Physicalnet:
Cross-network Applications for
Multi-user Sensor and Actuator Networks
Pascal A. Vicaire (pascal@cs.virginia.edu)
John A. Stankovic (stankovic@cs.virginia.edu)
University of Virginia
Goals

Programming sensor network applications
from any PC connected to the Internet

Global / cross-network applications
=> Access rights

Multi-user
=> Conflict resolution

Ease of programming
=> Discovery and manipulation of large sets of nodes
=> Heterogeneity
=> Mobility
=> Compatibility
Physicalnet

Global accessibilty



Physicalnet is a Service
Oriented Architecture
Each node has a unique
global identifier
Nodes are not tied to a
particular geographical
location
Users
Negotiators
Gateways
Service Providers
Physicalnet

Access rights


All Physicalnet services
are composed of states
and events
For each service:


For each state:




Localization rights
Reading rights
Writing rights
Priority
For each event:

Idem
Temperature Sensor Access Right Table
John
Mike
Peter
Tom
|
|
|
|
|
Priority
1
2
3
4
|
|
|
|
|
Location
L
L
-
|
|
|
|
|
Sensor
RW
RW
RW
--
|
|
|
|
|
Rate
RW
RRW
--
Physicalnet

Users
Conflict resolution


Service specific resolvers
to manage conflicts
between user
requirements
Examples:





First come first serve
OR, AND operators
Highest priority
Minimum
Negotiator
Requirement Table
App.
A1
A2
A3
Service
temp1
temp1
temp1
State/Event
samplingPeriod
samplingPeriod
samplingPeriod
Resolver
Service
temp1
State/Event
samplingPeriod
Args
10s
Access to actual state
value within application
Towards Service Providers
(Sensors / Actuators)
Args
10s
15s
20s
Physicalnet

Programming API






Large sets
Cross networks
Dynamic sets
heterogeneous sets
Mobility
Compatibility
Preliminary Results:

FireAlarm Application:



Code Size:
~80 lines of code
Installation time:
~15s for 36 nodes
distributed across 2
remote networks
Average responsiveness:
~3s
Conclusion



Our goal is to create a framework to facilitate the
programming of cross-network applications of
multi-user sensor and actuator networks.
Our solution uses a service oriented architecture
that supports node heterogeneity, node mobility,
access rights, conflict resolution mechanisms.
It provides a high level java API to specify
programs using dynamic logical sets of nodes.
Thank You!
Questions?
Pascal A. Vicaire (pascal@cs.virginia.edu)
John A. Stankovic (stankovic@cs.virginia.edu)
Why is it Difficult?

Global accessibility
=> Access rights




Resolution?
Specification?
Mechanisms?
Multiple users
=> Conflict resolution



Resolution?
Specification?
Mechanisms?

Ease of programming
=> Discovery and manipulation
of large sets of nodes
=> Sets that span multiple
networks
=> Heterogeneous sets of
nodes
=> Mobility
=> Compatibility with other
service oriented architectures