Kemal E. Tepe

Review: Survey of multipath routing protocols for mobile ad hoc networks

This survey investigates multipath routing protocols for mobile ad hoc networks (MANETs). The main objectives of multipath routing protocols are to provide reliable communication and to ensure load balancing as well as to improve quality of service (QoS) of MANETs. These multipath protocols are broadly classified into five categories based on their major goals. The goals are to improve delay, provide reliability, reduce overhead, maximize network life and support hybrid routing. Multipath routing protocols address issues such as multiple paths discovery and maintaining these paths. Issues, objectives, performances, advantages and disadvantages of these protocols are investigated and summarized. A checklist is provided as a guideline so that a network designer can choose an appropriate multipath routing protocol to meet the networks application objectives.

Game theoretic approach in routing protocol for wireless ad hoc networks

This paper introduces a game theoretic method, called forwarding dilemma game (FDG), which controls routing overhead in dense multi-hop wireless ad hoc networks. The players of the game are the wireless nodes with set of strategies {Forward, Not forward}. The game is played whenever an arbitrary node in the network receives a flooding packet. In FDG, every player needs to know the number of players of the game. That is why a neighbor discovery protocol (NDP) is introduced. In order for NDP to function, a field is attached to the flooding packets (routing overhead packets). The mixed strategy Nash equilibrium is used as a solution for the FDG. This provides the probability that the flooding packet would be forwarded by the receiver node. FDG with NDP is implemented in AODV protocol in Network Simulator NS-2 to verify its performance with simulations. FDG with NDP improves performance of the AODV compared to the same network with only AODV protocol in moderate and high node densities. FDG can be applied to any routing protocol that uses flooding in the route discovery phase.

Energy saving dynamic source routing for ad hoc wireless networks

In this paper, energy saving dynamic source routing (ESDSR) protocol is introduced to maximize the life-span of a mobile ad hoc network (MANET). Many theoretical studies show that energy consumption in MANET can be significantly reduced using energy-aware routing protocols compared to fixed-power minimum-hop routing protocols. Two approaches are broadly suggested for energy-aware routing protocols - transmission power control approach and load sharing approach. ESDSR integrates the advantages of those two approaches. In ESDSR, the routing decision is based on a load balancing approach. Once a routing decision is made, link by link transmit power adjustment per packet is done based on a transmit power control approach. We modified dynamic source routing (DSR) protocol to make it energy aware by a network simulator (network simulator-2 of University of California). The simulation results show that the proposed ESDSR can save energy up to 40% per packet and it can send 20 % more packets to destinations by spending the same battery power in compare to DSR.

Routing overhead analysis for reactive routing protocols in wireless ad hoc networks

Although several routing protocols have been proposed that can be used in mobile ad hoc networks, there is very little formal analysis that considers the communication overhead or in other word routing overhead for these procedures. This paper provides a new mathematical framework for quantifying the overhead of reactive routing protocols such as dynamic source routing (DSR) and ad hoc on-demand distance vector routing (AODV) in wireless ad hoc networks with random location of the nodes. The analysis is compared with the simulations and found to match with the simulation results . The result of this study can be used to predict scalability properties of routing protocols.

Minimum energy hierarchical dynamic source routing for Mobile Ad Hoc Networks

In this paper, Minimum Energy Dynamic Source Routing (MEDSR) and Hierarchical Minimum Energy Dynamic Source Routing (HMEDSR) protocols for Mobile Ad Hoc Networks (MANET) are proposed. The objective of MEDSR protocol is to reduce energy consumption in MANET while maintaining connectivity in the network. The objective of HMEDSR is to reduce the overhead of MEDSR. The overall result is that energy spent in transmitting overhead packets is reduced. This reduction allows more energy in transmitting data packets. The Dynamic Source Routing (DSR) protocol is modified to implement both MEDSR and HMEDSR protocols, and these implementations are tested with a network simulator (Network Simulator (NS-2)). The simulation results show that both MEDSR and HMEDSR protocols reduce energy consumption per data packet by 25% compared to DSR, but HMESDR further reduces energy consumption by 12% compared to MEDSR by controlling overhead packets.

Channel estimation for 5.9 GHz dedicated shortrange communications receiver in wireless access vehicular environments

A channel estimation scheme for the design of a 5.9 GHz dedicated short-range communications receiver for the purpose of vehicle-to-vehicle and vehicle-to-roadside communications is proposed. The receiver is based on the popular wireless local area network standard IEEE 802.11a, but with extended symbol duration. On the basis of analyses and simulations, the proposed receiver has superior design characteristics for the harsh channel conditions of wireless access vehicular environments. The performance of the proposed scheme is tested under varying velocity, signal-to-noise ratios, transmission modes, packet lengths and channel properties. The proposed design improves the overall packet error rate performance, enabling the system to achieve higher data rates and larger packet lengths at high relative velocities. Simulation results show slight improvements in the quadrature phase-shift keying transmission, whereas there is substantial improvement in the cases of 16- and 64-ary quadrature amplitude modulations compared to conventional design.

Extending Wireless Sensor Network Lifetime With Global Energy Balance

In this paper, a decentralized routing algorithm, called game theoretic energy balance routing protocol, is proposed to extend the network lifetime by balancing energy consumption in a larger network area using geographical routing protocols. The objective of the proposed protocol is to make sensor nodes deplete their energy at approximately the same time, which is achieved by addressing the load balance problem at both the region and node levels. In the region level, evolutionary game theory (EGT) is used to balance the traffic load to available subregions. At the node level, classical game theory (CGT) is used to select the best node to balance the load in the selected subregion. This two-level approach is shown to be an effective solution for load balancing and extending network lifetime. This paper shows the use of EGT and CGT in designing a robust protocol that offers significant improvement over existing protocols in extending network lifetime.

Reconfigurable simulator using graphical user interface (GUI) and object-oriented design for OFDM systems

Abstract In this paper, a design of a new object-oriented simulation environment and graphical user interface (GUI) for versatile orthogonal frequency division multiplexing (OFDM) systems is presented. This is achieved using high-level design, parallelism and usability for the simulation environment. GUI interface can serve as a learning/research tool for students or practiced professionals to investigate particular designs. It is evident that OFDM systems intended to be used in dynamic environments must be tested under various conditions in order to be designed for optimality. Hence, a simulation design is proposed coupling the GUI, parallelism, and high-level object-oriented design techniques to be beneficial to the researcher. A high-level design and GUI layouts of the proposed simulator is shown in details. Important OFDM parameters needed for reconfiguration of transmitter components, channel condition parameters, and receiver components are discussed. In addition, this paper provides a simple technique to implement simulation partitioning for increased parallel performance of reconfigurable object-oriented OFDM simulators. This simple technique applies to scenarios where there is disproportionate simulation duration between different OFDM configurations. It is shown to decrease total simulation time considerably.

Design and implementation of a testbed for IEEE 802.15.4 (Zigbee) performance measurements

AbstractsIEEE 802.15.4, commonly known as ZigBee, is a Media Access Control (MAC) and physical layer standard specifically designed for short range wireless communication where low rate, low power, and low bandwidth are required. This makes ZigBee an ideal choice when it comes to sensor networks for monitoring data collection and/or triggering process responses. However, these very characteristics bring into question ZigBees ability to perform reliably in harsh environments. This paper thoroughly explains the experimental testbed setup and execution to demonstrate ZigBees performance in several practical applications. This testbed is capable of measuring the minimum, maximum, and average received signal strength indicator (RSSI), bit error rate (BER), packet error rate (PER), packet loss rate (PLR), and the bit error locations. Results show that ZigBee has the potential capabilities to be used in all four tested environments.

Characterization of the adverse effect of neighborhood capture in MANET and on the way to a remedy

The current era of mobile communication is passing through the days of rapidly changing technologies. A technology which holds promise to bring surprise to the future users is ad hoc networks. The multiple access procedure in ad hoc networks is not error prone till now, although significant researches are going on in its MAC layer. The communications in ad hoc networks are adversely affected by the neighborhood capture problem along with some other problems like hidden station problem, exposed station problem as well as channel capture problem. This paper will characterize the adverse effect of neighborhood capture problem with two views of a remedy and some analytical results