Showing papers by "Zhongjiang Yan published in 2022"

Idea and Theory of Particle Access

Abstract: Aiming at some problems existing in the current quality of service (QoS) mechanism of large-scale networks (i.e. poor scalability, coarse granularity for provided service levels, poor fairness between different service levels, and improving delay performance at the expense of sacrificing some resource utilization), the paper puts forward the idea and thoery of particle access. In the proposed particle access mechanism, the network first granulates the information flow (that is, the information flow is subdivided into information particles, each of which is given its corresponding attributes), and allocates access resources to the information particle group which is composed of all the information particles to be transmitted, so as to ensure that the occupied bandwidth resources is minimized on the premise of meeting the delay requirements of each information particle. Moreover, in the paper, the concepts of both information particle and information particle group are defined; Basic properties of the minimum reachable access bandwidth of an information particle group are analyzed; The influences of time attribute and attribute of bearing capacity of an information particle group on the minimum reachable access bandwidth are analyzed; Finally, an effective method for the calculation of the minimum reachable access bandwidth of an information particle group is given, and a particle access algorithm based on dynamically adjusting the minimum reachable access bandwidth is proposed. The research of the paper pave a new way for further improving QoS mechanisms of large-scale networks, and lay the corresponding theoretical foundation.

Theory of Network Wave

Abstract: Aiming at the disorder problem (i.e. uncertainty problem) of the utilization of network resources commonly existing in multi-hop transmission networks, the paper proposes the idea and the corresponding supporting theory, i.e. theory of network wave, by constructing volatility information transmission mechanism between the sending nodes and their corresponding receiving nodes of a pair of paths (composed of two primary paths), so as to improve the orderliness of the utilization of network resources. It is proved that the maximum asymptotic throughput of a primary path depends on its intrinsic period, which in itself is equal to the intrinsic interference intensity of a primary path. Based on the proposed theory of network wave, an algorithm for the transmission of information blocks based on the intrinsic period of a primary path is proposed, which can maximize the asymptotic throughput of a primary path. In the cases of traversals with equal opportunities, an algorithm for the cooperative volatility transmission of information blocks in a pair of paths based on the set of maximum supporting elements is proposed. It is proved that the algorithm can maximize the asymptotic joint throughput of a pair of paths. The research results of the paper lay an ideological and theoretical foundation for further exploring more general methods that can improve the orderly utilization of network resources.

A Two-Level Adaptive Resource Allocation Algorithm for Quality of Service Guarantee in Home WiFi Networks

Abstract: Aiming at the problem that the service quality of audio and video, large file transmission and other services is difficult to guarantee in the home Wireless Fidelity (WiFi) network, this paper proposes a two-level adaptive resource allocation algorithm for quality of service guarantee (TRAQ), which can effectively avoid the starvation of large file transmission, to improve the success rate of audio and video service establishment and the fairness of multiple large file transmissions. Firstly, the quality-of-service guarantee problem of audio and video, large file transmission is modeled as the resource allocation problem in the scheduling period, with the goal of minimizing the Gini coefficient of multiple large file transmission rates and the constraint of ensuring the average transmission rate of all large files and the call loss rate of audio and video. Then, the arrival and service process of audio and video services is modeled as a M/M/m/m queuing model, and the first-level resource allocation ratio between the audio and video services and the large files services is obtained. Secondly, the second-level resource allocation ratio minimizing the Gini coefficient of large file transmission services is derived. Finally, the simulation results show that the proposed TRAQ not only balances the service requirements between the two types of services, but also achieves a certain transmission fairness within the large file transmission services.

A Coexistence Method of Short-Range Heterogeneous Network Based on Cell Cooperation

Abstract: The rapid economic development has promoted the rapid increase of mobile traffic and mobile devices. Short-range wireless networks working in unlicensed frequency bands have attracted widespread attention due to their advantages of openness, freeness and high rate. Therefore, there are many types of short-range wireless networks working in unlicensed frequency bands, such as WLAN, Bluetooth, ZigBee, etc. When the above two or more networks are arranged in the same place, serious interference between the networks will be caused by spectrum overlap. The hybrid MAC network can flexibly configure time slots of Time Division Multiple Access (TDMA) and Carrier Sense Multiple Access with Collision Avoid (CSMA/CA). Therefore, a coexistence method of short-range heterogeneous network based on cell cooperation (CM-HNCC) was proposed to solve the coexistence of hybrid MAC network and Wi-Fi. This algorithm can reduce the delay of high priority traffic and improve the throughput of hybrid MAC network under the premise of ensuring network fairness. Finally, the effectiveness of CM-HNCC is verified by establishing mathematical model and simulation.

On the necessity of separating MAC protocols into data and control planes

Abstract: —The network protocol architecture not only can be designed from the traditional view of layers, but also can be designed from the view of planes, i.e., the data, control and management planes. Media access control (MAC) is a function of the data link layer, and thus the MAC protocols involve of both the data and control planes. However, although the international wireless local area network (WLAN) standard, IEEE 802.11 or Wi-Fi, has developed over 20 years, the control plane of the MAC protocols is not explicitly described yet. Thus, does it need to separate the MAC protocols into data and control planes? If not, are there some problems in existing hybrid architecture? To answer above questions, we analyse the possible problems of the current MAC protocols in IEEE 802.11, particularly in std 802.11-2020. These problems can be seen as new starts for the next study of the WLAN for the next generation (WNG).

Edge Station Throughput Enhancement Method Based on Energy Detection Threshold and Transmission Power Joint Dynamic Adjustment

Abstract: With the surge in demand for wireless traffic and network quality of service, wireless local area network (WLAN) has developed into one of the most important wireless networks affecting human life. In high density scenarios, large numbers of Access Point (APs) and Stations(STAs) will be deployed in a limited area, means large amount of signals will be overlapped and coverage between Basic Service Sets (BSSs), interference and collisions will become more severe, and if the sensitivity of edge STA detection channel is not enough, such as the energy detection (ED) threshold and reception sensitivity mismatch of STAs, edge STA’s throughput may slow down seriously. So in this paper, we propose an edge STA throughput enhancement method based on ED threshold and TXPower joint dynamic adjustment to solve the problem of edge STA deceleration caused by ED threshold and reception sensitivity mismatch. By appropriately adjusting the ED threshold and TXPower of the BSSs with deceleration edge STAs, improving the sensitivity of edge STAs detection channel, and opportunity of edge STA’s transmission packet is not greatly affected. Through the method of establishing mathematical model and simulation verification, it has great practical significance.

Research on Backbone Routing Protocol of Ad Hoc Network Based on SDN

Abstract: In recent years, with the development of Internet of Things and UAV network, Ad Hoc networks have increased the number of nodes, enhanced node mobility, and become more sensitive in delay. However, the existing Ad Hoc network routing protocols have some disadvantages, such as high signaling overhead, slow response speed and slow convergence speed. In order to improve the efficiency of routing protocols, we propose a backbone routing protocol based on SDN (software defined network). The core idea of the protocol is as follows. Firstly, there is a logical centralized controller to implement the control plane strategy such as backbone node selection algorithm, and the centralized controller can switch between deep control and shallow control flexibly according to the network state. Secondly, the backbone nodes exchange control signaling, and other nodes transmit data through the backbone nodes, which can reduce the signaling cost and ensure the response speed and convergence speed of routes. Simulation results in multiple topologies show that the centralized backbone routing protocol significantly reduces the overhead of establishing routes and improves the throughput.

A Channel Reservation Mechanism in IEEE 802.11be for Multi-cell Scenarios

Abstract: With the surge in demand for latency-sensitive traffic, the next-generation Wireless Local Area Network (WLAN) standard IEEE 802.11be has recognized the improvement of worst-case latency and jitter as one of its core objectives. Reservation-based contention-free channel access scheme achieves lower latency. Nevertheless, the channel reservation still has some limitations. In a multi-cell scenario, the Access Point (AP) is not capable of managing external cell users, which will cause interference to the reserved users during the reservation period, resulting in deteriorating channel conditions and increasing latency. Hence, in this paper, we propose a channel reservation mechanism with multi-cell coordination capability, enabling the sharing of channel reservation information among different cell APs and restricting the corresponding users to remain in silence during the reservation period, to avoid interference from internal and external cell users on the reserved users. Moreover, we propose a management frame protection scheme based on channel reservation mechanism that reduces the probability of management frame loss by offering channel reservation to the management frames. The effectiveness of the channel reservation mechanism and the management frame protection scheme is verified by simulations. It is demonstrated that the latency of latency-sensitive traffic in a multi-cell scenario using the proposed mechanism is significantly improved over the existing works.

Theory of Network Wave (On a Primary Path)

Abstract: ： Aiming at the disorder problem (i.e. uncertainty problem) of the utilization of network resources commonly existing in multi-hop transmission networks, the paper proposes the idea and the corresponding supporting theory, i.e. theory of network wave, by constructing volatility information transmission mechanism between the sending nodes of a primary path, so as to improve the orderliness of the utilization of network resources. It is proved that the maximum asymptotic throughput of a primary path depends on its intrinsic period, which in itself is equal to the intrinsic interference intensity of a primary path. Based on the proposed theory of network wave, an algorithm for the transmission of information blocks based on the intrinsic period of a primary path is proposed, which can maximize the asymptotic throughput of the primary path. The research results of the paper lay an ideological and theoretical foundation for further exploring more general methods that can improve the orderly utilization of network resources.

A Collision Aware Multi-link Operation for Next Generation WLAN

Abstract: In a wireless local area network (WLAN), when the contention is fierce, most of the frames are collided and backoff windows are doubled, resulting in a low channel efficiency. 802.11 be introduces multi-link opertaions (MLO) but faces nonsimultaneous transmit and receive (NSTR) problem which limits the prospects of multi-links. In this paper a new multi-link operation scheme is proposed. When a link is transmitting, antennas from the other link usually suffer huge inteference and can’t receive properly. In the proposed scheme the interfered antennas are switched to the transmitting link to monitor collisions. If collisions are detected, one of the colliders stops transmitting. Collisions are thus eliminated at the early stage. Simulation shows that using this scheme, the channel efficiency of a highly competitive network stays at a high level compared to traditional solutions. Simulation also shows that the proposed scheme offers better QoS.

Joint Energy Detection and Transmission Power Adjustment for FIM Problem in High Density WLANs

Abstract: With the rapid development of mobile internet services, the intensive deployment of wireless local area network (WLAN) is inevitable. Traditional WLAN uses carrier sense/collision avoidance (CSMA/CA) mechanism to avoid interference between links as much as possible. In the multi access points (APs) scenario, the traditional CSMA/CA may lead to the flow in the middle (FIM) problem, resulting in a sharp reduction in the throughput of the intermediate nodes and affecting the fairness of the whole network. Existing researches have shown that the FIM problem is more serious in the high density WLAN network. The existing researches on the FIM problem mainly focus on the dynamic optimization of a single parameter, the fairness and performance of the network cannot be well guaranteed. Therefore, this paper proposes a FIM oriented down link (DL) multi-parameter joint dynamic control scheme. AP as a centralized controller, regularly obtains the transmission status of the whole network, reduces the transmission opportunities of the strong AP through adaptive dynamic power and energy detection threshold control (A-DPEC) algorithm, and improves the transmission opportunities of the starvation AP, so as to achieve the performance and fair balance of the whole network. The simulation results show that the proposed scheme outperforms the comparing schemes.

An Adaptive Beamtracking Method for the Next Generation mmWave WLAN

Abstract: With the development of next generation mobile communication and short distance communication, mmWave is becoming more and more critical. The transmission rate and bandwidth of mmWave are greater than that of low frequency band. mmWave can effectively provide large-flow and low-latency service over short distances. Next generation WLAN, such as 802.11ad/ay, already uses mmWave. mmWave uses the directional gain antenna, and beamtracking is performed to determine the new working beam when one end of the communication is displaced. The beamtracking method is designed in detail in 802.11ad /ay: beamtracking is performed after data is sent. This method takes the delay into account, but it is easy to lose packets when nodes move quickly. To address this issue, we design an adaptive beamtracking method (ABT), which adjusts the order of sending data and performing beamtracking according to the number of consecutive beamtracking request. It can take both throughput and delay into account. The simulation results show that the adaptive beamtracking method can achieve the same delay as the beamtracking method in 802.11ad/ay, and the throughput is greater than the beamtracking method in 802.11ad/ay.

Bidirectional Scanning Based Medium Access Control Algorithm in Directional Aviation Relay Network with Multiple Air Nodes

Abstract: Directional aviation relay networks are widely used to improve the performance of ad hoc networks. Aiming at the disadvantage of large data packet delay of directional aviation relay network with single air node, this paper proposes a medium access control algorithm based on multiple air nodes and bidirectional scanning, which can effectively reduce the total delay of data packets. First, the algorithm divides multiple air nodes into two groups, using clockwise and counterclockwise scanning modes respectively, to provide data relay and forwarding services for ground nodes. According to the number of air nodes and their scanning mode, as well as the sector in which the destination node of the to-be-sent traffic is located, the ground nodes determine whether the to-be-sent traffic uses a single-aircraft relay two-hop transmission or a double-aircraft relay four-hop transmission link in a distributed manner. Secondly, the theoretical model of unidirectional scanning and bidirectional scanning algorithm is built, and the theoretical packet delay distribution law of the two algorithms as well as the optimal ratio of bidirectional scanning algorithm in reducing packet delay compared with unidirectional scanning algorithm is obtained. Finally, the performance of the proposed algorithm is verified by simulation. The simulation results are consistent with the theoretical analysis, which show that in the case of 4 to 8 air nodes, compared with unidirectional scanning algorithm, the total delay of packets in bidirectional scanning algorithm is reduced by 23.10 $$\%$$ –28.81 $$\%$$ .

A Joint Optimization Method for Scheduling and Random Access Based on the Idea of Particle-Based Access in IEEE 802.11ax

Abstract: At present, there are some problems in the mechnism of guarantee for the delay of uplink service in IEEE 802.11, 1) Many studies have optimized the expectation of delay of random access, but cannot privide deterministic guarantee of delay. 2) Scheduling access can effiectively provides guarantee for the performance of the delay of service, but there are some very urgent packets that cannot tolerate the waiting time required by scheduling. 3) There are few studies that consider optimal the delay of both scheduling and random access. To solve these problems, this paper proposes a joint optimization method of scheduling and random access, based on the idea of minimum access bandwidth in the theory of particle access and the corresponding access strategy: EDF (Early Deadline First). As a result, the packets created by scheduling users are in the minimum access bandwidth range at each time, and the idle time-frequency resources are distributed as evenly as possible in time. Therefore, the probability of collision between random access users and the resulting long waiting time can be reduced. The simulation results show that under the condition of moderate total traffic, the joint optimization method proposed in this paper can significantly reduce the access delay of random users on the premise of ensuring the delay requirements of scheduling users. The research result of this paper provides a new idea for further optimizing the delay of the scheduling and random users.

Non-uniform Time Slice Parallel Simulation Method Based on Offline Learning for IEEE 802.11ax

Abstract: With the rapid development of wireless networks, wireless local area networks (WLAN) are becoming more and more complex and densely deployed, resulting in a significant increase in the time consumption of traditional serial simulations. Aiming at the time consumption problem of traditional discrete-event-based WLAN serial simulation, A parallel simulation method is proposed based on offline learning with non-uniform time slices, which effectively reduces the time consumption. Firstly, the parallel simulation task is modeled as a problem of completing the simulation task within a given time consumption threshold constraint based on the processes pool. Secondly, the time consumption factor is obtained by offline learning of the simulation platform. Thirdly, the parallel simulation algorithm of non-uniform time slice division (NUTSD) based on the time consumption factor is proposed to analyze and solve the problem. Finally, the method is simulated and verified. The simulation results show that this method can greatly reduce time consumption.