TDMA scheduling of group aware tree in Wireless Sensor Networks

Abstract

Data collection is an important operation in Wireless Sensor Networks. Sensors are deployed in given region of interest. They sense physical phenomenon and transfer data to a central node known as Sink. Tree is a widely used routing topology and Time Division Multiple Access (TDMA) is a widely used Medium Access Control (MAC) protocol. Sink is at the root of the tree. Often nodes in a tree aggregate the data coming from children with their own data. Data aggregation results in energy conservation and reduction in network traffic. Often sensor networks are heterogeneous in nature. Multiple groups (or types) of sensors are deployed in given region. In heterogeneous network, tree formation should consider presence of different groups. That is, a node should select node of same group as itself as parent. This is known as group aware tree formation. Other approach is static tree formation. In static tree formation, parent is selected without considering its group. Group aware tree formation increases chances of aggregation. Inspired from work done in [9] and [10], we have implemented group aware tree formation .Group aware tree formation is followed by TDMA scheduling of edges. Performance measures like energy consumption and number of time-slots used are examined. It is concluded that group aware tree formation results in less number of required timeslots compared to static tree and energy consumption is also less.

Fuzzy-Based Efficient Healthcare Data Collection and Analysis Mechanism Using Edge Nodes in the IoMT

“…The efficient selection of the parent node effectively aggregates data from nodes, which directly impacts total slot usage, control messages, and energy utilization in both the control and data phases. In this stage, the energy utilization of node i (E c i ) and E C is determined using Equations ( 5) and ( 6) [66]. E initial represents the starting energy level of the nodes in the network; E residual i denotes the residual energy at the end of this phase.…”

Time slot assignment for convergecast in wireless sensor networks

“…To reduce data delivery time and energy consumption, time slots are only assigned to sensor nodes in the event detection area and only for wireless links on paths to the sink node rather than to the entire network. Vasavada et al presented TDMA scheduling of a group aware tree for heterogeneous sensor nodes [24]. The tree is formed using group formations based on the types and applications of sensor nodes, and time slots are assigned to sensor nodes based on the number of their children, types of the children and their data generation rates.…”

“…Nevertheless, Jung et al presented an algorithm for finding the minimum scheduling time for convergecast in general networks [13]. [17] Stop-and-collect No Any No Annamalai [2] Code allocation Yes TDMA No Moscibroda [16] Network processing Yes TDMA No Gherairi [9] Partial scheduling Yes TDMA No Vasavada [24] Group information Yes TDMA No Villas [25] Spatial correlation Yes Any No Gandham [8] Storage size ≤ 2…”

“…Constraint (22) states that each sensor node transmits the data generated by itself and received from its children to forward, and Constraint (23) disallows a sensor node from transmitting data before it is received. Constraint (24) states the relationship between children and parent nodes. By Constraint (25), sensor nodes cannot use a time slot for transmit and receive operations at the same time.…”