Monopoles are generally considered more aesthetically pleasing. However, lattice structures can go much higher allowing more carriers and providing a greater coverage area. Community standards may dictate the type of structure allowed.
Yes, FCC requires local governments to allow towers for ??? (list Act)
To some extent towers can be planned. A community can restrict the height of towers and the location of the towers. Through careful planning a community can adopt an overall plan to help determine where the tower locations should be located to accomodate both the needs of the providers and the needs of the community.
Your local planning department may have an inventory of all towers as well as existing stuctures that could be used for antenna location.
Service providers such as CenturyTel, Verizon and Nextel operate in the 800-900 MHz range. These companies' analog systems were able to cover a large area per tower, but lacked features and efficiency. which drove them to start deploying digital systems with many features and a great deal more capacity. Radop spectrum allocated to celluar service providers is limied and should be used efficiently as possible.
The new digital systems have one drawback. They require a much greater signal strength in order to operate. With analog systems, when the signal got weaker, the more static you heard until the point you could n longer understand each other. With digital, one the signal falls below a certain level, the call is dropped.
Systems deployed by Sprint/IPCS, AT&T, Voicestream, NPI and Cricket operate at frequencies close to 2000 MHz, which require Near-Line-Of-Site (NLOS), meaning the signal is affected by buildings and trees, and can be severely hampered by terrain variations. These carriers are all digital and are classified as "PCS" (Personal Communication Services) and all have general the same coverage characteristics.