Telecom networks are the towers, cables and software that carry every call, message and video between your phone or your home and the internet. The company that owns such a network is called a telecom operator. India has four main mobile operators: Jio, Airtel, Vi and BSNL. The two largest are Jio and Airtel. Together, the operators sell mobile and broadband plans to hundreds of millions of people. Almost every product in this scene is built for operators or sold to them.
Consider a student in Guwahati who sends a photo on WhatsApp to her brother in Delhi. The photo leaves her phone as a radio signal. A tower nearby receives it. The towers, the equipment on them and the software that runs that equipment together form the radio access network (RAN). The radio unit on the tower turns the radio signal back into digital data. By early 2026, Indian operators had installed more than 5 lakh 5G base stations, the radio equipment on towers that serves phones. 5G is the current generation of mobile network.
Next, the tower sends the photo onward, over a fibre cable or a radio link. The link from a tower to the rest of the network is called backhaul. The zone backhaul and optical transport covers these links. They range from a microwave dish on a hilltop tower to the long-distance fibre systems between cities. Every link has a capacity and a delay, which bandwidth and latency explains.
The photo then reaches the operator's packet core. This is software that runs on servers in the operator's data centres. It checks that her SIM is genuine, keeps track of which tower her phone is using, and hands the photo to the internet.
While all this happens, the operator's business software records every megabyte she uses. If she is on a prepaid plan, her data balance drops at once. This software is called OSS and BSS, short for operations support systems and business support systems. It has its own zone, telecom OSS and BSS. It also activates new SIMs, prepares postpaid bills and works out what is owed to a foreign operator when a customer uses a phone abroad.
Homes and offices usually connect by cable instead. In most Indian cities, fibre runs from the operator's local exchange to each building through a passive optical network (PON). Where no fibre reaches, a house can get broadband by radio through fixed wireless access (FWA), or over the local cable TV wire. The zone fixed broadband access covers these routes.
The biggest change today is that the network is turning into software. The tower equipment and the core used to be sealed boxes, each bought from one company. Now they increasingly run as programs on ordinary servers. This change is called hardware-software disaggregation, and at the tower it is called Open RAN. It is also what lets a company run private 5G inside its own factory. Some brands sell mobile plans without owning any network at all. They rent capacity from an operator, and are called MVNOs.