The Design Space of Wireless Sensor Networks

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Nov 21, 2013 (3 years and 8 months ago)

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The Design Space of Wireless
Sensor Networks

Xin
-
Xian Liu

2005 03 22

Outline


Background


Performance Metrics


Sensor Network Architecture


Design Space


Conclusion

Background


Initial research into WSN was mainly
motivated by military application


A de facto definition of WSN as a large
-
scale,
ad hoc, multihop, tiny, resource
-
constrained


Sensor network

The components of a sensor node

Performance Metrics


Energy efficiency / system lifetime


Latency


Accuracy


Fault
-
tolerance


Scalability

Sensor Network Architecture


The network protocol is responsible for
supporting all communication between the
sensors and the observer


The performance of the protocol will be
highly influenced by the network dynamics
and by the specific data delivery model
employed

Communication Models


Communication within a sensor network can
be classified into two categories


Application communication


Infrastructure communication


Application communication is related to the
transfer of sensed data with the goal of
informing the observer about the phenomena

Communication Models


Within application communication, there are
two models:


Cooperative


Non
-
cooperative


Communication Models


Infrastructure communication refers to the
communication needed to configure,
maintain and optimize operation


In sensor networks, an initial phase of
infrastructure communication is needed to
set up the network


Data Delivery Models


Sensor networks can be classified in terms of
the data delivery required by the application
interest as:


Continuous


Event
-
driven


Observer
-
initiated


hybrid


Data Delivery Models


Continuous


The sensors communicate their data continuously
at a prespecified rate


Event
-
driven


The sensors report information only if an event of
interest occurs


Observer
-
initiated


The sensors only report their results in response
to an explicit request from the observer

Data Delivery Models


The actual flow of data packets between the
sensors and the observer


Flooding


Unicast


Multicast

Network Dynamics Models


The approach to construct and maintain a
path between observer and phenomenon will
differ depending on the network dynamics,
which we classify as


Static sensor networks


Dynamic sensors networks

Static Sensor Networks


In static sensor networks, there is no motion
among communication sensor, the observer
and the phenomenon


Dynamic Sensor Networks


In dynamic sensor networks, either the
sensors themselves, the observer, or the
phenomenon are mobile


Dynamic sensor networks can be further
classified by considering the motion of the
components


Mobile observer


Mobile sensors


Mobile phenomena

Design Space


We informally characterize each of the
dimension and, where appropriate, identify
property classes in order to support a
coarse
-
grained classification of sensor
network application


Design Space


Deployment


Random vs. Manual


One
-
time vs. Iterative


Mobility


Immobile vs. Partly vs. All


Occasional vs. Continuous


Active vs. Passive

Design Space


Cost


The cost of a single device may vary from
hundreds of Euros to a few cents


Size


The form factor of a single sensor node may vary
from the size of a shoebox to a microscopically
small particle



Design Space


Resources and Energy


Varying size and cost constrains directly result in
corresponding varying limits on the energy
available, as well as on computing, storage and
communication resources


We partition sensor nodes roughly into four
classes based on their physical size



brick, matchbox, grain, and dust

Design Space


Heterogeneity


Homogeneous vs. Heterogeneous


Communication Modality


Radio vs. Light vs. Inductive vs. Capacitive vs.
Sound


Infrastructure


Infrastructure vs. Ad Hoc

Design Space


Network Topology


Single
-
hop vs. Star vs. Networked Start vs. Tree


Coverage


Sparse vs. Dense vs. Redundant


Connectivity


Connected vs. Intermittent vs. sporadic


Design Space


Network Size


The network size may vary from a few nodes to
thousands of sensor nodes or even more


Lifetime


Depending on the application, the required
lifetime of a sensor network may range from some
hours to several years

Design Space


Other QoS Requirement


Depending on the application, a sensor network
must support certain QoS aspects such as


Real
-
time


Robustness


Tamper
-
resistance


Eavesdropping resistance


Conclusion


Clearly, a single hardware platform will most
likely not be sufficient to support the wide
range of possible applications


A modular approach, where the individual
components of a sensor node can easily
exchanged

References

[1] S. Tilak, N. B. Abu
-
Ghazaleh, and W.
Heinzelman, “A Taxonomy of Wireless Micro
-
Sensor Network Models,”MR2C, vol. 6, no. 2,
Arp.2002, pp. 28
-
36

[2] Kay Romer and Friedemann Mattern, ETH
Zurich, “The Design Space of Wireless
Sensor Networks,” IEEE Communications
Magazine, pp.54
-
61,December 2004