User's Manual

PN 8700-10 InterReach Unison User Guide and Reference Manual 8-1
620003-0
PRELIMINARY
SECTION 8
Designing a Unison Solution
Designing a Unison solution is ultimately a matter of determining coverage and
capacity needs. This requires the following steps:
1. Determine the wireless service provider’s requirements.
This information is usually supplied by the service provider:
• Frequency (i.e., 850 MHz)
• Band (i.e., “A” band in the Cellular spectrum)
• Protocol (i.e., TDMA, CDMA, GSM, iDEN)
• Peak capacity requirement (this, and whether or not the building will be split
into sectors, determines the number of carriers that the system will have to
transmit)
• Design goal (RSSI, received signal strength at the wireless handset,
i.e., –85 dBm)
The design goal is always a stronger signal than the cell phone needs. It
includes inherent factors which will affect performance (see Section 8.4.1 on
page 8-33).
• RF source (base station or BDA), type of equipment if possible
2. Determine the power per carrier and input power from the base station or
BDA into the Main Hub: Section 8.1, “Maximum Output Power per Carrier
at RAU,” on page 8-3.
The maximum power per carrier is a function of the number of RF carriers, the
carrier headroom requirement, signal quality issues, regulatory emissions require-
ments, and Unison’s RF performance. The power per carrier decreases as the
number of carriers increases.
3. Determine the in-building environment: Section 8.2, “Estimating RF Cover-
age,” on page 8-19.
• Determine which areas of the building require coverage (entire building, public
areas, parking levels, etc.)