Abstract:
The GSM network is the most popular network and many researchers are
interested to develop applications on it. GPRS is one of the technologies used to
transmit data packets over the GSM network that allow mobile communication with
the Internet.
One important problem is how to guarantee the QoS of data transmission in
the GPRS/GSM network. Several techniques have been proposed to control QoS in
the GSM network. One technique called the GQ-MAC protocol is able to guarantee
the QoS of four types of traffic: streaming, conversation, interactive and
background. Another technique is called Link Adaptation which helps improve the
performance of packet transmission in the GPRS network by adjusting the coding
scheme in changing environment. There are four coding schemes: CS1, CS2, CS3,
and CS4. Each coding scheme can transfer traffic at different data rate from lowest
to highest. The Link Adaptive technique uses BLER (Block Error Rate) calculation
to adjust the coding scheme used.
This research demonstrates an improvement to the performance of the GQMAC
protocol using the Link Adaptation technique. The proposed model increases
the performance of packet transmission for all traffic. Via CSIM simulation tool,
four experiments were conducted. The results show better performance of each
traffic transmission. Streaming traffic has higher data bit rate. Conversation traffic
has a greater number of users, and interactive traffic can guarantee the throughput.