الفهرس | Only 14 pages are availabe for public view |
Abstract One of the main constraints in wireless sensor networks (WSNs) is the energy consumption, which occurs due to the different transmission techniques applied on the network nodes. This thesis presents an extensive analysis of routing protocols in heterogeneous WSNs namely; Stable Election Protocol (SEP)-based protocols and Distributed Energy-Efficient Clustering (DEEC)-based protocols. The performance is evaluated in terms of; stability, instability period, network life-time, throughput, and energy consumption. This thesis proposes two protocols (1, 2) which depend on SEP and DEEC-based and present four proposed protocols. Firstly, we propose Enhanced Zonal-SEP (EZSEP) and Zonal Threshold-DEEC (ZTDEEC) protocols in which we divide the network field into certain zones to improve the connectivity of the far normal nodes that have lower energy than other nodes with base station (BS). Secondly, we propose Threshold-based EZSEP (TE-ZSEP) and Enhanced-ZTDEEC (EZ-TDEEC) protocols to modify the way we select the CHs in heterogeneous routing protocols. In these two protocols we redefine the threshold formula used in EZSEP and ZTDEEC to consider both energy and distance parameters. By combining the idea of dividing the network field into certain zones and the modified threshold formula, the proposed TE-ZSEP and EZ-TDEEC protocols can effectively improve the energy consumption in heterogeneous WSN and prolong its lifetime. To overcome the problem of energy consumption and large transmission distance between both normal nodes and cluster-heads (CHs) with BS exists in Zonal-SEP. We present proposed protocol (3), which has the three proactive routing protocols. The first protocol is a circle ZSEP (CZSEP), is a two-level heterogeneous energy protocol with a circle zone located at the Abstract III center of the network field to deploy the normal nodes and the advanced nodes are randomly distributed around this circle zone. The second protocol is CZSEP with helper nodes (CZSEP-HN) and is a three-level heterogeneous energy protocol. In CZSEP-HN they add helper nodes in certain places in the network field to minimize the energy consumption in CZSEP. Both CZSEP and CZSEP-HN can overcome the problem of large transmission distance between normal nodes and BS and between CHs and BS exists in conventional ZSEP. Finally, the third protocol is a modified CZSEP-HN (MCZSEP-HN) used to overcome the problem of energy consumption in CZSEP-HN. MCZSEP-HN is a four-level heterogeneous energy protocol with two circle zones one for normal nodes and the other for intermediate nodes. |