Wireless LAN systems based on IEEE 802.11 have been a proved and sought after technological innovation, over the past few years. In this paper, we discuss some of the technical aspects for testing and deploying a wireless LAN system at the University of New Mexico, Albuquerque, New Mexico. This shall serve as a model test bed for future research and development, under the aegis of Ibero American Science and Technology Education Consortium (ISTEC)

Abdallah, Chaouki T.

Jerez, Henry N.

Jordan, Ramiro

Raghavan, Sunil

English

University of New Mexico

University of New Mexico
UNM Digital Repository
Electrical & Computer Engineering Faculty
Publications Engineering Publications
11-6-2002
Wireless Camera and Site Survey Issues over an
IEEE 802.11 b based wireless network test bed
Chaouki T. Abdallah
Sunil Raghavan
Henry N. Jerez
Ramiro Jordan
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Recommended Citation
Abdallah, Chaouki T.; Sunil Raghavan; Henry N. Jerez; and Ramiro Jordan. "Wireless Camera and Site Survey Issues over an IEEE
802.11 b based wireless network test bed." 27th Annual IEEE Conference on Local Computer Networks (2002): 849-850. doi:10.1109/
LCN.2002.1181872.
Raghavan et al: Wireless Camera and Site Survey issues over an IEEE 802.11b based wireless network test bed 
Wireless Camera and Site Survey issues over an IEEE 802.11b 
based wireless network test bed 
Sunil Raghavan, Henry N. Jerez, Ramiro Jordan, Chaouki T. Abdallah 
Electrical and Computer Engineering Department, University of New Mexico, 
Albuquerque, New Mexico 87131.
{sunil,hjerez,rjordan,chaouki}@eece.unm.edu
Abstract
Wireless LAN systems based on IEEE 802.11 have been
a proved and sought after technological innovation, over
the past few years. In this paper, we discuss some of the
technical aspects for testing and deploying a wireless
LAN system at the University of New Mexico,
Albuquerque, New Mexico. This shall serve as a model
test bed for  future research and development, under the 
aegis of Ibero American Science and Technology
Education Consortium (ISTEC).
Keywords
Site Survey, IEEE 802.11b, access point, signal to noise 
ratio, wireless video.
1. Introduction 
This paper reports and analyzes the creation of a test 
bed for wireless equipments and devices, which shall
serve as an excellent learning guide for the future 
exponents of the facilities of the Electrical Engineering 
& Computer Engineering (EECE) Department at the 
University of New Mexico (UNM), Albuquerque, New 
Mexico. The basis of such a test bed would be a wireless
LAN system [1], which   links   to the backbone
wired Ethernet [2] network. The wireless protocol
employed is IEEE 802.11b [3].This test bed project is
scheduled to be replicated throughout Latin-America
across the ISTEC’s 120 member universities, 
establishing some of the labs overseas as well as using
the content generated in the project and contributing
with services to other members and the pioneering test
bed in New Mexico.
The plan of action for the whole scheme is a thorough
surveys of the proposed area of implementation,
comprising of a : Site Survey or a RF building survey
Wireless camera signaling survey and Wireless video
transmission survey. 
2. Site Survey 
We employed a Cisco Aironet   350 series Access 
Point, Cisco Aironet  350 Series Client Adapter Cards 
and a D-Link  DCS 1000W 802.11b VGA quality 
Wireless internet Camera, for the surveys. The 
measurements were based on the placement of a single 
access point, radiating anywhere between 5 –100 mW of 
power, at a suitable location, such that it would be
advantageous to all three floors of the building. This was
done to economize the number of access points that shall
be totally used in the end. The analyses were based upon 
the three performance parameters, namely: Signal
Quality, Received Signal Power in absolute percentage 
and Signal to Noise Ratio (SNR) in dB. Figures 1.(a) and 
(b) give an idea of the signal strength variations in dB
across a floor and the dependence of the above mentioned
parameters on the distance of the moving wireless PC
card attached to a laptop, from the access point. From
these data, attenuation due to distance can be easily 
observed, although there are slight fluctuations in the
values. Long distances between the access point and the
Ethernet card caused the signal to degrade. Also the fact 
that, a Line-of-sight between the access point and the
wireless PC card always gives the best signal quality, is
exemplified by the values obtained. Because of this, the 
location of the access point forms an important part of the 
design of a wireless network in a building.
Proceedings of the 27th Annual IEEE Conference on Local Computer Networks (LCN02) 
0742-1303/02 $17.00 © 2002 IEEE 
Raghavan et al: Wireless Camera and Site Survey issues over an IEEE 802.11b based wireless network test bed 
Figure 1.(a) and (b): Coverage Map and variation
of the  performance  parameters  with respect to 
the Normalized Distance in meters. 
The observed swings in the recorded parameters can be
explained by the material between the access point and 
the user, which  has an impact on the attenuation of the
signal. The concrete slabs that make up the floors of the
building have a much greater impact on the received 
signal that say the drywall that separates the rooms on
each floor.  As shown in Table 1,a reading taken of an
access point at 20 mW on the 2nd floor approximately 10 
m away in a room on the same floor gave a result of 
58% power and a rating of "Good" while a measurement
directly beneath that same access point approximately 2
m away on the 1st floor resulted in a signal power of 
19% and a rating of  “Poor”.
Table 1: A survey result over the three floors of 
the building.
We discovered in the survey that it is not   practical to
have one  access   point   at  100 mW radiate the entire 
building. Much stronger signals were attained outside
the building than in some parts of the interior. One
access point, with under 10 mW power levels, in the
center of the building still does not generate enough 
power to reach the far corners of the building, as well as 
some of the rooms. But power levels of around 20-30
mW were suited to the topography of the building and 
provided ideal and satisfactory coverage in most parts
of the structure. 
3. Wireless Camera Survey 
The wireless camera survey was conducted, with the
help of a D-Link DCS 1000W wireless internet camera,
attached to the access point via its MAC and IP address. 
The image from the camera was obtained from a 
computer screen by simply typing in the IP address of
the camera on a web browser.  We were able to access 
the image from an access device like a laptop using the
Wireless PC card, by connecting directly to the access 
point, or from a computer connected to the UNM
network, or from an independent Internet service
provider via the Internet.
Access
Device
Wireless Link
Speed
Image
Quality
Laptop       11  MBps   >20 Fps 
Pocket PC       11  MBps   >15Fps 
Laptop       5.5 MBps   >15Fps 
Pocket PC       5.5 MBps   >10Fps 
Table 2: Average link Speeds and image quality
of video transmissions received  by  the access 
devices.
A video stream result has been tabulated in Table. 2.
The received video quality was satisfactory throughout 
the entire mapped part of the building. It is however 
important to remember that these measurements were 
taken on a non saturated wireless medium.
4. Conclusions 
We have proposed and analyzed the initial setting up of
a wireless LAN infrastructure at the EECE Department
of the University of New Mexico. The initial site survey
and wireless camera gave us useful results and insights
into the future logistics and the planning schemes during
the actual realization phase of this on going initiative.
The implementation parameters of the scalable network
should closely mirror our test data and results, and shall
be appropriately reported in the near future.
References
[1] W. Stallings, “IEEE 802.11: Moving closer to practical 
wireless LANs”, IT Professional, Vol. 3, No. 3, pp. 17- 23,
May- June 2001. 
[2] IEEE 802.3 website:  http://grouper.ieee.org/groups/802/3. 
[3] IEEE 802.11 website and task groups therein: 
http://grouper.ieee.org/groups/802/11.
Proceedings of the 27th Annual IEEE Conference on Local Computer Networks (LCN02) 
0742-1303/02 $17.00 © 2002 IEEE 


Wireless Camera and Site Survey Issues over an IEEE 802.11 b based wireless network test bed

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Wireless Camera and Site Survey Issues over an IEEE 802.11 b based wireless network test bed

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