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Cell Site Layouts 3-21
60° STSR cell site connection
The Metrocell in a 60° STSR configuration uses at least three equipment frames, one CE Frame and two RF frames (see Figure
A 60° STSR Metrocell with four RF Frames has 16 channels for one sector (including the CCH and the LCR) and each sector requires two TRU/DPA shelves and two ATCs. It also requires twelve antennas; one TX/RX antenna and one RX only antenna for each sector. The outputs of the two ATCs for each sector are combined through one phasing transformer and connected to a duplexer. The output of duplexer is then connected to the main TX/RX Antenna of that sector. The diversity RX antenna of each sector is connected directly to the Receive Multicoupler (RMC) of that sector. Figure
Control Channel redundancy
Control Channel (CCH) redundancy is commonly provided with a Locate Channel Receiver (LCR) backup. With two RF Frames, the CCH of each sector is assigned to position 1 on the TRU/DPA Shelf of that sector and the LCR is assigned to position 4 on the same shelf. With four RF Frames, a typical assignment of the CCH and LCR for each sector is listed below:
| Control Channel | Locate Channel Receiver |
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Sector X | RF Frame 1/TRU Shelf 1/Position 1 | RF Frame 1/TRU Shelf 1/Position 4 |
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Sector Y | RF Frame 2/TRU Shelf 1/Position 1 | RF Frame 2/TRU Shelf 1/Position 4 |
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Sector Z | RF Frame 2/TRU Shelf 3/Position 1 | RF Frame 2/TRU Shelf 3/Position 4 |
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Sector U | RF Frame 3/TRU Shelf 1/Position 1 | RF Frame 3/TRU Shelf 1/Position 4 |
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Sector V | RF Frame 4/TRU Shelf 1/Position 1 | RF Frame 4/TRU Shelf 1/Position 4 |
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Sector W | RF Frame 3/TRU Shelf 3/Position 1 | RF Frame 3/TRU Shelf 3/Position 4 |
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This arrangement will have the CCH and the LCR supplied on a different DC power feed and a TCM card. No RF coaxial switch is required since the cavity of the LCR position on the ATC will tune to the CCH frequency when backup is required.