AIRCC's International Journal of Computer Science and Information Technology

Hemen Patel ¹, Syed S. Rizvi ¹, Laiali Almazaydeh ¹, Aasia Riasat ²

Affiliations
1 Department of Computer Science and Engineering, University of Bridgeport, Bridgeport, CT, US
2 Department of Computer Science, Institute of Business Management, Karachi, Sindh, PK

Abstract

A conservative distributed simulation requires all logical processes (LPs) to follow the causality constraint requirement. This implies that all event-messages are processed in strictly timestamp order. Apart from the timestamp of each event generated by LPs, synchronization between all LPs is the second most important requirements. Finally, there must not be a deadlock in the distributed environment. A deadlock may occur when there is no events present in the queue of LP. In such case, to avoid deadlock, Chandy-Misra-Bryant presented an algorithm called Null Message Algorithm (NMA) [3]. These null messages are passed as an event-message to other LPs and it stored in one of queues of LPs. This null message indicates that till the time stamp of that null message, all other events in the queue which have lesser time stamp than null message's time stamp are safe to process. It means that there won't be any arrival of any events from that logical process until current simulation time is equal to the time stamp of the null message. With the time stamp of the null message, a Lookahead value is added to the time stamp of that null message. This Lookahead value can be measure on certain kind of parameters such as delay to transmit a message, propagation delay, etc. therefore, calculating value of Lookahead is the most important part as Lookahead value affects the performance of the conservative distributed event simulation. Proper value of Lookahead can reduce the number of null messages which decreases the traffic of the network. In this paper, we demonstrate some calculation on the Lookahead which shows the performance of the distributed event simulation.

Keywords

Conservative Distributed Simulation, Null Messages, Logical Process with Null Message, Look Ahead.

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Laiali Almazaydeh ¹, Eman Abdelfattah ¹, Manal Al- Bzoor ¹, Amer Al-Rahayfeh ¹

Affiliations
1 Computer Science and Engineering Department, University of Bridgeport, Bridgeport, CT 06601, US

Abstract

The efficiency of sensor networks strongly depends on the routing protocol used. In this paper, we analyze three different types of routing protocols: LEACH, PEGASIS, and VGA. Sensor networks are simulated using Sensoria simulator. Several simulations are conducted to analyze the performance of these protocols including the power consumption and overall network performance. The simulation results, using same limited sensing range value, show that PEGASIS outperforms all other protocols while LEACH has better performance than VGA. Furthermore, the paper investigates the power consumption for all protocols. On the average, VGA has the worst power consumption when the sensing range is limited, while VGA is the best when the sensing range is increased.

Keywords

Sensor Networks, Routing Protocol, LEACH, PEGASIS, VGA, Sensoria Simulator, Energy Consumption, Network Performance.

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