Cellular Networks, Base Stations, and 5G RAN

- Cellular Networks

Cellular networks are high-speed, high-capacity voice and data communication networks with enhanced multimedia and seamless roaming capabilities for supporting cellular devices. 

With the increase in popularity of cellular devices, these networks are used for more than just entertainment and phone calls. They have become the primary means of communication for finance-sensitive business transactions, lifesaving emergencies, and life-/mission-critical services such as E-911. Today these networks have become the lifeline of communications.

Mobile communication is the fastest growing field in the telecommunications industry. The cellular radio network is the most successful mobile communication system. It can be used to transmit both voice and data. 

Data transmission over a cellular network is a new service, which makes data networks accessible from mobile terminals via cellular telephones. Cellular networks are in the process of becoming high speed data networks. 

The fact that the cellular user base is mobile, and that the user base is extremely large, makes the development of mobile data applications very lucrative. The development of these applications, have to take into consideration the nature of the cellular network, and will depend on the effective development of new communication protocols.

[Wireless Fronthaul - The Fiber Optic Association (FOA)]

- Cellular Network Operation

A cellular network is composed of a web of base stations, each covering a delimited area (cell) and routing communications in the form of radio waves to and from users’ terminals.

Mobile communications follow the general principle of telephony: connecting two remote users through the network equipment of an operator responsible for managing the service. 

But unlike fixed phones, in the mobile network, it is not copper wires or fibre optics but radio transmissions that provide the final link. A user’s mobile telephone communicates through the air with an base station antenna, which in turn links to the central exchange of the operator – a computer. This routes the communication to the corresponding party on the fixed network or via other base stations. 

To communicate, a mobile user must be within range of base stations. This has a limited range, and covers only a small area around it called the “cell” (hence the alternative name of “cellular networks” often used for mobile networks). 

To cover maximum territory, and ensure that users are always able to call, operators deploy thousands of cells, each equipped with antennas, ensuring that their cells overlap and thus never lose the current location of the users.

- Mobile Telephone Switching Office (MTSO)

Mobile fronthaul involves the movement of data and voice from a cell site Remote Radio Head (RRH) to a centralized Baseband Unit (BBU), which then connects to the Mobile Telephone Switching Office (MTSO).

A Mobile Telephone Switching Office (MTSO) represents the heart of a cellular network. The MTSO interfaces with all the base stations in the network through landline cable connections. Additionally, it connects the network to Public Switched Telephone Networks (PSTN) such as Verizon. 

Therefore, all telephone traffic between the cellular network and the PSTN or other networks passes through the MTSO. A cellular network is constructed in stages by adding more cells to increase coverage and capacity. The construction of each cell requires base station installation and connection of the base station to the MTSO through a landline cable connection.  

MTSO is a system that automatically keeps track of a cell phone user’s relative signal by monitoring readings from cell phone towers near the user. MTSO systems also automatically switch a cell phone’s service from one cell phone tower to another depending on which tower will provide the user with the best possible reception. 

Additionally, the MTSO is responsible for connecting all individual cell phone users in an area to a “central office”, which then connects those users to long-distance areas.