User's Manual Part 2

RBS 2109 User’s Guide

P008645B

Customer

Interface

DSX-1

RBS 2 RBS 3RBS 1

A(C) B(D)

Figure 56 System View for Transmission Interface T1, Short Haul

1. Determine the length of the cable between the RBS and the customer

interface (the cross-connection point DSX-1). See figure above.

If multidrop is used, then calculate the attenuation of the entire RBS chain,

since LBO A (C) is determined by the total attenuation of the chain. LBO B

(D) is determined by the total attenuation to the last RBS in the chain.

If the cable length is not known, then set the LBO parameters to ‘‘Short

h., 0 – 133 feet’’.

2. Use the cable length and the table below to set the correct LBO parameters

in the OMT.

Table 36 Setting LBO Parameters to Short Haul in OMT

Cable Length LBO Setting

Feet Metres

(in the OMT)

0 – 133 0 – 40

Short h., 0 – 133 feet

133 – 266 40 – 81

Short h., 133 – 266 feet

266 – 399 81 – 122

Short h., 266 – 399 feet

399 – 533 122 – 162

Short h., 399 – 533 feet

533 – 655 162 – 200

Short h., 533 – 655 feet

3. Set unused ports to ‘‘Short h., 0 – 133 feet’’.

Example of an LBO Parameters Calculation for Short Haul

P010472A

Customer

Interface

(DSX-1)

RBS 1

A C B D

RBS 2

A C B D

200 feet

(61 metres)

100 feet

(30 metres)

Figure 57 Calculating LBO Parameters for Short Haul

N/LZT 720 0090 Uen R1A 2004-09-17