ZTE Corporation ZXG-OB06 Benutzerhandbuch

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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. 
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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