Zte ZXG10 OB06, Техническое руководство

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ZXG10 OB06 ZTE Integrated Outdoor GSM Base Station Technical Manual
26 Confidential and Proprietary Information of ZTE CORPORATION
provides the power supply and the alarm interfaces. The man-machine
interface (MMI) is an interface between the local O&M terminal (LMT) and
OB06.
Interfaces
Abis Interface
The Abis interface is defined as an interface between OB06 and BSC.
The Abis interface sends the signal from the BSC to the OB06, usually the
standard E1 signal of PCM 2M. The signals are generally the standard PCM
2M E1 signals, transmitted physically over the 75ohm coaxial cable in the
unbalanced mode or the 120 ohm cable in the balanced mode or through
digital microwave, fiber transmission (SDH/PDH) or satellite link.
Physically, the Abis interface is an E1 interface and uses thin coaxial cables
for connection.
Protocols on the Abis interface are hierarchical, and the protocol hierarchy
of circuit service is shown in Figure 10. The Abis interface does not process
the packet service protocol, and it is transparent for the packet signaling.
F
I G U R E
1 0 C
I R C U I T
S
E R V I C E
P
R O T O C O L
L
A Y E R E D
S
T R U C T U R E O F
A
B I S
I
N T E R F A C E
OB06
BTSM
LAPD
Sig.L1
BSC
Sig.L2
LAPD
BTSM
RR
Abis interface
On the Abis interface, the circuit service protocols fall into three layers:
1. Layer-1 (physical layer) is the PCM digital link at the rate of 2,048
Kbit/s.
2. Layer-2 (data link layer) is based on the LAPD.
3. Layer-3 transparently transmits the layer-3 messages on the A
interface and manages radio resources.
The protocols related to the Abis interface are as follows: