Anish Mathew Kurien

RSSI based indoor and outdoor distance estimation for localization in WSN

Research has revealed that the correlation between distance and RSSI (Received Signal Strength Indication) values is the key of ranging and localization technologies in wireless sensor networks (WSNs). In this paper, an RSSI model that estimates the distance between sensor nodes in WSNs is presented. The performance of this model is evaluated and analyzed in a real system deployment in an indoor and outdoor environment by performing an empirical measurement using Crossbow IRIS wireless sensor motes. Our result shows that there is less error in distance estimation in an outdoor environment compared to indoor environment. The results of these evaluations would contribute towards obtaining accurate locations of wireless sensor nodes.

A Survey of Resource Management Toward 5G Radio Access Networks

The next generation 5G radio access network (RAN) system is believed to be a true world wide wireless web (WWWW). This is because such system will seamlessly and ubiquitously connect everything, and support at least 1000-fold traffic volumes, 100 billion connected wireless devices, and diversified use cases as well as quality of service (QoS) requirements (e.g., reliability, latency, data rates, coverage, security, and privacy) of multimedia applications by 2020. Recently, a number of research challenges including the explosive growth in mobile traffic volumes, unprecedented connected devices, and diversified use cases have been identified for the 5G RAN systems. In addition, specific technologies such as multitier communication, massive MIMOs, mmWave backhauling, extreme densifications of nodes (UDNs), full-duplex communications (FDCs), and energy harvesting techniques have emerged in the literature to resolve some of these challenges of the 5G RAN systems. However, the research activities defining specific technical advancements for 5G RAN systems are yet to continue in the next half decade before specifications for standardization and commercialization are concluded. Motivated by the limited number of existing surveys of such technical advancements in a broader perspective (i.e., interference, spectrum-efficient, and energy-efficient management schemes), this paper seeks to take stock of state-of-the-art (SOTA) on such technical developments. Our attention focuses on relevant radio interference and resource management (RIRM) schemes that have been proposed in the last five years. Our contribution lies in the analysis, synthesis, and summarized alignments of the conventional RIRM schemes toward overcoming the identified challenges for the 5G RAN systems. Finally, the review highlights a number of open research issues deduced from recently proposed RIRM schemes.

Network coding and competitive approach for gradient based routing in wireless sensor networks

Energy efficiency is a key design criterion for routing protocols in wireless sensor networks since sensor nodes are strongly constrained in terms of energy supply. Gradient-Based Routing (GBR) is a well known energy efficient routing protocol that is used in WSNs. However, there exist shortcomings in the GBR scheme such as: (1) sinks make use of flooding to broadcast interest messages which leads to a lot of duplication packets which are transmitted. This leads to the waste of a lot of energy in the network and (2) nodes deliver messages in a point to point manner. As a result, the potential of data retransmissions in the network is high due to the unstable network environment in WSNs. In this study, network coding and a competitive approach are proposed to solve the above two problems. Firstly, an energy efficient broadcast algorithm using network coding for GBR (GBR-NC) is proposed. This algorithm aims to reduce network traffic, and furthermore, reduce the energy consumption and prolong the lifetime of the network. Secondly, two competing algorithms (GBR-C and auto-adaptable GBR-C) are proposed for GBR. The basic idea of the proposed competing algorithms is to reduce the retransmission attempts and save the energy by considering two forward candidates. Simulation results show that the proposed schemes give better results when compared to the traditional GBR in terms of energy efficiency.

Optimization of Antenna Placement in 3G Networks Using Genetic Algorithms

Third generation (3G) cellular networks are being implemented in many countries at high rate. Due to the fact that manual cell planning is a time consuming process and prone to a degree of error and inefficiency, there is a need for automated approaches to optimise coverage, capacity and quality of cellular networks in a fraction of the time. This paper studies the application of genetic algorithms to solve the antenna placement problem (APP) in universal mobile telecommunication system (UMTS) networks. The parameters of the genetic algorithm are tuned so that the algorithm converges optimally. The main task of the algorithm is to find the best set of base station locations so as to maximise coverage and quality of service measured as the signal-to-interference and noise ratio (SINR), as well as minimise the network cost by using fewer base stations. Assuming that a flat area is considered, the performance of the proposed algorithm was evaluated with 98% of the users in the network being covered with a good quality signal.

Energy Efficient Topology Control Algorithm for Wireless Mesh Networks

The control of the topology of a network makes it possible for the network nodes to reduce their power of transmission while ensuring that network connectivity is preserved. This paper explains the need for energy consumption control in Wireless Mesh Networks (WMNs) and proposes a Local Minimum Shortest-Path Tree (LM-SPT) algorithm for topology control for the WMNs. The algorithm is distributed with each node using only the information gathered locally to determine its own transmission power. The implementation is done in two phases. The construction of a minimum local shortest-path tree is first done. The removal of all unidirectional links is then done. The performance of the algorithm is demonstrated via several simulation tests. The resultant network topology preserves network connectivity in addition to possessing other desirable features such as: (1) reduction in the average node degree, (2) evenly distributed power consumption among the nodes as well as (3) a reduced total power consumption leading to longer connectivity periods.

Active Throughput Estimation Using RTT of Differing ICMP Packet Sizes

Network measurements always play a vital role for good network management purposes and are essential for quality of service (QoS) requirements. Packet delay derivations are critical measurement parameters in diagnosing simple network performance measures. The traditional ping tool is popular for target host connectivity testing and average delay measurements. However, ping is a poor indicator of round trip time (RTT) measurements at the network layer. In this paper, an active round trip time (RTT) packet delay measurements using Internet control message protocol (ICMP) data packets of varying sizes is proposed. It was observed that in the proposed RTT measurement technique, peak throughput values were obtained compared to the ping measurements. The proposed approach eliminates the need for special purpose cooperation and/or software applications at the destination in the measured network path when using the ICMP Echo Request/ Reply technique.

Enhancing video streaming in 802.11 Wireless Mesh Networks using two-layer mechanism solution

Multihop Wireless Mesh Networks have emerged as the next generation in wireless network technology. This is due to the advantages provided by the mesh network technology. WMNs provides ease of installation, cost effective deployments, high level of scalability, wide coverage area and capacity, network flexibility and self-configuration capabilities. However, despite these advantages, many research challenges still remain in WMNs. One such challenge is the support of real time applications such as video streaming. This paper proposes a two-layer mechanism for the transportation of real-time video. In this mechanism, rate adaptation is implemented in the data link layer for channel error control, link stability and reliability. In addition, the network layer routing protocol is optimized for congestion control and optimal route selection by using congestion information from the data link layer and link quality metric from the network layer. Simulation results show that the proposed mechanism improves the network performance in terms of throughput, delay and jitter in multihop wireless mesh networks when UDP is used as the transport protocol.

Doppler Effect Analysis and Modulation Code Derivation

To reduce the risk of accidents, traffic, and other safety related problems on public roads, the Wireless Access in Vehicular Environment (WAVE) standard was created. The WAVE also known as Dedicated Short Range Communications (DSRC) at 5.9 GHz, is part of the Federal Highway Authoritys Vehicle Infrastructure Integration (VII). This standard merely supports Vehicle-to-Vehicle (V2 V) and Vehicle-to-Infrastructure (V2I) communications for emerging Intelligent Transportation Systems (ITS). Due to the high mobility of this network, nodes involved in communication suffer from intermittent signal degradation. This is partly due to Doppler Effect (DE). This paper investigates and analyses the DE over wide Doppler Shift (DS) ranges. The results of the analysis clearly demonstrate that, sustainable communication links is achievable with DS ranging up to 1400 Hz if an appropriate Modulation Code Scheme (MCS) can be selected. It also demonstrates that a BPSK Rate of 1/2 is not always a good candidate when combating DE.

Link-Based VoIP Aggregation in Mesh Networks

Voice over IP (VoIP) over wireless mesh network (WMNs) has become a topic of great interest in both enterprise and research arena. The IEEE 802.11 standard is the most popular wireless LAN standard for extending the access point (AP) based network. However, it does not provide guaranteed quality for real-time applications such as VoIP. Besides, with the large number of injected flows in WMNs, only a handful of these packets can be supported due to protocol overhead, packet collision and Interferences. In this paper, a link-based aggregation is proposed and its performance improvement is compared with those of fixed aggregation and performance under standard access network. Simulation results show that the proposed aggregation scheme increases the number of supported flow while also reducing end-to-end delay, jitter, and packet loss of VoIP in WMNs.

A Topology Control Algorithm for Effective Power Efficiency and Throughput for Wireless Mesh Networks

Wireless mesh networks (WMNs) have become a better alternative for extending wireless Local Area Networks (WLANs) to provide network coverage up to the furthest of far flung rural areas. This has been implemented by using a meshed backbone network interconnecting the mesh access points (MAPs) that manages each of the WLANs. The routing algorithms use the mesh backbone to establish inter-WLAN routes which are subsequently used by the distantly distributed mesh clients to communicate in a multihop fashion. In this work, a fully scalable power-efficient localized distributed topology control algorithm is proposed to effectively construct such a meshed backbone network of access points. The performance of the algorithm is evaluated via several simulations carried out in the NS-2 simulation environment. The resultant network topology is shown to have (1) reduced average node degree which leads to reduced traffic interference, (2) increased throughput and (3)increased network lifetime.