For both
Manish and SSK
microwave com. equipm. are consist of IDU(indoor unit)+ODU(outdoor unit.ODU is consist of redio and antenna(dish).generally we call odu in place of redio.antenna or dish can be classified in two ways
1.size
2.frequency
size is nothing but the dia of dish
and it dpends upon the distance of the link longer the distance bigger the size.
dishes come according to frequency range available in india are
7,15,18 in telecom basically.for in city links generally we use 15 or 18 ghz but for backbone(main link or longer) we use 7Ghz.this also depends upon a Tx parameter annual availabilty(means your link will be stable x% for through out the year depending upon the local atmosphereic conditions.for exp. u can plan for any 18 Km link with 15 Ghz with 1.2 Mtr dish with good recieve level but the annual availability will be less so u will have to go with 7Ghz.
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