1. Introduction
The field of transportation systems research is fast developing, necessitating creative ideas, modeling, and analysis for new advances. Using methodologies and strategies for engineering and supervising these systems across numerous industries, this field applies system approaches to the design, development, and administration of complex systems. In order to improve the functionality and efficiency of transportation systems, key areas include the integration of networking, computing, and physical processes, such as smart grids, IoT systems, and autonomous technologies [
1]. The significance of EVs in the energy market can be found in their huge capability to simplify the crisis of fossil fuels and minimize the poisonous emission of gases, which has also acquired the attention of people all over the world. EVs have several benefits, like saving energy, reducing emissions, and preserving the environment. However, the inclusive design of EVs faced several issues. Because of the EV network’s mobility and heterogeneity, poor network management may lead to data congestion and overloading of charging ports. As a result, it is important to thoroughly examine the EV network’s information and energy management. Meanwhile, the driving ability of EVs is not sturdy enough to fulfil the hopes of vehicular users, which brings specific problems while travelling longer distances. Due to the emergence of EVs, the power grid load can become more apparent. Recently, electricity trading amongst vehicles has acquired a reliable charging mode, which has also been extensively studied [
2]. Based on the benefits of EVs, collaboration amongst vehicles is supposed to be improved to increase driving ability and also effectively prevent the overload issue in power grids [
3]. Multiple organizations exist in the IoV, and the transactions are dispersed. As a result, ensuring the security of users’ information is a difficult task [
4]. The IoV represents an open and combined network model that influences the improved sensing, computation, and communication abilities of its data sources like prediction of traffic [
5], RSUs [
6], IoT devices, smart city applications [
7], planning of routes [
8], and management of traffic [
9]. By triggering vehicles to mingle with infrastructure and opponent vehicles, the connected vehicle paradigm turns automobiles from tools for mobility into intelligent service platforms. As a result of reducing greenhouse gas emissions from the combustion of petroleum, electrification of transportation is speeding up the commercialization of electric vehicles. This article presents a thorough analysis of the deployment and administration of architectural layers, taking into account the energy flow, data communication, and computing methods and other various aspects.
EVs have attracted universal acknowledgment as a method of offering elevated energy efficiency, low-cost oil usage, and low gas emissions. Nevertheless, the growing acceptance of EVs in the future has created a huge number of energy desires, which also lead to an intrinsic yet complex issue for the providers of a CS of having to maintain effectual services of energy at its CS. For instance, in the unforeseen circumstances of a huge number of EVs immediately requiring to charge their batteries all at once, then their equivalent CSs can face a high energy transmitting cost due to congestion [
10,
11]. In addition, because of the vibrant energy charging desires from EVs, the CS can face overestimation or underestimation of the energy supply amongst the EVs. Thus, the CS providers need to provide an effectual economic model to increase their profits by attaining cheap energy transfer using dynamic energy desires.
To handle dynamic energy desires and energy efficiency optimization, one requires to precisely forecast the demands of energy from EVs. To predict the energy desires in an EV network, the authors in [
12,
13,
14] devised machine learning techniques like multiple regression, k-nearest neighbor, deep neural network, shallow neural network, and online reinforcement learning to enhance the demands of the energy prediction accuracy of particular EVs. However, these techniques are not beneficial for a complete EV network as they compute the prediction independently at each CS. It is essential to influence global models or shared information that are used for predicting the energy desires to attain enhanced prediction accuracy amongst the complete network [
15].
Connected Electric Vehicles (CEVs) contribute to an improvement in road safety and the reduction in traffic congestion in urban areas. CEVs, or electric vehicles, are of paramount importance in energy markets due to their capacity expansion and adaptable battery models, which enable them to function as mobile power plants. The system possesses the capacity to participate in electricity trading activities in the event that supply stations are offline. The International Energy Agency (IEA) has recorded a considerable quantity of battery-operated electric vehicles (EVs), in the millions. The count is supposed to attain 60 million by 2030. Thus, an elevated penetration of CEVs can make electricity and data exchange a complex process. To handle this process, the ability of CEVs within a smart city has to be devised to promote social welfare and economic problems around the electricity routing and data exchange. The CEV may be a good option for creating workable business plans and streamlining the energy trading process [
16]. The road for both data and power decentralization is provided by CEVs’ capacity to supplant crucial micro-grid model functions including load balancing, disaster recovery management, and voltage and frequency regulation. The CEV might expedite the shift to a smart electricity paradigm by enhancing societal welfare, increasing profitability, and facilitating auctions. It is very difficult to build an effective energy trading system between nearby nations, nevertheless, given the present power structure. One novel and exciting challenge for preventing RSU congestion and using the least amount of energy possible is flow redirection [
17,
18].
With this backdrop, the aim of this study is to design an approach for optimal electricity trading and a deep flow redirection mechanism for the IoV using Flow-DNET and TSOA. The four different entities, such as EVs, auctioneers, RSUs, and the IoV server are considered. Energy trading is a mechanism in which different EVs purchase power and RSUs function as auctioneers, receiving and bidding on requests for electricity from EVs. Throughout the auction process, the TSOA optimal trading model is utilized to select the most advantageous CS, with the new objective model factors including the energy and pricing approach also being considered. Once the electricity trading is conducted, the flow redirection is performed. Here, the redirection factor is computed for every RSU in order to decide whether the charging station is overloaded or under loaded. If the CS is overloaded, the Flow-DNET model is utilized for finding the redirection policy. Here, the newly devised TSOA is obtained by integrating Taylor series and SOA.
Figure 1 illustrates the newly devised architecture of the IoV communication network model for EV electricity trading. The centralized cloud server, localized aggregator, cloud–vehicle interface, control and management layer, preprocessing layer, and data processing layer are the essential segments in this architecture.
The major contributions of the paper are:
The electricity trading is performed using TSOA by considering the new objective model, such as energy and the pricing strategy for choosing the best CS. A hybrid of the SOA and Taylor series develops the TSOA.
The huge power accessible with the CS can be taken by EVs for refilling their batteries. The intellectual transportation can assist this by exchanging information regarding the power requirements amongst CS’s to EVs and deciding the specific CS for performing energy trading. This motivates us to devise a new method for energy trading. Various electricity trading and flow redirection techniques are devised in the IoV, and there are several entities contained in the IoV network whose transactions are dispersed. Nevertheless, ensuring information security amongst IoV network consumers is a multifaceted challenge.
The rest of the sections are arranged as follows:
Section 2 reveals the review of classical electricity trading and flow redirection techniques in the IoV.
Section 3 describes the system of IoV for effective electricity trading.
Section 4 displays the proposed model for performing electricity trading.
Section 5 discusses the efficiency of the classical model by comparing it with existing techniques.
Section 6 offers the conclusion.
2. Literature Survey
Automobiles integrate modern devices for the latest Wireless Access Technology (WAT). The apparatus consists of a display screen, numerous application units, a central processing unit, a sensor, an antenna, a camera, radar, and a global positioning system receiver. Their integration as on-board components in vehicles enables vehicular communication, improving affordability, comfort, and safety. Communication devices known as RSUs facilitate communication between on-road vehicles in environments with sparse traffic networks [
19,
20].
Figure 2 exemplifies various aspects of taxonomy classification on the IoV. As a result of substantial research and technological developments in wireless channel communication, the conventional Intelligent Transport System (ITS) has changed to focus more on vehicle communication. In addition to facilitating communication between on-road vehicles, client applications would have access to a range of WAT to connect to servers situated in smart clouds because of the heterogeneous network environment of the IoV.
The five main types of communications between vehicles that make up the IoV communications-based heterogeneous network architecture taxonomy and a heterogeneous network coordination example along with associated services are shown in
Figure 3. Implementing a diverse fleet network architecture is a difficult undertaking. V2R, V2V, Vehicles to Sensors (V2S), Vehicles to Personal Devices (V2P), and Vehicles to Infrastructure (V2I) are some of the categories.
A distinct WAT is used to facilitate communication between each IoV car. Additionally, for vehicles and RSUs, various communication devices are part of the communication architecture. Because of the variety of devices included, the design of the IoV’s communication architecture is more complex than that of VANETs, but it still remains focused on the market. The IoV’s heterogeneous vehicular network infrastructure greatly enhances the navigation and supervision of cars. It can offer a dependable framework for online and multimedia applications on the go for a multitude of mobile devices. The following sections emphasize the layered architecture, network concept, benefits, problems, and future elements of the IoV.
The IoE refers to the modernization and automation of electrical infrastructure development between energy producers and consumers. A detailed outline of the framework is provided by [
22] along with an amazing explanation of the components and structure of this subsystem for service-oriented management for creating sustainable energy development through the Internet of Everything. There are many benefits to using the IoE, such as increased efficiency, significant cost savings, and a reduction in energy waste. Everything is evolving in the energy market today, including the role of the consumer, the integration of smart technologies, and digitalization. IoV refers to a network of automobiles equipped with middle-tier technology, software, and sensors that allow data transfer and communication over the Internet in accordance with predefined protocols. “VANETs” are a type of mobile ad hoc network that provides communication between automobiles and roadside appliances. It is anticipated that, eventually, the IoV will become an “Internet of autonomous vehicles”. One element that is anticipated to support autonomous, connected, electric, and shared (ACES) mobility in the future is the IoV. The authors suggested a distributed multihop task outsourcing decision model to efficiently perform responsibilities. Two primary parts are included in the model: vehicle selection, which finds nearby cars that can be unloaded, and task selection, which finds the best response. The discrete bat approach and greedy algorithm tackle generalized allocation offloading next. The greedy method, sometimes called bat-based strategy, performs better than the scheme where the task vehicle randomly chooses nearby vehicles to transfer in terms of time delay performance, computing power, and task size environment. The aforementioned plan carries out all operations locally [
23]. The business model of the energy market is the most needed for research and development, with a particular emphasis on prosumers and consumers’ energy trading within local contexts.
Figure 4 illustrates the transition from an item-based energy network to a service-based management system. First, the energy internet and management structure have been presented. Next, we examine studies on implementing EV aggregators (AGs) to provide the energy and data infrastructure needed for the IoV. The overview of EV scheduling features both vehicle-to-grid (V2G) and charging scheduling based on the deployed AGs. Additionally, we survey relevant studies on computers and information communication for each scenario.
Figure 5 demonstrates how the electrical system acts as the central facilitator for the connection of different energy transfer networks. Particularly with the increased penetration of renewable energy, the central role of electricity has been reinforced. Furthermore, the electricity network is being created and modified to store the increasing level of renewable energy. This system employs several “power-to-X” conversion technologies to effectively align the supply and demand of renewable energy across extended durations and distances. These technologies include heat-to-liquid, and power-to-gas. Four energy conduits equipped with modern energy conversion technology integrate and coordinate all energy domains, as shown in
Figure 6. At the end, it produces a multi-energy system that is affordable and heavily dependent on renewable resources.
The nine classical electricity trading and flow redirection techniques in the IoV are illustrated along with its merits and demerits. Reference [
4] developed a V2V electricity trading technique on the basis of Bayesian game pricing using blockchain-assisted IoV. The communication-oriented network subsystem with oriented layers is shown in
Figure 7.
Thereafter, the pricing game was executed by smart contracts. The method was not adapted in order to attain effective outcomes. Reference [
17] developed the Decentralized Electricity Trading Framework (DETF) amongst CEVs using consortium blockchain, game theoretic models, and machine learning. We developed a decentralized smart contract system with a stochastic trading mechanism to facilitate CEVs in acquiring and selling electricity in the most lucrative manner. The methodology did not use a comprehensive real-world experimental platform that integrated renewable energy sources with micro-grid architecture [
24]. China’s power market effectively establishes incentive agreements and safely trades energy, serving as an example. The digital signature technique ensures the accuracy and dependability of financial transaction data. The energy blockchain technology establishes a decentralized system that ensures data integrity and secure storage. The Practical Byzantine Fault-Tolerant (PBFT) approach ensures the consistency of the data block. The PBFT approach minimizes the time it takes to send data while simultaneously enhancing the process velocity. Penalties for automobiles that violate the restrictions are not included in this approach, and the objective is to enhance stability. In [
25], there is a methodology that utilizes electric vehicles (EVs) to effectively control power switching and manipulate the direction of energy flow. In order to address power loss and other requirements, the CS developed Electric Vehicles as a Service (EVaaS). However, this approach required substantial computational capacity [
26]. The intellectual IoV devised a tri-layer transmission system to reduce overall energy consumption and mitigate latency problems. In this instance, we inputted the planning issue into a Deep Reinforcement Learning (DRL) system. Regrettably, the design did not include any optimization strategy to enhance the system’s performance [
27]. In order to decrease the average reaction time in fog-assisted Internet of Vehicles models, a resilient offloading approach was developed for real-time traffic management. This method was utilized to organize the movement of traffic between fog nodes and address the issue of optimizing offloading in this particular scenario. In [
28], a control and regulation technique was devised whose goal was to attain a balanced production or consumption model. However, this technique was not able to optimize the available state of charge (SoC). For the energy-efficient task offloading, [
29] devised UAV-CCIO, or UAV-Enabled Computing and Communications Intelligent Offloading. The UAV consumed less energy and travels less distance without routing; therefore, it uses no energy. In [
30], the authors developed a consortium blockchain to minimize dependence on trusted third parties. In addition, the PBFT algorithm was incorporated with the consensus algorithm to minimize resource consumption and improve consensus efficiency. However, the system’s reliability was affected because of the interference of bad nodes. In [
31], the suitable charging station for electric vehicles was determined by scheduling the charging points using a vehicle ad hoc network. Fake security concerns and environmental changes may delay and expend data. To save computer power and identify hazards, automated anomaly detection was devised in [
32]. In [
33], the authors proposed an algorithm for finding the optimal charging station for EVs using the proposed sailfish optimization algorithm. This method utilized only a single optimization for finding the CS. In order to optimize the finding of a CS, the development of a hybrid optimization technique will provide a better solution. In [
34], the authors present an energy-aware optimization (EAO) technique for improving CAEV energy efficiency by taking into account the vehicle traffic nexus. Moreover, this method developed a torque monitoring management approach to control and maintain the electric powertrain for optimal efficiency. The authors proposed an improved MRNN classifier and 2CKECC method in [
35] to forecast IoV vehicular mobility, security, and content caching. Although the energy consumption of this method was low, this method utilized more steps to execute it. Here, an innovative Harris Self-Avoiding Hawks Optimization (HSAHO) was devised to select the relay vehicles (RVs). However, the processing time of this scheme was high. In [
36], an efficient EV charging technique was established based on mobile edge computing (MEC). Here, the global controller served as a centralized cloud platform that enabled analytics from a CS and the coordinates of charging reservations for mobile EVs to predict CS availability. The charging performance and communication efficiency of the model was high, but the performance was reduced due to network congestion.
3. System Model
Electric cars have the potential to enhance road safety and alleviate traffic congestion in cities. The enhanced battery system’s flexibility and capacity of EVs may render them indispensable in the electricity market. Due to its ability to transfer energy internally, it is particularly advantageous in scenarios when power sources are momentarily or entirely unavailable.
Figure 8 illustrates the system paradigm for power trading in the Internet of Things (IoT) system. Consider a city divided into
blocks, which contains an IoV server, a group of electric vehicles
, and a set of RSUs
. Here, the RSUs act as auctioneers and electric vehicles have bidirectional charging and discharging capabilities. An electrical seller is a self-sufficient vehicle with a specified quantity of energy that may be shared with other buyers or used to power itself. The RSU enables charging and discharging between EVs. Vehicle flow arrival is denoted by RSU
and follows the Poisson process with
.
The notation table is depicted in
Table 1.
3.1. Energy Model
The energy model [
25] is discussed below. To develop an effectual electricity trading technique, it is imperative to discover the consumed energy by each EV. Here, the CS proceeds as an energy borrower and the EV reacts as an energy distributor. Thus, every EV should have energy obtainable in its battery to fulfil the desires of the requested charging stations. The quantity of energy with
EVs can contribute to the request for a CS based on the threshold value of
. Thus, the accessible SoC with
EV
can contribute to the requested CS as,
The energy accessible with
EVs
can be given to the requested CS and is formulated as,
is the rated energy of
EVs and is formulated as,
The remaining energy required to reach
by
EVs after assuming
EVs
as the buyer is given as,
The energy required by
to reach
is given by,
is computed similarly to that of EVs.
After charging
from
, update the SoC, which is given by,
After updating the SoC of
,
3.2. Mobility Model
The mobility model [
25] is stated to exemplify the development of EVs and to compute the alteration in the EV’s position considering velocity, acceleration, and location in a particular instance. The whole city is split into several
blocks to model the mobility of EVs. Each block comprises various EVs and CSs. To maximize earnings and accomplish the most efficient energy exchange, EVs seek to trade with other EVs and charging stations (CSs) in the same block. Nonetheless, they may interchange products and services with any other charging station. The biggest difference between CSs and EVs is the amount of energy they use. We may calculate the distance between the two by determining
where CS is
and
using a symbol to indicate the EV’s location. The distance between two locations
and
is determined by the actual path
, which is calculated based on the Manhattan block design:
The EV computes the distance of each CS and sends these data to the energy trading model that computes the net profit of the EV considering this distance.
3.3. Pricing Model
There are two scenarios in which pricing is determined: when an electric vehicle has excess energy available for sale and when a charging station needs to buy energy [
25]. Electric vehicle owners have the ability to choose the price at which their cars participate in energy transactions. Batteries power electric vehicles for propulsion. The EVs choose a System on Chip (SoC) to regulate the expenses associated with charging and discharging the battery.
is fixed in such a way that the overall supplying cost is higher compared to the receiving price.
3.4. Redirection Model
The redirection model [
26] is presented below. To balance the offloading flows of tasks, the RSUs are adapted to be reachable amongst each other. As flows occurring at the RSUs can be different, a high-loaded RSU can redirect flows to a low-loaded RSU. Here, the following constraints must be fulfilled:
Indicators are given by . The states of the communication channel are supposed to be equal and kept unaltered during one scheduling time slot. Assume is caused by transmitting offloading tasks amongst RSU and RSU . If redirected flow , the RSU transmits flow to RSU and delay exists.
The
produced by redirecting flows from RSU
to the RSU with time slot
is evaluated as,
Furthermore, the consumption of the energy of redirection for RSU
at time slot
is given by
. The final arriving task flows at RSU
can be given as,
4. Proposed TSOA-Based Flow-DNET for Optimal Electricity Trading
The goal is to design an approach for optimal electricity trading and deep flow redirection mechanisms for the IoV using Flow-DNET and TSOA.
Figure 9 represents the schematic view of the optimal electricity trading model in the IoV using the proposed TSOA-based Flow-DNET. Four different entities, such as EVs, auctioneers, RSUs, and IoV servers, are considered. In the energy trading market, electric vehicles (EVs) act as buyers by transmitting power demand to RSUs. After that, an auctioneer may employ RSUs to make it easier for people to place bids on these requests. Finding the best charging station is the job of the auctioneer, who employs the revised goal model that factors in things like energy and pricing strategies. The TSOA optimal trading model serves as the foundation for this choice. The TSOA optimal trading model redirects the current after the power transaction is completed. For every RSU, the TSOA optimal trading model computes the redirection factor to determine if the charging stations are overloaded or underloaded. If a charging station is overloaded, we utilize the Flow-DNET model to find the redirection policy. Here, the Flow-DNET is newly devised using a deep network based on the optimization algorithm, called TSOA. Moreover, the TSOA is obtained by combining the Taylor series [
26] and SOA [
37].
The different parts of IOV architecture, taxonomy, integrated energy systems, compressive views, essential components, communication-oriented architecture, and system models are all shown in
Figure 10. It provides readers with a holistic understanding of the interconnected and integrated nature of the IOV landscape. This visual synthesis brings together diverse elements from the previously explored technologies. Beginning with the “architecture of IOV,” the integrated framework delves into the foundational structures that underpin IOV systems. It extends its reach to include the insights from “taxonomy,” providing a structured classification of IOV components and entities. The figure further explores the “Integrated Energy System for IOV,” demonstrating the interplay between energy considerations and the overall IOV infrastructure.
Moving beyond isolated views, the framework introduces a “Compressive View,” encapsulating a condensed but inclusive representation of the IOV landscape. It then dissects the “Essential Components,” emphasizing the key elements crucial for the functioning of the IOV.
4.1. Electricity Trading
EVs (EV buyers) send a request to auctioneers.
The auctioneers broadcast the information to the seller and buyer.
The trading scheme is based on three conditions and will be executed.
RSUs provide electricity to buyers.
If the RSU does not have sufficient energy to sell, it begins trading by finding a suitable seller.
If the above two conditions fail (OR) and the RSU is overloading, then redirection will be performed.
Figure 11 represents the proposed Taylor Social Optimization model algorithm flow with an optimal solution.
4.1.1. Trading Using Proposed TSOA
The proposed TSOA, which combines the Taylor series and SOA, serves the trading purposes in this context. The subsections provide a comprehensive explanation of the phases involved in the proposed TSOA, the fitness function, and the method used for solution encoding. The redirection factor is computed by every RSU to determine the charging stations’ overload or underload status.
The choice of result representation is crucial in determining the optimal solution for optimization problems. To streamline the energy transfer on the Internet of Vehicles, EV providers are selected based on the planned Transmission System Operator Agreement (TSOA). The optimization process begins with an initial value (the solution set) and progresses towards the optimal value. The vendor assignment solution set comprises a group of EV sellers who are enthusiastic about exchanging energy with clients. The solution vector is generated randomly, resulting in a diverse group of EV sellers. The suitability of the solution set then determines the optimal quantity of EV merchants. By using a fitness function, we can ascertain the optimal number of electric vehicle vendors to include in the trading procedure.
Figure 12 illustrates the solution representation that utilizes the produced TSOA. Please provide a roster of electric vehicle suppliers who are enthusiastic about doing business in this area.
When calculating an EV vendor index, we consider distance, energy consumption, and advertising expenditures. The following statement shows the fitness examination for optimization concerns:
Here, the utility function of the
CS relies on the energy required and price announced by EVs, and thus, the utility function of the
CS is given by,
If the price announced by the
EV is expressed as
and revenue availability with the
CS is
such that
, then the objective function can be given by,
The trading is performed using the proposed TSOA, which is generated by adding the Taylor series and SOA. Here, the SOA [
37] is a population-driven technique that involves two different justice principles, namely the equality of opportunity principle and the equality of community principle. This algorithm is very effective in solving economic dispatch problems and performs well on unconstrained and constrained functions. The Taylor series [
38] describes the function of complicated attributes with several terms. The hybridization of both the Taylor series with SOA achieves efficient performance by resolving optimization problems. The proposed TSOA steps are as follows:
The preliminary step is initialization of the solution, which is expressed as
, where
.
The fitness has already been described in
Section 4.1.1 using Equation (13).
As per SOA [
37], the equality of opportunity states that the consequent position of each entity is given by,
Here, the best position is given as,
The density point is given as,
Equation (17) can be expressed as,
From the Taylor series [
38],
Assume
and substitute
and
,
Substitute Equation (23) in Equation (20),
The final update equation of the proposed TSOA is given as,
Hence, the computation of the principle of community is expressed by,
Here, the empty point is expressed as,
The density point is given as,
The empty point is given as,
The density points are given as,
The empty points are given as,
The fitness of the update solutions is recalculated to obtain the best alternative for the best EV vendor selection.
Up to the maximum number of iterations, we discover the optimal solutions repeatedly.
The pseudocode of TSOA is illustrated in Algorithm 1.
Algorithm 1. Pseudocode of proposed TSOA |
Input: : Set of solutions, : current iteration, : maximum iteration |
Output: Best solution |
Begin |
Initialize random population ; |
Evaluate population; |
Best solution; |
For do |
Evaluate empty point; |
For do |
; |
; |
Compute using Equation (26) |
End |
If better than then |
|
End |
Evaluate new population |
Best solution; |
Compute Density point; |
For do |
Evaluate using Equation (27) |
End |
If better than then |
|
End |
Evaluate new population |
Best solution; |
End |
Print best solution |
Here, energy trading is performed between EVs and CSs in the IoV network. The developed model considers various aspects like the capacity of EV batteries, the mobility of EVs, and pricing when making energy trading decisions. The method helps reduce the response time and improves the reliability of the network. The goal of energy supply in EVs is to make a profit, whereas for CSs, it is balancing the load. EVs move to CSs for either charging or discharging of their batteries. After reaching the CS, the final SoC of the CS and EV battery pool is changed. Each EV aims to acquire the maximum SoC level by charging the needed energy from the available CSs. The trading algorithm is depicted in Algorithm 2.
Algorithm 2. Trading algorithm |
For and |
Compute |
If |
Compute and |
Announce to RSU’s |
For and |
If |
Compute and |
End if |
End for |
End if |
End for |
Compute and |
For |
Call TSOA |
Draw from corresponding EV’s |
Update and |
End for |
4.2. Flow Redirection Using Proposed Flow-DNET
After electricity trading, the system performs flow redirection to evaluate the redirection factor for each RSU and determine if the CS is overloaded or underloaded. If the CS is overloaded, we utilize the Flow-DNET model to find the redirection policy. In this case, the trading is considered a failure. Thus, a broadcast message will be sent to neighboring RSUs by the RSU. The neighboring RSU acknowledges the corresponding RSU by computing redirection factors, namely the load, number of EVs processed, distance, capacity, and delay.
Here, the load is given by,
The distance is obtained from the mobility model, which has already been described in
Section 3.2., and the capacity is the assumption.
The delay is obtained from the redirection model, which has already been described in
Section 3.4.
The flow redirection is predicted using a DBN [
39]. Here, the input attributes like the load, capacity, number of EVs processed, distance, and delay are considered as inputs to the DBN. The structure of the DBN is revealed in
Figure 13. One MLP layer and two RBM layers compose the DBN. The load, number of EVs managed, distance, capacity, and delay are the redirection factors that comprise the input for the first RBM in the DBN’s visible layer. The second RBM receives the output from the hidden layer and passes it on to the MLP.
The visible layer considers the load, capacity, number of EVs processed, distance, and delay as its input, and the hidden layer of the first RBM is given by,
The two biases linked to neurons amongst both layers for the first RBM are expressed as,
The weights from the first RBM are given by,
where the weight vector size is given by
. Thus, the hidden layer output from the first RBM is provided with its bias and weights linked to each visible neuron and is expressed as,
Thus, the output generated from the first RBM is given by,
Thus, the learning of the second RBM layer starts with the hidden layer output of the first one. The first RBM output is the visible layer input of the second RBM. Thus, the count of visible neurons is equal to the count of hidden neurons in the first RBM and is given by,
The hidden layer of the second RBM is expressed as,
For the second RBM, the weight vector is given by,
The output of the
hidden neuron is given by,
Hence, the output of the hidden layer generated is expressed as,
The aforementioned equation establishes MLP input in which neurons count in the input layer as
. The MLP input layer is given by,
The MLP hidden layer is obtained by,
Consider
as the bias of the
hidden neuron in which
. The third layer represents the MLP output, which is given as,
MLP poses two weight vectors, one amongst the input layer and hidden layer, and the other amongst the hidden layer and output layer. Assume
is given by,
The hidden layer output is given by,
The weights amongst the hidden layer and output layer are expressed as,
Hence, the output vector is evaluated with the weight and hidden layer output as,
Thus, the output is the priority level for RSU redirection where the priority is that the output to the RSU has maximum priority, and the flow will be redirected.