Westell DSP85 Original Series, Руководство пользователя

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Digital Repeater Line
DSP85 Series
WESTELL.COM
© 2016 Westell Technologies 14 June 2016 Doc. No. 960-1666-MNL rJ
1.877.844.4274 Page 61 of 77
Appendix C LTE Attenuator and Installation Notes
C.1 Important LTE Attenuator and Installation Notes - Donor and Server Isolation
Inadequate isolation between the outside and inside antennas may cause regenerative feedback in the system.
Carefully consider the layout and placement of the system. Set repeater gain well below line of sight donor path loss,
as shown in C.1.1 Line of Sight Propagation Path Loss Table. Higher gain settings may be possible if the internal
building structure and system layout adds additional attenuation and the installer is confident about the values of
that attenuation.
C.1.1 Line of Sight Propagation Path Loss Table
Table C-1: Line of Sight Propagation Path Loss Table
Distance between donor and
server antenna
Free space path loss Max gain 2
Max gain with 20 dB
attenuation from building
structure 2
10 m 1 50 dB 1
55 dB
1
55 dB
1
40 m 1 62 dB 1
55 dB
1
67 dB 1
60 m 1 65.5 dB 1
55 dB
1
70.5 dB 1
100 m 70 dB 55 dB 75 dB
120 m 71.5 dB 56.5 dB 76.5 dB
143 m 73 dB 58 dB 78 dB
160 m 74 dB 59 dB 79 dB
180 m 75 dB 60 dB 80 dB
200 m 76 dB 61 dB 81 dB
239 m 77.5 dB 62.5 dB 82.5 dB
268 m 78.5 dB 63.5 dB 83.5 dB
284 m 79 dB 64 dB 84 dB
300 m 79.5 dB 64.5 dB 84.5 dB
318 m 80 dB 65 dB 85 dB
NOTE
1
Antenna separation under 100 meters requires additional attenuation greater than
20 dB.
NOTE
2
Maximum gain assumes no loss or gain in donor seen, coax distribution, or active
DAS.