures can easily lead to overall network paralysis, high deployment costs, insufficient coverage in remote or complex environments, and fixed data transmission paths that are vulnerable to attacks. This architecture can no longer adapt to the needs of diversified and distributed communication scenarios. With the continuous iteration of wireless communication technologies, wireless Mesh technology based on international ISM (Industrial, Scientific, Medical) frequency bands, relying on its core characteristics of self-organization, self-healing, and multi-hop forwarding, has become the optimal carrier for building decentralized communication networks.

The decentralized mesh communication structure based on wireless Mesh proposed in this white paper integrates the advantages of multiple ISM frequency bands such as LoRaWAN, 2.4G, and 5.8G, breaks the hierarchical limitations of traditional centralized networks, and adopts a collaborative forwarding mode between users and routers, combined with asymmetric key encryption and a flexible group key management mechanism. It achieves low-cost, high-reliability, high-security, and wide-coverage distributed communication, providing a new solution for scenarios such as personal communication, IoT terminal interconnection, emergency rescue, and remote area communication, and promoting the upgrading of communication networks towards decentralization, flattening, and security.

1.2 Purpose of the White Paper

This white paper aims to comprehensively and systematically elaborate on the core design, technical principles, operation mechanisms, application scenarios, and development prospects of the decentralized mesh communication structure based on wireless Mesh. It provides a standardized reference for relevant technological research and development, product implementation, and industrial applications, and at the same time conveys the technical value and application potential of this communication structure to all sectors of the industry, promoting its popularization and innovative development in various fields.

1.3 Scope of Application

This white paper is applicable to communication technology R&D enterprises, IoT equipment manufacturers, emergency management departments, remote area communication construction units, scientific research institutions, and relevant practitioners, serving as a basis for technical reference, product design, project implementation, and academic research. It is also applicable to all sectors of society interested in decentralized communication and wireless Mesh technology, for understanding the core technologies and application directions of this field.

I. Core Concepts and Technical Foundation

1.1 Definition of Core Concepts

1.1.1 Wireless Mesh Decentralized Mesh Communication Structure

The decentralized mesh communication structure based on wireless Mesh is a distributed communication network that does not rely on central nodes (such as core gateways and base stations) and is formed by multiple nodes (user equipment, routers) connected and cooperating with each other through wireless links. All nodes in the network are equal in status and can independently complete networking, data forwarding, and fault self-healing. Data transmission adopts a multi-hop forwarding mode without fixed transmission paths, realizing a decentralized architecture where "every node is a relay station" and completely getting rid of the dependence on centralized infrastructure.

1.1.2 Definition of Core Roles

• Router: As the core forwarding node of the network, it is responsible for receiving and forwarding all data in the network, and at the same time undertakes the functions of network networking guidance and node status monitoring, which is the key to ensuring network connectivity. It can be flexibly deployed according to scenario requirements, supporting multi-band switching to adapt to different communication distance and rate needs.

• User: As the terminal node of the network, its core function is to initiate and receive communication data. At the same time, according to the network load and its own equipment capabilities, it can voluntarily undertake data forwarding tasks and become a temporary relay node, further expanding the network coverage and improving data transmission reliability. User equipment can include mobile phones, IoT terminals, dedicated communication equipment, etc.

1.2 Core Technical Foundation

1.2.1 Selection of Wireless Communication Frequency Bands

This communication structure adopts internationally general ISM frequency bands such as LoRaWAN, 2.4G, and 5.8G, which do not require frequency band authorization, reducing deployment costs. At the same time, it takes into account the communication needs of different scenarios to achieve complementary advantages:

• LoRaWAN frequency band: Belonging to the Low-Power Wide-Area Network (LPWAN) frequency band, it has the characteristics of long transmission distance (up to several kilometers in suburban areas), low power consumption, and strong anti-interference ability. It is suitable for long-distance, low-rate, low-power IoT terminal communication, such as remote area sensor data transmission and low-power equipment interconnection in emergency communications.

• 2.4G frequency band: A globally general unlicensed frequency band with moderate wavelength, which has both penetration and diffraction capabilities, strong compatibility, and moderate coverage (10~30 meters indoors). It is suitable for short-distance, medium-rate terminal interconnection, such as home IoT equipment and short-distance personal communication, which can meet daily data transmission needs with low equipment costs.

• 5.8G frequency band: A high-frequency ISM frequency band with extremely wide bandwidth (up to 24 available channels), low interference, and high transmission rate (supporting 160MHz ultra-wideband with a rate of up to 2.4Gbps). It is suitable for high-rate data transmission scenarios, such as high-definition video transmission and large-capacity file interaction, but has weak penetration ability, making it suitable for open environments or short-distance high-speed communication scenarios.

The network can automatically switch to the appropriate communication frequency band according to node location, communication needs, and environmental interference, realizing a flexible networking mode of "using LoRaWAN for long distances, 5.8G for short-distance high speeds, and 2.4G for daily interconnection", which takes into account coverage, transmission rate, and power consumption needs.

1.2.2 Core Characteristics of Wireless Mesh Technology

Wireless Mesh technology is the core support of this communication structure. Its characteristics of self-organization, self-healing, and multi-hop forwarding determine the feasibility and reliability of the decentralized network. The core characteristics include:

• Self-organization: After being powered on, nodes (routers, user equipment) can automatically scan surrounding nodes, initiate networking requests, quickly form a mesh communication topology without manual configuration, and adapt to dynamically changing node distribution scenarios, such as rapid networking of temporarily deployed equipment in emergency rescue.

• Self-healing: When a node (router or user undertaking forwarding tasks) in the network fails, goes offline, or the link is interrupted, the network will automatically detect the faulty node, re-plan the data transmission path, and switch to other available nodes for multi-hop forwarding to ensure uninterrupted communication. The self-healing delay is low, and the data packet loss rate can be controlled within 1%.

• Multi-hop forwarding: Data from the initiating node to the target node can be relayed through multiple intermediate nodes (routers or users) without direct connection, greatly expanding the network coverage and solving the problem of limited coverage of a single node. It is especially suitable for scenarios where traditional networks are difficult to cover, such as remote areas and complex terrain.

• Distributed control: There is no central node dominance. All router nodes equally undertake data forwarding and network management functions, avoiding overall network paralysis caused by single-point failures, improving network stability and invulnerability, and meeting the core needs of decentralized communication.

1.2.3 Asymmetric Key Encryption Technology

Asymmetric key encryption (public-key encryption) is the core technology to ensure network communication security. It uses a pair of keys (public key and private key). The public key can be publicly transmitted, and the private key is independently kept by the user and cannot be leaked. The advantages of its core principle are as follows:

1. Separation of encryption and decryption: The sender encrypts data using the receiver's public key, and only the receiver's private key can decrypt the data, ensuring that the data is not stolen or tampered with during transmission. Even if the data is intercepted, it cannot be parsed without the corresponding private key;

2. Identity authentication: Through the method of private key signature and public key verification, the real identity of the sender can be confirmed, preventing security risks such as forged data and impersonated communication, and ensuring the authenticity and non-repudiation of communication;

3. Convenient key management: There is no need to synchronize keys across the entire network. Users only need to keep their own private keys, and public keys can be automatically synchronized through the network, reducing the risk of key leakage and adapting to the characteristics of scattered nodes and no central management in decentralized networks. This communication structure adopts the Elliptic Curve Diffie-Hellman (ECDH) algorithm to optimize the asymmetric key encryption process, ensuring security while reducing computational overhead and adapting to various terminal equipment.

II. System Architecture Design

2.1 Overview of the Overall Architecture

The decentralized mesh communication structure based on wireless Mesh adopts a flat and distributed architecture without core nodes. It is divided into three layers as a whole: the terminal layer, the forwarding layer, and the encryption layer. Each layer works collaboratively to realize a full-process closed loop of networking, data transmission, and security protection. The architecture design takes into account flexibility, reliability, and security, and can flexibly expand the number of nodes according to scenario requirements.

2.2 Detailed Design of the Hierarchical Architecture

2.2.1 Terminal Layer

The terminal layer is composed of all user equipment, which is the data source and data receiving end of the network, covering personal terminals (mobile phones, computers), IoT terminals (sensors, controllers), dedicated communication terminals (emergency walkie-talkies, remote area communication equipment), etc. The terminal layer has the following core capabilities:

• Communication capability: Supports multi-band switching of LoRaWAN, 2.4G, and 5.8G, and can automatically adapt to the optimal frequency band according to communication distance and rate requirements to realize communication with other terminals or routers;

• Optional forwarding capability: User equipment can independently choose whether to undertake data forwarding tasks according to its own hardware performance and power status. When the network load is high or some nodes are offline, it can automatically switch to a temporary relay node to assist routers in completing data forwarding and expand network coverage;

• Key management capability: Each user equipment independently generates a pair of asymmetric keys (public key and private key), keeps its own private key, synchronizes and stores the public keys of other users (for point-to-point encrypted communication) and group keys (for group communication), and supports key update and revocation.

2.2.2 Forwarding Layer

The forwarding layer is composed of router nodes, which are the core backbone of the network. It is responsible for forwarding all data in the network, networking guidance, and node status monitoring. At the same time, it connects the terminal layer and the encryption layer to realize encrypted forwarding and decrypted reception of data. The forwarding layer has the following core capabilities:

• Multi-hop forwarding capability: Receives data sent by the terminal layer or other routers, selects the optimal forwarding path with the best link quality and the least number of hops according to node status and link quality, and relays the data to the target node, supporting multi-path redundancy to improve data transmission reliability;

• Networking management capability: Guides new nodes (users, routers) to join the network, assigns network identifiers, monitors the online status and link quality of all nodes, and automatically triggers the self-healing mechanism to re-plan the forwarding path when a node fails or goes offline;

• Frequency band adaptation capability: Supports simultaneous operation of multiple frequency bands such as LoRaWAN, 2.4G, and 5.8G, and can automatically select the forwarding frequency band according to data type (high rate, long distance), taking into account transmission efficiency and coverage;

• Data transfer capability: Does not store any communication data, only responsible for data forwarding and encrypted transfer, ensuring data privacy and security, and meeting the privacy protection needs of decentralized networks.

2.2.3 Encryption Layer

The encryption layer is the core guarantee of network security, running through the terminal layer and the forwarding layer. Based on asymmetric key encryption technology, it realizes point-to-point communication encryption, group communication encryption, and the full life cycle management of keys, ensuring the security and privacy of data transmission and storage. The encryption layer has the following core capabilities:

• Point-to-point encryption: When communicating between users, the sender encrypts data using the receiver's public key, and the receiver decrypts the data using its own private key, realizing end-to-end encrypted transmission to prevent data from being stolen or tampered with;

• Group encryption: Supports multi-user group communication, and realizes encrypted transmission of data within the group through group keys generated by the group owner. Non-group members cannot obtain the group key and cannot parse the communication content;

• Key management: Responsible for the generation, distribution, update, and revocation of keys, including the independent generation of users' personal asymmetric keys, and the hierarchical generation and permission control of group keys, ensuring the security and timeliness of keys.

2.3 Networking Process Design

The networking process of the decentralized mesh communication structure based on wireless Mesh is fully automatic without manual intervention. The specific process is as follows:

1. Router deployment: Deploy router nodes in the target area. After being powered on, they automatically start, scan surrounding available frequency bands (LoRaWAN, 2.4G, 5.8G), determine the optimal working frequency band, initiate networking broadcasts, and wait for other nodes to join;

2. User node joining: After being powered on, user equipment automatically scans surrounding routers or user nodes that have joined the network, sends a networking request. After receiving the request, the router verifies the node identity (preliminary verification through public key), assigns a network identifier, and completes node access;

3. Topology formation: The accessed nodes (routers, users) automatically establish wireless links with surrounding nodes to form a mesh topology. Each node records information about reachable surrounding nodes and establishes a routing table;

4. Dynamic optimization: The network real-time monitors the link quality and online status of each node. When new nodes are added, nodes fail, or links are interrupted, it automatically updates the routing table and re-plans the forwarding path to ensure network connectivity;

5. Forwarding configuration: User equipment can independently choose whether to enable the forwarding function. After enabling, the equipment will serve as a temporary relay node to receive and forward data from other nodes, expanding the network coverage.

III. Core Operation Mechanisms

3.1 Data Forwarding Mechanism

This communication structure adopts a two-way multi-hop forwarding mechanism of "router-led and user-assisted", taking into account data transmission efficiency and network reliability. The core rules are as follows:

• Core forwarding by routers: As the backbone of the network, routers are responsible for receiving all data in the network, selecting the optimal path with the best link quality and the least number of hops according to the routing table, and forwarding the data to the target node. When a link is interrupted, it automatically switches to a backup path to realize fast data forwarding with a forwarding delay of ≤50ms per hop.

• User-assisted forwarding: User equipment with the forwarding function enabled can receive data sent by surrounding nodes (other users, routers) and forward it to the next node. It is especially suitable for router coverage blind areas or high network load scenarios, further expanding the network coverage and improving the success rate of data transmission. User equipment with the forwarding function disabled only undertakes the sending and receiving of its own data and does not participate in forwarding.

• Data priority: Different forwarding priorities are set according to data types. Emergency data (such as emergency rescue instructions) is forwarded first, and ordinary data (such as daily chat and file transmission) is forwarded normally to ensure the real-time performance of key data. At the same time, data aggregation technology is adopted, and routers summarize data from multiple terminals and report it in batches to reduce network load.

• Link optimization: The network real-time monitors the signal strength and interference of each link, automatically switches communication frequency bands, avoids interfering frequency bands, optimizes the forwarding path, reduces the data packet loss rate, and ensures the stability of data transmission.

3.2 Encrypted Communication Mechanism

3.2.1 Point-to-Point Encrypted Communication

Point-to-point communication between users adopts an asymmetric key encryption mechanism to ensure data security throughout the process. The specific process is as follows:

1. Key generation: Each user equipment independently generates a pair of asymmetric keys (public key and private key). The private key is encrypted and stored locally on the user equipment and cannot be leaked. The public key can be automatically synchronized to all other nodes in the network for other users to use for encrypted communication.

2. Encrypted transmission: When the sender initiates communication, it obtains the receiver's public key, encrypts the communication data using the public key to generate encrypted data, and forwards it to the receiver through the forwarding layer (router or user-assisted forwarding).

3. Decrypted reception: After receiving the encrypted data, the receiver decrypts the data using its own private key to obtain the original communication data. If the data is tampered with or forged, the decryption process will fail, and the receiver will refuse to receive the data, ensuring the integrity and authenticity of the data.

4. Identity authentication: When sending data, the sender signs the data using its own private key. The receiver verifies the signature using the sender's public key to confirm the real identity of the sender, preventing security risks such as impersonated communication and data forgery.

3.2.2 Group Encrypted Communication

Multiple users can realize group communication through the same key. According to the different key management methods, groups are divided into two modes: with dominant mode and without dominant mode. The two modes adapt to the needs of different scenarios, and the core mechanisms are as follows:

3.2.2.1 With Dominant Mode

The mode with dominant mode is a group communication mode in which the group owner leads key management. It adopts a mechanism of "group owner-led, hierarchical authorization, and key time limit control", taking into account the security and flexibility of group communication. The specific rules are as follows:

1. Key generation: A device acts as the group owner, independently generating a pair of group keys (group public key and group private key). The group public key is used for encrypting data within the group, and the group private key is kept by the group owner for generating subordinate keys and updating keys.

2. Key distribution: The group owner generates new sub-keys through its own private key and distributes them to subordinate users who need to join the group. The sub-keys are used in conjunction with the group public key and can only decrypt the encrypted data within the group, ensuring that non-group members cannot obtain the communication content.

3. Hierarchical authorization: The group owner can generate sub-keys with management permissions through its own private key and distribute them to designated subordinate users, authorizing them as administrators. Administrators can use the authorized keys to invite new users to join the group (generate new sub-keys and distribute them to new users), assist the group owner in managing the group, and realize hierarchical management of the group.

4. Key update: The validity of permissions is determined by the validity period of the key. The group owner or administrator needs to regularly (set the validity period according to scenario requirements) generate new group sub-keys and distribute them to all group members to realize key update and ensure communication security. If the key is not updated after expiration, members will not be able to continue participating in group communication and need to obtain a new key again.

5. Member management (kick-out function): If it is necessary to kick out a user or an administrator, the group owner only needs to generate a new sub-key during key update and distribute it to all group members except the kicked-out person. The kicked-out person who does not obtain the new key will not be able to decrypt the new data in the group, thereby realizing the kick-out function without additional deletion operations, simplifying the management process.

6. Offline key update: Offline group members can send a key update request to the group owner separately after going online. After the group owner verifies their identity (through user public key or preset identity information), it distributes the new sub-key to the member to ensure that they can normally participate in group communication without affecting the overall communication efficiency of the group.

3.2.2.2 Without Dominant Mode

The mode without dominant mode is a group communication mode without a clear group owner and not relying on a single node to manage keys. It is mainly divided into two categories: unencrypted groups and symmetric encrypted groups. It does not require complex hierarchical key management, and only needs to obtain the corresponding key to join. The specific rules are as follows:

• Unencrypted group: All data in the group is transmitted in plaintext without any encryption operations. Any user accessing the network can join the group, receive and send data in the group as long as they obtain the group identifier. This mode is suitable for scenarios that have no requirements for communication privacy and only need to realize simple group interaction (such as public notifications, temporary collaborative communication). Its advantage is convenient access and no key management cost, and its disadvantage is extremely low data security, which is vulnerable to theft and tampering.

• Symmetric encrypted group: Adopts a symmetric key encryption method, that is, all members in the group use the same set of symmetric keys (the same key is used for encryption and decryption). There is no need for the group owner to distribute keys. Any user can join the group as long as they obtain the symmetric key, and use the key to encrypt, transmit, decrypt, and receive group data. The key can be independently shared by group members (such as offline transmission, point-to-point encrypted sending) without a fixed management node. If it is necessary to kick out a member, all group members need to synchronously replace the new symmetric key and not share the new key with the kicked-out person to realize member kick-out. This mode is suitable for small-scale, high-trust group scenarios (such as family internal, small team temporary communication). Its advantage is high encryption and decryption efficiency and simple operation, and its disadvantage is that the key is easy to leak, there is no unified key update management mechanism, and the security is lower than that of the mode with dominant mode.

The two group modes can be flexibly selected according to the user's needs for security and convenience. The mode with dominant mode focuses on security and controllability, and is suitable for scenarios that require communication privacy and member management. The mode without dominant mode focuses on convenience and efficiency, and is suitable for scenarios with low security requirements and the need to quickly form groups.

3.3 Node Management Mechanism

3.3.1 Node Access and Revocation

When a node (user, router) accesses the network, it needs to pass identity verification (based on public key verification). After the router approves it, it assigns a unique network identifier to complete the access. When a node is revoked, it automatically sends a revocation notification to surrounding nodes, deletes its own routing information, and the network automatically updates the topology to ensure the accuracy of the routing table.

3.3.2 Node Status Monitoring and Self-Healing

Routers real-time monitor the online status and link quality of all nodes in the network. When a node failure, offline, or link interruption is detected, the self-healing mechanism is immediately triggered to re-plan the data transmission path and switch to other available nodes to ensure uninterrupted data transmission. After the faulty node is restored, it automatically reconnects to the network, and the network updates the routing table to restore normal forwarding functions. This self-healing capability greatly improves the invulnerability of the network, with a self-healing rate of more than 99.9%, which is far superior to traditional centralized networks.

3.3.3 Load Balancing

The network real-time monitors the forwarding load of each router and user-assisted forwarding. When the load of a node is too high, it automatically distributes some forwarding tasks to nodes with lower load, avoiding data packet loss and increased delay caused by overloading of a single node, ensuring overall network load balancing and improving data transmission efficiency. At the same time, dynamic channel selection technology is used to avoid interfering frequency bands and further optimize network performance.

IV. Technical Advantages and Innovations

4.1 Core Technical Advantages

4.1.1 Decentralized Architecture with Strong Invulnerability

There is no dependence on core nodes. All nodes work collaboratively on an equal basis. A single-point failure will not lead to overall network paralysis. The network has extremely strong self-healing capabilities, which is suitable for scenarios without infrastructure coverage such as emergency rescue and remote areas. It can maintain unobstructed communication in extreme environments and solve the pain point of traditional centralized networks where "a single-point failure leads to overall network paralysis".

4.1.2 Multi-Band Fusion with Flexible Coverage

It integrates the advantages of multiple ISM frequency bands such as LoRaWAN, 2.4G, and 5.8G, and can automatically switch frequency bands according to scenario requirements, taking into account long-distance, medium-rate, and high-rate communication needs. The coverage can be expanded from tens of meters (indoor) to several kilometers (suburban), adapting to diversified scenarios such as personal, family, IoT, and emergency. There is no need to deploy additional dedicated frequency band equipment, reducing deployment costs.

4.1.3 Safe and Reliable with In-Place Privacy Protection

It adopts asymmetric key encryption technology, realizing end-to-end encryption for both point-to-point and group communication, ensuring that data is not stolen or tampered with during transmission. Keys are independently kept by users, group keys are managed hierarchically and updated regularly, and members can be kicked out without additional operations, simplifying management while ensuring communication security. Routers only responsible for data forwarding and do not store any communication data, protecting user privacy. Compared with traditional encryption schemes, this scheme achieves a better balance between security and efficiency. The Bit Error Rate (BER) of eavesdroppers can reach more than 95%, while maintaining the same transmission reliability as the unencrypted state.

4.1.4 Low Deployment Cost and Strong Scalability

It adopts unlicensed ISM frequency bands, which do not require frequency band authorization. Routers can be flexibly deployed, and user equipment can assist in forwarding, eliminating the need for large-scale deployment of core infrastructure, reducing hardware investment and deployment costs. The network supports dynamic increase and decrease of nodes, which can flexibly expand the number of nodes according to scenario requirements, adapting to communication needs of different scales. Nodes reuse terminal and routing functions, further reducing networking costs. Compared with traditional centralized networks, the networking cost can be reduced by 30%~50%.

4.1.5 Automatic Networking with Convenient Operation and Maintenance

Node access, networking, self-healing, and load balancing are all automated without manual intervention, reducing operation and maintenance costs. Users can independently choose whether to participate in forwarding, flexibly adapting to different equipment capabilities. Group management is realized through key update, with a simple process and no complex management operations, suitable for non-professional operation scenarios.

4.2 Innovations

• Collaborative forwarding mode between users and routers: Breaking the limitation of traditional Mesh networks where only routers are responsible for forwarding, allowing user equipment to assist in forwarding according to their own capabilities, further expanding network coverage and improving network reliability, especially suitable for scenarios with scattered nodes and insufficient router deployment.

• Hierarchical group key management and time limit control: Through the group owner generating keys, hierarchically authorizing administrators, and regularly updating keys, flexible group management is realized. Member kick-out and permission update are all completed through key operations, simplifying the management process and ensuring the security of group communication, solving the problems of complex permission management and easy key leakage in traditional group communication.

• Multi-band adaptive switching: Integrating the advantages of multiple ISM frequency bands, automatically switching to the optimal frequency band according to communication distance, rate, and interference, taking into account coverage and transmission efficiency, adapting to diversified scenarios, breaking the application limitations of a single frequency band, and realizing multi-scenario adaptation of "long distance, high speed, and low power consumption".

V. Application Scenarios

Based on the advantages of decentralization, wide coverage, high security, low cost, and easy deployment, the decentralized mesh communication structure based on wireless Mesh can be widely applied in many fields, including personal communication, IoT, emergency rescue, remote area communication, etc. The specific scenarios are as follows:

5.1 Emergency Rescue Communication

In natural disaster scenarios such as earthquakes, floods, and typhoons, traditional communication infrastructure (base stations, gateways) is easily damaged, leading to communication interruptions. This communication structure can quickly deploy routers and emergency terminals to realize automatic networking without relying on existing infrastructure. Rescuers can conduct point-to-point and group communication through terminals to transmit key information such as rescue instructions and personnel positions. User terminals (such as rescue walkie-talkies and mobile phones) can assist in forwarding data, expanding the communication coverage of the rescue area and ensuring the efficient development of rescue work. At the same time, the low-power consumption characteristic can ensure that terminal equipment works for a long time without power supply, adapting to extreme rescue scenarios.

5.2 Remote Area Communication

In remote areas such as rural areas, mountainous areas, and deserts, the deployment cost of traditional communication infrastructure is high and the coverage is difficult, resulting in inconvenient communication. This communication structure can realize a wide-coverage communication network by deploying a small number of routers combined with the auxiliary forwarding of user equipment, meeting the daily call and data transmission needs of local residents. At the same time, it adapts to the long-distance transmission characteristics of the LoRaWAN frequency band, realizing the transmission of sensor data in remote areas (such as agricultural monitoring and environmental monitoring), helping the digital construction of remote areas without investing a lot of funds in building centralized base stations.

5.3 IoT Terminal Interconnection

In scenarios such as smart homes, industrial IoT, and smart agriculture, a large number of IoT terminals (sensors, controllers, smart equipment) need to achieve distributed interconnection, requiring low power consumption, wide coverage, and high security. This communication structure can realize automatic networking of IoT terminals, realizing long-distance, low-power terminal interconnection (such as agricultural sensors and industrial controllers) through the LoRaWAN frequency band, and short-distance, high-rate terminal interconnection (such as smart home equipment and high-definition monitoring) through the 2.4G and 5.8G frequency bands. The encryption mechanism ensures the secure transmission of terminal data, preventing data leakage and equipment being controlled, adapting to the core needs of IoT scenarios.

5.4 Personal and Family Communication

In family scenarios, small routers can be deployed to realize distributed interconnection of mobile phones, computers, and smart home equipment, getting rid of the dependence on home broadband gateways. Even if the broadband is interrupted, communication between home internal equipment can still be realized. Users can protect personal privacy through point-to-point encrypted communication and realize convenient interaction between family members through group communication. At the same time, the 5.8G frequency band can support high-speed transmission of high-definition video and large-capacity files, improving the family communication experience.

5.5 Temporary Scenario Communication

In temporary scenarios such as large-scale events, temporary construction sites, and field exploration, it is necessary to quickly build a temporary communication network to meet the communication needs between personnel. This communication structure can quickly deploy routers and terminal equipment to realize automatic networking with a short deployment cycle and low cost. The network can flexibly increase or decrease nodes according to the number of personnel and scenario scope, adapting to the dynamic needs of temporary scenarios. After the event, it can be quickly dismantled and the equipment can be reused, reducing the deployment cost of temporary communication.

VI. Challenges and Prospects

6.1 Facing Challenges

• Technical challenges: The switching efficiency of multi-band fusion still has room for improvement. In complex interference environments, the timeliness and stability of frequency band switching need to be further optimized. The load control of user-assisted forwarding needs to be improved to avoid excessive power consumption and performance degradation of some user equipment due to excessive forwarding. The computational efficiency of asymmetric key encryption needs to be optimized to adapt to low-performance IoT terminals.

• Standardization challenges: At present, the networking protocols and encryption standards of wireless Mesh technology are not yet fully unified, and the compatibility of equipment from different manufacturers is poor. It is necessary to promote the construction of industry standardization to realize interconnection and intercommunication of different equipment and reduce the application threshold.

• Application challenges: In some scenarios, users' awareness of decentralized communication is low, and acceptance needs to be improved. At the same time, some scenarios (such as industrial IoT) have extremely high requirements for communication real-time and reliability, and further technical optimization is needed to meet the needs of high-end scenarios. In addition, the convenience of key management needs to be improved to reduce the operation difficulty for non-professional users.

6.2 Future Prospects

With the continuous development of wireless communication technology, encryption technology, and IoT technology, the decentralized mesh communication structure based on wireless Mesh will usher in a broader development space. In the future, it will focus on advancing in the following directions:

• Technical optimization: Further improve the switching efficiency of multi-band fusion, optimize the load control algorithm of user-assisted forwarding, and reduce equipment energy consumption. Optimize the asymmetric key encryption algorithm to improve encryption efficiency and adapt to low-performance terminals. Introduce AI technology to realize intelligent optimization of network topology and intelligent prediction of faults, improving network reliability and operation and maintenance efficiency. Combine Physical Layer Security (PLS) technology to achieve unconditional security and resist emerging security threats such as quantum cryptanalysis.

• Standardization promotion: Promote the standardization of networking protocols, encryption standards, and equipment interfaces in the industry, realize interconnection and intercommunication of equipment from different manufacturers, build a complete industrial ecosystem, reduce application costs, and promote the large-scale popularization of technology.

• Scenario expansion: Further expand application scenarios, in-depth layout in fields such as industrial IoT, smart cities, emergency rescue, and remote area communication, optimize products and technical solutions according to specific scenario needs, and improve scenario adaptation capabilities. Explore the integrated application with 5G and satellite communication to realize a "space-ground integrated" decentralized communication network, breaking the coverage limitations of ground communication.

• Ecosystem construction: Attract more enterprises and scientific research institutions to participate in technological R&D and product implementation, build a complete industrial ecosystem of "chip-equipment-application-service", promote the industrialization development of technology, and make decentralized communication technology benefit more fields and users.

VII. Conclusion

The decentralized mesh communication structure based on wireless Mesh, based on ISM frequency bands such as LoRaWAN, 2.4G, and 5.8G, integrates wireless Mesh technology and asymmetric key encryption technology, building a distributed communication network with "decentralization, self-organization, self-healing, and high security". Through the collaborative forwarding of routers and users, this structure realizes the communication needs of wide coverage and low cost. Through flexible encrypted communication mechanisms and group management mechanisms, it ensures the security and flexibility of communication. Its flat and distributed architecture completely gets rid of the dependence on centralized infrastructure, effectively solving the pain points of traditional communication networks such as single-point failures, insufficient coverage, high costs, and security risks.

This communication structure can be widely applied in many fields such as emergency rescue, remote area communication, IoT terminal interconnection, and personal and family communication, with extremely high technical value and application potential. Although it still faces challenges such as technical optimization, standardization promotion, and application popularization, with the continuous iteration of technology and the continuous improvement of the industrial ecosystem, the decentralized mesh communication structure based on wireless Mesh will surely become an important development direction of future communication networks, providing a new solution for the decentralized, secure, and diversified development of the global communication industry, and promoting the high-quality development of the digital economy.

Appendix

Appendix 1 Explanation of Key Technical Terms

• Wireless Mesh Network: A distributed multi-hop topology network with core characteristics of self-organization, self-healing, and distributed control. Nodes can realize data interaction through direct connection or multi-hop forwarding without relying on central nodes.

• ISM Frequency Band: Industrial, Scientific, Medical frequency band, which is an unlicensed frequency band, globally general, without the need for frequency band authorization, suitable for scenarios such as wireless communication and IoT.

• Asymmetric Key Encryption: Also known as public-key encryption, it uses a pair of keys (public key and private key). The public key can be made public, and the private key is kept by the user. The sender encrypts data using the receiver's public key, and the receiver decrypts the data using its own private key to realize secure communication.

• Multi-hop Forwarding: Data from the initiating node to the target node is relayed through multiple intermediate nodes without direct connection, expanding the network coverage.

• Self-Healing: The ability of the network to automatically detect and re-plan the data transmission path to ensure uninterrupted communication when a node fails or a link is interrupted.

Appendix 2 Reference Standards and Literature

1. IEEE 802.11s: Wireless Mesh Network Protocol Standard

2. LoRaWAN Protocol Specification (LoRa Alliance)

3. Application Specification for Asymmetric Encryption Technology (GB/T 32918-2016)

4. 《Asymmetric Physical Layer Encryption Over Stationary Time Selective Wireless Communication Channel》(IJISRT)

5. 《Multi-Dimensional Exploration and Innovative Development of Key Management Schemes in Secure Group Communication》

6. 《In-Depth Analysis of Mesh Network Technology: From Distributed Topology to Complex Scenario Implementation》

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