The Research And Implementation Of GPRS Performance Improvement Strategy

This thesis intends to build robust solution for GPRS network to save the bandwidth, which is the most precious resource in telecommunication network. Most of GPRS data is carried by RTP/UDP/IP packets which include long header field. The encapsulation process of the hierarchical transmission protocols wastes a substantial part of the wireless bandwidth for the transmission of control information (header) that does not have any specific function for the management of wireless channel itself.Based on the data compression theory and the current research result, this thesis adopts the 3GPP bandwidth saving model to develop a solid data compression system for GPRS network. 3GPP bandwidth saving model uses IP header multiplex and RTP header compression to reduce the traffic data. IP header multiplex will merge the IP packets which have the same source IP. address and the same destination IP address into a larger IP packet. This method can notably reduce the IP header information. RTP header compression uses the key RTP timestamp data and RTP sequence number data to build a compressed RTP header which only consumes 3 bytes.This thesis describes the development of the bandwidth saving system. The thesis demonstrates the high level design and the module design of bandwidth saving system and finally describes the test result. The system uses PF_RING open source module to build the data packet transportation platform to capture high load data traffic. PF_RING will capture the data packets at the network interface card directly and dispatch the packets to handling module according data packet type. For the raw IP packets, the system will do the IP header multiplex and RTP header compression. For the multiplexed IP packets, the system will deconstruct the IP packets and do RTP header decompression to rebuild the raw IP packet. It is shown in the test result that the traffic data can reduce by 30% and this system has a reliable performance.