Personal Digital Cellular (PDC) was a 2G mobile

telecommunications Telecommunication is the transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems. It has its origin in the desire of humans for communication over a distance greater than that ...

standard used exclusively in

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 ...

. After a peak of nearly 80 million subscribers to PDC, it had 46 million subscribers in December 2005, and was slowly phased out in favor of 3G technologies like

W-CDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Int ...

and

CDMA2000 CDMA2000 (also known as C2K or IMT Multi‑Carrier (IMT‑MC)) is a family of 3G mobile technology standards for sending voice, data, and Signaling (telecommunication), signaling data between mobile phones and cell sites. It is developed by 3GP ...

. At the end of March 2012, the count had dwindled down to almost 200,000 subscribers. NTT Docomo shut down their network, mova, on April 1, 2012 at midnight.

Technical overview

D-AMPS IS-54 and IS-136 are second-generation ( 2G) mobile phone systems, known as Digital AMPS (D-AMPS), and a further development of the North American 1G mobile system Advanced Mobile Phone System (AMPS). It was once prevalent throughout the America ...

and

GSM The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation ( 2G) digital cellular networks used by mobile devices such ...

, PDC uses TDMA. The standard was defined by the RCR (later became ARIB) in April 1991, and NTT DoCoMo launched its Digital mova service in March 1993. PDC uses 25 kHz carrier, pi/4- DQPSK modulation with 3-timeslot 11.2 kbit/s (full-rate) or 6-timeslot 5.6 kbit/s (half-rate) voice

codec A codec is a device or computer program that encodes or decodes a data stream or signal. ''Codec'' is a portmanteau of coder/decoder. In electronic communications, an endec is a device that acts as both an encoder and a decoder on a signal or ...

s. PDC is implemented in the 800 MHz (downlink 810–888 MHz, uplink 893–958 MHz), and 1.5 GHz (downlink 1477–1501 MHz, uplink 1429–1453 MHz) bands. The air interface is defined in RCR STD-27 and the core network MAP by JJ-70.10.

NEC is a Japanese multinational information technology and electronics corporation, headquartered in Minato, Tokyo. The company was known as the Nippon Electric Company, Limited, before rebranding in 1983 as NEC. It provides IT and network soluti ...

Motorola Motorola, Inc. () was an American multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent public companies, Motorola ...

, and

Ericsson (lit. "Telephone Stock Company of LM Ericsson"), commonly known as Ericsson, is a Swedish multinational networking and telecommunications company headquartered in Stockholm. The company sells infrastructure, software, and services in inform ...

are the major network equipment manufacturers. The services include voice (full and half-rate), supplementary services (call waiting, voice mail, three-way calling, call forwarding, and so on), data service (up to 9.6 kbit/s CSD), and packet-switched wireless data (up to 28.8 kbit/s PDC-P). Voice codecs are

PDC-EFR Personal Digital Cellular (PDC) was a 2G mobile telecommunications standard used exclusively in Japan. After a peak of nearly 80 million subscribers to PDC, it had 46 million subscribers in December 2005, and was slowly phased out in favor of 3 ...

and PDC-HR. Compared to

, PDC's weak broadcast strength allows small, portable phones with light batteries at the expense of substandard voice quality and problems maintaining the connection, particularly in enclosed spaces like elevators.

PDC-EFR

PDC Enhanced Full Rate is a

speech coding Speech coding is an application of data compression of digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic d ...

standard that was developed by ARIB in

and used in PDC mobile networks in Japan. The carriers use one of those codecs as PDC-EFR: CS-ACELP 8 kbit/s (a.k.a. NTT DoCoMo Hypertalk) and

ACELP Algebraic code-excited linear prediction (ACELP) is a speech coding algorithm in which a limited set of pulses is distributed as excitation to a linear prediction filter. It is a linear predictive coding (LPC) algorithm that is based on the cod ...

6.7 kbit/s (a.k.a.

J-PHONE is a Japanese multinational conglomerate holding company headquartered in Minato, Tokyo which focuses on investment management. The Group primarily invests in companies operating in technology, energy, and financial sectors. It also runs ...

Crystal Voice). The PDC-EFR CS-ACELP uses

G.729 G.729 is a royalty-free narrow-band vocoder-based audio data compression algorithm using a frame length of 10 milliseconds. It is officially described as ''Coding of speech at 8 kbit/s using code-excited linear prediction'' speech coding (CS-ACEL ...

. The PDC-EFR ACELP is compatible with the AMR mode AMR_6.70.

PDC-HR

PDC Half Rate is a

standard that was developed by ARIB in

and used in PDC mobile networks in Japan. It operates with a bit-rate of 3.45 kbit/s and is based on Pitch Synchronous Innovation

CELP Code-excited linear prediction (CELP) is a linear predictive speech coding algorithm originally proposed by Manfred R. Schroeder and Bishnu S. Atal in 1985. At the time, it provided significantly better quality than existing low bit-rate algori ...

(PSI-CELP).ARIB RCR STD-27L, Personal Digital Cellular Telecommunication System RCR Standard
5.2 Half-rate speech CODEC

Operators of PDC service

* NTT DoCoMo (''mova'' brand): Service terminated on March 31, 2012 *

SoftBank Mobile is a Japanese multinational conglomerate holding company headquartered in Minato, Tokyo which focuses on investment management. The Group primarily invests in companies operating in technology, energy, and financial sectors. It also runs the Vi ...

(''SoftBank 6-2'' brand): Service terminated on March 31, 2010 *

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 ...

** au: Service terminated on March 31, 2003 ** TU-KA: Service terminated on March 31, 2008

Standardization organizations

Association of Radio Industries and Businesses The , commonly known as , is a standardization organization in Japan. ARIB is designated as the center of promotion of the efficient use of the radio spectrum and designated frequency change support agency. Its activities include those previously ...

(ARIB) *

Telecommunication Technology Committee The Telecommunication Technology Committee (TTC; ja, 情報通信技術委員会) is a standardization organization established in 1985 and authorized by Japan's Ministry of Internal Affairs and Communications to conduct research and to develop an ...

(TTC)

References

{{Mobile telecommunications standards Mobile telecommunications standards Japanese inventions