Base Station System GPRS Protocol

Communications protocol

A communications protocol is a system of digital message formats and rules for exchanging those messages in or between computing systems and in telecommunications...

. Information between SGSN and BSS

Base Station Subsystem

The base station subsystem is the section of a traditional cellular telephone network which is responsible for handling traffic and signaling between a mobile phone and the network switching subsystem...

. This protocol provides radio related Quality of Service

Quality of service

The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...

 and routing information that is required to transmit user data between a BSS and an SGSN. It does not carry out any form of error correction.

BSSGP is used to handle the flow control between SGSN and BSS. The flow control mechanism implemented in SGSN node, only for GSM, is used to prevent congestion and loss of data due to overload in the BSS. This mechanism controls the flow from the SGSN to the BSS but not in the uplink direction.

The primary functions of BSSGP include:

• Provision by an SGSN to a BSS of a radio related information used by the RLC/MAC function in the download link.
• Provision by a BSS to an SGSN of radio related information derived from the RLC/MAC function in the uplink.
• Provision of functionality to enable two physically distinct nodes, an SGSN, a BSS, to operate node management control functions (QoS, flow control).

http://www.protocols.com/pbook/pdf/gprs.pdf