The Wray Castle Microwave Link Planning course is structured as a comprehensive step-by-step guide through the practical aspects of the link planning process. A series of exercises, during which students will design and plan a microwave link network, reinforce the learning gained in the theory sessions. The key topics of availability and reliability, path profiling and clearance criteria, power budgets, rainfall and multipath fading, diversity techniques and frequency planning are all covered.
The course majors on the ITU-R models for calculating rainfall fade depth, the impact of the melting layer, non-selective and selective fading (signature method), enhancement or “up-fades” and space and frequency diversity improvement. Mention is also made of other models such as the Crane rainfall model, the Vigants – Barnett multipath model and the dispersive fade margin (DFM) concept. Methods for the conversion of DFM into signature method parameters are provided.
Developments in Microwave radio technology are also examined. Every effort is being made by equipment vendors to increase the capacity and throughput of fixed link transceivers. Multilevel modulation schemes are explained, along with cross polar interference cancellation (XPIC) and MIMO techniques, adaptive modulation, header compression, channel bonding and high capacity E band radios.
It is important for the link planner to understand antenna characteristics and performance. To this end the course explains how to interpret antenna radiation pattern envelopes (RPEs), the concept of antenna gain, cross polar discrimination (CPD), front to back ratio and beamwidth.
This course provides students with the confidence, knowledge, practical skills and tools to plan all types of fixed radio links including backhaul links, access links and core network transmission links.