Zte ZXG10 OB06, Техническое руководство

Страница: 47 / 117

Chapter 3 - Interfaces and Communications
Confidential and Proprietary Information of ZTE CORPORATION 33
In ZXG10 OB06 (V1.0), LapD is realized in the LapD module of RSL. The
position of the LapD module in RSL is shown in Figure 15.
F
I G U R E
1 5 P
O S I T I O N O F
L
A P
D M
O D U L E
LapD module
OAMM FURRM
Physical layer
BSC
The LapD module communicates with the physical layer and L3. The L3
protocol is processed in FURRM.
OAMM configures the parameters such as TEI and values of the timer
necessary for the LapD module to run.
The LapD module provides two types of information transmission modes
for the FURRM: I-frame multi-frame operation and UI frame operation.
1. I-frame multi-frame operation
The L3 message is sent in the information frame mode which requires
the confirmation from the receiver. This mode provides a whole set of
control mechanism for error recovering and flow control, the
establishment mechanism and release mechanism for multi-frame
operations.
The I-frame structure is shown in Figure 16, including the flag
sequence, address field, control field, information field and check field.
F
I G U R E
1 6 F
R A M E
S
T R U C T U R E O F
L
A P
D
flag
Address Control Information
FCS flag
SAPI TEI N(S) N(R)
1 0-260 2 1
The address field contains SAPI and TEI. It performs addressing for
different units through TEI in the Abis interface link. Generally, a unit
has multiple functional entities, and the logical physical links between
different functional entities are identified by the functional address