ZTE Corporation ZXG-OB06 Manuale Utente

 
ZXG10 OB06 ZTE  Integrated Outdoor GSM Base Station Technical Manual 

Confidential and Proprietary Information of ZTE CORPORATION 

Protocol Introduction 

Two important external interfaces for the ZXG10 OB06 (V1.0) are the Abis 
and the Um interface. 

On the Abis and the Um interface, the ZXG10 OB06 (V1.0) processes the 
LapD protocol, LapDm protocol and RR/MM/CM protocol. The following are 

descriptions of the three protocols in combination with the actual system 
circumstance. 

LapD Protocol 

LapD (link access procedure of “D” channel) is a data link procedure for 

signaling transmission between ZXG10 OB06 (V1.0) and BSC, with the 
purpose of using the D channel to transmit messages between Layer-3 

entities. 

LapD is a point-to-multipoint communication protocol that employs the 
frame structure. 

In the ZXG10 OB06 (V1.0), LapD implements the following functions: 

1.  Providing one or multiple data connections in the D channel 

The data link connections are identified by the DLCIs in the frames. 
DLCI consists of the Terminal Equipment Identifier (TEI) and Service 

Access Point Identifier (SAPI), indicating the service and entity that are 
accessed. 

2.  Delimitation, location and transparency of the frame 
3.  Sequence control, ensuring sequential transmission of the frames 
4. Error detection 
5. Error recovering 
6.  Notifying the management entity of the un-recoverable error 
7. Traffic control 
Functions 1, 2 and 4 hereof are implemented automatically by the 

hardware, while functions 3, 5, 6 and 7 are implemented through the 
software.