Research Profile of My Group

flangeeasyMobile - Wireless

Nov 21, 2013 (4 years and 1 month ago)

64 views

Research Profile of My Group


Guoliang Xing

Department of Computer Science

City University of Hong Kong

Facts of My Group


Members


Three PhD students


CityU, CityU
-
USTC, CityU
-
WuhanU


One Master student


Two research assistants (joint supervision)


Part of CityU wireless group


6 faculty members


more than 20 research staff/students


~3 million HK$ government funding in 2007
-
08

Research Directions


Controlled mobility


Data fusion based target detection


Power management


Sensing coverage

2007
-
08 Conference Publications



Controlled mobility



Rendezvous Design Algorithms for Wireless Sensor Networks with a
Mobile Base Station
, G. Xing, T. Wang, W. Jia, M. Li,
MobiHoc 2008
,
44/300=14.6%.


Rendezvous Planning in Mobility
-
assisted Wireless Sensor Networks
,

G.
Xing
,
T. Wang, Z. Xie and W. Jia
;

RTSS 2007
,
44/171=25.7%
.



Data fusion based target detection


Mobility
-
assisted Spatiotemporal Detection in Wireless Sensor
Networks
, G. Xing; J. Wang; K. Shen; Q. Huang; H. So; X. Jia,
ICDCS
2008
,
102/638=16%.


Collaborative Target Detection in Wireless Sensor Networks with
Reactive Mobility,
R. Tan, G. Xing, J. Wang and H. So,
IWQoS 2008



Power management



Link Layer Support for Unified Radio Power Management in Wireless
Sensor Networks
. K. Klues, G. Xing and C. Lu,

IPSN 2007

38/170=22.3%.


Dynamic Multi
-
resolution Data Dissemination in Storage
-
centric
Wireless Sensor Networks.
H. Luo, G. Xing, M. Li, and X. Jia,
MSWiM
2007
,
41/161=24.8%.

Earlier Work on Sensor Networks

ACM/IEEE Transactions Papers


1.
Minimum Power Configuration for Wireless Communication in
Sensor Networks
,
G. Xing

C. Lu, Y. Zhang, Q. Huang, R. Pless, ACM
Transactions on Sensor Networks, Vol 3(2), 2007, extended MobiHoc
2005 paper


2.
Impact of Sensing Coverage on Greedy Geographic Routing
Algorithms
,
G. Xing
; C. Lu; R. Pless; Q. Huang. IEEE Transactions on
Parallel and Distributed Systems (TPDS),17(4), 2006, extended MobiHoc
2004 paper



3.
Integrated Coverage and Connectivity Configuration for Energy
Conservation in Sensor Networks
,
G. Xing
; X. Wang; Y. Zhang; C. Lu;
R. Pless; C. D. Gill, ACM Transactions on Sensor Networks, Vol. 1 (1),
2005, extended SenSys 2003 paper,
one of the most widely cited work
on the coverage problem of sensor networks, total number of
citations is
358

in Google Scholar.

Focus of this Talk


Controlled mobility



Rendezvous Planning in Mobility
-
assisted Wireless
Sensor Networks
,

G. Xing
,
T. Wang, Z. Xie and W. Jia
;

RTSS 2007
,
44/171=25.7%
.


Power management



Link Layer Support for Unified Radio Power
Management in Wireless Sensor Networks
. K. Klues, G.
Xing and C. Lu,

IPSN 2007

38/170=22.3%.


Sensing Coverage


Integrated Coverage and Connectivity
Configuration for Energy Conservation in Sensor
Networks
,
G. Xing
; X. Wang; Y. Zhang; C. Lu; R.
Pless; C. D. Gill, ACM Transactions on Sensor
Networks, Vol. 1 (1), 2005, extended SenSys 2003
paper

Motivations


Sensor nets face the fundamental performance
bottleneck


Many applications are data
-
intensive


Multi
-
hop wireless relays are power
-
consuming


A tension exists between the sheer amount of data
generated and limited power supply


Controlled mobility is a promising solution


Number of related papers increases significantly in
last 3 years: MobiSys, MobiHoc, MobiCom, IPSN

Mobile Sensor Platforms


Low movement speed (0.1~2 m/s)


Increased latency of data collection


Reduced network capacity

Networked Infomechanical
Systems (NIMS) @ CENS, UCLA

Robomote @ USC
[Dantu05robomote]


XYZ @ Yale
http://www.eng.yale.edu/
enalab/XYZ/


Basic idea


Some nodes serve as “rendezvous points” (RPs)


Other nodes send their data to the closest RP


Mobiles visit RPs and transport data to base station


Advantages


In
-
network caching + controlled mobility


Mobiles can collect a large volume of data at a time


Minimize disruptions due to mobility


Mobiles contact static nodes at RPs at scheduled time

mobile node

rendezvous
point

An Example

source
node

The field is 500
×

500 m
2


The mobile moves at 0
.
5 m/s


It takes ~
20 minutes

to visit
six randomly distributed RPs



It takes >
4 hours
to visit 200
randomly distributed nodes.


The Rendezvous Planning Problem


Formulated as graph problem


An optimal algorithm for limited
-
mobility
without data aggregation


Two approx. algorithms with aggregation


Focus of this Talk


Controlled mobility



Rendezvous Planning in Mobility
-
assisted Wireless
Sensor Networks
,

G. Xing
,
T. Wang, Z. Xie and W. Jia
;

RTSS 2007
,
44/171=25.7%
.


Power management



Link Layer Support for Unified Radio Power
Management in Wireless Sensor Networks
. K. Klues, G.
Xing and C. Lu,

IPSN 2007

38/170=22.3%.


Sensing Coverage


Integrated Coverage and Connectivity
Configuration for Energy Conservation in Sensor
Networks
,
G. Xing
; X. Wang; Y. Zhang; C. Lu; R.
Pless; C. D. Gill, ACM Transactions on Sensor
Networks, Vol. 1 (1), 2005, extended SenSys 2003
paper

MAC

Send/Receive

Buffers

Radio Power

Management

Clear Channel

Assessment

Backoff Controller

Radio State

Machine

Send/Receive Interfaces

Power Management Interfaces

Backoff Control Interfaces

Radio Component

Traditional Core Radio
Functionality

CCA
Functionality

Incoming and
Outgoing data
buffers

State machine

Integrated
Radio Power
Management

Real Implementations do not separate these functional
components so nicely

Implementation


Implemented UPMA in TinyOS 2.0 for both Mica2
and Telosb motes


Developed interfaces with different types of MAC


CSMA based: S
-
MAC
[Ye et al. 04]
, B
-
MAC
[Polastre et al. 04]


TDMA based: TRAMA
[Rajendran et al. 05]


Hybrid: 802.15.4, Z
-
MAC
[Rhee et al. 05]


Separated sleep scheduling modules from B
-
MAC


Implemented two new sleep schedulers on top of
B
-
MAC


Focus of this Talk


Controlled mobility



Rendezvous Planning in Mobility
-
assisted Wireless
Sensor Networks
,

G. Xing
,
T. Wang, Z. Xie and W. Jia
;

RTSS 2007
,
44/171=25.7%
.


Power management



Link Layer Support for Unified Radio Power
Management in Wireless Sensor Networks
. K. Klues, G.
Xing and C. Lu,

IPSN 2007

38/170=22.3%.


Sensing Coverage


Integrated Coverage and Connectivity
Configuration for Energy Conservation in Sensor
Networks
,
G. Xing
; X. Wang; Y. Zhang; C. Lu; R.
Pless; C. D. Gill, ACM Transactions on Sensor
Networks, Vol. 1 (1), 2005, extended SenSys 2003
paper

An Integrated Model



Assume a number of active nodes can achieve:


K
-
coverage
: every point is monitored by at least K active sensors


N
-
connectivity
: network is still connected if N
-
1 active nodes fail


Bounded routing paths
: hop count between any two nodes can be
predicted


Focus on fundamental relations between the constraints

Sleeping node

Communicating nodes

Active nodes

Sensing range

A network with 1
-
coverage and 1
-
connectivity

Connectivity
vs.

Coverage:
Analytical Results


Network connectivity does
not

guarantee coverage


Connectivity only concerns with node locations


Coverage concerns with
all

locations in a region


If
R
c
/
R
s



2


K
-
coverage


K
-
connectivity


Implication: given requirements of K
-
coverage and N
-
connectivity, only needs to satisfy max(K, N)
-
coverage


Solution: Coverage Configuration Protocol (CCP)


If
R
c
/
R
s

< 2


CCP + SPAN
[chen et al. 01]

Student Profiles


Self
-
motivated


Ambitious and persistent


Theory background


Graph theory, optimization, probabilistic
theory, computational geometry


Hands
-
on experiences


C/C++ programming, embedded systems,
OS, network programming

Problem Formulation


Given a tree
T(V,E)

rooted at
B

and sources
{s
i
}
, find RPs,
{R
i
}
, and a tour no longer than
L=vD
that

visits
{B}
U
{R
i
},

and








The problem is NP
-
hard (reduction from the
Traveling Salesman Problem)

minimized

is

)
,
(

i
s


S
i
i
T
R
s
d
d
T
(s
i
,R
i
)



the on
-
tree distance between
s
i

and
R
i

Rendezvous Planning under Limited
Mobility


The mobile only moves along routing tree


Simplifies motion control and improves reliability

XYZ @ Yale

An Optimal Algorithm


Sort edges in the descending order of the
number of sources in descendents


Choose a subset of (partial) edges from
the sorted list whose length is
L/2


The mobile tour is the pre
-
order traversal
of the chosen edges

Thanks!


Unified Power Management Architecture


SyncSleep

Other Interface

Protocol 3

Protocol 2

MAC

PHY

Async Listening

Others

Sync Scheduler



DutyCycling Table

OnTime

OffTime

LPL Table

Mode

Preamble

Other Table

Param 0

Param 1

PreambleLength

ChannelMonitor

On/Off





Protocol 0

Protocol 1

Power Management Abstraction

Power
Manager

parameters specified by
upper
-
level protocols

AsyncSleep

interfaces of sleep
schedulers

sleep scheduling
protocols

1.
Consistency check

2.
Aggregation

interfaces with MAC