Motorola 557925-001-00 appendix - page 3

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In ns st ta al ll la at ti io on n
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Ro ou ut ti in ne e
The goal of the installation can be stated relative to received signal strength (RSSI):
• -70dBm signal strength or better in every room
• Maximum of three co-channel cells within the carrier detect range
Perfect non-overlapping cell coverage is impossible to achieve. Read Appendix A for a
description of the carrier detect range and its effect on media access.
The network architect can control three variables when deciding where and how to install the
Wireless WallPlate network. Each variable has a different degree of effect on the overall network
performance.
• Physical placement is an important determinant of success. Because of the fast
installation routine, WallPlate placement is easy to adjust onsite during the installation.
• Channel assignment is used to create overlapping coverage cells and reduce the co-
channel cell overlaps. In most countries, channels 1 – 11 are available; where only
channels 1, 6, 11 are non-overlapping for 802.11g modulation.
• Transmit power can be adjusted to fine-tune the signal strength and reduce some co-
channel interference. The WallPlates can be adjusted in 1dB increments from 14dBm to
1dBm. NOTE: Transmit power alone will not overcome an installation with too great a
density.
Full Site Survey
The goal of any wireless site survey covers two key purposes:
• Determine the number of APs required for adequate RSSI into each hotel guest room.
• Determine where and how to backhaul and power the AP installed in the hotel corridor.
Because the hotel guest is in the room, and not in the hallway, co-channel interference between
hallway-installed APs is usually not considered during a site survey. The focus is on pumping
enough power into the rooms to connect the hotel guest. When APs are installed in the hotel
corridor, mistakes are nearly impossible to correct. Adding an additional AP to cover a weak area
of the hotel is extremely difficult. Typical corrective action usually involves a higher gain antenna.
This is often ineffective if poor coverage is due to obstructions or multi-path reflections. Thus, an
extensive and expensive site survey is required.
Lite-Site Survey
With the Wireless WallPlate, the possible install locations include each room in the hotel.
Because of the fast installation, corrective action is very easy to execute if additional WallPlates
are required. Thus the site survey can be done quickly or not at all, with adjustments made
during the installation time.
Since the same construction material is used throughout the property, a complete room to room
site survey is unnecessary.
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