Combined terminal and network measurement for bottleneck localization

When a user experiences a poor quality of service (QoS) in a converged network environment, the operators or ISPs need to locate the bottleneck, i.e. to localize which part of the end-to-end (E2E) network path causes the degradation. We present a novel multipoint measurement system that gathers performance information not only from links in the network path, but also from the end devices. In wireless domain, this enables to separate the radio access network and fixed network segments. The measurement method is also applicable to pure fixed line networks. The system is able to perform one-way measurements and even break the E2E delay into one-way link-to-link components, which gives clear benefit over traditional round-trip time (RTT) measurements. The system was verified with laboratory 3G/HSPA (High Speed Packet Access) measurements that revealed a performance bottleneck in the studied 3G network. We also show measurement results in a live Wi-Fi city area network.