Service Manual

GSM-204-323
NIU
31st Oct 01
Technical Description: Horizon macro outdoor
68P02902W02-A
CONTROLLED INTRODUCTION
Tech. 6–17
NIU
functionality
The NIU provides two E1/T1 interfaces into the network (link 0 and link 1) as
well as LAPD encoding/decoding and clock recovery from a selected E1/T1 link.
The second E1/T1 interface (link 1) is not used for NIUs placed in positions at
A1 and B1, as shown in Figure 6-1.
An NIU control processor provides network interface configuration and
supervision, controlled by the MCUF. The NIU control processor maintains two
independent control links in the redundant configuration (one to each MCUF),
each using timeslot 0 of MCUF link 0.