The Truth About Cell Towers

Traditional Cell TowerHave you ever wondered why we need cell towers? For starters, cell phones have a low-wattage transmitter requiring a signal repeater within range of the device. The repeaters keep moving the signal from tower to tower until it reaches the cell phone. To complete the call, it’s necessary to have a cell tower (or cell antenna) placed in intervals along our highways, cities, and towns.


How many cell towers are required in one area?

The number of towers required is proportional to the human population in the area. This is referred to as “cell tower proliferation”, the mathematical principle used to determine the number of cell towers required in a given area. Cell tower proliferation has become a popular subject for urban ecologists. Cell towers are essentially radio relay stations installed due to the short range of cell phone transmitters and receivers.


What is a Cell Site?

Cell Site in ArizonaA “cell site” is where antennas and electronic communication equipment are placed. Cell sites are usually on a radio mast, tower, or building creating a cellular network. The elevated structure supports antennas, transceivers, digital signal processors, and GPS receivers for primary and backup electrical power sources.

A cell site is often incorrectly called a “cell tower”, even if the antennas are mounted on a building rather than a tower. The majority of cell sites worldwide are located on structures other than towers. In GSM networks, the correct term is Base Transceiver Station and colloquial British English synonyms are “mobile phone mast” or “base station”. The term “base station site” might better reflect the increasing co-location of multiple mobile operators. Therefore, multiple base stations at a single site. Depending on an operator’s technology, even a site hosting just a single mobile operator may house multiple base stations, each serving a different air interface technology.


What is the range of cell towers?

In practice, cell sites are grouped in high-population areas that would have the most potential users. Cell phone traffic through a single site is limited by the base station’s capacity as there is a limited number of calls or data traffic that a base station can handle at once. This limitation is another factor affecting the spacing of cell mast sites. In suburban areas, masts are commonly spaced 1–2 miles apart and in dense urban areas, masts may be as close as ¼-½ mile apart.

Cell Mast PostThe maximum range of a mast depends on the same circumstances. Some technologies, such as GSM, normally have a fixed maximum range of 22 miles, which is imposed by technical limitations. CDMA and IDEN have no built-in limit, but the limiting factor is the ability of a low-powered personal cell phone to transmit back to the mast.

As a basic guide, based on how tall the mast is and how flat the terrain is, it is possible to send a signal up to 30 – 45 miles. When the terrain is hilly, the maximum distance can vary from as little as 3 – 5 miles due to encroachment of intermediate objects into the wide center fresnel zone of the signal. Depending on terrain and other circumstances, a GSM Tower can replace between 2 and 50 miles of cabling for fixed wireless networks.


What are GSM, CDMA, iDEN, and PCS?

Concealed Telecommunication TowerGSM, or “Global System for Mobile” is a network used by carriers such as T-Mobile and AT&T. They sell mobile phones locked with their access specifications. These devices are referred to as “Locked Phones”. GSM is widely used by cell phone users in Europe and other countries.

CDMA stands for “Code Division Multiple Access”. It uses several protocols in second-generation (2G) and third-generation (3G) wireless communications. CDMA is a form of multiplexing that allows numerous signals to occupy a single transmission channel and optimize available frequency usage. This technology uses both the PCS and Cellular signals.

iDEN, or “Integrated Digital Enhanced Networks” transmit frequencies in the 806 to 866 MHz range. This range is used by carriers like Nextel/Sprint, Southern LINC, and Boost. It’s a stand-alone mode transmitter.

PCS stands for “Personal Communication Service”. Referred to as “digital mode”, it represents the signals that transmit between 1850 and 1992 MHz (megahertz). These frequencies are used by phone standards such as CDMA, TDMA, and GSM. Most carriers including AT&T, T-Mobile, and Verizon use PCS networks in combination with cellular.


What do cell towers look like?

Cell phone tower disguised as a cactusA cell tower can look like a traditional tower or be inconspicuous and blend in with the surrounding area. These hidden towers are known as “concealed cell sites” or “stealth cell sites”. These cell towers often resemble palm trees, pine trees, cacti, and large crosses at a church. Cell towers also act as radio relay stations, due to the short range of cell transmitters/receivers.

Our construction crew is experienced in all facets of telecommunication. From tower construction to radio installation, RP Companies has the equipment and manpower to meet your cell tower needs.