au, or au by KDDI, is a Japanese

mobile phone operator A mobile phone operator, wireless provider, or carrier is a mobile telecommunications company that provides wireless Internet GSM services for mobile device users. The operator gives a SIM card to the customer who inserts it into the mobile devi ...

. au is a brand marketed by

KDDI () is a Japanese telecommunications operator formed on October 1, 2000 through the merger of DDI Corp. (Daini-Denden Inc.), KDD (Kokusai Denshin Denwa) Corp. (itself a former listed state-owned enterprise privatized in 1998), and IDO Corp. It ...

in the main islands of Japan and by Okinawa Cellular in

Okinawa is a Prefectures of Japan, prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 Square kilometre, km2 (880 sq mi). ...

for their mobile cellular services. au is the second-largest wireless carrier in Japan, with 60.398 million subscribers as of March 2021.

Naming

According to the brand creator, the name 'au' is based on the Japanese verbs for 'meet' (会う) and 'unite' (合う) (both pronounced 'au'). However, KDDI explains that au comes from two letters which stand for few words. 'A' is for access, always and amenity, and 'U' is for unique, universal and user. There is also a phrase, 'access to u(you)' that goes along the brand name.

History

The network that would eventually become Au was originally set up as two networks: DDI and IDO. IDO's network was based upon the NTT Hi-cap analog cellular system, and began operations in December 1988 in the Kanto and Tokai regions. DDI's network was run by independent phone companies, and began service in 1989 using the TACS system elsewhere in Japan. Nippon Idou Tsushin (IDO) was owned by

Toyota is a Japanese multinational automotive manufacturer headquartered in Toyota City, Aichi, Japan. It was founded by Kiichiro Toyoda and incorporated on . Toyota is one of the largest automobile manufacturers in the world, producing about 10 ...

, whereas DDI was owned by Kyocera Corporation. was established in November 2000 by Kyocera as part of the DDI Cellular network. In 2001, the company was merged into KDDI (which had been formed in 2000 by the merger of DDI, KDD, and IDO), but its brand name was retained and applied to all mobile phone service under KDDI group. Au established a nationwide 3G network in 2003, replacing its previous

cdmaOne Interim Standard 95 (IS-95) was the first ever CDMA-based digital cellular technology. It was developed by Qualcomm and later adopted as a standard by the Telecommunications Industry Association in TIA/EIA/IS-95 release published in 1995. Th ...

service with CDMA 1X WIN ( 1xEV-DO Rev A) service. Au started selling the

iPhone 4S The iPhone 4S (originally styled as iPhone 4 S, retroactively stylized with a lowercase 's' as iPhone 4s as of September 2013) is a smartphone that was designed and marketed by Apple Inc. It is the fifth generation of the iPhone, succ ...

from 14 October 2011. Au launched LTE service as 'Au 4G LTE' in September 2012. Au launched 5G service as 'UNLIMITED WORLD au 5G' in 26, March 2020.

Products and services

*EZweb: A service which provides various features for mobile phone users, including e-mail, web browsing, picture and video sharing, video conferencing, access to location-based services, games and

Emoji An emoji ( ; plural emoji or emojis) is a pictogram, logogram, ideogram or smiley embedded in text and used in electronic messages and web pages. The primary function of emoji is to fill in emotional cues otherwise missing from typed conv ...

. The service runs on traditional

mobile phone networks at a data rate of 64 kbit/s or on the new 1xEV-DO Rev A network with up to 3.1 Mbit/s downstream and 1.8 Mbit/s upstream bandwidth. In spring 2004, au became the first cellular phone based data service provider to offer an unlimited use flat-rate plan in Japan. *EZweb@mail: Multimedia messaging service. *C-mail:

Short Message Service Short Message/Messaging Service, commonly abbreviated as SMS, is a text messaging service component of most telephone, Internet and mobile device systems. It uses standardized communication protocols that let mobile devices exchange short tex ...

*EZchakuuta: A service which allows users to use song segments, usually 30 seconds or less, as ring tones. Chakuuta's rights are held by

Sony Music Entertainment Japan , often abbreviated as SMEJ or simply SME, and also known as Sony Music Japan for short (stylized as ''SonyMusic''), is a Japanese music arm for Sony. Founded in 1968 as CBS/Sony, SMEJ is directly owned by Sony Group Corporation and is oper ...

. *Chaku Uta Full: A service distributing full length songs over the mobile network. The selection offered is mainly pop music. The coding format is 48 kbit/s

HE-AAC High-Efficiency Advanced Audio Coding (HE-AAC) is an audio coding format for lossy data compression of digital audio defined as an MPEG-4 Audio profile in ISO/IEC 14496–3. It is an extension of Low Complexity AAC (AAC-LC) optimized fo ...

. The size of one piece of music is about 1.5

MiB The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

. Downloaded content is secured on a memory card (

miniSD Secure Digital, officially abbreviated as SD, is a proprietary non-volatile flash memory card format developed by the SD Association (SDA) for use in portable devices. The standard was introduced in August 1999 by joint efforts between SanDis ...

microSD Secure Digital, officially abbreviated as SD, is a proprietary non-volatile flash memory card format developed by the SD Association (SDA) for use in portable devices. The standard was introduced in August 1999 by joint efforts between SanDi ...

Memory Stick PRO Duo The Memory Stick is a removable flash memory card format, originally launched by Sony in late 1998. In addition to the original Memory Stick, this family includes the Memory Stick PRO, a revision that allows greater maximum storage capacity and ...

, M2) plugged into the mobile, using

CPRM Content Protection for Recordable Media and Pre-Recorded Media (CPRM / CPPM) is a mechanism for controlling the copying, moving, and deletion of digital media on a host device, such as a personal computer, or other player. It is a form of digit ...

copy protection. ''Chaku-Uta Full'' is the trademark of Sony Music Entertainment Japan. *EZappli: BREW applications. *EZmovie: Movie player. *EZchannel *EZ Machi Uta: A service that allows users to customize their ringback tones with music, etc. *EZnavigation: A service which is a component of EZWeb and allows GPS-enabled handsets to plot their position. *EZnaviwalk: Gives scrolling map and audio navigation to guide you to your destination. Also displays restaurant, shop and weather information for the area. *EZnewsflash: Using

BCMCS Broadcast and Multicast Service (BCMCS) is an interface for providing broadcast and multicast services in 3GPP2 CDMA2000 mobile networks. BCMCS can be used to transfer light video and audio clips or other data to a large group of mobile subscrib ...

technology. *PC Site Viewer * LISMO: au Listen Mobile Service. (Character mascot for this service is LISMO-kun). *Global Passport: Global roaming service (CDMA and GSM), the first AU handset requiring a "SIM card" (IC Card). *Global Expert: Successor to above *EZ FeliCa: Osaifu-Keitai, a payment system. *EZ television: An EZappli when watching analog terrestrial broadcasting. Ended on 24 July 2011 in most areas and on 31 March 2012 in Iwate, Miyagi, and Fukushima prefectures. *EZ television 1seg: Supports

1seg is a mobile terrestrial digital audio/video and data broadcasting service in Japan, Argentina, Brazil, Chile, Uruguay, Paraguay, Peru and the Philippines. Service began experimentally during 2005 and commercially on April 1, 2006. It is designe ...

digital terrestrial broadcasting for phones and mobile devices. Also supports data broadcasts. EZ television 1seg does not support analog television. *au 4G LTE: FDD-LTE service. *AU internet: an internet service provided by AU through KDDI from

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...

References

External links

* {{Authority control KDDI Mobile phone companies of Japan Telecommunications companies of Japan Japanese companies established in 2000 Japanese brands Telecommunications companies established in 2000 Retail companies established in 2000