Adaptive Power-Saving Mechanism for VoIP Over WiMAX Based on Artificial Neural Network

The IEEE 802.16 system offers power-saving class type II as a power-saving algorithm for real-time services such as voice over internet protocol (VoIP) service. However, it doesn't take into account the silent periods of VoIP conversation. This chapter proposes a power conservation algorithm based on artificial neural network (ANN-VPSM) that can be applied to VoIP service over WiMAX systems. Artificial intelligent model using feed forward neural network with a single hidden layer has been developed to predict the mutual silent period that used to determine the sleep period for power saving class mode in IEEE 802.16. From the implication of the findings, ANN-VPSM reduces the power consumption during VoIP calls with respect to the quality of services (QoS). Experimental results depict the significant advantages of ANN-VPSM in terms of power saving and quality-of-service (QoS). It shows the power consumed in the mobile station can be reduced up to 3.7% with respect to VoIP quality.

Predictive Methods of Always Best-Connected Networks in Heterogeneous Environment

Heterogeneous networks are comprised of dense deployments of pico (small cell) base stations (BSs) overlaid with traditional macro BSs, thus allowing them to communicate with each other. The internet itself is an example of a heterogeneous network. Presently, the emergence of 4G and 5G heterogeneous network has attracted most of the user-centric applications like video chatting, online mobile interactive classroom, and voice services. To facilitate such bandwidth-hungry multimedia applications and to ensure QoS (quality of service), always best-connected (ABC) network is to be selected among available heterogeneous network. The selection of the ABC network is based on certain design parameters such as cost factor, bandwidth utilization, packet delivery ratio, security, throughput, delay, packet loss ratio, and call blocking probability. In this chapter, all the above-mentioned design parameters are considered to evaluate the performance of always best-connected network under heterogeneous environment for mobile users.

Moving From Topology-Dependent to Opportunistic Routing Protocols in Dynamic Wireless Ad Hoc Networks

Mobile ad hoc networks (MANETs) are a collection of wireless devices like mobile phones and laptops that can spontaneously form self-sustained temporary networks without the assistance of any pre-existing infrastructure or centralized control. These unique features have enabled MANETs to be used for communication in challenging environments like earthquake-affected areas, underground mines, etc. Mobility and speed of devices in MANETs have become highly unpredictable and is increasing day by day. Major challenge in these highly dynamic networks is to efficiently deliver data packets from source to destination. Over these years a number of protocols have been proposed for this purpose. This chapter examines the working of popular protocols proposed for efficient data delivery in MANETs: starting from the traditional topology-based protocols to the latest opportunistic protocols. The performances of these protocols are analyzed using simulations in ns-2. Finally, challenges and future research directions in this area are presented.

Visualization-Driven Approach to Fraud Detection in the Mobile Money Transfer Services

Mobile money transfer services (MMTS) are widely spread in the countries lacking conventional financial institutions. Like traditional financial systems they can be used to implement financial frauds. The chapter presents a novel visualization-driven approach to detection of the fraudulent activity in the MMTS. It consists in usage of a set of interactive visualization models supported by outlier detection techniques allowing to construct comprehensive view on the MMTS subscriber behavior according to his/her transaction activity. The key element of the approach is the RadViz visualization that helps to identify groups with similar behavior and outliers. The scatter plot visualization of the time intervals with transaction activity supported by the heat map visualization of the historical activity of the MMTS subscriber is used to conduct analysis of how the MMTS users' transaction activity changes over time and detect sudden changes in it. The results of the efficiency evaluation of the developed visualization-driven approach are discussed.

Massive Access Control in Machine-to-Machine Communications

This chapter proposes a new hybrid MAC protocol for direct communication among M2M devices with gateway coordination. The proposed protocol combines the benefits of both contention-based and reservation-based MAC schemes. The authors assume that the contention and reservation portion of M2M devices is a frame structure, which is comprised of two sections: contention interval (CI) and transmission interval (TI). The CI duration follows p-persistent CSMA mechanism, which allows M2M devices to contend for the transmission slots with equal priorities. After contention, only those devices which have won time-slots are allowed to transmit data packets during TI. In the proposed MAC scheme, the TI duration follows TDMA mechanism. Each M2M transmitter device and its corresponding one-hop distant receiver communicate using IEEE 802.11 DCF protocol within each TDMA slot to overcome various limitations of TDMA mechanism. The authors evaluate the performance of the proposed hybrid MAC protocol in terms of aggregate throughput, average transmission delay, channel utility, and energy consumption.

Optimizing Channel Utilization for Wireless Broadcast Databases

A very large number of broadcast items affect the access time of mobile clients to retrieve data item of interest. This is due to high waiting time for mobile clients to find the desired data item over wireless channel. In this chapter, the authors propose a method to optimize query access time and hence minimize power consumption. The proposed method is divided into two stages: (1) The authors present analytical models and utilize the analytical models for both query access time over broadcast channel and on-demand channel; (2) they present a global index, an indexing scheme designed to assist data dissemination over multi broadcast channel. Several factors are taken into account, which include request arrival rate, service rate, number of request, size of data item, size of request, number of data item to retrieve, and bandwidth. Simulation models are developed to find out the performance of the analytical model. Finally, the authors compare the performance of the proposed method against the conventional approach.

SMARC

Next-generation network promises to integrate cross-domain carriers; thus, infrastructure can be provided as a service. 5G-PPP's vision is directed toward solving existing 4G LTE mobility challenges that congest core networks, disrupt multimedia and data transfer in high mobility situations such as trains or cars. This research adopts 5G methodology by using software-defined networking (SDN) to propose a novel mobile IP framework that facilitates seamless handover, ensures session continuity in standard and wide area coverage, and extends residential/enterprise indoor services across carriers under service level agreement while ensuring effective offload mechanism to avoid core network congestion. Performance excels existing protocols in setup and handover delays such as eliminating out-band signaling in bearer setup/release and isolating users' packets in virtual paths. Handover across cities in wide area motion becomes feasible with lower latency than LTE handover inside city. Extending indoor services across carriers becomes equivalent to LTE bearer setup inside a single carrier's PDN.

Classification of Channel Allocation Schemes in Wireless Mesh Network

Wireless mesh network (WMN) is a widely accepted network topology due to its implementation convenience, low cost nature, and immense adaptability in real-time scenarios. The components of the network are gateways, mesh routers, access points, and end users. The components in mesh topology have a dedicated line of communication with a half-duplex radio. The wireless mesh network is basically implemented in IEEE 802.11 standard, and it is typically ad-hoc in nature. The advantageous nature of WMN leads to its extensive use in today's world. WMN's overall performance has been increased by incorporating the concept of multi-channel multi-radio. This gives rise to the problem of channel assignment for maximum utilization of the available bandwidth. In this chapter, the factors affecting the channel assignment process have been presented. Categorizations of the channel assignment techniques are also illustrated. Channel assignment techniques have also been compared.

Visualizing Pathway on 3D Maps for an Interactive User Navigation in Mobile Devices

3D maps have become an essential tool for navigation aid. The aim of a navigation aid is to provide an optimal route from the current position to the destination. Unfortunately, most mobile devices' GPS signal accuracy and the display of pathways on 3D maps in the small screen of mobile devices affects the pathway architectural from generating accurate initial positions to destinations. This chapter proposed a technique for visualizing pathway on 3D maps for an interactive user navigation aid in mobile devices. This technique provides visualization of 3D maps in virtual 3D workspace environments which assists a user to navigate to a target location. The Bi-A* path-finding algorithm was used for establishing dynamic target location in Voronoi diagram/Delaunay triangulation. This approach could navigate more than two users in a 3D walk-space and at the same time showing their whereabouts on 3D projections mapped. The map shows the users' location in the scene to navigate from source to the target and the target also moves to the source to meet on the same physical location and image plane.

Dynamic Fog Computing

The emerging Internet of Things (IoT) systems enhance various mobile ubiquitous applications such as augmented reality, environmental analytics, etc. However, the common cloud-centric IoT systems face limitations on the agility needed for real-time applications. This motivates the Fog computing architecture, where IoT systems distribute their processes to the computational resources at the edge networks near data sources and end-users. Although fog computing is a promising solution, it also raises a challenge in mobility support for mobile ubiquitous applications. Lack of proper mobility support will increase the latency due to various factors such as package drop, re-assigning tasks to fog servers, etc. To address the challenge, this chapter proposes a dynamic and proactive fog computing approach, which improves the task distribution process in fog-assisted mobile ubiquitous applications and optimizes the task allocation based on runtime context information. The authors have implemented and validated a proof-of-concept prototype and the chapter discusses the findings.