Jan 17, 2018
Wireless sensor and actor networks: research challenges
Ian F. Akyildiz, Ismail H. Kasimoglu Elsevier Ad Hoc Networks 2004
JY Hong WSAN : Research Challenges
Contents Introduction Physical characteristics of WSAN Effective
sensor-actor coordination Effective actor-actor coordination
Protocol stack for WSAN Conclusion WSAN : Research Challenges WSAN
: Research Challenges
Introduction (1/3) WSAN (Wireless Sensor and Actor Network)
Definition Observing the physical world Processing the data and
Making decisions Performing appropriate actions Applications
Battlefield surveillance, microclimate control in building,
nuclear, biological and chemical attack detection, home automation,
environmental monitoring WSAN : Research Challenges WSAN : Research
Challenges
Introduction (2/3) Elements of WSAN Sensor Low-cost Limited
sensing, computation wireless communication capabilities Hundreds
or thousands sensors are deployed in target area Actor Resource
rich nodes Higher transmission power Dense deployment not necessary
WSAN : Research Challenges WSAN : Research Challenges
Introduction (3/3) WSAN unique characteristics Real-time
requirement Rapid respond to sensor input Coordination In order to
make decisions on the most appropriate action Sensor-actor and
actor-actor coordination may occur Example Fire extinguisher
system, Malicious person detecting system Difference from WSN Actor
exists Complex coordination WSN is not be well-suited for WSAN WSAN
: Research Challenges Battle field Surveillance system - 1
Satellite Communication Main Task Manager Target Detection Target
Tracking Target Identification Battle field Monitoring Sensor Node
Sink Node Gateway Military Tactical Networks Sensing Field WSAN :
Research Challenges Battle field Surveillance system - 2
Types of actors WSAN : Research Challenges WSAN : Research
Challenges
DARPA Urban Challenge 2007 November 3, at California Victorvile
Driverless car racing Traffic Signal detection sensor Collision
prevention sensor Central computer and GPS WSAN : Research
Challenges Physical characteristics of WSAN (1/4)
The physical architecture WSAN : Research Challenges Physical
characteristics of WSAN (2/4)
Automated vs. Semi-Automated Architecture Focus on the Automated
Architecture Low latency Long network lifetime Automated
Architecture Semi-Automated Architecture WSAN : Research Challenges
Physical characteristics of WSAN (3/4)
The component of Sensors The component of Actors Sensor Actor node
, . reliable , , . actor . WSAN : Research Challenges Physical
characteristics of WSAN (4/4)
Example of Several Actors WSAN : Research Challenges Effective
sensor-actor coordination (1/5)
Most important characteristic To provide low communication delay
Main investigating problems What are the requirements of this
communication? Consume low energy Real-time traffic Ordered
delivery of information Synchronization Which sensors communicate
with which actors? Redundancy Elimination Actor selection How is
this communication realized? Single hop vs. Multi hop Depends on
the deployment and location of actor node Real-time traffic WSN .
Actor WSAN : Research Challenges Effective sensor-actor
coordination (2/5)
Redundancy elimination Minimal set of actors and sensors Some
applications Level of Redundancy Mutually Exclusive Some level of
redundancy Mutually exclusive : do not overlap, for example; WSAN :
Research Challenges Effective sensor-actor coordination (3/5)
Multi-Actor vs. Single-Actor (a) Multi-Actor : Drawback of lack of
coordination - Too many unnecessary actors can be activated (b)
Single-Actor : To avoid above situation - Sensors should coordinate
with sensors - One actor to collect the data WSAN : Research
Challenges Effective sensor-actor coordination (4/5)
Single Actor Main challenges is to determine the single actor node
Select SA based on below criteria Distance Minimum energy path The
action range of the actor No guarantee One actor is not well-suited
due to the coverage and energy constraints Actor-Actor Coordination
Actor publishes the announcement message Select one or more other
actors to perform the appropriate actions WSAN : Research
Challenges Effective sensor-actor coordination (5/5)
Research Challenges For both Single-Actor and Multiple-Actor
Ordered delivery of information Synchronization Selection of an
actor or a set of actors In Multiple-Actor The redundancy in the
set of actors Trade-offs between Single-Actor and Multiple-Actor
WSAN : Research Challenges Effective actor-actor coordination
(1/3)
In case of actor-actor communication occur Small action range or
insufficient energy by one actor Multiple actors receive the same
event information Multiple actors are required to cover the entire
event region Synchronization requirement The event is spreading to
other actors acting areas Task assignment problem Single-Actor Task
(SAT) vs. Multi-Actor Task (MAT) Centralized Decision (CD) vs.
Distributed Decision (DD) WSAN : Research Challenges Effective
actor-actor coordination (2/3)
Task assignment In MAT, if multiple actors receive event
information Distributed Decision case Negotiate with each actors
Choose Best Actors Centralized Decision case Actors directly
transmit to the pre-determined actor node In MAT, if only one actor
(SA) receives event information Centralized Decision Announcement
message to other actors Select Best Actors WSAN : Research
Challenges Effective actor-actor coordination (3/3)
Research challenges Algorithms Communication model between actors
Ordered execution of tasks for a series of events Synchronization
Executed by a set of actors Redundancy in the set of actors The
partial execution of tasks Efficient data transmission algorithm
for announcement message and negotiation Minimize the task
completion time Communication protocol, Real time properties of
WSAN WSAN : Research Challenges Protocol stack for WSAN
No standard protocol stack for WSN and WSAN WSAN protocol stack
Communication plane, Coordination plane, Management plane Cross
Layering WSAN : Research Challenges WSAN : Research
Challenges
Conclusion The effectiveness of WSN will be increased The actors
are deployedin the network ,WSAN Many applications Realization of
WSAN Satisfy the requirements of the coexistence of sensors and
actors We investigated research challenge Real-time communication
protocol Sensor-Actor coordination Actor-Actor coordination WSAN :
Research Challenges WSAN : Research Challenges
Questions or Comments WSAN : Research Challenges