5G (Fifth Generation Mobile Network) is the mobile communication standard succeeding 4G LTE. Based on specifications developed by 3GPP (international standards body), it targets three key capabilities: up to 20 Gbps ultra-high-speed communication (eMBB), sub-1 ms ultra-low latency (URLLC), and 1 million simultaneous connections per square kilometer (mMTC). While 4G's theoretical maximum speed is approximately 1 Gbps, 5G aims for 20 times that.
Service launched in Japan in March 2020, with four carriers - NTT Docomo, KDDI (au), SoftBank, and Rakuten Mobile - deploying networks. Two frequency bands are used: Sub-6 (below 6 GHz, primarily 3.7 GHz and 4.5 GHz bands) and millimeter wave (28 GHz band). Sub-6 has longer range suited for wide-area coverage but speeds only a few times faster than 4G. Millimeter wave enables ultra-high-speed communication but has strong directionality and poor building penetration, so deployment centers on limited areas like stadiums and train stations.
5G's ultra-low latency also improves voice call quality. While 4G uses VoLTE (Voice over LTE) for voice calls, 5G introduces VoNR (Voice over New Radio), enabling native high-quality calls on the 5G network. VoLTE required routing through 4G signaling, but VoNR completes calls entirely on 5G, promising faster connection times and improved audio quality. Each carrier is progressively rolling out VoNR support.
For general consumers, 5G benefits are currently limited. Video streaming and app downloads are faster, but everyday web browsing and social media show little perceptible difference from 4G. 5G's true value emerges in industrial applications requiring ultra-low latency and massive connectivity, such as autonomous driving, telemedicine, and smart factories. As base station deployment expands, coverage is growing, but rural areas still have limited 5G coverage, so checking coverage maps before purchasing a device is important.