Accurate Emulation of Wireless Sensor Networks

flangeeasyMobile - Wireless

Nov 21, 2013 (3 years and 6 months ago)

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Accurate Emulation of Wireless Sensor
Networks



Hejun Wu

Joint work with


Qiong Luo, Pei Zheng*,
Bingsheng He,

and Lionel M. Ni



Department of Computer Science

The Hong Kong University of Science & Technology, China


*Arcadia University, USA






Proxy

Sink




User Client

Sensor mote

Wireless Sensor Networks (WSNs)





Proxy

Sink




User Client

Sensor mote

Wireless Sensor Networks (WSN)


Query

Sensor mote





Proxy

Sink




User Client

Wireless Sensor Networks (WSN)

Query Result

Motivation of VMNet


Substitute for sensor nodes in research


Easy to handle


Low price


A realistic & controllable environment


Debugging


Testing


Evaluating Performance



Parameter setting and validation for


Simulation


Modeling

Applications

Network protocols

OS

Drivers

VMNet architecture

VMNet architecture


VM
1

VM
2

VM

k



PC 1


VM
0
(sink)





Virtual Channel

Virtual Channel

LAN


Applic
a
tion

User Inte
r
face

Gateway

Virtual

har
d
ware

Network
Manager

VM
m
+1

VM
m
+2

VM
m+
k

PC n

Real
software

Virtual

har
d
ware


EM

Real
software

Virtual

har
d
ware


EM

Real
software

Virtual

har
d
ware


EM



EM

Real
software

Virtual

har
d
ware


EM

Real
software

Virtual

har
d
ware


EM

Real
software

Virtual

har
d
ware


EM



Virtual Channel

PC 0

Components in a VM


Virtual

mote

Real mote binary code

Virtual
sensor
board

Virtual radio
frequency
module

Virtual
UART( In
Virtual Sink)



Virtual CPU

EM (Emulation Manager)

Virtual

main board

Virtual
socket

Virtual
clock

Virtual Radio Channel

Delay
Module

Bit error
Module

To VRFM

Collision
Module

Bits

From VRFM

Control messages To/From

Network Manager (NM)

UDP packet from other
VMs via LAN

UDP packet to other
VMs via LAN

Collision signal

to VRFM

Queue

Key Features of VMNet


Open architecture


Easy to transform to other WSN hardware emulation


Detailed emulation


CPU instructions


Operations of the components


CPU, Sensor and Radio


Accurate running status logs


Accurate time emulation


Granularity: microsecond level


power consumption evaluation

Open architecture design


Conflict between generality & accuracy


Generality is desirable


Ability to emulate various WSNs


Accuracy


Close to the specified target WSN


Highly modularized structure of a VM


Ensures the reusability


Virtual socket in a VM


Uniform interface between modules



Virtual

mote

Real mote binary code

Virtual
sensor
board

Virtual radio
frequency
module

Virtual
UART( In
Virtual Sink)



Virtual CPU

EM (Emulation Manager)

Virtual

main board

Virtual
socket

Virtual
clock

Highly modularized structure

Performance Evaluation on
Applications of WSNs


Based on the fact that


Operation and time can be deduced by


Instructions executed by the CPU in a sensor mote


An instruction always takes constant time


VMNet approach in performance evaluation


Logging and reporting



Operations and time

Logging in VMNet


The operations :


VMNet logs


Running states


the operations of each
component (e.g.
III
)


CPU clocks


describe the start time
and end time


CPU

Sensor

Radio


Compute

(
C
)

Acquire (A)

Transmit (T)

Idle

(
I
)

Idle (I)

Receive(R)

Hibernate

(
H
)

Power down
(P)

Control(C)

Idle(I)

Power down (p)

Running

states

Time (In terms of CPU
clock cycles)

III

1926031985

IIR

1926032167

CIR

1926034874

The operations of components

A fraction of a VMNet log

Conclusion



Detailed emulation


Useful for many areas in a WSN


Architecture, OS, and sensor network query
processing.


Provides


parameter and validation for simulation & modeling



Performance evaluation


Especially valuable for query processing


Query Optimization:



choose a query plan with minimum energy and time cost


Query processor benchmark study

Future Work


Power consumption evaluation


Work in progress


Scalability


Mobile WSN emulation



Graphical Interface for VMNet


In the near future


Use multiple PCs to emulate a WSN