日本的網路涵蓋

日本 的數字代表什麼

有兩個數字重要，但每家業者只引用其中一個。一般速度為 74 Mbps，它告訴你順的時候是什麼樣子。

值得看的是第十百分位，21 Mbps。那是一天當中最差的那一成：車站上方的基地台塞滿了，你周圍的人全都掛在同一個訊號上。中位數高、底線低的國家，就是那種一路順到你真正需要它的那一刻的國家。

如果這趟行程少不了視訊通話或熱點分享，請以忙碌時的數字來規劃，而不是一般速度。

在日本網路壅塞時會發生什麼

壅塞不是故障，是星期二晚上。問題在於你的 eSIM 能拿它怎麼辦，而多數旅遊 eSIM 的答案是：沒辦法。一個國家一份批發合約、一張網，站在路邊除了再跟別家買第二張 eSIM 之外沒有出路。

在這裡 Orbislo 的流量走 KDDI 和 SoftBank。你所在的網變差時，我們會在旅程中途、不必你開口就把你換到另一張網，事後才告訴你，而不是當下打斷你。

日本的行動電信業者

• NTT Docomo: NTT Docomo held 32.9 percent of Japan's mobile contracts at the end of March 2026 on the ministry's count, rising to 39.5 percent once lines it supplies wholesale to virtual operators are included, making it the largest of the four licensed networks.
• KDDI: The KDDI group held 26.2 percent of mobile contracts at the end of March 2026, or 31.4 percent including the lines it supplies to virtual operators.
• SoftBank: SoftBank held 18.7 percent of Japan's mobile contracts at the end of March 2026, or 24.6 percent including the lines it supplies to virtual operators, according to the communications ministry's quarterly figures.
• Rakuten Mobile: Rakuten Mobile held 3.6 percent of mobile contracts as a network operator at the end of March 2026. Virtual operators running on the other networks together held 18.5 percent.
• Rakuten Mobile, 700 MHz: In October 2023 the ministry approved Rakuten Mobile's plan to build base stations in the 770 to 773 MHz block. Rakuten was the only applicant for that 700 MHz band spectrum, which was assigned with conditions attached.

日本的舊世代網路

• KDDI and Okinawa Cellular switched off au's 3G service, CDMA 1X WIN, on 31 March 2022, after running it since November 2003. From 1 April 2022 au handsets that could not make VoLTE calls stopped working.
• SoftBank ended its 3G service on 15 April 2024, having postponed the January date after the Noto Peninsula earthquake. Customers living in Ishikawa Prefecture kept 3G inside that prefecture until 31 July 2024.
• NTT Docomo closed its FOMA 3G network and the i-mode service on 31 March 2026. Since then a phone that cannot make VoLTE calls, or has VoLTE switched off in its settings, cannot make voice calls on Docomo at all.

日本的 5G

• In April 2019 Japan assigned its first 5G spectrum to four operators: NTT Docomo and KDDI with Okinawa Cellular received two 100 MHz blocks each between 3.6 and 4.6 GHz, SoftBank and Rakuten Mobile one each, and every operator also received a 400 MHz block between 27.0 and 29.5 GHz.
• In December 2024 the ministry approved SoftBank's plan for the 4.9 to 5.0 GHz band, the only application it received, adding a further 100 MHz of 5G spectrum to SoftBank's network.
• At the end of March 2025, 5G reached 98.4 percent of Japan's population when the four operators' coverage is combined, and between 88.4 and 99.9 percent in each prefecture. The government's target is 99 percent nationally and in every prefecture by March 2031.
• By the end of March 2026 Japan counted 126.32 million 5G contracts, up 12.7 percent in a year, against 108.85 million 4G contracts, so 5G lines now outnumber 4G ones.

日本網路須知

• Since 1 April 2026 the four network operators run JAPAN Roaming: when a disaster or major outage knocks out one network, its customers can switch to another at up to 300 kbps, or in some cases make emergency calls only. The phone shows a network name such as JPN-ROAM D, K, S or R.
• JAPAN Roaming is switched on only for large scale disasters or major network failures, not for everyday or small outages. Smartphones from roughly the spring 2026 models onward are expected to support it, and some older models gain support through software updates.
• The January 2024 Noto Peninsula earthquake took up to 839 mobile base stations off air across the four networks, 799 of them in Ishikawa Prefecture, as power cuts and severed transmission lines spread. KDDI, SoftBank and Rakuten Mobile finished emergency restoration on 15 January and Docomo on 17 January, except where landslides blocked access.