An Access Selection Scheme in 5G Heterogeneous Wireless Networks for Smart Distribution Grids

With the increasing number of users and the complexity of services, only single communications network cannot meet its request in smart distribution grid(SDG).Therefore, heterogeneous network is an effective way to solve this situation. In this paper, a new approach of heterogeneous wireless network for SDG based on the chi-square distance is proposed and investigated. The algorithm firstly estimate weights of network attributes using analytic hierarchy process(AHP) according to different types of service which depends more on the consideration for the user side. Secondly, the CRITIC and anti-entropy weighting method are used to determine the objective weight according to the actual network parameters, and the final weight is obtained by the comprehensive weighting method based on the alignment minimization. Finally measure the chi-square distance from each candidate network to the ideal network, and the candidate network of smallest chi-square distance is the best access network.

The industrial Internet of Things (IIoT) is one of the key applications in 5G heterogeneous networks. To support high energy efficiency (EE) and reliability of IIoT equipment, it is important to design an efficient resource allocation algorithm in dynamic and complex environments. However, most of the studies on 5G heterogeneous IIoT networks did not address the transceiver hardware impairment (HWI) issues (e.g., phase noises, amplifier nonlinearities, and quantization errors) and the corresponding algorithms may not be applicable in practice. To this end, in this article, we investigate a realistic beamforming algorithm in a multicell downlink multiple-input single-output heterogeneous IIoT network by incorporating HWIs in our design. In particular, a beamforming design problem is formulated as a nonconvex optimization problem for maximizing the total EE of all equipment subject to the quality of service constraints of the IIoT equipment in both the macrocell and femtocells and the maximum transmit power constraints of base stations. In light of the intractability of the considered problem, we develop an EE-based iterative beamforming algorithm to tackle the formulated problem by employing the semidefinite relaxation method, Dinkelbach’s method, and the successive convex approximation method. Simulation results show that the proposed algorithm can achieve higher EE and bring less interference power to the macrocell IIoT equipment by comparing it with baseline algorithms.

Deep excavation construction safety has become a challenging and crucial aspect of modern infrastructure engineering, and its risk assessment is frequently carried out using the Fuzzy Analytic Hierarchy Process (FAHP). However, when using FAHP to evaluate the risks of deep excavation construction, the results of the weightings obtained through subjective weighting are heavily influenced by the subjective factors of the evaluators. In addition, using linear operators to calculate the risk level can easily cause a weakening effect on the influence of prominent risk factors, resulting in poor rationality of the evaluation results. To address these problems, this paper constructs a deep excavation construction risk evaluation model based on combined weighting and nonlinear FAHP. The WBS-RBS method is used to guide the construction of the risk evaluation index system for deep excavation construction. The combined weighting values of subjective and objective weightings are calculated through the game theory combined weighting method. The fuzzy relation matrix is constructed using the membership degree vector obtained from the expert evaluation method. Nonlinear operators are introduced for comprehensive calculation. According to the maximum membership degree principle, the final risk level of the excavation construction is obtained. The newly constructed model is applied to the risk analysis of the deep excavation construction of the Rongmin Science and Innovation Park project in Xi’an. The evaluation result for the excavation construction risk is N= [0.3125, 0.3229, 0.1939, 0.0854, 0.0854], and according to the maximum membership degree principle, the risk level of the excavation is classified as Level 2, which is a relatively low risk. Based on the deep excavation construction of the Rongmin Science and Innovation Park project, this paper discusses the differences between the new model and the traditional FAHP evaluation method, further verifies the reliability of the new model, optimizes the construction plan based on the evaluation results, avoids risks, and determines its guiding significance.

Many studies have shown that Vegas TCP has a better throughput and stability than Reno TCP in homogeneous networks with a single TCP flavor, but performs less well in heterogeneous networks in which two TCP flavors coexist. The progressive behavior of Reno TCP and the conservative behavior of Vegas TCP cause a bias when they are used simultaneously, and thus Vegas TCP fails to obtain a fair share of the bandwidth. This paper examines the origins of this bias and proposes a threshold-based congestion control mechanism designed to alleviate the resulting unfairness problem. The simulation results show that the proposed scheme achieves a higher throughput than the conventional Vegas TCP scheme and preserves the stability of the conventional scheme when used in heterogeneous wired and wireless networks.

The wireless technologies in a heterogeneous wireless network usually differ in terms of, but not limited to, their offered bandwidths, operating frequencies and costs, coverage areas, and latencies. Currently, no single wireless technology claims to provide cost-effective services, which offers high bandwidths and low latencies to all mobile users in a large coverage area. This is where the need for well-organized vertical handoffs (VHOs) between heterogeneous wireless technologies become evident. This paper presents a new VHO algorithm which takes into account a complete set of system attributes to fulfill two tasks. The first task is to perform the VHO Necessity Estimation (VHONE) utilizing several parallel Fuzzy Logic Controllers (FLCs) with reduced rule sets to estimate the VHO necessity. The second task is the selection of the best network as the target for VHO, where a ranking algorithm is developed based on TOPSIS. Priority Weights for the different system attributes are calculated based on a Fuzzy Analytical Hierarchy Process (FAHP). Later, simulations based on four traffic classes (conversational, streaming, background, and interactive) in the presence of three wireless networks (WLAN, WMAN, and WWAN), are carried out using a comprehensive wireless simulation test-bed that contains all the necessary Radio Resource Management (RRM) modules.

Heterogeneous wireless networks (HWNs) present a challenge in selecting the optimal network for user devices due to the overlapping availability of multiple networks. In order to help users choose the best HWN connection, this research is trying to build a decision-making framework that takes user preferences and network performance characteristics into account. Using a multi-attribute decision-making (MADM) method that incorporates fuzzy logic and the Fuzzy Analytic Hierarchy Process (FAHP), our goal is to improve the decision-making process for network selection. The suggested system takes into account a number of network metrics, including latency, jitter, bandwidth, and cost, and uses user preferences to determine the relative importance of each to guarantee a tailored and adaptable recommendation. Our results demonstrate that the algorithm greatly enhances the efficiency of network selection and the level of user happiness, with UMTS being the best option for conversational services, WiMAX being the best for streaming, and LTE being the best for interactive services. Through the incorporation of user-centric decision-making into the network selection process, this research enhances adaptive wireless communication systems, leading to better user experience and network efficiency.

Network reliability analyses have received much attention in heterogeneous wireless network performance evaluation during the last few years. In this paper, a method for heterogeneous wireless network reliability evaluation to meet the required levels of heterogeneous wireless network differences of various graph-theoretic connectivity measures is proposed. A concept of heterogeneous wireless network reliability degree is proposed and a heterogeneous wireless network reliability entropy-based method for analyzing the proposed reliability measure is discussed. This method is based on heterogeneous wireless network survivability and stability analyses. Its core is the computation of some heterogeneous wireless network combinatorial invariants. These invariants, once computed, directly provide pure and simple framework for computation of heterogeneous wireless network reliability. We illustrate how a new approach to assessing the performance of in heterogeneous wireless networks. Our results also illustrate how the characteristics of the heterogeneous wireless networks may affect the performance of the different measures. We also present some simulation results.

A new multi-rat scheduling algorithm for heterogeneous wireless networks

To improve the handover performance for both handovered and background flows in 5G heterogeneous networks, we take an approach of cloud control to allocate the optimized CWND value at handovers. Based on the UC3 cloud controlling network architecture, we propose an optimized handover mechanism in this paper. Our key idea is to calculate a CWND value at a cloud server using information collected by wireless access networks. We will describe the optimized handover mechanism and our research plan.

As many access technologies develop, more and more heterogeneous wireless networks appear around us. In this case, when whole mobile networks move from the visiting network to another, the handoff attracts the attentions especially. The exited handoff methods with network mobility merely extended the scheme of handoff in MIPv6 or integrated the exited methods into the uniform scheme but it can not make the good effect to really and truly solve the fast and smooth (packet lossless) handoff in heterogeneous wireless networks. In this paper, the fast handoff scheme is given and it provides Multi-Mobile Router (MMR) with a vicinage table to keep information about their vicinages access router. Using this method, it performs the Fast Handoff with network mobility effectively in heterogeneous wireless networks. In addition, we introduce the new entity TCS (temporary control server) to manage MMR procedure in order to complete fast handoff and reduce the power consumption of MMR. By analysis and simulations, we demonstrate that fast handoff scheme has the better performance than Basic NEMO.

The wireless network environment in the future is going to include various heterogeneous wireless networks. In a heterogeneous wireless network environment, vertical handoff processes caused by the movement of users are inevitable. However, the research related to how to achieve seamless vertical handoff and improve QoS guarantees in today's heterogeneous wireless networks is still something to work on. Therefore, this paper proposed the Advanced Vertical Handoff Translation Center (Advanced VHTC) architecture for Wi-Fi/WiMAX heterogeneous wireless networks, aiming to improve the quality of services in heterogeneous wireless networks by means of packet formats translation between heterogeneous wireless networks and the MIH-based seamless vertical handoff mechanism, which cut down the time for vertical handoff and obtain high quality and persistent connection service. Lastly, with the brilliant results of a complete simulation, this paper will show the performance in terms of delay, jitter, packets loss and throughput to prove that the Advanced VHTC for next generation heterogeneous wireless networks can provide good QoS guarantees and obtain persistent transmission with high performance while performing seamless vertical handoff.

The current industrial Internet is usually composed of heterogeneous network infrastructure. In order to adapt to different business scenarios, 5G network needs to improve the ability to flexible orchestration and realize the vertical deployment of service and infrastructure integration. Based on 5G network orchestration architecture and open source mano (OSM) technology, a 5G network scenario orchestration platform superimposed on heterogeneous 5G network resource orchestrator is designed. Furthermore, in order to effectively combine heterogeneous 5G network resources and provide reliable bearer for high-performance business scenarios, this paper designs a reliable path orchestration algorithm to establish equivalent backup paths between unrelated heterogeneous networks. This paper implements the scenario-based orchestration platform design for heterogeneous 5G networks and provides an equivalent path orchestration algorithm. Simulation experiments show that the proposed algorithm can provide highly reliable orchestration services under the condition of sharing heterogeneous network resources.

In response to the multi-source uncertainties and potential risks facing the safe and stable operation of distribution grids, this study proposes a multi-dimensional comprehensive resilience assessment framework that integrates the Fuzzy Analytic Hierarchy Process (FAHP) with the Risk Entropy Weighting Method. First, a multi-dimensional evaluation indicator system is established, encompassing physical resilience, operational reliability, and intelligent response capabilities; Second, FAHP is used to calculate the subjective weights of the indicators, while the risk entropy weighting method is employed to quantify the information entropy of the indicators and obtain objective weights. A game theory-based combined weighting model is then used to achieve dynamic equilibrium between subjective and objective weights. Furthermore, an improved TOPSIS-based comprehensive evaluation algorithm is proposed, incorporating Mahala Nobis distance and dynamic weighting strategies to enhance the accuracy of scheme ranking. Finally, multi-scenario simulations were conducted on an improved IEEE 33-node system. The results indicate that the proposed evaluation system can effectively quantify the resilience level of distribution grids, with evaluation results matching the actual operational status of the system at a rate of 92.7%, significantly outperforming traditional single-weighting methods.

Base station planning is an important and complex problem of wireless telecommunication system, especially when it comes to a heterogeneous network. In the electric power system, the wireless terminal communication network is the key to solving low degree of the power distribution network automation and incomplete coverage of the grid information data collection, two main problems in the process of developing smart grids. There are two standards for power telecommunication in China, namely the 1. 8GHz standard and the 230MHz standard. This paper proposes a method for planning wireless terminal access network based on Fuzzy Analytic Hierarchy Process (FAHP) to choose the proper standard for the base station. The simulation results show that the method proposed can efficiently finish planning the two-standard heterogeneous network and guarantee the communication requirements of the terminal.

It is envisaged that next generation wireless networks (NGWN) will be heterogeneous, consisting of multiple radio access technologies (RATs) coexisting in the same geographical area. In these heterogeneous wireless networks, mobile terminals of different capabilities (heterogeneous terminals) will be used by subscribers to access network services. We investigate the effect of using heterogeneous mobile terminals (e.g. single-mode, dual-mode, triple-mode, etc.) on call blocking and call dropping probabilities in cooperative heterogeneous wireless networks. We develop analytical models for heterogeneous mobile terminals and joint radio resource management in heterogeneous wireless networks. Using a two-class three-RAT heterogeneous wireless network as an example, the effect of using heterogeneous terminals in the network is evaluated. Results show the overall call blocking/dropping probability experienced by subscribers in heterogeneous wireless networks depends on the capabilities of mobile terminals used by the subscribers. In the worst case scenario, when all subscribers use single-mode mobile terminals, each subscriber is confined to a single RAT and consequently, joint radio resource management in heterogeneous wireless network has no improvement on new call blocking and handoff call dropping probabilities. However, in the best case scenario, when all subscribers use three-mode terminals, new class-1 call blocking probability decreases from 0.37 (for 100% single-mode terminals) to 0.05, at the arrival rate of 6 calls per minute. New class-2 call blocking probability also decreases from 0.8 to 0.52. Similarly, handoff class-1 call dropping probability decreases from 0.14 to 0.003, and handoff class-2 call dropping probability decreases from 0.44 to 0.09.