User's Manual

2. Preliminary Decisions
AMPS EAC-2100 Manual: (Draft, 02/01) Page 1-3
1.2 About the TIA/EIA-136 EAC-2100
This section provides a brief overview of how the EAC-2100 operates. For a more detailed discussion,
refer to Volume 3, Technical Information.
1.2.1 Use of Boosters
Cellular telephone systems transmit signals in two directions between cell sites and subscriber
telephones within the signal coverage area. The signal path from the cell site to the subscribers
is called the forward path, and the path from subscribers to cell site is the reverse path.
If weak signal transmissions occur within the coverage area because of terrain obstructions, a
relatively inexpensive way to extend transmission range is to install a signal booster that
receives the signal, amplifies it, and reradiates it. (See Figure 1-2.)
1.2.2 Frequency Allocation
TIA/EIA-136 cellular systems use 1850-1910 MHz for reverse and 1930-1990 MHz for
forward transmissions. These frequency bands are divided into A, B, C, D, E, & F blocks.
1.2.3 EAC-2100 Operation
The EAC-2100 booster is available in either a two-channel or a four-channel configuration.
Each RF channel is capable of handling three full -rate TDMA channels. Therefore, a four-
channel EAC-2100 can provide one DCCH channel and 11 DTC DTC channels.
Also, two EAC-2100 boosters may be operated together to provide up to eight RF-channel
operation (1 DCCH plus 23 DTC DTC channels). A digital control cable connects the two
cabinets together to allow one cabinet to handle the DCCH duties.
A block diagram of the EAC-2100 is shown in figure 1-2. Up to four 800 MHz TDMA
modules are used. These modules are similar to those used in the EAC-2000, with the main
difference being that they have a lower output power level in the reverse direction. Like the
EAC-2000, these modules provide the frequency translation feature necessary to allow high-
gain repeater operation.
Block converters are used to convert the PCS band to the 800 MHz band, and likewise the 800
MHz band to the PCS band. A Forward Block Converter and a Reverse Block Converter is
used. Each block converter has its own synthesizer and local-oscillator control for performing
the block conversion process.
1.2.3 EAC-2100 Operation (Continued)