Impact of GPRS buffering on TCP performance - Electronics Letters

Introduction: The General Packet Radio Service (GPRS) is a packetoriented extension to the Global System for Mobile Communications (GSM) that supplies higher data rates and sharing of radio resources. The performance of the Internet protocols in GPRS is dependent not only on the quality of the radio link, but also on buffering in the GPRS network. According to [1–3], the over-sized network buffers used in many commercial networks may result in very long round trip times (RTTs) for the Transmission Control Protocol (TCP) when the buffers in the cellular network are filled. Suggested remedies [1, 3] typically require infrastructure changes. In the work reported in this Letter we experimentally investigated the impact of GPRS buffering on TCP. In contrast to related work, [1–3], we experimented with different buffer settings and evaluated the effect on TCP behaviour. Our work is based on measurements in a GPRS testbed consisting of real network nodes with real protocol implementations and an emulated radio environment.