Capture effect in residential Ethernet LAN

Abstract

A residential local area network (LAN) will be needed to connect all the home intelligent appliances, including set-top boxes and personal computers (PCs), to the information superhighway as well as to inter-connect them inside the home. Ethernet is the most promising candidate due to its low cost and vast installed base. It, however, is also known as having a capture effect which refers to the phenomena that the losing node in a collision is more likely to loose again, thereby causing long delay variations and disruption of a constant bit-rate (CBR) video stream for an extended period of time. This paper examines the impact of the Ethernet capture effect on video services in a residential environment. Actual PC data traffic was used in a simulation to investigate the impact of jitter caused by the capture effect on video traffic. The results indicate that capture effect rarely occurs in an actual residential, or small business Ethernet LAN, and is likely to occur only when PC performance has improved in the future. The frequencies and duration of the captures are also characterized. The resultant video packet jitter can be removed by a simple playout buffer. The findings suggest that Ethernet can meet the performance requirement of residential network at a very low cost.