Cellular Networks: Fuelling Wireless Communication
If there is one type of wireless network that a majority of the population is intimately familiar with cellular network or mobile network would be it. It’s intimately familiar because mobile phones and devices have become the most ubiquitous of consumer electronics, with some people owning 2 or more of them, and who are constantly connected to the network. Most users, however, are unaware of the inner workings of a mobile network and why it is possible to stay connected despite the distance between cell towers.
What is a cellular network?
This refers to a radio network that is distributed over a large geographical area through cells that have a fixed location transceiver, which is also known as the base station or cell site. One mobile network follows a cellular design, similar to a mesh of hexagonal cells, with each one containing a single base station. The cells slightly overlap at the edges to ensure that no part of the network loses a signal. This explains why a call is never dropped, even when a user is driving between base stations.
A mobile network technology follows a hierarchical structure that is made up of different parts.
Base transceiver station (BTS) allows mobile phones or other user equipment to directly communicate with cellular devices, routing calls to designated base centre controller, for example.
Mobile switching centre (MSC) provides an interface or connection with the landline-based public switched telephone network.
Public switched telephone network (PSTN) enables subscribers to connect to a wider telephony network.
The rest of the structure is composed of the core circuit switched network that handles text and voice calls, and a packet switched network that takes care of mobile data.
For communication or connection to happen, mobile networks must have information necessary to track the location of their subscriber’s’ user equipment. Mobile devices, on the other hand, must have details of appropriate channels for signal transmission.
This can be a strong dedicated control channel that enables transmission of digital information from a base station to a mobile phone and vice versa, or a strong paging channel that tracks a mobile phone through MSC when calls are routed to it.
Advantages of Cellular Networks
Being able to communicate on the move is just one of the many advantages that a cellular network has to offer. Considering its wider coverage and geographical reach, it also paved the way for other benefits.
Compared to a single large transmitter, a mobile network has more capacity since it can use the same frequency over multiple links provided that they are in different cells
Because of the proximity of cell towers, mobile devices only require less amount of power than a satellite or single transmitter would meet
Cell towers can be added whenever and wherever they are necessary, allowing for a coverage area to be expanded indefinitely
Disadvantages of Cellular Network
Despite the convenience it offers, a mobile network also has limitations, especially in data transmission.
When the base station does not have enough space to accommodate new arriving packets, congestion will happen resulting in unacceptable packet delay or even loss of new packets.
Signal power can fade or reduce due to multipath fading or shielding. The former is where signals are transmitted and received along different paths, resulting in signals cancelling each other completely. Shielding, on the other hand, is where field strength fails, especially within tunnels, around hills or inside certain areas of a building.
Because the same frequency can be used by multiple sales, co-channel interference is likely to happen.