Please provide well described answers for these questions.

Q1 The air interface between the mobile handsets and the equipment at antennas and towers are only wireless part of mobile networks. What other equipment is required to get cell signals into the backhaul network?

Q2. Using Orthogonal Frequency-Division Multiplexing in LTE networks removes the need for guard bands. What impact does this have on the available spectrum?

Q3.In a Mesh Network, all nodes connect to one another in a flat or non-hierarchical manner. Core or backbone networks are often designed in this manner. Why is that?