A 4G Link Level Emulator for Transport Protocol Evaluation.

Stefan Alfredsson , KAU, Anna Brunström , KAU and Mikael Sternad , UU.

2nd Swedish National Computer Networking Workshop , Karlstad, Nov. 2004.

Outline:

The Wireless IP project studies problems that are crucial in the evolution of UMTS towards high data rates, as well as in future 4G technologies aimed at rapidly mobile terminals. The goal is to attain higher througputs for packet data in particular in downlinks, without bandwidth expansion and while providing acceptable quality of service for various classes of traffic.

Abstract:

This paper presents a wireless link and network emulator, based upon the Wireless IP 4G system proposal from Uppsala University and partners.

In wireless fading downlinks (base to terminals) link-level frames are scheduled and the transmission is adapted on a fast time scale. With fast link adaptation and fast link level retransmission, the fading properties of wireless links can to a large extent be counteracted at the physical and link layers. A purpose of the emulator is to investivate the resulting interaction with transport layer protocols. The emulator is built on Internet technologies, and is installed as a gateway between communicating hosts.

The paper gives an overview of the emulator design, and presents preliminary experiments with three different transport protocols. The results clearly show the effect of changing link layer parameters on the different transport protocols.

Related publications:

Earlier paper at VTC2003, on the simulator.

Paper 1 at VTC2003, on the proposed adaptive OFDM 4G downlink.

Paper 2 at VTC2003, on the proposed adaptive OFDM 4G downlink.

Paper 3 at VTC2003, on OFDM channel estimation and channel prediction.

Source:

Pdf, (264K)