User's Manual

Designing an LGCell Solution
7-2 LGCell 4.0 Installation, Operation, and Reference Manual PN 8100-40
620004-0 Rev. B
• Obtain floor plans to determine floor space of building and the wall layout of
the proposed areas to be covered. Floor plans will also be useful when you are
selecting antenna locations.
• If possible, determine the building’s construction materials (sheetrock, metal,
concrete, etc.)
• Determine type of environment
– Open layout (e.g., a convention center)
– Dense, close walls (e.g., a hospital)
– Mixed use (e.g., an office building with hard wall offices and cubicles)
4. Develop an RF link budget: Section 7.4, “Link Budget Analysis,” on page
7-31.
Knowing the power per carrier, you can calculate an RF link budget which is used
to predict how much propagation loss can be allowed in the system, while still
providing satisfactory performance throughout the area being covered. The link
budget is a methodical way to derive a “design goal”. If the design goal is pro-
vided in advance, the link budget is simply: allowable RF loss = max. power per
carrier – design goal.
5. Determine the appropriate estimated path loss slope that corresponds to the
type of building and its layout, and estimate the coverage distance for each
RAU: Section 7.2, “Estimating RF Coverage,” on page 7-18.
The path loss slope (PLS), which gives a value to the RF propagation characteris-
tics within the building, is used to convert the RF link budget into an estimate of
the coverage distance per antenna. This will help establish the LGCell equipment
quantities you will need. The actual path loss slope that corresponds to the spe-
cific RF environment inside the building can also be determined empirically by
performing an RF site-survey of the building. This involves transmitting a cali-
brated tone for a fixed antenna and making measurements with a mobile antenna
throughout the area surrounding the transmitter.
6. Determine the items required to connect to the base station: Section 7.5,
“Connecting a Main Hub to a Base Station,” on page 7-44.
Once you know the quantities of LGCell equipment you will use, you can deter-
mine the accessories (combiners/dividers, surge suppressors, repeaters, attenua-
tors, circulators, etc.) that are required to connect the system to the base station.
The individual elements that must be considered in designing an LGCell solution are
discussed in the following sections.