Performance evaluation of two transport protocols for image transmission over CDPD networks

• Main Author: Zhou, Jun
• Language: English
• Published: 2009
• Online Access: http://hdl.handle.net/2429/8413

Due to the low bandwidth and harsh noise characteristics of cellular wireless networks, the transmission of images over these networks may require a long time, especially if the transport protocol used is the standard Transmission Control Protocol (TCP), which has been tuned for more reliable wireline networks. In this thesis, we study and compare the performance of two efficient image transmission schemes suitable for low bit rate wireless data networks. The Cellular Digital Packet Data (CDPD) network is chosen as the example wireless data network in this research. Scheme 1 uses the standard TCP in conjunction with a flexible image transmission strategy, in which the amount of image data sent is negotiated by the client according to a desired image quality. Scheme 2 uses a new file transfer protocol called Image File Transfer Protocol (IFTP), and is built on the top of the User Datagram Protocol (UDP) in the transport layer. IFTP keeps the error and retransmission control in the application, and transmits the progressive JPEG image scan by scan in a sequence according to the scan priorities. An extensive OPNET model is developed for the performance evaluation of the two proposed image transmission schemes. Simulation results show that IFTP is functionally sound in a multi-link network and outperforms the TCP-based scheme in terms of image transmission time.