  This paper has been withdrawn by arXiv. arXiv admin note: author list
truncated due to disputed authorship and content. This submission repeats large
portions of text from this http URL by other authors. Duty cycle mode in WSN
improves energy-efficiency, but also introduces packet delivery latency.
Several duty-cycle based MAC schemes have been proposed to reduce latency, but
throughput is limited by duty-cycled scheduling performance. In this paper, a
Traffic-adaptive Time-division Multiple Access (TTMA), a distributed TDMA-based
MAC protocol is introduced to improves the throughput by traffic-adaptive
time-slot scheduling that increases the channel utilisation efficiency. The
proposed time-slot scheduling method first avoids time-slots assigned to nodes
with no traffic through fast traffic notification. It then achieves better
channel utilisation among nodes having traffic through an ordered schedule
negotiation scheme. By decomposing traffic notification and data transmission
scheduling into two phases leads each phase to be simple and efficient. The
performance evaluation shows that the two-phase design significantly improves
the throughput and outperforms the time division multiple access (TDMA) control
with slot stealing.
