UMTS layers parametrisation for real-time flows
H. Van Peteghem, Laurent Schumacher, Christophe De Vleeschouwer · 2007
This paper describes the emulation of a UMTS Rel'99 radio access network on a Linux-based testbed. The impact of design choices at transport (TCP vs. UDP), data link - RLC (Acknowledged vs. Transparent Mode) and physical (spreading factor 4 vs. 8) layers on the user experience at the reception of Real-Time flows is demonstrated for both synthetic and real life Conversational and Streaming traffics. Over a typically impaired wireless channel, it appears that Transparent Mode is not suited for Streaming flows, as it results in significant PER on UDP or significant delays on TCP, whereas it is acceptable for Conversational flows.