Abstract:
Wireless sensor networks consist of a large number of resource constraint sensor nodes. Due
to it’s wide range of applications, it has drawn much attention in the research community. As
wireless sensor networks use shared medium, designing an energy efficient MAC protocol is
highly desirable for maintaining other application specific performance requirements.
Between contention-based and schedule-based MAC protocols; contention-based MAC
protocol consumes much energy and cost higher for collision, idle listening and overhearing
problem. In the contrary, schedule-based MAC protocol ensures energy efficient operation at
the cost of high end-to-end delay. Although existing lightweight medium access control
(LMAC) protocol is an energy efficient protocol, it introduces high end-to-end delay and low
network throughput due to the long waiting time. The low throughput problem of LMAC
protocol has already been mitigated in multichannel LMAC (MC-LMAC) protocol by
ensuring energy efficient operation. However, the delay problem still exists for the same
reason of the long waiting time. Therefore, it is highly expected to design an energy efficient
MAC protocol for delay sensitive and high throughput applications.
In this research work, a low latency multichannel LMAC (LL-MCLMAC) protocol is
presented for WSNs which significantly reduces the end-to-end delay while improving the
system throughput further. In the proposed protocol, the delay problem of existing LMAC
and MC-LMAC protocol has been significantly improved by allowing a node to send its
packet using two timeslots of a channel from multiple channel. The timeslot pair are kept half
of the frame time separated which is decided by an algorithm. Moreover, the schedule-based
operations ensure an energy efficient operation and use of multichannel results high
throughput. A simulation model using OMNeT++ and MiXiM is designed to show the
effectiveness of the proposed protocol. Finally, performance of proposed protocol is
compared with the existing LMAC and MC-LMAC protocol, in terms of number of received
packets, end-to-end delay, energy consumption and network lifetime. Simulation results
clearly show that LL-MCLMAC achieves significant improvement in end-to-end delay and
network throughput over existing LMAC and MC-LMAC protocols while ensuring an
energy efficient operation.
