4G refers to a generation of mobile network technology that succeeded 3G. It was developed to provide mobile broadband with substantially greater capacity and lower latency than earlier cellular systems, enabling services such as high-quality video streaming, faster web browsing, and more responsive cloud applications over wireless connections to the internet.

Technical background

Standards for 4G were defined to meet targets set by international bodies for next-generation radio and core network performance. True 4G implementations (for example, LTE-Advanced and WiMAX 2) meet the formal requirements for the IMT-Advanced specification. Commercial deployments often used technologies branded as 4G—most notably initial releases of LTE—which delivered large practical speed improvements even if they did not fully satisfy the original technical criteria.

Timeline and rollout

Work on 4G technologies began in the 2000s. Early LTE networks were introduced in the late 2000s and proliferated through the 2010s, becoming the dominant form of mobile broadband in many regions. Subsequent evolutions, including LTE-Advanced and carrier aggregation techniques, increased peak and average throughput over time. A further generation, known as 5G, started commercial deployments around 2019 and expanded significantly in 2020 and afterward.

Typical performance and uses

  • Peak and average data rates vary by implementation and spectrum; real-world speeds are commonly measured in tens to hundreds of megabits per second for LTE-class networks.
  • Improved latency and capacity made mobile video, online gaming, and real-time cloud services more practical on handheld devices.
  • 4G networks also supported technologies such as Voice over LTE (VoLTE) to carry voice traffic as IP packets rather than traditional circuit-switched calls.

Legacy and transition

Many operators continue to maintain 4G infrastructure alongside newer 5G equipment because 4G remains a workhorse for wide-area mobile coverage and device compatibility. As 5G networks expand, 4G often serves as a fallback and provides broad coverage where 5G is not available.