Hey Experts,

I want to establish a Wireless ISP business in my town.
What are the equipments I need to cover a 2/3km range.
I've heard about some problem may cause if I do wireless. Someone told me if you set up a Access point with M2 it will send signal to 2/3km range but the client with a laptop or a smart phone will not able to send back signals to the access point. What is the solution here?

I have to say, in my city we have an Airforce Base. So, we have less obstacles as most of the buildings have less then 8-10 levels.

Thanks in advance...

Whoever told you about the devices not being able to transmit the 2/3km back to the tower was right.
You're going to need to install a mesh of smaller dual-band units, using one wlan interface as the "backhaul" to the central location(s) on one band, and the second wlan interface as the local AP with an omnidirectional (usually) antenna.

An Omnitik that operates in 5Gz would be a good primary "tower" unit, and I would build the local APs using components - highly directional antenna for backhaul, two A/B/G/N wlan cards (allows you to use either 2.4 or 5.8 for local APs if needed) and an RB that has at least 3 expansion slots (so you can make dual-band AP service if needed in certain locations or everywhere if you decide to upgrade), and finally the omni antenna(s) for local AP. (I recommend one that has two chains so you can get better noise immunity / higher N speeds possible)

Your biggest challenge is going to be spectrum planning / interference mitigation. These days, everything has a radio in it, and interference is everywhere. You'll need to be flexible because you can do a scan one day and have a great clear channel and come back later to find some guy blasting away with tons of power on a weird half-channel that overlaps everything.

Depends on amount of clients per Ap. Generally it is smart to use sector antennas for Ap and panel or dish antennas for clients. Dishes are good also for ptp links. For mobiles use 2.4 Ap with small low gain omni or panel antennas and do not expect more than 100m radius per one cell. Also you need to plan spectrum usage.