University of Helsinki Department of Computer Science

Department of Computer Science

Department information


IIP Mixture Project (Spring 2003 - Spring 2005)

(predecessor projects IIP Mobile and IIP Wireless)

In collaboration with

- Brief project description

The standardization body for the Internet protocols, the Internet Engineering Task Force (IETF), is specifying various performance enhancements to TCP and is documenting the impact of problematic link-layer characteristics to the Internet protocols. In addition, mitigations to the performance implications of problematic link characteristics and approaches to enhance the performance that the Internet protocols, particularly TCP, attain in the face of particular link characteristics are being documented.

The research projects IIP Mobile and IIP Wireless run for two years addressing primarily issues in TCP/IP on wireless links. This research project is a direct follow-up of the two projects but the focus is shifted towards Internet solutions that are able to handle heterogeneous traffic on wireless links.

The key areas of interest include studies on how different types of competing traffic (traffic mixtures) behave and how the behaviour could be affected with IP QoS-based packet treatment. In particular, how co-existence of active queue management and DiffServ-based packet treatment reckon with 3G QoS architecture is best arranged, and how different applications should exploit the application protocol in order to allow efficient operation at the transport layer. In addition, the current work on enhancing TCP algorithms and protocol for wireless environment (2.5G and 3G) will be continued.

Additionally, IIP Mixture develops further a real-time software emulator called Seawind. Seawind enables measurements of protocol implementations in modeled networking environments. Seawind provides a rich set of ways to define transfer characteristics including delays and errors. The software has also means to conduct large sets of experiments in an autom atic fashion. In addition, tools of analyzing measurement data has been integrated into the Seawind software.

- Papers and presentations

- Seawind Network Emulator

- Modifications to Linux TCP

- Project members

Kimmo Raatikainen
Markku Kojo

Davide Astuti
Laila Daniel
Andrei Gurtov
Lauri Hyttinen
Ilpo Järvinen
Tuomas Kulve
Jaakko Kyrö
Simone Leggio
Aki Nyrhinen
Oriana Riva
Jarno Saarto
Pasi Sarolahti

markku Kojo -