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Cross Layer Adaptation of Check intervals in low power listening MAC protocols for lifetime improvement in Wireless Sensor Networks.

Escolar S, Chessa S, Carretero J, Marinescu MC - Sensors (Basel) (2012)

Bottom Line: We propose Cross Layer Adaptation of Check intervals (CLAC), a novel protocol intended to reduce the energy consumption of the nodes without significantly increasing the delay.CLAC uses routing and MAC layer information to compute a delay that matches the packet arrival time.The simulation results confirm that CLAC improves the network lifetime at no additional packet loss and without affecting the end-to-end delay.

View Article: PubMed Central - PubMed

Affiliation: Computer Science Department, University Carlos III of Madrid, Avda. Universidad 30, Madrid 28911, Spain. mariasoledad.escolar@uc3m.es

ABSTRACT
Preamble sampling-based MAC protocols designed for Wireless Sensor Networks (WSN) are aimed at prolonging the lifetime of the nodes by scheduling their times of activity. This scheduling exploits node synchronization to find the right trade-off between energy consumption and delay. In this paper we consider the problem of node synchronization in preamble sampling protocols. We propose Cross Layer Adaptation of Check intervals (CLAC), a novel protocol intended to reduce the energy consumption of the nodes without significantly increasing the delay. Our protocol modifies the scheduling of the nodes based on estimating the delay experienced by a packet that travels along a multi-hop path. CLAC uses routing and MAC layer information to compute a delay that matches the packet arrival time. We have implemented CLAC on top of well-known routing and MAC protocols for WSN, and we have evaluated our implementation using the Avrora simulator. The simulation results confirm that CLAC improves the network lifetime at no additional packet loss and without affecting the end-to-end delay.

No MeSH data available.


Related in: MedlinePlus

Network lifetime (in days) for 10-node (left) and 22-node (right) tree topologies.
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f10-sensors-12-10511: Network lifetime (in days) for 10-node (left) and 22-node (right) tree topologies.

Mentions: The lifetime of the network is computed for each experiment according to Equation (2). We only consider values of DC above 10% which, based on our experiments, guarantee network connectivity. Note that for DC equal to 20%, network connectivity is guaranteed for tree topologies but not for linear topologies with p = 5 and p = 10. We compare the network lifetime using CLAC against the lifetime using CTP/BoX-MAC. We express the results of the network lifetime in days. Figure 9 illustrates the results for the 10- and 20-node linear topologies. We observe that the network lifetime decreases when DC increases, which matches the fact that a larger DC implies a bigger energy consumption. With a DC = 100% the lifetime converges to 5.5 days for all experiments. As the figure shows, a larger p implies a longer network lifetime. For positive values of p, which implies a proportional increase of the delay, we obtain a lower DC and, subsequently, longer network lifetimes. This fact can be observed in Figure 9 where the longest network lifetimes are achieved for p = 10. From this figure we observe that CLAC improves the network lifetime when compared to BoX-MAC for all values of DC and p. On the right hand side of Figure 9, we see network lifetimes more similar to CTP/BoX-MAC (except for DC = 20%). This behavior is due to the increase in the network size, which causes a bigger load for the forwarding nodes (remember that the network lifetime is the lifetime of the node that first dies). Figure 10 shows the network lifetime for 10- and 22-node tree-based topologies, both of which have a longer lifetime compared to linear topologies. In a linear topology, the node which is the nearest to the sink must receive N−1 packets and transmit N packets in each round, being N the number of nodes in the linear topology. It also accumulates the delays produced by each hop, which leads to high idle listening and consequently a lot of retransmissions. It follows that node 1 in a linear topology is very overloaded trying to receive and retransmit many packets, while, in the case of the tree, the overall traffic is split among the children of the root. Therefore, node 1 dies in a linear topology much earlier than in a tree topology. With a low DC the situation gets worse since the contention increases. For tree-based topologies the lifetime is increased, and CLAC doubles the lifetime obtained by CTP/BoX-MAC for some values of DC and p.


Cross Layer Adaptation of Check intervals in low power listening MAC protocols for lifetime improvement in Wireless Sensor Networks.

Escolar S, Chessa S, Carretero J, Marinescu MC - Sensors (Basel) (2012)

Network lifetime (in days) for 10-node (left) and 22-node (right) tree topologies.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472841&req=5

f10-sensors-12-10511: Network lifetime (in days) for 10-node (left) and 22-node (right) tree topologies.
Mentions: The lifetime of the network is computed for each experiment according to Equation (2). We only consider values of DC above 10% which, based on our experiments, guarantee network connectivity. Note that for DC equal to 20%, network connectivity is guaranteed for tree topologies but not for linear topologies with p = 5 and p = 10. We compare the network lifetime using CLAC against the lifetime using CTP/BoX-MAC. We express the results of the network lifetime in days. Figure 9 illustrates the results for the 10- and 20-node linear topologies. We observe that the network lifetime decreases when DC increases, which matches the fact that a larger DC implies a bigger energy consumption. With a DC = 100% the lifetime converges to 5.5 days for all experiments. As the figure shows, a larger p implies a longer network lifetime. For positive values of p, which implies a proportional increase of the delay, we obtain a lower DC and, subsequently, longer network lifetimes. This fact can be observed in Figure 9 where the longest network lifetimes are achieved for p = 10. From this figure we observe that CLAC improves the network lifetime when compared to BoX-MAC for all values of DC and p. On the right hand side of Figure 9, we see network lifetimes more similar to CTP/BoX-MAC (except for DC = 20%). This behavior is due to the increase in the network size, which causes a bigger load for the forwarding nodes (remember that the network lifetime is the lifetime of the node that first dies). Figure 10 shows the network lifetime for 10- and 22-node tree-based topologies, both of which have a longer lifetime compared to linear topologies. In a linear topology, the node which is the nearest to the sink must receive N−1 packets and transmit N packets in each round, being N the number of nodes in the linear topology. It also accumulates the delays produced by each hop, which leads to high idle listening and consequently a lot of retransmissions. It follows that node 1 in a linear topology is very overloaded trying to receive and retransmit many packets, while, in the case of the tree, the overall traffic is split among the children of the root. Therefore, node 1 dies in a linear topology much earlier than in a tree topology. With a low DC the situation gets worse since the contention increases. For tree-based topologies the lifetime is increased, and CLAC doubles the lifetime obtained by CTP/BoX-MAC for some values of DC and p.

Bottom Line: We propose Cross Layer Adaptation of Check intervals (CLAC), a novel protocol intended to reduce the energy consumption of the nodes without significantly increasing the delay.CLAC uses routing and MAC layer information to compute a delay that matches the packet arrival time.The simulation results confirm that CLAC improves the network lifetime at no additional packet loss and without affecting the end-to-end delay.

View Article: PubMed Central - PubMed

Affiliation: Computer Science Department, University Carlos III of Madrid, Avda. Universidad 30, Madrid 28911, Spain. mariasoledad.escolar@uc3m.es

ABSTRACT
Preamble sampling-based MAC protocols designed for Wireless Sensor Networks (WSN) are aimed at prolonging the lifetime of the nodes by scheduling their times of activity. This scheduling exploits node synchronization to find the right trade-off between energy consumption and delay. In this paper we consider the problem of node synchronization in preamble sampling protocols. We propose Cross Layer Adaptation of Check intervals (CLAC), a novel protocol intended to reduce the energy consumption of the nodes without significantly increasing the delay. Our protocol modifies the scheduling of the nodes based on estimating the delay experienced by a packet that travels along a multi-hop path. CLAC uses routing and MAC layer information to compute a delay that matches the packet arrival time. We have implemented CLAC on top of well-known routing and MAC protocols for WSN, and we have evaluated our implementation using the Avrora simulator. The simulation results confirm that CLAC improves the network lifetime at no additional packet loss and without affecting the end-to-end delay.

No MeSH data available.


Related in: MedlinePlus