[Dataset] utah/CIR (v. 2007-09-10)

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the initial version

@MISC{utah-CIR-2007-09-10,
  author = {Neal Patwari},
  title = {{CRAWDAD} data set utah/CIR (v. 2007-09-10)}, 
  howpublished = {Downloaded from http://crawdad.cs.dartmouth.edu/utah/CIR},
  month = sep,  
  year = 2007
}
					

This dataset contains over 9300 measured CIR (channel impulse responses)
in a 44-node wireless network.

We recorded over 9300 measured channel impulse responses in a 44-node 
wireless network. Multiple measurements are provided for each of 
the 44*43=1892 pairwise links between the nodes. 

This data set was used in [patwari-signatures] to test a temporal link 
signature-based location distinction algorithm. It can be used for TOA 
and RSS measurements [patwari-relative], as well as to test other 
time-synchronization algorithms.

The measurement transmitter was a 40 MHz chip rate DS-SS signal generator. 
The center frequency was 2.443 GHz. The receiver was a software radio 
(Sigtek model ST-515) designed to receive the signal, cross-correlate 
it with the known transmitted signal, and thus have a high-bandwidth 
estimate of the (complex) channel impulse response.

The transmitter and receiver were closely synchronized, to within 1-2 
nanoseconds of each other, using GPS and rubidium oscillators, and 
extensive re-calibration. The data thus allows you to know the actual 
propagation delay of the RF signal.

The measurement campaign consisted of 44 node locations, as shown 
in [map of node locations]. The measurements were conducted in 
a standard office area. By moving the transmitter and receiver between 
node locations 1-44, we measured every link in the network.

The data set is not for commercial use. Please cite the appropriate references, 
and acknowledge Motorola Labs, Florida Communications Research Lab, and 
the University of Utah, when using the data set in published work.

[Traceset] utah/CIR/matlab (v. 2007-09-10)

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the initial version.

@MISC{utah-CIR-matlab-2007-09-10,
  author = {Neal Patwari},
  title = {{CRAWDAD} trace set utah/CIR/matlab (v. 2007-09-10)}, 
  howpublished = {Downloaded from http://crawdad.cs.dartmouth.edu/utah/CIR/matlab},
  month = sep,  
  year = 2007
}
					

This traceset contains matlab traces of over 9300 measured channel impulse 
responses in a 44-node wireless network.

-  Environment and System

The measured environment, the Motorola Labs, Florida Communication 
Research Lab facility, is a typical modern office building,
with partitioned cubicle offices, metal and wooden furniture, 
computers, and test and measurement equipment. There are further 
scatterers near the measurement area, including windows, doors, 
and cement support beams. There are 44 device locations, shown 
in [map of node locations], within a 14m by 13m rectangular area.

The measurement system is comprised of a direct-sequence
spread-spectrum (DS-SS) transmitter (TX) and receiver (RX)
(Sigtek model ST-515). The TX outputs a plain DS-SS signal, 
specifically, an unmodulated pseudo-noise (PN) code signal 
with a 40 MHz chip rate and code length 1024. The center 
frequency is 2443 MHz, and the transmit power is 10 mW. 
The TX and RX are both battery-powered with equipment and 
batteries placed on carts. Both TX and RX antennas are 2.4 GHz 
sleeve dipole antennas at 1m height above the floor. The antennas 
are omnidirectional in the horizontal plane with gain of 1.1 dBi. 
Note that the cart, the receiver, and objects near to the antenna 
also affect the antenna pattern, which makes the effective 
antenna pattern non-omnidirectional.

The RX is essentially a software radio which records I and Q samples 
at a rate of 120 MHz and downconverts them to baseband. 

- Measurement Collection

The campaign measures the channel between each pair of the 44 device 
locations. There is only one TX and one RX, so one link is measured 
at a time, and between link measurements, the transmitter or receiver 
is moved. All 44x43 = 1892 TX and RX permutations are measured. At each
permutation of TX and RX locations, the RX measures N = 5 link signatures, 
over a period of about 30 seconds. A total of 44x43x5=9460 measurements 
are recorded. Due to the large quantity and manual nature of the experiment, 
the measurements are completed over the course of eight days.

- Radio Channel Dynamics
These measurements could not be conducted during normal business hours, 
and as a result, the physical environment is relatively static. 
Due to the size of the TX and RX equipment (and the rechargeable marine 
batteries used to power them) the equipment carts would not comfortably
fit into an occupied cubicle along side its occupant. Instead, 
the measurements were conducted after 6pm. While two or three people were 
typically working in the measurement environment, the activity level was 
low relative to daytime. Daytime measurements in a busy office will be 
an important for future measurement-based verification.

About 1% of the time, we notice that a link signature has a very low 
signal-to-noise ratio (SNR). Since measurements are made in the 2.4GHz 
ISM band, other wireless devices occasionally interfere. Whenever a high 
noise floor is measured for a link, that measurement is dropped, thus some
links have fewer than 5 measurements.

[Trace] utah/CIR/matlab/savedSig.mat (v. 2007-09-10)

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the initial version

@MISC{utah-CIR-matlab-savedSig.mat-2007-09-10,
  author = {Neal Patwari},
  title = {{CRAWDAD} trace utah/CIR/matlab/savedSig.mat (v. 2007-09-10)}, 
  howpublished = {Downloaded from http://crawdad.cs.dartmouth.edu/utah/CIR/matlab/savedSig.mat},
  month = sep,  
  year = 2007
}
					

Matlab trace of measured CIR (Channel Impulse Response) data.

The download tarball contains two .mat files (savedSig.mat and deviceLocs.mat) and 
an example Matlab script (Plot_Sig_From_Meas.m) as an example of how to access 
and plot the CIR data.

The file savedSig.mat is in Matlab .mat format (using Matlab 6.5) and 
contains three variables:
- savedSig
- savedStartTime_ns
- delta_t

Data is saved in Matlab .mat format (using Matlab 6.5). 

savedSig is a 2-D Matlab cell array. Element savedSig{i,j} 
accesses the measurements for link with transmitter at i and receiver 
at j, where i and j are between 1 and 44. The measurements themselves 
are stored in a matrix, with each row representing one CIR. There are 
typically five rows in the matrix, although sometimes fewer.

To save space, only the non-noise part of the CIR measurement is provided. 
Matlab cell array savedStartTime_ns{i,j}(k) provides the delay of 
the first sample of the kth measured CIR of link (i,j). The sampling period 
is delta_t. The script Plot_Sig_From_Meas.m contains more detailed descriptions 
of the data.

[Trace] utah/CIR/matlab/deviceLocs.mat (v. 2007-09-10)

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the initial version

@MISC{utah-CIR-matlab-deviceLocs.mat-2007-09-10,
  author = {Neal Patwari},
  title = {{CRAWDAD} trace utah/CIR/matlab/deviceLocs.mat (v. 2007-09-10)}, 
  howpublished = {Downloaded from http://crawdad.cs.dartmouth.edu/utah/CIR/matlab/deviceLocs.mat},
  month = sep,  
  year = 2007
}
					

Matlab trace of device location data.

The download tarball contains two .mat files (savedSig.mat and deviceLocs.mat) and 
an example Matlab script (Plot_Sig_From_Meas.m) as an example of how to access 
and plot the CIR data.

The file deviceLocs.mat is in Matlab .mat format (using Matlab 6.5) and contains 
one variable:
- deviceLocs.mat

Data is saved in Matlab .mat format (using Matlab 6.5). 

savedSig is a 2-D Matlab cell array. Element savedSig{i,j} 
accesses the measurements for link with transmitter at i and receiver 
at j, where i and j are between 1 and 44. The measurements themselves 
are stored in a matrix, with each row representing one CIR. There are 
typically five rows in the matrix, although sometimes fewer.

To save space, only the non-noise part of the CIR measurement is provided. 
Matlab cell array savedStartTime_ns{i,j}(k) provides the delay of 
the first sample of the kth measured CIR of link (i,j). The sampling period 
is delta_t. The script Plot_Sig_From_Meas.m contains more detailed descriptions 
of the data.

[Author] Neal Patwari

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[Paper] patwari-relative

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[Paper] patwari-signatures

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The ability of a receiver to determine when a transmitter has changed location 
is important for energy conservation in wireless sensor networks, for physical 
security of radio- tagged objects, and for wireless network security in detec- 
tion of replication attacks. In this paper, we propose us- ing a measured 
temporal link signature to uniquely identify the link between a transmitter and 
a receiver. When the transmitter changes location, or if an attacker at a 
di®erent location assumes the identity of the transmitter, the pro- posed link 
distinction algorithm reliably detects the change in the physical channel. This 
detection can be performed at a single receiver or collaboratively by multiple 
receivers. We record over 9,000 link signatures at di®erent locations and over 
time to demonstrate that our method signi¯cantly increases the detection rate 
and reduces the false alarm rate, in comparison to existing methods.