Power-Controlled Topology Optimization and Channel Assignment for Hybrid MAC in Wireless Sensor Networks

Latency bounded and energy efficient MAC for wireless sensor networks

“…Moreover, LB-MAC exhibits better energy efficiency than PTOCA. In [24], PTOCA exhibited better performance in terms of energy efficiency than the legacy IEEE 802.15.4 MAC with CSMA duty-cycling [11] and Hybrid MAC [22], because of its topology optimisation functionality. In the current implementation of LB-MAC, we applied the same topology optimisation mechanism with PTOCA.…”

“…In addition, as it uses a pre-planned superframe structure and randomly selective channel assignment mechanism, it has no adaptability to various network conditions. To overcome these problems, PTOCA [24], which is an enhancement of [22] provides the powercontrolled topology optimisation and channel assignment mechanisms, with high network throughput as a primary design criterion. However, in time-critical industrial applications such as plant automation and control systems, which are the target scenarios of our work, Hybrid MAC [22] and PTOCA [24] are not suitable because of their unpredictability for end-to-sink latency, as they commonly use the transmission channel assignment mechanisms without considering the routing path of data.…”

“…LB-MAC uses the topology control mechanism of PTOCA [24], a power-controlled topology optimisation, to minimise the local contention level of the tree network. By using it, each node in the network calculates its optimal transmission power level to be able to maintain its routing path to the sink node.…”

“…It assists in the scheduling of the TDMA superframe, as it reduces the interference level of the nodes resulting in making the 'available channel resource' sufficient, which will be described in Section 3.2. The detailed performance analysis of PTOCA can be found in [24].…”

“…We consider various performance metrics of a network running LB-MAC and compare them with those of PTOCA [24]. In this section, we first present the configurations of the simulation, then present the results obtained in detail.…”