Site Survey UCSC -Engineering 2
Linda Rosewood – Lynne Sheehan – Bob Vitale
Objective: Learn About & Understand
Propagation in the Engineering 2 Building
1. Compare 802.11b/g coverage using
2.2dBi “duck” and 5.2dBi ceiling
mount antennas.
2. Investigate interesting propagation
effects
-through walls, windows, between
floors, down corridors.
3. Map a coverage area for the 2nd
floor using APs positioned in the
corridor and positioned in a lab. Do
South Corridor
the results help determine AP
Note “decorative” metal ceiling tiles
placement for building?
2nd Floor Survey Areas
Loc #2: Rear Corridor Ceiling, AP above
5.5dBi antennas hang below
Faculty offices
Labs
Conference
room
Loc #1: Inside Lab, survey done
with 2.2dBi “ducks” and 5.5dBi
ceiling mount omnis
Conference room
Academic Support
Ducks vs. Ceiling Mount Omni
5.5dBi Suspended
Ceiling Mount
Omni- Directional
Antennas
Cisco AIR-ANT1728
Cost: $105 each
2.2dBi Rubber Duck
Antennas
Cisco AIR-ANT4941
Cost: $15 each
E2 2nd Floor West Survey –
Rubber Duck vs. Ceiling Mt Omni
13
14
12
11
5
4
6
9
3
2
7
8
TestPoint
1
Value (+= 5.5dBi omni better)
10
15
16
RubberDuck
Ceiling Mount Omni
Diff
Location
#
Name
Average
STDEV
Average
STDEV
+ = om
1
Room 208
3 feet from AP
63
7
61
10
-2
2
Outside Rm 208
Main Cooridor
49
7
54
5
5
3
Bench 1
Outside Rm 210
49
6
54
5
5
4
Bench 2
Outside Rm 215
33
5
37
9
3
5
Room 216
cube close to AP
32
3
35
4
2
6
Room 216
cube furtherest away
31
4
33
4
2
7
Room 215
card towards AP
22
4
23
5
2
8
Room 215
card away from AP
19
2
19
3
1
9
Room206
Card pointed South
A/C Unit between AP/Card
49
4
54
3
4
10
Room 205
cube closest to windows
39
4
45
2
6
11
Hall behind
Room 208
53
10
59
7
6
12
Room 237B
Office w/Door closed
45
3
49
3
4
13
Interactive Space
48
3
49
8
1
14
Benches outside
E2-219
21
4
25
6
4
15
Room 201
Last Cubicle on Windows
37
3
42
5
5
16
Cowboy Chairs
2nd Chair in
20
6
18
3
-2
17
Room 308
Immediately above AP
16
2
16
3
0
E2 2nd Floor – East Survey
Proposed Location
2nd AP for E2 2nd Floor – East
Is there a difference at 173 feet?
Glass Corridor vs. Free Space
60
Glass Corridor vs Free Space Outdoor Propagation
Distance on both is 173 feet
Free Space - Outdoor (173ft)
Glass Corridor
50
Data
Signal:Noise
40
Average
Std Dev
Max
Min
30
20
10
0
1
29 57 85 113 141 169 197 225 253 281 309 337 365 393 421 449 477 505 533 561 589
Data Point
FreeSpace
35
5
44
11
Glass
Corridor
39
15
51
0
802.11b Propagation
FreeSpace vs. Through Coated Glass
Compare Propagation: Glass vs. Free Space
80
70
Free Space (10ft) Indoor
Glass Window (10ft)
Free Space (10ft) Outside
Signal:Noise
60
50
40
30
Average Loss due to Glass
Using Indoor Free Space Measurement: 19dB
Using Outdoor Free Space Measurement: 24dB
20
10
0
1
13 25 37 49 61 73 85 97 109 121 133 145 157 169 181 193 205 217 229 241 253 265 277 289 301 313 325 337 349 361 373 385 397 409 421 433 445 457
Data Points
Compare Propagation: Metal Stud Wall vs. Free Space
80
Indoor Free Space (5ft total dist)
With Wall Insert (5ft total dist)
70
Signal:Noise
60
50
40
30
Average Loss due to Metal Stud Wall
Using Indoor Free Space Measurement: 3dB
20
10
0
1
7
13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187 193 199 205 211
Data Points
Proposed 2nd Floor Coverage Plan
Channel 6
Channel 1
Faculty offices
Conference
room
Channel 1
Labs
Channel 11
Conference room
Academic Support