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US Navy Seaweb program Undersea acoustic sensing, signaling, communications & networks. Networked through-water digital com/nav Scalable wide-area wireless grid Composable architectural flexibility Fixed and mobile autonomous nodes Gateways to command centers Persistent and pervasive - PowerPoint PPT Presentation
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SeawebUS Navy Seaweb program Undersea acoustic sensing, signaling, communications & networks
Sponsors: ONR, PEO LMW, SOCOM PEO IIS, CTTSO, PEO C4I & Space, PEO IWS, OSD, DARPA, SBIR
Collaborations:
TTCP Unet (Undersea networking)
DARPA DTN (Disruption-Tolerant Networking)
ONR DADS (Deployable Autonomous Distributed Sys)
ONR ASAP (Adaptive Sampling & Prediction)
OSD Coalition Warfare
Seaweb is in routine use by several client programs
POC: [email protected], (831) 402 5666
Networked through-water digital com/nav
Scalable wide-area wireless grid
Composable architectural flexibility
Fixed and mobile autonomous nodes
Gateways to command centers
Persistent and pervasive
Low source level, wide band, high freq
TRANSEC attributes
Integrating sensors, UUVs, SSNs
J. Rice, “Enabling Undersea FORCEnet with Seaweb Acoustic Networks,” Biennial Review 2003, SSC San Diego TD 3155, pp. 174-180, Dec 2003
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SeawebUS Navy Seaweb programApplied research, “Discovery & Invention”, 6.2 fundingArt of the possible for Maritime sensor networks & Undersea Distributed Networked Systems (UDNS)
Iridium satellite
Ashore & afarcommand centers
Racom buoy withIridium, FreeWave,
Telesonar
UUVs
SDV
SSN/SSGNwith Seaweb server
Telesonar repeater nodes
ASW / ISR / MCMnodes
Float
Telesonar modem
Acoustic release
Weight
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SeawebSPAWAR SBIR topic N93-170 advanced and commercialized DSP-based acoustic comms
SBIR contractor: Teledyne Benthos (formerly Datasonics, Inc.)
SBIR Phase-1ATM-850 (not shown)
1997-2003 achievement:Stable COTS hardwareCOTS & Navy firmware8X less expensive40X more efficient
1993-97
all analog
10 b/s FSK
Pre-SBIRATM-845 ATM-865
1997-99
TMS320C50
2nd generation telesonar
Spiral development
SBIR Phase-2ATM-875
2000-2007
TMS320C5410
3rd generation telesonar
Spiral development
SBIR Phase-3ATM-885
1995-97
Multi-band MFSK
1st generation telesonar
Technology transfer from MIT/WHOI
2007: 4th gen telesonar with TRANSEC features
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SeawebTBEDNavy’s first experimental digital sensor network1995-96
“TBED” Telemetry Buoy Environmental DataNSWC Coastal Systems Station, Panama City, FLObjective: telemeter environmental data from distributed seafloor sensor nodes to one or more gateway nodes
Sea test in 1996Gulf of Mexico, 60 km offshore Panama City, 45-m water8-km node-to-node ranges achieved4 Datasonics ATM-850 telesonar modems150-bit/s, 1024-bit messages
Flooding protocol designed for up to 10 nodesAdvantages: Simple, COTS modem firmware, Plug & play, Routing tables not required, Centralized control not requiredDisadvantages: Redundant communications, Not bandwidth efficient for fixed network, High latencyAnalogous to terrestrial “Zebranet”Well suited for delay-tolerant AUV mobile networks
J. Rice, et al, “Evolution of Seaweb Underwater Acoustic Networking” Proc IEEE Oceans 2000
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SeawebSeaweb ’98 engineering experimentBuzzards Bay, MA, September 1999An undersea wireless sensor network employing ten telesonar modems and an RF gateway buoy
70°46´
41°43´
41°35´70°36´
Isobath contours at 5-meter intervals
1 km1 km Racom-1Racom-1
ATM-875
10-m water depths
10 ATM-875 telesonar modems
3-FDMA
3 sensor nodes
FreeWave gateway
Bi-directional routing tables
Scaleable architecture
M. D. Green, J. A. Rice and S. Merriam, “Underwater acoustic modem configured for use in a local area network,” Proc. IEEE Oceans ’98 Conf., Vol. 2, pp. 634-638, Nice France, September 1998
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SeawebSeaweb ’99 engineering experimentBuzzards Bay, MA, August 1999SSC San Diego, Delphi, Benthos, SAIC
FreeWave 900-MHz LOS gateway
Cellular Digital Packet Data (CDPD) gateways
Seaweb server
15 ATM-875 nodes
Seaweb ‘99 firmware
FDMA-6 network
Node addressing
Ranging
Handshake protocol
Adaptive power control
Remote-controlled routing
Commercial sensors
J. Rice, et al, “Evolution of Seaweb Underwater Acoustic Networking” Proc IEEE Oceans 2000
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Seaweb
ATM-885 modems
FreeWave LOS gateway
Cellular Digital Packet Data (CDPD) gateways
Asynchronous TDMA
Rerouting
RTS/CTS handshake + ARQ
Isobath contours at 5-meter intervals
Seaweb 2000 engineering experimentBuzzards Bay, Aug-Sept 2000
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SeawebDemonstrated capabilities:
FRONT ocean observatoryNational Oceanographic Partnership Program
FRONT-4 Jan-June, 2002
FRONT-3 March-June, 2001
D. L. Codiga, et al, “Networked Acoustic Modems for Real-Time Data Telemetry from Distributed Subsurface Instruments in the Coastal Ocean: Application to Array of Bottom-Mounted ADCPs,” J. Atmospheric & Oceanic Technology, June 2005
Concept
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Seaweb
US participation in Canada’s ICESHELF 2002 April experiment in the Arctic Ocean
80-150 m water covered by rough ice of 2-8 m thickness and large subsurface ridges and keels
Upward-refracting water
Ice-mounted Seaweb network, first test of acoustic networking in the Arctic
Prepares for RDS-4 experiment with interoperable US and Canadian ASW sensor nodes
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Seaweb
Experimental DADS sensor node
Demonstrated capabilities:
FBE India June 2001
J. Rice, et al, “Networked Undersea Acoustic Communications Involving a Submerged Submarine, Deployable Autonomous Distributed Sensors, and a Radio Gateway Buoy Linked to an Ashore Command Center,” Proc. UDT Hawaii, October 2001
(Prior Seaweb tests with USS Dolphin submarine: Sublinks ’98, ’99, 2000)
SSN with BSY-1 sonar Seaweb TEMPALT
Ashore ASW command center
Seaweb server at SSN and ASWCC
Acoustic chat and GCCS-M links to fleet
SSN/MPA cooperative ASW against XSSK
Flawless ops for 4 continuous test days
Racom buoy
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SeawebSeaweb message example:
Multi-Access Collision Avoidance (MACA) Internet Protocol (IP)
RT
SCTS
DA
TA
RTS
RT
S
RTS
CTS
CT
S
CTS
DATA
DA
TA
DATA
G. Hartfield, Performance of an Undersea Acoustic Network during Fleet Battle Experiment India, MS Thesis, Naval Postgraduate School, Monterey, CA, June, 2003
Source node
Destination node
Fixed routing tables
Precursor to Seaweb cellular routing
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SeawebDemonstrated capabilities:
Seaweb network with UUVsUS/Canada collaborationGulf of Mexico, Feb 1-8, 2003
6 fixed repeater nodes
FreeWave radio links
3 glider UUV mobile nodes
Shipboardcommand center
Over-the-horizoncommand center
2 Racom buoy gateway nodes
Iridium satellite radio links
Mobile gateway nodes
Mobile sensor nodes
200 km logged by UUVs
300 hrs logged by UUVs
Node-to-multinode comm/nav
UUV nosesection
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SeawebSeaweb navigation development
Seaweb 2005 UUV ExperimentsMonterey Bay, May 9-11, July 20-22St. Andrews Bay, December 5-9
constellation of 6 Seaweb repeater nodes
fixed on seabed
SlocumUUV
Shipboardcommand center
Racom buoy gateway node
Iridium satellite
constellation
ARIES UUV
GPS satellite
constellation
NPS
M. Hahn, Undersea Navigation via a Distributed Acoustic Communications Network, MS Thesis, Naval Postgraduate School, June 2005
S. Ouimet, Undersea Navigation of a Glider UUV using an Acoustic Communications Network, MS Thesis, Naval Postgraduate School, Sept 2005
EMATTUUV
M. Reed, Use of an Acoustic Network as an Underwater Positioning System, MS Thesis, Naval Postgraduate School, June 2006
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SeawebDemonstrated capability:
All Seaweb communications yield the node-to-node range as a by-product of the link-layer RTS/CTS handshake.
The broadcast ping command returns ranges to all neighboring nodes.
(a) Networked command (b) Broadcast ping (c) Echoes (d) Networked telemetry
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SeawebSeaweb cellular grid deploymentTheater ASW Experiment – TASWEX 04Submarine comms @ speed & depth (CSD)
Average speed 6.5 knotsAverage 1 repeater every 20 min
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Seaweb
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SeawebSeaweb 2004 grid post mortemImpacted by trawling along the 300-m isobath3 nodes removed, 6 nodes displaced or damaged
COMEX FINEXFINEX
H. Kriewaldt, Communications Performance of an Undersea Acoustic Wide-Area Network, MS Thesis, Naval Postgraduate School, December 2005
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SeawebSeaweb 2005 experimentFebruary 2005, Panama City, FL
SRQ link-layer mechanism
NSMA (Neighbor Sense Multiple Access, a cross-layer variation on CSMA)
Ranging and node localization
Iridium-equipped Racom buoy
Compressed image telemetry
NPS, SSCSD, CSS, Benthos
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SeawebDemonstrated capability:Selective Automatic Repeat Request (SRQ) is a link-layer mechanism for reliable transport of large datafiles even when the physical layer suffers high BERs
Node A Node BRTS
CTS
HDR
SRQ
HDR
SRQ
HDR
3. Node A transmits a 4000-byte Data packet
using 16 256-byte subpackets, each with an independent CRC.
4. Node B receives 12 subpackets successfully; 4 subpackets contained uncorrectable bit errors.
5. Node B issues an SRQ utility packet, including a 16-bit mask specifying the 4 subpackets to be retransmitted.
6. Node A retransmits the 4 subpackets
specified by the SRQ mask.
7. Node B receives 3 of the 4 packets successfully (future implementation of cross-layer time-diversity processing will recover 4 of 4). B issues an SRQ for the remaining subpacket.
8. Node A retransmits the 1 subpacket
specified by the SRQ.
2. Node B is prepared to receive a large Data packet as a result of RTS/CTS handshaking.
1. Node A initiates a link-layer dialog with
Node B.
9. Node B successfully receives and processes Data packet.
J. Kalscheuer, A Selective Automatic Repeat Request Protocol for Undersea Acoustic Links, MS Thesis, Naval Postgraduate School, June 2004
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SeawebSeaweb telesonar repeater node
Seaweb telesonar modem, circa 2000-2007
Texas Instruments TMS320C5410 DSP
Teledyne Benthos COTS hardware
US Navy firmware
Spectral bandwidth = 5 kHz (9-14 kHz)
SL = 174 dB (typ) re 1μPa @ 1m
Modulation = Multi-channel 4-FSK
Forward Error Correction
Raw bit rate = 2400 bit/s
Data packets = 800 b/s
Utility packets = 150 b/s
DI = 0 dB (omni)
DI = 0 dB (omni)
K. Scussel, “Acoustic Modems for Underwater Communications,” Wiley Encyclopedia of Telecommunications, Vol. 1, pp. 15-22, Wiley-Interscience, 2003
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Seaweb
Spectral bandwidth up to 20 kHz, Operating frequency up to 70 kHz
Processing speed increased by 2X, Memory increased by 20X
Xmit efficiency improved by 50%, Rcvr efficiency improved by 50%
One new digital board can support 4 T/R boards (for multi-band, MIMO, spatial diversity, etc)
SBIR Ph-2 Option will integrate SBIR N99-011 directional ducer (Image Acoustics, Inc)
SBIR Ph-3 5-year delivery-order contract being negotiated by SSC San Diego
Transmit/Receive Board Digital Board
ATM-885board set
New ATM-900board set
Small Business Innovative Research
SBIR N03-224 is producing the 4th-gen telesonar modem
Contractor: Teledyne Benthos, Inc.Sponsor: PEO C4I & Space, PMW 770
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SeawebCurrent work
The Seaweb network organizes and maintains itself under the control of autonomous master nodes or Seaweb servers at command centers
Preparation 5 days
Analyze mission requirementsMeasure or predict environmentModel transmission channelsPredict connectivity range limitsSpecify spacing, aperture, and node mixPre-program master node only
Installation 1 day
Activation 1 hr
Obey spacing constraintsTest master node link to gateway
Awaken network nodesDiscover neighbors
Initiation 2 hrs
Registration 1 hr
Obtain reciprocal channel responsePerform 2-way rangingSound own depthInitialize spectral shaping
Report link data & node configurationAssimilate data at master node
Optimization 1 hr
Operation 90 days
Compute optimal/alternate routesAssign protocols
Monitor energy, links, and gatewaysOptimize life, TRANSEC, and latency
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SeawebCurrent research
Adaptive modulation
Reconstruct transmitted waveform
Estimate channel scattering function
Map channel characteristics against available repertoires
and signal techniques
Decision
RTS
Data
CTS
Node BNode ADemodulate
RTStransmission
SpecifyData-packet
commsparameters
Determine h(τ, t ) / Doppler / SNR
S. Dessalermos, Undersea Acoustic Propagation Channel Estimation, MS Thesis, Naval Postgraduate School, Monterey, CA, June 2005
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SeawebCurrent research
Asymmetric links
SubmarineSubmarineLow-rate C2
Autonomous Autonomous nodenode
High-ratedata telemetry
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SeawebUnet through-water acoustic signaling range regimesCategorized at Unet Workshop 5 and refined at Unet Workshop 6
Range regime
Node-to-node range (m)
Frequencies (kHz)
Use
Very short 5 – 50 >100Proximity communications,
e.g., Seamule
Short 50 – 500 30-100Local-area networks,
e.g., Seastar
Medium 500 – 5k 8-30Wide-area networks,
e.g. Seaweb
Long 5k – 50k 1-8 Tactical paging
Very long 50k – 500k <1 Blue-water paging
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SeawebAcoustic link budget
Pxmt
Prcv
PSLpressurespectrum
level
SNR
AN
TL DIrcvDIxmt
Each term in the standard radio link budget is analogous to specific quantities in the sonar equation.
SNR(f) = PSL(f) – TL(f) – AN(f) + DIxmt(f) + DIrcv(f)
We develop the acoustic link budget as a wideband model because, unlike most radio channels, the acoustic channel exhibits strong frequency dependency.
27
SeawebSonar equation analysis (TL+AN) for 500-m range and 4 noise spectra
W= 20kHz
PSL
TL
+ N
SL
(d
B r
e 1μ
Pa)
Frequency (kHz)
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Seaweb
Seaweb WAN
Current research
Seastar local-area networks
Data are fused/beamformed at the central node
Seastar LAN increases the carrying capacity of the undersea environment by an order of magnitude
Central node reports compressed information through the wide-area network
Applications include sensor arrays, sensor clusters, autonomous MCM vehicles, and SDV/DDS dive teams
DADS magnetometer array a near-term pilot application
Prototype Seastar at AUVfest 2007, 2 NPS thesis students
ONR 321MS 6.2 funding
Asymmetric links: high-BW links from peripheral nodes to central node; low-BW links from central node to peripherals and peer-to-peer
Point-to point communications at short ranges (50 to 500 m) employ the 30-100 kHz band
Seastar LAN
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SeawebOver 40 Seaweb deploymentsSpirally developed USW com/nav capability
FBE-I, 2001
TASWEX04
Q
GH KU
R
G
GG
K
U
R
R
R
RDS-4, 2002
Iceweb, 2002
Q272 SeawebGoM, 2003
FRONT-4, 2002
Seaweb NSW, 2004
NPS