Information Technology Reference
In-Depth Information
Table 5.1 Summary of nonfunctional properties of the different WSN intergration approaches
IrisNet
Hourglass
Janus
JWebDust
SWE
Basic
concept
Database
view
SANs as
services
in a stream
processing
overlay
Centralized
broker
SQL DB
backed
with
framework
services
Web-service-
based
standards
framework
Framework
structure
Distributed,
two-
tiered
In principle
distributed
but not
realized
Centralized
broker
N-tier (5)
SPS acts as
central-ized
broker
Data
represen-
tation
User-defined
DB schema
per
application
Topic and
predicate
per service
Exported as
functions
at SAN
Basic sensor
types
XML-based
descriptions
Heterogen.
of SANs
Yes
Yes, support
for low
capability
by proxies
Yes
Yes, limited to
TinyOS
support
Yes, SOS
facilitates
unified
interface
Flexibility
of queries
Limited to
database
schema/
XPATH
selections
Limited to
HCDL
expressi-
veness
Limited to set
of functions
provided at
a SAN
Limited to
SQL-like
queries
over sensor
types
SOS allows
simplistic
queries
Low, due to
centralized
nature
Low-Medium,
all data
have to go
through
centralized
DB system
Medium-high,
direct WSN
access;
however,
centralized
broker
Scalability
Medium
Medium, large
signalling
overhead
for circuit
management
Interaction
types
Query,
streaming,
event-based
Streaming
RPC-like
interactions,
query and
event-
based
Query,
streaming,
event-based
Query, streaming
via SOS,
event-based
via SAS/
WNS
Level of
Mediation
Low, exact
knowledge
required
(schema)
Medium, service
discovery
and CM
Medium,
provides
discovery
of APIs
Low, may
implement
broker in
middle tier
Medium, SPS
Implemen-
tation
available
Yes
Yes, basic
functions,
single
domain
Yes
Yes
Yes, components
(continued)
 
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