Title: WAP endorser presentation San Francisco 8 Jan 98
1A Short Bio Dr. Zhanyang Zhang
- Education Ph.D and MS degrees from CUNY
respectively in 1995 and 1988. EE degree from
Jilin University, China in 1982 - Academic Position Assistant Professor,
Computer Science Department at College of Staten
Island (9/2003 present) - Industry Experience - Full time and consultant
positions in telecommunication, finance and
pharmaceutical industries (1993-2003)
2Areas of Research Interests
- Past Research
- Database, Data Warehouse and Data Mining
- 3G-Wireless Data Network and Wireless Data
Network Security - E-Commerce and M(obile)-Commerce
- Current Research
- Wireless Ad hoc Networks
- Mobile Database
- Wireless Sensor Networks
3Wireless Sensor Network andApplications
Zhanyang Zhang, Ph. D zhangz_at_mail.csi.cuny.edu Col
lege of Staten Island City University of New
York Oct 4th, 2004
4Outline
- Introduction
- Communication architecture
- Protocol stack
- Applications
- Research Problems and Opportunities
- A Stimulating Signal Approach toward Sensor
Location, K-Coverage and Energy-Saving Problems
5Introduction
- Sensor Networkslow-cost, rapid deployment,
self-organizing, and fault tolerance. - Application areas heath, military, and home.
- Large number of sensor nodes that are densely
deployed. - Nodes use their processing abilities to locally
carry out simple computations and transmit the
required and partially processed data. - Ad hoc networks are not suitable for the sensor
networks because of their unique features and
application requirements.
6Features of Sensor Networks
- What is a Sensor Network?
- 1000s of sensors deployed to collect, process and
store information e.g. weather conditions. - Local communication to achieve global objectives
- Popular application areas
- Medical, Military, Natural Habitat monitoring,
micro-organisms monitoring, etc - Factors to consider when deploying sensors
- Low power
- Large numbers
- Frequent motion, task dynamics / Device failures
- Distributed sensing
- Exception free, unattended operation
7Design Factors
- Fault Tolerancethe ability to sustain sensor
network functionalities without any interruption
due to sensor node failures because of lack of
power, physical damage, or environmental
interference. - Scalabilitythe density of sensor nodes can range
from few sensor nodes to few hundred sensor nodes
in a region. - Production Coststhe cost of sensor node should
be much less than 1 in order for the sensor
network to be feasible
8Continue.. Design Factors
- Sensor Network Topology- Predeployment and
deployment phase- Post-deployment phase-
Redeployment of additional nodes phase - Environmentcan work in different environments.
- Transmission Medialinks between nodes can be
formed by radio, infrared, or optical media. - Power Consumptionbattery lifetimedesign of
power-aware protocols and algorithmsPower
consumption sensing, communication, and data
processing
9Design Issues
- Sensor Network Vs Wired / Wireless network
- Data centric addressed by data values rather
than identities - Application Specific tailored for specific
tasks - Types of coordination between sensors to achieve
above goals - Centralized
- single point of failure
- energy inefficient
- nonscalable
- Distributed localized algorithms
- robust to network partitions/ node failures
- short range of communication - energy efficient
- scalable low communication overhead
- simpler self-configuration
10Hardware Architecture
Location finding system
Mobilizer
Sensing Unit
Processing Unit
Transceiver
Processor
Sensor
ADC
Storage
Power Unit
Power generator
11Communication Architecture
Internet and Satellite
Sink
C
D
A
E
B
Task manager node
Sensor nodes
Sensor field
User
12Protocol Stack - Sensor Networks
13 The Physical Layer
- Frequency selection.
- Carrier frequency generation.
- Signal detection.
- ModulationBinary and M-ary modulation
schemesthe binary modulation scheme is more
energy-efficient - Low transmission power and simple transceiver
circuitry make Ultra wideband (UWB) an attractive
candidate.
14The Data Link Layer
- Multiplexing of data streams.
- Data frame detection.
- Medium access and error control.
- Ensures reliable point-to-point and
point-to-multipoint connections in a
communication network.
15Medium Access Control
Continue.. The Data Link Layer
- Must achieve two goals- the creation of the
network infrastructure- share communication
resources between sensor nodes fairly and
efficiently. - Traditional MAC cant be adopted into sensor
networks, because- there is no central
controlling agent like the base station.- power
efficiency directly influences network lifetime
in sensor network.
16Network Layer
- Task energy efficient routes
Route 1 Sink-A-B-T, total PA4, total a 3
Route 2 Sink-A-B-C-T, total PA6, total a
6 Route 3 Sink-D-T, total PA3, total a
4 Route 4 Sink-E-F-T, total PA5, total a 6
Sink
a
32
11
a
E (PA1)
a
42
A (PA2)
- Approaches
- Max route route 4
- Min Energy (ME) route route 1
- Min hop (MH) route route 3
- Max-Min PA node route route 3
D (PA3)
a
21
a
62
B (PA2)
a
52
a
71
a
82
a
F (PA4)
T
a
92
C (PA2)
17Data Aggregation, data fusion
Continue.. Network Layer
C
B
A
E
D
F
G
Sink
18Routing techniques
Continue.. Network Layer
- Floodingeach node receiving a data or management
packet repeats it by broadcasting. - Gossipingsend the incoming packets to a
randomly selected neighbor.
19Transport Layer
- Transport layer protocols are still
unexplored they may be purely UDP-type
protocols, because each sensor node has limited
memory and power.
20The Application Layer
- Sensor Management Protocol (SMP)makes the
hardware and software of the lower layers
transparent to the sensor network management
applications. System administrators interact with
sensor networks using SMP. - Task Assignment And Data Advertisement Protocol
(TADAP)provides the user software with efficient
interfaces for interest dissemination. - Sensor Query and Data Dissemination Protocol
(SQDDP)provides user applications with
interfaces to issue queries, respond to queries
and collect incoming replies.
21Application - Habitat Monitoring
- Goal monitor breeding preferences of Leachs
Storm Pretel on Great Duck Island, Maine - usage pattern of nesting burrows
- changes in the burrow and surface environmental
parameters during the breeding season - differences in the micro-environments with and
without large numbers of nesting petrels
22Habitat Monitoring - Sensors
- Hardware deployed
- 32 MICA motes in cases
- MICA weather board with sensors temperature,
pressure, etc. - Groups of nodes Patches
- Gateway to transmit data via the transit network
to the base station. - Mobile PDAs Gizmos, to program the motes in
the field.
23Setup / Design Requirements
- Hierarchical network
- Network longevity 9 months
- Operating off the grid other source of energy
Solar - Management from a distance
- Stable and predictable system behavior
- In-situ interactions with motes
- Store data at all levels to prevent data loss
- Easy re-tasking facilities
24Challenging Problems
- Sensor Location Problem Locating sensor within
the deployed area. - K-Coverage Problem Every point in the monitor
area requires at least K sensors to cover it. - Sensor Network Energy Saving To maximum sensors
and/or sensor networks lifetime. - Sensor Data Modeling, Management, and Stream Data
Mining
25Research Opportunities
- Sensor Location Solutions
- GPS-Free
- Meet application requirements
- Low overhead (communication, processing, energy
consumption) - Previous Works
- Triangulation
- At least 3 reference nodes with known locations
- Ultra-sound or RF beacons
- Time of Arrival (TOA) or signal strength
- High computation complexity and energy consumption
26Research Opportunities
- Sensor Location Solutions
- GPS-Free
- Meet application requirements
- Low overhead (communication, processing, energy
consumption) - Previous Works
- Triangulation
- At least 3 reference nodes with known locations
- Ultra-sound or RF beacons
- Time of Arrival (TOA) or signal strength
- High computation complexity and energy consumption
27Cricket System at MIT
28Current Research Project
- A Stimulating Signal Model
- Sensors sensing ability
- Location guided laser beam
- Sensor Cluster Location Algorithm (SCLA)
- Scale Well
- Low overhead (communication, processing, energy
consumption) - Limitations
- Open Areas
- Line-of-path
- Estimate Geo-boundary of cluster
29Preliminary Outcome
- Results
- Identify Sensor Clusters for each virtual grid
- Geo-proximity of Cluster Locations
- Number of members in each Cluster (A potential
solution for K-coverage problem for sensor
networks) - Alternate sleep and active status of Cluster
members with a schedule algorithm to prolong
sensor network lifetime - Cost Analysis
- Let M be the number grids, N be the max number of
sensors in a grid, L be the max number of hops
between a cluster header and base station. - Cost(M,N,L) lt MN ML in terms of messages sent
30References
- 1 Next Century Challenges Scalable
Coordination in Sensor Networks - Deborah
Estrin, Ramesh Govindan, John Heidemann and
Satish Kumar, Mobicom 1999. - 2 A Survey on Sensor Networks -Ian F.
Akyildiz, Weilian Su, Yogesh Sankarasubramaniam
and Erdal Cayirci, IEEE Communications Magazine,
vol. 40, no. 8, August 2002. - 3 Wireless Sensor Networks for Habitat
Monitoring -Mainwaring et al., WSNA 2002. - 4 Habitat Monitoring on Great Duck Island
- http//www.greatduckisland.net
31Acknowledgement
- Hussein Alzoubi
- Hussein_alzoubi_at_hotmail.com
- Rami Alnamneh
- Ramir11_at_yahoo.com
32Questions?
Thank you!