A framework for cross-layer measurement of 3G and Wi-Fi combined networks

3G networks and Wi-Fi networks could complement each other as each has different advantages of coverage and access capacity. A combined 3G and Wi-Fi network is one part of a heterogeneous IP network which has ubiquitous access capacity. However, the characteristics of the lower layers in the wireless network portion of such a heterogeneous IP network could significantly affect the performance of higher layers, and further, the overall performance of the whole network. A single-layer approach to performance analysis could not provide enough information to present the correlation between lower and higher layers. A cross-layer measurement approach for combined 3G and Wi-Fi network is presented which aims to correlate the characteristics of the physical layer (e.g. channel power and signal-to-interference ratio) to key parameters of higher layer (e.g. packet-loss ratio, and round trip time).