A practical perspective on design of a Long-haul microwave link in hilly -non LOS terrain

Currently Microwave media has become integral part of Mobile backhaul infrastructure in India. In spite of large Optical Fiber foot print across the country, operators are finding it difficult to lay the cable in certain routes due to techno commercial issues like, Right of way (ROW), hilly, inaccessible terrain. Even though Microwave(MW) media is the right choice for such situations many a times Long-haul Microwave links cannot be established due to tall obstructions falling on the Line of sight (LOS) path. LOS cannot be achieved even with tall towers of 100M height (ht). MW links with tall towers beyond 100M are not economical due to high tower cost. Alternative is to plan multiple hops with additional repeaters. Cost of such MW link with multiple hops may be quite high and comparable to that of Optical Fiber link. With judicious Terrain review it is possible to identify a Wedge path, in the hilly terrain for MW transmission with low and medium tower heights. This article discusses a test case to evaluate an optimum approach along with techno commercial analysis to design a Inter City Long-haul MW link between two cities of Karnataka, India and various issues related with MW links planning and spectrum regulations in India