Full formTechnology
STZstands forStrict Trunk Zone
Full Form of STZ
What is STZ?
Strict Trunk Zone, commonly abbreviated as STZ, is a specialised telecommunications zone defined by the Department of Telecommunications in India to regulate long-distance calling rates and trunk route charges between specific cities. Under this framework, certain pairs of cities are grouped into STZs, meaning that calls between them are treated as local or short-distance calls rather than long-distance STD calls, even if the geographical distance is significant. This concept was introduced to simplify billing and promote affordable communication in commercially important city pairs. The Telecom Regulatory Authority of India and operators like BSNL, MTNL, and private players have historically used STZ classifications while revising tariff plans. STZ is frequently tested in Indian competitive exams covering general awareness, particularly in the banking, SSC, and telecom-related sections, where students are asked about telecom jargon and regulatory concepts.
STZ का फुल फॉर्म
सख्त ट्रंक ज़ोन
Example
While applying for a new postpaid connection, the executive explained that calls between Mumbai and Pune fall under the Strict Trunk Zone and will be charged at local rates.
STZ — frequently asked questions
What is the full form of STZ?
STZ stands for Strict Trunk Zone, a telecommunications classification in India that groups specific city pairs for local-rate calling.
Why is Strict Trunk Zone important in Indian telecom?
It allows telecom operators to charge local call rates between paired cities, reducing costs for subscribers on commercially important routes.
Which cities fall under STZ in India?
Cities like Mumbai-Pune, Delhi-Jaipur, and Chennai-Bangalore have historically been part of Strict Trunk Zones as defined by DoT guidelines.
Is STZ still relevant with mobile network reforms?
Yes, the concept is referenced in telecom tariff structures and continues to appear in competitive exam syllabi on general awareness.