User's Manual

InterReach Unison Installation, Operation, and Reference Manual 6-1
D-620003-0-20 Rev J CONFIDENTIAL
SECTION 6 Designing a Unison Solution
Designing a Unison solution is 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 determined by the service provider:
• Frequency (that is, 850 MHz)
• Band (that is, “A” band in the Cellular spectrum)
• Protocol (that is, TDMA, CDMA, GSM, iDEN)
• Peak capacity requirement (this, and whether or not the building is 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, that
is, –85 dBm)
The design goal is always a stronger signal than the cell phone needs. It
includes inherent factors which affect performance (refer to Section 6.4.1 on
page 6-24).
• 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: refer to Section 6.1, “Maximum Output Power Per
Carrier at RAU,” on page 6-3.
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. Typically, the power per carrier decreases
as the number of carriers increases.
3. Determine the in-building environment: refer to Section 6.2, “Estimating RF
Coverage,” on page 6-12.
• Determine which areas of the building require coverage (entire building, public
areas, parking levels, and so on.)
• Obtain floor plans to determine floor space of building and the wall layout of
the proposed areas to be covered. Floor plans are also useful when selecting
antenna locations.