5 Types of Cell Phone Towers: Components & Functions

The wireless network that provides voice and data services to cell phone users is known as a cell phone network or cellular network.

In this tutorial, we will explore monopole, lattice, guyed, stealth, and rooftop towers, all essential for seamless connectivity. A geographic area is divided into individual hexagonal cells, each equipped with a cellular tower and base station (BTS in GSM, eNodeB in CDMA, and eNB in LTE).

Cellular networks support hundreds of mobile cell phones operating on different frequencies, slots, and codes to enable simultaneous operations. They also maintain connections while moving from cell to cell.

Figure 1: Simple GSM cellular network

In a cellular network, the location where antennas and electronic communication equipment are situated is known as a cell site. It is usually constructed at a higher elevation and houses antennas, transceivers, DSPs, control circuitry, GPS receivers, power sources, and shelter structures.

Function: The primary role of a cell tower is to mount antennas for transmitting and receiving RF signals to/from mobile cell phones or devices. To cover larger areas, cell towers are elevated to heights of approximately 50 to 200 feet. The cell tower communicates with nearby towers through RF frequencies.

Cell tower types depend on the density of mobile phone users and the specific applications they serve. Different cell types include macrocells (10 miles), microcells (1 mile diameter), picocells (250 yards), and femtocells (limited to building).

Cell phone users access cell towers and their resources through various techniques, with FDMA, TDMA, and CDMA being the most popular.

At high power levels, RF radiation from cell phone towers can affect human beings due to its heating effect. Therefore, radiation levels are kept within limits specified by regulatory bodies. This also applies to cell phone radiation.

Cell Phone Tower Components or Parts

Figure 2: Basic cell phone tower components

Let’s examine the parts and functions of a cell tower:

• Cell phone tower structure: Different types of tower structures are described below. Proper support is needed to elevate these structures above ground level.

• RF and baseband equipment: The equipment is mainly of two types: indoor and outdoor (or roof-mounted). Indoor equipment is usually placed in a room and connected to outdoor equipment or antennas via coaxial cables. RF equipment converts baseband information into a format compatible with RF antennas. Baseband equipment provides interfacing with voice/data equipment. Often, baseband and RF equipment are combined and known as a modem.

• RF Antennas: Each telecom carrier uses multiple antennas on the cell tower. Typically, each site houses 3 to 18 antennas. The number of antennas increases based on the subscriber capacity.

• Other utilities: Major utilities include power supply, UPS (Uninterrupted Power Supply), and AC to DC rectifiers used to power electronic circuits and equipment. UPS serves as a battery backup system in case of main power failure.

A cell site has various interfaces: with PSTN for wired telephony, with PSDN for internet connectivity, and with other cellular towers. The cell tower site is connected with other sites using fiber optic cables, terrestrial microwave links, satellite links, etc.

Types of Mobile Towers

Mobile cellular communication relies on various types of towers to transmit signals and provide coverage. Here are five different types of towers used for mobile cellular communication. These towers, with their varying sizes and capabilities, work together to create a network that provides seamless mobile cellular communication across different environments and scenarios.

1. Macrocell Towers: These are the most common type, typically tall structures used to cover large geographic areas. They provide wide-area coverage and are often used in urban, suburban, and rural settings.

2. Microcell Towers: These are smaller towers designed to cover a smaller geographic area, often in urban environments with high population density. They are used to enhance capacity and coverage in areas with high user concentrations.

3. Picocell Towers: Even smaller than microcells, picocells are used to cover very localized areas, such as shopping malls, airports, or indoor spaces. They are deployed to improve signal strength and data capacity in specific, high-traffic locations.

4. Femtocell Towers: These tiny cell towers are designed for residential or small business use. They are typically used to improve indoor coverage and can be connected to the user’s internet connection to facilitate cellular communication within a limited area.

5. Cell on Wheels (COWs): These mobile cell towers can be transported to temporary locations, such as during large events, natural disasters, or situations where additional network capacity is needed. COWs are mounted on trailers or trucks and can be deployed rapidly to address temporary communication needs.

Figure 3: Different types of cell phone towers

There are 5 different types of towers viz. Monopole, Lattice, Guyed, Stealth and Rooftop towers.

1. Monopole Towers: These towers are single, self-supporting poles often used in urban and suburban areas. They are aesthetically pleasing and have a relatively small footprint compared to other tower types. They require one foundation, and their height does not exceed about 200 feet. In this type, antennas are mounted on the exterior of the tower.

2. Lattice Towers: These towers consist of a framework of metal beams arranged in a lattice pattern. They are commonly used in both urban and rural settings and are known for their structural stability. These towers are usually seen along highways. They have three or four sides.

3. Guyed Towers: These towers have a central mast supported by guy wires (cables) attached to the ground. They are often used in rural areas and can be taller than other types of towers due to the additional support from the guy wires. These towers are cheap to construct and cover a larger area. They are about 300 feet and above in height. Radio and TV stations use this type of cell phone tower.

4. Stealth Towers: These towers are designed to blend into their surroundings to reduce visual impact. They may be disguised as trees, flagpoles, or other structures to minimize the visual impact on the landscape.

5. Rooftop Towers: These towers are installed on top of buildings and structures. They are commonly used in urban areas where space is limited, and the tower can be integrated into existing infrastructure.

Summary

Understanding the 5 different types of cell phone towers, including monopole, lattice, guyed, stealth, and small cell towers, is crucial for grasping the intricacies of mobile communication. Each type of tower, with its unique components and functions, plays a vital role in ensuring seamless connectivity and robust network coverage. By exploring these diverse structures and their operational mechanisms, we can appreciate the technology that keeps us connected in our increasingly digital world.