User's Manual

Designing a Fusion Wideband Solution
Page 88 InterReach Fusion Wideband Installation, Operation, and Reference Manual
© 2015 TE Connectivity D-620616-0-20 Rev K • TECP-77-044 Issue 9 • March 2015
Example Design Estimate for an 1900 MHz CDMA Application
1 Design goals:
• PCS
(1920 MHz = average of the lowest uplin
k
and the highest downlink frequency in 1900
MHz PCS band)
• CDMA provide
r
• eight CDMA carriers in the system
• –85 dBm design goal (to 95% of the bu
ilding); the minimum received power at the
wireless device
• Base station with
simplex RF connections.
2 Power Per Carrier: The
tables in “Maximum Output Power Per Carrier” on page 65 provide
maximum Power Per Carrier information. Table 58 on page 75 indicates that Fusion
Wideband can support eight carriers with a recommended maximum Power
Per Carrier of 9.0
dBm. The input power should be set to the desired output power minus the system gain.
3 Buildi
ng information:
• 16 floor building with 9,290 sq. meters (100,000 sq. ft.) per floor;
total 148,640 sq. meters
(1,600,000 sq. ft.)
• wall
s are sheetrock construction, suspended ceiling tiles
• antennas used are omni-directional, ceiling mounted
• standard office environment, 80% hard wall offices and 20% cubicles.
4 Link Budget: I
n this example, a design goal of –85 dBm is used. Suppose 3 dBi
omni-directional antennas are used in the design. Then, the maximum RF propagation loss
should be no more than 97.0 dB (9.0 dBm + 3 dBi + 85 dBm) over 95% of the area being
covered. It is important to note that a design goal such as –85 dBm is usually derived taking into
account multipath fading and log-normal shadowing characteristics. Thus, this design goal will
only be met “on average” over 95% of the area being covered. At any given point, a fade may
bring the signal level underneath the design goal.
Note that this method of cal
culating a link budget is only for the downlink path. For
information to calculate link budgets for both the downlink and uplink paths, refer to “Link
Budget Analysis” on page 90.
Table 80.
Approximate Radiated Distance from Antenna for 2.5 GHz TDD LTE Applications
Facility
Distance from Antenna
Meters Feet
Open Environment 59 194
Moderately Open Environment 47 152
Mildly Dense Environment 41 134
Moderately Dense Environment 35 112
Dense Environment 25 83