Experiences and measurements in operational PTP synchronized mobile networks

The presentation introduces structures of several packet based mobile backhaul networks in different parts of the globe. Backhaul technologies include fiber, microwave, and GPON. The base stations are frequency synchronized using the currently ubiquitous PTP unicast mode summarized in IEEE 1588 Annex A.9. The presentation then presents delay measurements carried out in some of these networks. The delays are processed using MAFE (maximum average frequency error) and FDPP (floor delay packet population) defined in the new version of ITU-T Recommendation G.8260. The results are compared with proprietary MAFE masks and the PDV (packet delay variation) limit defined in G.8261.1. A tuning history example is used to illustrate the fluctuations caused by PDV. In the end, migration towards PTP time profile is discussed.