Bandwidth Estimation of in-Home Power Line Networks
Bandwidth information is critical to robust real-time multimedia transmission. However, existing bandwidth estimation (BWE) methods developed for the Internet or wireless networks are inadequate for power line networks due to the difference in media access control scheduling policies and channel noise characteristics. In this paper, we investigate the characteristics of in-home power line networks and present a real-time BWE scheme. By varying the packet size at a given physical-layer line rate, we find that the transmission rate has a cutoff point at which the data traffic starts to suffer from packet loss and that the cutoff rate is approximately proportional to the packet size. Moreover, as the transmission rate becomes greater than the cutoff point, the packet loss rate increases. Based on the evaluation of in-home power line networks, we propose a BWE scheme that estimates the cutoff rate from physical-layer line rate, data transmission rate, packet size, and packet loss rate. This scheme applies an iterative packet probing algorithm to estimate the available bandwidth. Experimental results show that the proposed scheme achieves good estimation accuracy.