Database Reference
In-Depth Information
Network Reprogramming.
TheOTAPisusedtotransmitanexecutableim-
age to slot 3 of each node. The OTAP is based on
Deluge
[HC04] but has
been extended to enable different executable images to be sent to each node
in the WSN. This is necessary because
SNEE
generates query execution plans
with distinct tasks for each node in the WSN, rather than sending the same
query execution plan to nodes in the WSN. This enables
SNEE
to be more
economical with respect to memory consumption
4
.
Start Query.
Nodes reboot into the query execution plan, which starts running
when the Sensor Network Connectivity Bridge issues a
start
command. Com-
mands are disseminated using
Drip
[TC05] a mechanism used to propagate
small values across all nodes in a WSN
5
.
Evaluate Query.
The nodes evaluate the query execution plan, sending results
back to gateway node.
Stop Query.
Query results are produced until a
stop
command is issued.
This paper has outlined the lifecycle for
SNEE
queries. An experimental eval-
uation measuring metrics including energy consumption and lifetime of
SNEE
queries, using simulation and real hardware, is presented in [GBG
+
11]. The de-
velopment of a query compiler/evaluator for WSNs leaves open a collection of
query lifecycle management issues; this paper describes an approach in which
support tasks such as OTAP and metadata collection are represented as sepa-
rate programs that work together with query executables to support declarative,
energy ecient environment monitoring.
Acknowledgements.
This work is part of the SemSorGrid4Env project funded
by the European Commission's Seventh Framework Programme.
References
[GBG
+
11]
Galpin, I., Brenninkmeijer, C.Y.A., Gray, A.J.G., Jabeen, F., Fernan-
des, A.A.A., Paton, N.W.: SNEE: a query processor for wireless sensor
networks. DAPD 29(1-2), 31-85 (2011)
[HC04]
Hui, J.W., Culler, D.E.: The dynamic behavior of a data dissemination
protocol for network programming at scale. In: SenSys, pp. 81-94 (2004)
[TC05]
Tolle, G., Culler, D.E.: Design of an application-cooperative management
system for wireless sensor networks. In: EWSN, pp. 121-132 (2005)
4
See [GBG
+
11] for memory consumption figures of
SNEE
for the query execution
plan image, excluding management functionality.
5
This is an implementation of the dissemination framework described in
