TY  - JOUR
T1  - TDMA Based Collision Free MAC Protocol in Underwater Acoustic Networks
AU - Kim, Sunmyeng AU - Ergashev, Muzaffar 
JO  - Journal of Engineering and Applied Sciences
VL  - 13
IS  - 21
SP  - 9132
EP  - 9140
PY  - 2018
DA  - 2001/08/19
SN  - 1816-949x
DO  - jeasci.2018.9132.9140
UR  - https://makhillpublications.co/view-article.php?doi=jeasci.2018.9132.9140
KW  - Underwater acoustic networks
KW  -clustering
KW  -collision free
KW  -layering
KW  -time slot
KW  -COD-TS
AB  - Number of MAC protocols have been proposed for Underwater Acoustic Networks (UANs).
However, unique characteristics of acoustic communication such as very slow data rate inconsistent long
propagation delay and long physical header degrade the performance of the most existing works. In order to
improve network performance, COD-TS has been proposed. COD-TS utilizes clustering algorithm to organize
nodes into clusters. To avoid inter-cluster collisions, cluster heads exchange schedule information between
them based on CDMA. COD-TS has two problems. Near-far effect has not been considered for schedule
information packets. It exchanges schedule information at high power, causing collisions to member nodes in
the neighboring cluster. Therefore, it causes degradation of network performance. We introduce a cluster based
underwater TDMA protocol (CU-TDMA) which is collision free and energy efficient. In the CU-TDMA, first
an UAN is partitioned into layers based on water pressure. Then, nodes in each layer are organized into
clusters. To address the inter-layer inter-cluster and intra-cluster collisions, we present a TDMA algorithm. We
compare the performance of the proposed protocol with the COD-TS in simulations. The results show that the
proposed protocol outperforms the COD-TS protocol in terms of throughput and energy efficiency.
ER  -