1. Performing Site Surveys
IFIP-UNU ADVANCED COURSE ON NETWORKING AND SECURITY Module II-Wireless Communications Section 9
Performing Site Surveys

2. Overview
This module provided the necessary background and knowledge needed prior to performing a site survey. A good site survey will help determine the feasibility of the desired coverage, the radio frequency interference, and the wired connectivity limitations. In preparing for any site survey, an engineer has multiple factors to consider. Some of the major factors to consider include the applications and infrastructure that an institution wants to implement.

3. Learning Objectives Define the purpose of a Pre-Site Survey form.
Identify unexpected obstacles that you may face while performing a site survey.
Identify unexpected situations that you may face while performing a site survey.
Identify what type of site survey you will be performing prior to arrival at the customer’s site.
Obtain information needed to perform the site survey.
Determine the customer’s application needs and design a wireless LAN.
Identify the equipment needed to build a site survey kit.
Determine importance of items included in the site survey kit.
Define the purpose of a Pre-Site Survey form.

4. Key terms NFPA Spectrum Analyzer Vertical Application
Horizontal Application

5. Site Survey

6. Investigate Customer Requirements

7. Site Survey Steps
The process of performing a site survey includes the following steps:
Gather tools and configuration
Research and investigate industry specific concerns
Gather the recommended equipment list, or site survey kit
Implement the site survey
Document the site survey

8. LAN Limitations

9. Important Considerations
It is important for a site survey engineer to accomplish the following:
Come prepared to answer questions
Dress appropriately
Instill a sense of confidence in the customer
Wear or carry company credentials
Have business cards available
Bring the proper equipment

10. Applications

11. WLAN Applications

12. Be Prepared Come prepared to ask and answer questions
Instill a sense of confidence in the customer
Bring proper equipment

13. 5 GHz vs. 2.4 GHz Retail Both technologies will work in these markets.
POPULAR CHOICES
5 GHz /802.11a Uses
2.4 GHz/802.11b Uses
Hospitality X
Manufacturing X
Healthcare X X
Higher Education X X
Enterprise Office X X
Financial Institutions X
Retail X
Transportation X
Warehousing X

14. Interference Electrical devices in hospitals can cause interference
SpectraLink phone systems are common
Telemetry equipment
Know the obstacles

15. Hotel/Hospitality Multi-floor construction Numerous rooms Throughput
Fewer users per access point

16. Hotels/Hospitality (cont.)
Security
Aesthetics
Older hotel buildings
Hard Cap ceiling
Poured concrete walls
Newer hotels have drop tile ceilings

17. Hot Spots Hot Spot Provider Public areas Subscribers
Survey not so necessary
Effective range feet
Provide-agnostic network
Public areas
Coffee shops, Restaurants, Hotels
Airports, Convention Centers,
Marinas, Parks
Cisco Hot Spot locator link:

18. Education Children are
Curious
Can be destructive
Antennas and access points should hidden to avoid damage

19. Education (cont.)
Many schools are already equipped with Apple Macintosh PCs
Cisco Aironet’s MAC driver only works with
Mac OS 9.x
Mac OS X 10.1
Workgroup Bridge a possible solution
Using Workgroup Bridge leaves equipment exposed

20. Small Office
Quickly emerging market
New solutions being developed

21. 54 Cubes—4 Conference Rooms
Enterprise Office
2.4 GHz
4 Access Points
5 GHz
16 Access Points
54 Cubes—4 Conference Rooms
54 Cubes—4 Conference Rooms
95 Feet
Conference Room
120 Feet
Reception
Conference Room
Conference Room
120 Feet
Conference Room
Reception
Conference Room
95 Feet

22. Transportation Rail Yards Rail Cars Made of wood and metal
Transport a variety of cargo
Large and create narrow pathways between tracks

23. Transportation (cont.)
Airports
Easy two-dimensional coverage
Typically open area
Long open pathways
Post 9/11 issues
Rules and regulations
Baggage ramp area

24. Transportation (cont.)
High traffic areas
Equipment can be damaged or stolen if not put away properly

25. Government Secure facilities Variety of facilities Security clearance
Equipment checklists

26. WLAN Design

27. Wireless LAN Design Client type and mobility Cards
PCM, LMC, PCI
Repeaters and Workgroup Bridges
Third party devices
Barcode scanners, Telephony, Wi-Fi™ devices

28. Wireless LAN Design (cont.)
“Pools” of higher data rate coverage
Stationary vs. Mobile
54 Mbps
11 Mbps

29. Wireless LAN Office Design (cont.)
Most office user
Not truly mobile
Not trying to check while walking
Pools of coverage
Where are higher data rates needed?
Typically at desks
Conference rooms

30. Wireless LAN Office Design (cont.)
Break Room
V.P.
Storage

31. Customer Applications
Know what the customer needs from the wireless LAN
and web users have different needs than a CAD developer
Client/Server
Thin client

32. Rate Shifting Survey performed at each data rate?
5 GHz cell
Survey performed at each data rate?
Coverage cell for each rate mapped
Higher rates – shift to proper areas
Lower rates – overlap and frequency
2.4 GHz cell

33. Copper vs. Wireless LAN Lower pricing on WLAN equipment
Moving a terminal once makes RF the better solution
Popularity increasing
Consider future wireless LAN expansion while surveying

34. Data Collection Most devices do not support 802.11a yet
Some devices only require 2 Mbps
Will data collection devices be the only clients using WLAN?
Survey for 2 Mbps coverage
Some devices can rate shift

35. Data Collection (cont.)
Multiple workers sending lots of information
Needs of the application
Evaluate the application

36. Mobile Users Wireless data collection means mobility!
Coverage must be seamless

37. Highly Mobile Users
Data collection device mounted to forklift = Highly mobile user
Needs to be able to work “on the move”
Achieved through proper site survey and application design

38. Building to Building Design

39. Path Considerations Radio line of sight Earth bulge Fresnel zone
Antenna and cabling
Data rate

40. Line of Sight The following obstructions might obscure a visual link:
Topographic features, such as mountains
Curvature of the Earth
Buildings and other man-made objects
Trees
Line of sight!

41. Longer Distances
Line of Sight disappears at 6 miles (9.7 Km) due to the earth curve

42. Fresnel Zone
Fresnel Zone

43. Improving Fresnel Effect
Raise the antenna
New structure
Existing structure
Different mounting point
Remove trees

44. Site to Site Fresnel Zone
Antenna Height
Fresnel zone consideration
Line-of-Sight over 25 miles (40 Km) hard to implement
Antenna Height (Value “H”)
Total Distance
60% (Value “F”)
Earth Curvature (Value “C”)

45. Antenna Alignment
Line of Sight

46. High gain omni-directional
Antenna Issues
High gain omni-directional
Directional antenna
No Downtilt
One-way communications

47. Antenna Issues (cont.) 8.50 downtilt 200 ft./61 m 14.50 700 ft./213 m
8 Miles/13 Km

48. Site Survey Equipment

49. Access Points 802.11b 802.11a Survey with correct access point
With RP-TNC
Reverse Polarity Threaded Naval Connector (RP-TNC)
1200 Series Access Point (2.4 GHz)
Without RP-TNC
1100 Series Access Point
802.11a
1200 Series with 5 GHz Module
Survey with correct access point
Customer purchases an 1200 Series Access Point - survey with a 1200 Series Access Point

50. Client Cards
Client Cards
PC Cards
LM Cards
MMCX Cable Connectors

51. Antennas Two of every antenna you may have to use Diversity
Availability of antennas

52. Battery Pack and Cables
Charger
Cables
Serial or RJ-45 to DB-9 roll-over cable
RP-TNC Assembly

53. Mounting Brackets Mounting bracket Mounting solutions
Bright color tape
Velcro
Beam clamps
Zip ties
Secure the access point!

54. Access Point Markers Mark access point and antenna locations
Bright colors
Durable but easily removed

55. Antenna Attenuator Difficult to carry one cable of each length
Splitters, cables, and lightning arrestors add loss
Duplicate the loss with a single device

56. Measuring Devices Measuring wheel (horizontal distances)
Height measurement
Rope marked in 10’ or 3 meters increments (vertical distances)

57. Digital Camera Easiest way to document unusual situations
Need to photograph antenna mounting locations & methods

58. Travel Case Portable travel case Quick deployment Sufficiently padded
Checkable as luggage
Quick deployment

59. Cisco Aironet Site Survey Kit
Cisco Aironet In-Building Site Survey Kit
Airline approved travel case
Custom cut foam inserts
Inventory includes:
Access point with 2 RP-TNC connectors
2.4 GHz
5 GHz Radio module (optional)

60. Cisco Aironet Site Survey Kit
PC Card Adapter with Integrated Antenna
802.11b – 11 Mbps (2.4 GHz)
Optional a – 54 Mbps (5 GHz)
2.2 dBi Dipole Antenna
2 dBi Diversity Omni-directional Ceiling Mount Antenna
6.5 dBi Diversity Patch Wall Mount Antenna

61. Documentation and Utilities

62. Pre-site Survey Form Assists you in assessing
Type of survey needed
How long it will take
Equipment needed
Introduction to the customer’s facility
General fact gathering form

63. Aironet Client Utility: Site Survey
The Site Survey utility allows a user to perform a site survey to determine the best placement of the access points in order to provide the desired coverage.
The Site Survey can run in either Passive or Active mode. The Active mode is used to perform site surveys.
The Site Survey utility can be set to display results as percentages, or as actual values (for example, as dBm, or decibels per milliwatt). Complete the following steps to switch from percentage to dBm.
1. Click on the Preferences icon on the main page.
2. Select the dBm radio button under Signal Strength Display Units .
Now your ACU Site Survey will show signal to noise ratio.

64. Link Status Meter

65. Site Survey

66. Preparation Prior to arrival Ensure your equipment is operational
Configure equipment (if possible)
Determine if manlift is needed
Who will provide the lift?
Make sure batteries are fully charged

67. Site Survey

68. Site Survey (cont.)

69. Channel Selection AP1 Channel 1 AP 4 AP 6 Channel 11 AP 5 Channel 6

70. Data Rates
Surveyed at 5.5 Mbps
Surveyed at 2 Mbps

71. Antenna Choice, Power Level, & Cell Size

72. Site Survey Problems Process of trial and error
Experience = more trial, less error
Talk with other engineers
Site surveys can be puzzles
More than one solution

73. Site Survey Problems (cont.)
Frustration and laziness are your enemies
Take a break
May be necessary to start survey over
Always design the WLAN properly
Do not try and “force” your original plan to work

74. Site Survey

75. Freezers Perishable Goods 36o F Freezer 0o F Freezer -5o F

76. Antenna Splitters
WRONG!
Freezer OK OK
2.4 GHz Technology

77. Multi-floor Survey
AP 4
AP 3
AP 2
AP 1

78. Site Survey
Trauma Room
No coverage

79. Interference
Coverage cell seems small in comparison with previously surveyed access points
Coverage from access point seems to be intermittent
Mount antennas in open areas for best RF propagation
Look for objects that may interfere with RF signal
May need to use Spectrum Analyzer to find interference

80. Electrical Transformers
Interference (cont.)
Cardboard
Paper
Wood
Firewalls
Fluorescent Lighting
Microwave Ovens
Electrical Transformers

81. Mounting and Installation

82. WLAN Design Considerations
Access points have to be connected to the network
Should be familiar with:
Network components
Media
Topology
Need to have some knowledge

83. Plenum
A compartment or chamber to which one or more air ducts are connected
Forms part of the air distribution system
Cat 5 cable available in plenum and non-plenum
Non-plenum sheath is PVC and gives off toxic fumes when melted

84. Plenum (cont.) Cat 5 available Plenum areas
Non-Plenum
Plenum areas
Egg crate ceiling tiles
No insulation
Firewalls
Non-plenum areas use ducting in plenum for air return

85. Plenum (cont.) No chance for toxic fumes to get inside the ducting
Non-plenum areas
Ductwork
Lack of firewalls
Insulation

86. Firewalls Easily identified Act as barriers to contain fires
Hinders 2.4 GHz signal
Stops 5 GHz signal

87. Keep Closed Firewalls (cont.) Some firewalls may have doors
Fire doors can hamper the RF signal as well
Survey with doors closed
Automatic Fire Doors
Keep Closed

88. Risers Sometimes referred to as “wiring closets”
Used for wiring between floors
Stacked on top of each other
Riser walls are firewalls
If a riser is plenum-rated, only install plenum rated equipment

89. 1200 Series Access Point Mounting
Mounting holes
Mounting solutions
Concrete
Drywall
I-Beam
Ceiling
Secure the access points

90. Mounting on a Horizontal or Vertical Surface

91. Mounting on a Suspended Ceiling

92. Attaching and Securing the Access Point to the Mounting Bracket

93. 1100 Series AP: Variety of Mounting Configurations
Desktop
Stand
Ceiling
Mount
Hang on
Cube Wall
Wall
Mount

94. Access Point Mounting (cont.)
Do not cover access point lights
Mount “upside-down” so Ethernet indicator lights can be seen from the floor
Label access points

95. Antenna Mounting Some antennas not shipped with mounting brackets
Modify brackets
Fit your needs
Can be used with a variety of antennas
Mast Mount
Patch
Ceiling Mount

96. Antenna Mounting (cont.)
Solid and secure
Do not hang antennas by their cable
Cable can break or become damaged
Antenna can sway and provide a “moving cell”

97. Antenna Mounting (cont.)
Sometimes antennas are mounted in unusual ways
Specify in your report exactly how the antenna is to be mounted

98. Summary
Identify unexpected obstacles that you may face while performing a site survey.
Identify unexpected situations that you may face while performing a site survey.
Identify what type of site survey you will be performing prior to arrival at the customer’s site.
Obtain information needed to perform the site survey.
Determine the customer’s application needs and design a wireless LAN.
Identify the equipment needed to build a site survey kit.
Determine importance of items included in the site survey kit.

99. Labs

100. Labs of Section 9 Lab 10.2.7.1 Site Survey Active Mode
Lab Survey the Facility