Design of Location Management for Heterogeneous Wireless Networks

Resource management in heterogeneous wireless networks has been approached from various angles by the research community. The complexity of the network and the heterogeneity of clients make the conclusive comparison of the various resource allocations challenging. This work introduces superBS, an approach defining a theoretical optimal resource allocation that adheres to the required resource management policies and can be used as a reference for the performance of considered algorithms, mitigating the heterogeneity of the system. Two applications that leverage superBS are developed, an implementation of a heuristic resource management algorithm, and the enhancement of a popular fairness metric with support for clients of different classes and traffic demands. Simulations demonstrate the performance of superBS and the proposed algorithms.

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.

Designing a good joint radio resource management (JRRM) is a major challenge in heterogeneous wireless networks. Many analytical as well as simulation models of heterogeneous wireless networks are not based on fairly realistic assumptions so that the research outputs may be less practical. We design a JRRM taking into consideration different features of component access technologies in a heterogeneous wireless environment. We also consider different important realistic features of access networks, such as asymmetry of their overlap and the variability of network resources according to traffic conditions. We use the network simulator (NS-2) to validate our design. The simulation results show that the blocking probability improves when different considerations are taken into account.

In order to enable the autonomic network resource management, we resort to game theory to facilitate the spectrum sharing between heterogeneous wireless networks. We set the spectrum sharing objective to improve spectrum efficiency and maximise network revenue. Based on this goal, we propose a revenue sharing bargain game to model the spectrum sharing behaviour of intra-operator radio access networks (RANs) and a price bargain game to model the spectrum trading behaviour between inter-operator RANs. Furthermore, we adopt multi-agent architecture to implement the spectrum sharing schemes autonomously. Both bargaining mechanisms are analysed using bargaining game theory, and consequently the implementations are refined and simplified based on the analysis. Simulation results show that the proposed mechanisms outperform the conventional fixed spectrum management method in network revenue, spectrum efficiency and call blocking rate.KeywordsAutonomic spectrum managementGame theoryMulti-Agent

In this paper, we propose a novel approach to jointly address energy management and network throughput maximization problems for heterogeneous IoT low-power wireless communication networks. In particular, we consider a low-power communication network in which the IoT devices can harvest energy from a dedicated RF energy source to support their transmissions or backscatter the signals of the RF energy source to transmit information to the gateway. Different IoT devices may have dissimilar hardware configurations, and thus they may have various communications types and energy requirements. In addition, the RF energy source may have a limited energy supply source which needs to be minimized. Thus, to maximize the network throughput, we need to jointly optimize energy usage and operation time for the IoT devices under different energy demands and communication constraints. However, this optimization problem is non-convex due to the strong relation between energy supplied by the RF energy source and the IoT communication time, and thus obtaining the optimal solution is intractable. To address this problem, we study the relation between energy supply and communication time, and then transform the non-convex optimization problem to an equivalent convex-optimization problem which can achieve the optimal solution. Through simulation results, we show that our solution can achieve greater network throughputs (up to five times) than those of other conventional methods, e.g., TDMA. In addition, the simulation results also reveal some important information in controlling energy supply and managing low-power IoT devices in heterogeneous wireless communication networks.

Location-aware computing is widely discussed to be one attractor of the future ubiquitous networks for intelligent home and telematics services. Apart from technical difficulties in providing accurate position information there is also a lack of a clearly defined framework how to create innovative and secure services using location information. In this paper, we identify QoS, interworking and security problems in location-aware computing. We propose a number of concepts and infrastructures for location-aware security services including micro and macro mobility management in ubiquitous home networks and heterogeneous wireless networks. We further explain how the proposed approach can be applied to seamless secure interworking among wireless LANs and 3G, 4G cellular systems. Our approach might be helpful in the discussion for the frameworks especially highlighting evolutionary steps for the next ubiquitous networks.KeywordsLocation-awarenessubiquitous computing4Gsecurityinterworkingagentshome network

Recently, there has been great interest in the community over heterogeneous wireless networks in order to support services with high quality. The integration of Wimax and Wi-Fi technologies in communication systems such as Voice ,FTP ,Video conducted heterogeneous system reveal that the proposed network selection technique can effectively decide the optimum network through making trade-offs among network condition, user preference while avoiding frequent handoffs. We identify vertical handover decision algorithm suitable for multimode mobile devices based on the Analytic Hierarchy Process (AHP) and evaluates its performance through simulation by Opnet. This paper gives a comparative analysis of two queuing systems FIFO and WFQ by showing the advantages of using suitable weight which was calculated by AHP. The simulation results show that WFQ technique has a superior quality than FIFO. It could be opportunity to network designers and suppliers are providing the resources to servers more efficient use.

Due to the heterogeneity and versatility of emerging services and applications in wireless networks, it has been a great challenge on improving the network utility by taking advantage of the spatial and temporal diversity of radio resource consumption. This paper is committed to solving this problem by introducing a service-aware spectrum sharing algorithm (SSA) in a joint radio resource management (JRRM) architecture, where a spectrum pool is adopted for leisure spectrum resource management in heterogeneous wireless networks. Based on an objective utility function, the JRRM unit could optimize the spectrum scheduling decisions for the composing networks with awareness of the related supporting services. Moreover, to facilitate a precise decision process, we illustrate an transmission rate requirement prediction model (TRPM) that is adaptive to the system condition variants to forecast service requests. Experiment results show that the proposed SSA can solidly enhance the system performance in terms of radio resource usage ratio, system throughput, user service access ratio, and eventually achieve better network utility.

The wide majority of existing trust-based systems in wireless networks are today bound to a single service. As such, they cannot use past experiences related to other services. Even those that support multiple services hide this heterogeneity by regrouping all past experiences and contexts into a single metric, which strongly degrades the quality of results. To go beyond these restrictions, we designed a novel context-aware and multi-service trust model for heterogeneous wireless networks that involve nodes with different resources capabilities. Simulation results prove the proper functioning of the proposed system and its effectiveness against common attacks hindering trust models.

The coexistence of multiple access technologies deployed by different operators is fundamental for future fourth-generation mobile networks. In spite of this heterogeneity, seamless interoperator/intersystem mobility is a mandatory requirement. In this article we present a seamless mobility management approach that does not require changes to existing network infrastructure. The novelty of the proposed approach is that mobility management is fully controlled by the terminal, and network selection is user-centric, power-saving, cost-aware, and performance-aware. Total mobility management, including interface management, handover decision, and execution, is also detailed

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.

Orchestration of heterogeneous wireless networks: State of the art and remaining challenges

One of the most promising frameworks to handle mobility management in wireless heterogeneous networks is the Media Independent Handover (MIH) standard. Among the services MIH is providing to achieve efficient mobility management, Information Services allow data exchanging between heterogeneous network nodes. In this paper, we propose an implementation of this Media Independent Information Services (MIIS) on Network Simulator 2 (NS2). With this implementation, new mobility and handoff scenarios can be realized. As an example, we study the case where a mobile node gathers relevant data of nearby networks through only one interface while keeping the others disconnected in order to save battery power. Results show that our implementation is fully functional and demonstrate how useful can be MIIS for mobility management.

Mobility management in heterogeneous networks is an important area since the mobile network may be moving between multiple types of access networks which involve several service providers such as 802.11b WLAN, 802.16 WiMAX and UMTS Networks. In crowded environments, the bottleneck is often between the access link and the mobile network. Being able to prioritize the traffic and allocate a minimum bandwidth guarantee for each user is crucial in this environment. This study presents a novel dynamic QoS provisioning mechanism for network mobility in heterogeneous networks integrated with IEEE 802.21 Media Independent Handover (MIH) protocol. Network Mobility (NEMO) Basic Support protocol has three important nodes Mobile Network Nodes (MNNs), Mobile Router (MR) and Home Agent (HA). The dynamic QoS provisioning mechanism which consists of traffic marking, prioritizing and scheduling are implemented at the mobile network node domain. While the admission control module is implemented at a mobile router domain. Several experiments are conducted to evaluate the mechanism. The results have shown the importance of less packet loss and delay and higher packet forwarding rate.

With the development of heterogeneous networks, multimode terminals are becoming more and more popular. However, when there are several different kinds of sessions requiring transmission simultaneously, how to distribute these sessions among the available access networks according to the different features of the flows and the current link conditions of the candidate networks is a new challenge. In this paper, we propose a new solution to the flow distribution problem for multimode terminals. Our proposal, automatic flow distribution (AFD), includes a network selection algorithm located at the terminals and an admission control algorithm located at the access points of the networks. Consequently, the terminals and the networks can cooperate with each other and realize automatic flow distribution among the different available access networks. We utilize the notion of priority, ensuring that the more important sessions have preferential use of the network resources. In addition, in order not to excessively deteriorate the transmission performance of the lower priority flows, a probabilistic suspension scheme is introduced. Finally, the AFD method utilizes the concept of "entropy" to automatically compute the weights of different attributes which influence the flow distribution decision making, thus avoiding the users' difficulty to specify the weights manually.