What is BTS or Base Transceiver Station? Though most of us would not even be aware of the term BTS, over 80% of India’s population is using this technology to stay connected via their wireless network devices. Yes, this includes cell phone communication and Wi-Fi by large and the technology has proven to be revolutionary since the invention of landline phones.

In this article, let us discuss definition of BTS, function of BTS in mobile communication and of course its application. However, before we move on to that, let us understand how mobile phones work.

How mobile phones work

All mobile phones use a radiation known as radio frequency radiation for two way communication. The mobile phones are equipped with radio receiver and transmitter which receive and transmit radiation to communicate with the nearest located bts tower. This bts architecture then allows such radiation or signal to be passed through landline phone system and establish smooth communication.

Base Transceiver Station- An Overview

A cellular tower several meters high is not an uncommon sight as we drive along a highway or watch out from the train. These BTS towers look heavily laden with wires and have some triangular structures all through with electronic system at its base. The BTS station acts like a communication interface between the modern cell phones and the traditional landline phones. The wireless communication system functions through radio waves that belong to the microwave region of the electromagnetic spectrum. Any cell phone radio waves first hit the BTS which them transmits it through the landline phone network.

BTS Architecture

The BTS stations often feature multiple arrays of antennas mounted several feet above ground. As we know that signals or radio waves travels in straight line and needs a clear line of sight, the height of base station is maintained as per specified BTS architecture. This ensures that no obstacles such as trees, hills or buildings come in between the radio signal and the antenna.

The cost of BTS tower is quite high and thus it becomes impossible for individual service providers to set up their base stations. Thus, a tower is divided into several racks and each rack is rented out by one of the many cellular service providers for effective BTS transmission. The rack is often triangular shaped since each cell of the rack is usually divided into three different sectors.

Two kinds of antennas are used for different purposes. Omnidirectional antennas are used in areas which have low wireless communication traffic or for indoor cells while sector antennas are capable of receiving and transmitting massive cellular signals and cater to wider audience. Similarly the antennas also vary in size depending upon the cellular frequency that they operate on.

The BTS tower features a concrete set up at its base which is meant to house the tower’s electronics. The antennas are connected to this electronic hub via cables and electronic circuits.

Different kinds of BTS sites

Depending upon the location where a base station is required to be set up, BTS installation may vary.  The sites are broadly divided into four categories which are mentioned below:-

• Greenfield Sites
  

  In absence of tall buildings where BTS tower can be installed or in case of availability of ample space to set up the tower, the base stations are installed on ground. Greenfield sites refer to such ground sites which are available in green spaces, deserts, roads or any open area. The height and capacity of the BTS tower in such sites are usually high which leads to higher cost of installation. The site being located on ground is easily accessible and thus requires fencing and better maintenance which results in higher maintenance cost.

• Roof Top Sites
  

  As the name suggests, these sites are located on the roof of buildings and are often found in highly populated areas. Securing a place on a building’s roof is relatively easier and more economical for BTS installation which makes it most preferred by builders.

• In-Building Sites
  

  Few private buildings which are densely populated may serve as site for BTS tower installation. This usually happens when the residents of the building requests for such installation for better wireless communication. However, in such installation, some components may be entirely different from a roof top site installation.

• Micro Sites
  

  Few city areas with higher population such as Main Square, markets, tunnels, etc. require easier BTS installation. This involves smaller components and antennas. Such installations are usually wall mounted.

How BTS Transmission works?

Every face of the triangular structured rack in the tower houses three antennas of which one is meant for transmitting signals and two for receiving. Diversity reception technology is adopted by virtue of which the base station compares the signal received by two antennas and selects the best one for transmission. The technology is also meant to manage the extreme differences in power between the cell phone transmitter and base station transmitter. The former which is negligible in size when compared to the later. The transmitter antenna in the base station is placed between the two receiving antennas, though separated be several meters.

The following amplifiers play an important role in receiving clear signals and transmitting strong ones:-

• Power Amplifier – Located in the electronic hub, this amplifier is responsible for generating strong signals and transmit them through the landline network. This amplifier is connected to the transmitting antennas on the BTS tower via coaxial cables
• Low Noise Amplifier – They are connected to receiving antennas and detect weak signals and remove background noises which leads to better and clear signals.

Both power amplifier and low noise amplifiers are connected to transceiver rack which converts the radio waves to digital signals and then passes it on to electronic switching device which act as an interface in routing the calls between BTS and main telephone system.

Other components such as base station controller and AC/DC power rectifier system also play important roles in ensuring that the system functions seamlessly.