Transcript Document

Research and Test of
Non-Intrusive Wireless
Networks for Opportunistic
Spectrum Utilization
Univeristy Of California Davis
PI: Zhi Ding (ECE) and Xin Liu (CS)
Subaward: I-Jeng Wang, APL, Johns Hopkins
Univ
NSF NeTS Workshop
2006@UCLA
Project Goals and Scope
 Investigating opportunistic access networks that
can provide secondary service and are
 spectrally-agile
 non-instrusive to primary or legacy networks
 low cost and broadly applicable
 Collaborating with APL (JHU) to measure spectral
activity of key target areas of the secondary
network
ESCAPE: Embedded SpeCtrally
Agile radio Protocol for Evacuation
 Problem:
 One or more users in a group may detect the return of primaries
 To disseminate such information fast and reliably
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Interference from primary transmission
Interference from regular secondary transmission
No simultaneous transmission and reception
In-band signaling
 ESCAPE:
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PHY: predefined evacuation message using a given spreading code
MAC: transmit as soon as the warning message is received
Routing: flooding
Performance metrics
 Evacuation time, success probability, peak and average interference during
evacuation, false-alarm rate
 Design parameters
 Spreading code length, power, number of repetition for a given objective
 X. Liu, Z, Ding, Embedded SpeCtrally Agile radio Protocol for
Evacuation, under submission.
Sensing-based Opportunistic
Channel Access
 To collaboratively detect whether a channel is idle and is a
good opportunity
 Is the channel “idle”?
 Three proposed algorithms to make sensing decision so that the
outage probability is below a certain threshold
 Observation: collaborative sensing is very helpful
 To do: more robust fading model and measurements with spatial
correlation
 Is the channel a good one; i.e., to finish a transmission?
 An algorithm based on channel sensing statistics.
 X. Liu and S. Shankar, “Sensing-based opportunistic channel access”,
ACM MONET, vol. 11, no. 4, August, 2006.
Data Collection at JHU/APL
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Public safety band at Howard County, MD
Two measurements suites, set at 5, 200, 600 meters apart
Forward and reverse channels
Objective: temporal and spatial correlation
System setup:
 The spectral data are sampled with 14 bits at 64 MS/s.
 The samples are collected in snapshots of 16384 each, covering
~20 MHz every 100 ms.
 This snapshot size allows for DFT bins of ~ 3.9 kHz, which is
enough resolution to discriminate between adjacent forward or
reverse channels as their centers are never closer than 25 kHz.
5 meters apart
fixed – site 1
mobile – site 1
10 dB threshold
fixed – site 1
mobile – site 1
Side-by-side – distance = 5 meters
fixed - site 1
mobile - site 1
Current and Future
Research Emphasis
 Integrative studies of physical layer, MAC layer,
and network layer
 Performance evaluation and model validation.
 Data collection, analysis, and public distribution
 Feasibility and capacity analysis of 2ndary
network interacting with both non-interactive and
interactive primary systems
 Compatibility with CSMA-based primary users
 Quantification of capacity and interference tradeoff
Links to other projects
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Xin Liu (University of California, Davis) CAREER: Smart-Radio-Technology-Enabled
Opportunistic Spectrum Utilization
Dirk Grunwald, Doug Sicker, John Black (University of Colorado), NeTS-ProWIN: Topology And
Routing With Steerable Antennas
Uf Turelli, Kevin Ryan (Stevens Institute of Tech), Milind M. Buddhikot, Scott Miller (Lucent Bell
Lab), Dynamic Intelligent Management of Spectrum for Ubiquitous Mobile Network
(DIMSUMnet)
Kang G. Shin, University of Michigan, Efficient Wireless Spectrum Utilization with Adaptive
Sensing and Spectral Agility
Qing Zhao, UC Davis, An Integrated Approach to Opportunistic Spectrum Access
Randall Berry, Michael Honig and Rakesh Vohra, Northwestern University, Smart Markets for
Smart Radios
Mario Gerla, Stefano Soatto, Michael Fitz, Giovanni Pau, UCLA, Emergency Ad Hoc Networking
Using Programmable Radios and Intelligent Swarms
Saswati Sarkar, University of Pennsylvania, Dynamic Spectrum MAC with Multiparty Support in
Adhoc Networks
Marwan Krunz, Shuguang Cui, University of Arizona Resource Management and Distributed
Protocols for Heterogeneous Cognitive-Radio Networks
Dennis Roberson, Cindy Hood, Joe LoCicero, Don Ucci (Illionis Institute of Technology), Uf Tureli
(Stevens Institute of Technology) Wireless Interference and Characterization on Network
Performance
Narayan Mandayam, Christopher Rose, Predrag Spasojevic, Roy Yates, WINLAB Rutgers
University, Cognitive Radios for Open Access to Spectrum
Links to other projects
 Platform/Testbed projects
 Dirk Grunwald (U. Colorado), John Chapin (Vanu, Inc), Joe Carey
(Fidelity Comtech) A Programmable Wireless Platform For Spectral,
Temporal and Spatial Spectrum Management
 Jeffrey H. Reed, William H. Tranter, and R. Michael Buehrer, Virginia
Tech, An Open Systems Approach for Rapid Prototyping Waveforms
for Software Defined Radio
 D. Raychaudhuri (WINLAB, Rutgers University) ORBIT: Open Access
Research Testbed for Next-Generation Wireless Networks
 B. Ackland, I. Seskar & D. Raychaudhuri, (WINLAB, Rutgers
University), T. Sizer (Lucent Technologies), J. Laskar(GA Tech) High
Performance Cognitive Radio Platform with Integrated Physical and
Network Layer Capabilities
 Babak Daneshrad, University of California, Los Angeles,
Programmable/Versatile Radio Platforms for the Networking
Research Community
 Prasant Mohapatra, University of California, Davis, Quail Ridge
Wireless Mesh Networks: A Wide Area Test-bed