Abstract: Wireless sensor networks (WSNs) applications, that are similar to that of other distributed systems, and a time-synchronization protocol has been developed. The time synchronization of WSNs is required for coordination and data consistency. To improve accuracy for WSNs by controlling the root node is still a problem. The Flooding Time Synchronization Protocol (FTSP) is a one of protocol for synchronization. FTSP utilizes a simple election process based on minimum node IDs. In this paper, we propose (FTSP) a new election root node method by neighbor node (NB). We analyzed the time synchronization error by calculating the average of the pairwise differences of the reported global times by a new root election. The time average was reduced suggesting FTSP based on neighbor node is more advantages than lower ID and neighbor node method conferred significantly better accuracy than lower ID method.

• Publication Date: 05-May-2013
• DOI: 10.15224/978-981-07-6261-2-23
• Views: 0
• Downloads: 0

Abstract: Receive Signal Strength Indicator (RSSI) is one of performance metrics in wireless communications. The value indicates whether receiver could receive a packet. Since signal can reflex and refract from soil surface, underground nodes may not be able to communicate with aboveground nodes. One way solving this problem is to control the antenna orientation where antenna’s radiation pattern is in an appropriate direction. Therefore, in this work, we develop two types of sensor nodes which are 2-and 3-antenna nodes to improve RSSI values for underground-to-aboveground communications. Results show RSSI values of 2-and 3- antenna have better than those of 1-antenna sensor node approximately 0.85 and 1.43 dBm for manual installation and 2.64 and 6.97 dBm for random installation respectively.

• Publication Date: 05-May-2013
• DOI: 10.15224/978-981-07-6261-2-22
• Views: 0
• Downloads: 0