Between the Base Transceiver Station (BTS) and the Base Station Controller (BSC) in GSM (Global System for Mobile Communications) networks, several protocols are used to facilitate communication and control. Here are the key protocols involved:
GSM Protocols Between BTS and BSC:
1. Abis Interface:
The Abis interface is the standardized interface between the BTS and the BSC in GSM networks. It is responsible for the exchange of control and user data between these two network elements.
2. Base Transceiver Station Application Part (BTSAP):
BTSAP is a protocol that operates at the Abis interface and facilitates communication between the BTS and the BSC. It is part of the signaling procedures that manage the connection and control of the radio resources.
3. Base Station System Application Part (BSSAP):
BSSAP is a protocol used at the Abis interface and extends into the A interface between the BSC and the Mobile Switching Center (MSC). BSSAP handles signaling and control functions, including call establishment, location updating, and handovers.
4. Radio Link Control (RLC):
RLC is responsible for the reliable and efficient transfer of user data on the radio link. It operates at the Abis interface and manages aspects such as error correction, flow control, and segmentation and reassembly of data.
5. Radio Frequency (RF) Control:
RF Control is a set of protocols that manage the radio frequency-related aspects of the communication between the BTS and the BSC. It includes procedures for power level control, handovers, and synchronization.
6. Abis Subnetwork Dependent Convergence Protocol (AS-DCP):
AS-DCP is used to convey control information related to the radio resources. It operates at the Abis interface and plays a role in configuring and managing the radio channels.
7. Abis Management Application Part (AMAP):
AMAP is a protocol used for the management of Abis interface resources. It handles tasks such as configuration management and fault detection.
8. Abis Remote Operations Protocol (AROP):
AROP is a protocol used for remote operations and maintenance of the BTS over the Abis interface. It facilitates activities such as software updates, performance monitoring, and fault diagnostics.
9. Abis Interface Radio Link Control (AIRLC):
AIRLC is responsible for the radio link control functions specific to the Abis interface. It manages the reliable and error-free transmission of control and signaling messages.
These protocols collectively ensure the effective operation, control, and management of the radio resources and communication between the BTS and the BSC in GSM networks.