A Heterogeneous Wireless Network Selection Algorithm for Smart Distribution Grid Based on Chi-square Distance

A new multi-rat scheduling algorithm for heterogeneous wireless networks

Future wireless Internet is expected to consist of various heterogeneous wireless access networks with different properties to support different type of services. In order to improve the accuracy of the vertical handover decision for such heterogeneous networks, this paper proposes an adaptive multi-criteria vertical handover framework. This framework focuses on several main aspects of a vertical handover. It is able to trigger a handover intelligently and make a handover decision effectively and adaptively.

Decision making is the hot topic in business management. Recently, there have been investigations in Call Admission Control (CAC) to handle the handover events in wireless network environments. Wireless networks have been seen to support different handoff mechanisms, in which the user can switch from one wireless network to another such as from IEEE 802.11 to IEEE 802.16. Many wireless standards, such as IEEE 802.16e and IEEE 802.11, have been proposed to satisfy diverse requirements for mobile users.. Several strategies have been proposed to realize seamless handoff in the heterogeneous networks; in this paper, we analyze the performance of some novel intelligent handoff mechanisms with multiple attributes. The mobile set dynamically selects the optimal network and provides the user with high throughput of Quality of Service (QoS) as to minimize the blocking probability of the system in heterogeneous networks. We evaluate some intelligent handoff mechanisms such as Technique for Order Preference by Similarity to Ideal Solutions (TOPOSIS), Simple Additive Weight (SAW), Analytic Hierarchy Process (AHP) and Fuzzy Logic and Grey Relational Analysis (GRA). From the results, blocking probability and dropping rate can be referenced to support better QoS.

In this paper, we conducted an experiment using a PC to evaluate the proposed novel selection policy for a communication system in heterogeneous wireless networks. It entailed the use of an analytic hierarchy process (AHP) algorithm that took the mobility of the user terminals into account. In particular, the AHP algorithm demonstrated an excellent improvement in overall performance with existing wireless systems. We confirmed the performance improvement by applying the AHP under the conditions where Wi-Fi and WiMAX were operating in heterogeneous wireless networks. The experimental results showed that the proposed policy using AHP provided a total amount of uploaded data that was 1.3-fold higher than WiMAX, 1.28-fold higher than Wi-Fi and 1.14-fold higher than conventional modes. AHP also provided almost full connection duration.

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.

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.

Quality of experience (QoE) has been a user-centric performance metric for multimedia communications. Existing communication protocols over heterogeneous networks are mostly based on quality of service, which ignores the user satisfaction and subjective evaluation. In this paper, the authors propose a novel QoE-aware multimedia communication framework for heterogeneous wireless networks. Specifically, the authors make three main contributions in this paper: (i) a general QoE model has been established by jointly characterising the multimedia applications and heterogeneous networks, (ii) the issue of multimedia communications over heterogeneous networks has been transformed as a stochastic optimisation problem, and (iii) the optimal solution is provided by designing a QoE-aware multimedia scheduling scheme. Importantly, the proposed scheme is simply enough for online implementation. Numerical simulations have demonstrated the efficiency and robustness of the proposed scheme.

Communication networks beyond 3G will see the interconnection of heterogeneous radio access networks in order to always provide the best quality of service in the most efficient way to users with multi-mode terminals. This scenario poses a number of critical issues, which have to be faced in order to get the best from the integrated network. In this paper we investigate the issue of parallel transmission over multiple radio access networks: in particular we propose simple but effective radio resource management algorithms, whose performance is investigated by means of a simulative approach in UMTS-IEEE802.11a and IEEE802.16e-IEEE802.11a heterogeneous networks (adopted as case studies). An insight on TCP level critical aspects, strictly related to the parallel transmission over multiple access networks, is also provided.

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.

This paper presents a dynamic bandwidth allocation scheme for multiple services in heterogeneous networks. A utility function is introduced first, whose parameters are determined by the modified multi-state Analytic Hierarchy Process (AHP) which adapts to different load levels according to dynamic thresholds. Based on this, a bandwidth allocation algorithm is proposed for Constant Bit Rate (CBR) and Variable Bit Rate (VBR) services depending on not only utility fairness among different networks, but also the fairness between new arrival and ongoing services. Simulation results show that the proposed algorithm is effective in guaranteeing both the fairness of the edge users and the network system performance, i.e. keeping low block probability in the wireless network system.

How many small cell (SC) access points (APs) are required to guarantee a chosen quality of service in a heterogeneous network? In this chapter, we answer this question considering two different network models. The first is the downlink of a finite-area SC network where the locations of APs within the chosen area are uniformly distributed. A key step in obtaining the closed-form expressions is to generalize the well-accepted moment matching approximation for the linear combination of lognormal random variables. For the second model, we focus on a two-layer downlink heterogeneous network with frequency reuse-1 hexagonal macro cells (MCs), and SC APs that are placed at locations that do not meet a chosen quality of service from macro base stations (BSs). An important property of this model is that the SC AP locations are coupled with the MC coverage. Here, simple bounds for the average total interference within an MC makes the formulation possible for the percentage of MC area in outage, as well as the required average number of SCs (per MC) to overcome outage, assuming isolated SCs. Introduction Heterogeneous cellular networks (HCNs) are being considered as an efficient way to improve system capacity as well as effectively enhance network coverage [1, 2]. Comprising multiple layers of access points (APs), HCNs encompass a conventional macro cellular network (first layer) overlaid with a diverse set of small cells (SCs) (higher layers). Cell deployment is an important problem in heterogeneous networks, both in terms of the number and positioning of the SCs. Traditional network models are either impractically simple (such as the Wyner model [3]) or excessively complex (e.g., the general case of random user locations in a hexagonal lattice network [4]) to accurately model SC networks. A useful mathematical model that accounts for the randomness in SC locations and irregularity in the cells uses spatial point processes, such as Poisson point process (PPP), to model the location of SCs in the network [5–10]. The independent placement of SCs from the MC layer, has the advantage of analytical tractability and leads to many useful SINR and/or rate expressions. However, even assuming that wireless providers would deploy SCs to support mobile broadband services, the dominant assumption remains that SCs are deployed randomly and independent of the MC layer [11].

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.

SummaryNetwork selection mechanisms have a significant role in guaranteeing the QoS for users in a heterogeneous wireless networks environment. These mechanisms allow the selection of an optimal wireless network to satisfy the needs of users. Users are provided with the opportunity to select from multiple connectivity opportunities available all over various wireless networks. Furthermore, the network operators themselves can execute active selection strategies that facilitate proper decision making, in which user preferences are considered. This study proposes a new noncooperative competing game‐theoretic model and strategy space based on user preference. This model can solve network selection problems and capture the inter‐linkages of decisions taken by various networks. A generalized simple additive weighting method is incorporated into the framework of noncooperative game theory. In addition, the utility function is employed to assess the usefulness of the system. Simulation results and analysis illustrate the efficacy of the suggested model in attaining optimum network utility for heterogeneous wireless networks while optimizing user satisfaction. Copyright © 2014 John Wiley & Sons, Ltd.

Integrating vehicular ad hoc network and 3G networks helps to use suitable characteristics of networks in exchanging information. In the proposed integrated network, mobile gateways are used as gateways between two networks. Selecting optimum network and gateway is the key point in the phase of vertical handover decision-making process. The multi-criteria algorithms provide simultaneous attention to several important aspects of vertical handover process which improves system efficiency in accordance with the objectives of the defined heterogeneous network. In the proposed method, analytic hierarchy process method is used to determine the weights of the criteria and the modified VIKOR (from Serbian: VIseKriterijumska Optimizacija i Kompromisno Resenje that means: Multi-criteria Optimization and Compromise Solution, with pronunciation: VIKOR) method is used for decision making in heterogeneous networks. The simulation results show that the proposed algorithm is suitable for selecting the optimum gateway in a heterogeneous wireless networks and it improves the average number of vertical handovers, average delay, and throughput in sparse vehicular networks.

One of the most important features of the evolving Fourth Generation (4G) wireless communication system is heterogeneous wireless access in which users could connect to several wireless access networks simultaneously. The new feature brings new challenges for the bandwidth allocation (BA) among heterogeneous networks. A non-cooperative bandwidth allocation game (NCBAG) algorithm for heterogeneous wireless networks is proposed in this paper. A BA problem is modeled as a non-cooperative game, and formulated to maximize the total utility of different networks. The existence of Nash equilibrium is verified for the proposed game model. The utility functions are developed for different applications to avoid assigning too much bandwidth to single user. Simulation results show that our proposed scheme can not only achieve high utility, but also reduce the blocking probability within a few steps of iteration.