Editing Personal Digital Cellular

{{Refimprove|date=August 2009}}

'''Personal Digital Cellular''' ('''PDC''') was a [[2G]] [[mobile computing|mobile]] [[telecommunications]] standard used exclusively in [[Japan]].{{Citation needed|date=August 2009}}

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]] and [[CDMA2000]]. 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.<ref>{{cite web |url=http://www.nttdocomo.com/pr/2009/001428.html |title=DOCOMO to Terminate mova and DoPa 2G Services |year=2012 |access-date=March 1, 2012 |archive-date=February 29, 2012 |archive-url=https://web.archive.org/web/20120229220629/http://www.nttdocomo.com/pr/2009/001428.html |url-status=dead }}</ref>

==Technical overview==
Like [[D-AMPS]] and [[GSM]], PDC uses [[Time division multiple access|TDMA]]. The standard was defined by the [[ARIB|RCR]] (later became [[ARIB]]) in April 1991, and [[NTT DoCoMo]] launched its Digital mova service in March 1993. PDC uses 25&nbsp;kHz carrier, pi/4-[[DQPSK]] modulation with 3-timeslot 11.2&nbsp;kbit/s (full-rate) or 6-timeslot 5.6&nbsp;kbit/s (half-rate) voice [[codec]]s.

PDC is implemented in the 800&nbsp;MHz (downlink 810–888&nbsp;MHz, uplink 893–958&nbsp;MHz), and 1.5&nbsp;GHz (downlink 1477–1501&nbsp;MHz, uplink 1429–1453&nbsp;MHz) bands. The air interface is defined in RCR STD-27 and the core network MAP by JJ-70.10. [[NEC Corporation|NEC]], [[Motorola]], and [[Ericsson]] are the major network equipment manufacturers.{{Citation needed|date=August 2009}}

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&nbsp;kbit/s [[Circuit Switched Data|CSD]]), and packet-switched wireless data (up to 28.8&nbsp;kbit/s [[PDC-P]]). Voice codecs are [[PDC-EFR]] and [[PDC-HR]].

Compared to [[GSM]], 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 encoding|speech coding]] standard that was developed by [[ARIB]] in [[Japan]] and used in PDC mobile networks in Japan. The carriers use one of those codecs as PDC-EFR: [[CS-ACELP]] 8&nbsp;kbit/s (a.k.a. [[NTT DoCoMo]] Hypertalk) and [[ACELP]] 6.7&nbsp;kbit/s (a.k.a. [[SoftBank Mobile|J-PHONE]] Crystal Voice).<ref>[http://www.arib.or.jp/english/html/overview/doc/5-STD-27_L-2p3-E.pdf ARIB RCR STD-27L, Personal Digital Cellular Telecommunication System RCR Standard] "5.3  CS-ACELP speech CODEC" and "5.4  ACELP Speech CODEC"</ref><ref>[http://www.ieice-hbkb.org/files/02/02gun_08hen_03.pdf IEICE Knowledge-Base Category 2. Part 8. Chapter 3. The encoding methods for mobiles] [[Institute of Electronics, Information and Communication Engineers|IEICE]]</ref>

The PDC-EFR CS-ACELP uses [[G.729]]. The PDC-EFR ACELP is compatible with the [[Adaptive multi-rate compression|AMR]] mode AMR_6.70.

===PDC-HR===
'''PDC Half Rate''' is a [[Speech encoding|speech coding]] standard that was developed by [[ARIB]] in [[Japan]] and used in PDC mobile networks in Japan. It operates with a bit-rate of 3.45&nbsp;kbit/s and is based on Pitch Synchronous Innovation [[CELP]] (PSI-CELP).<ref>[http://www.arib.or.jp/english/html/overview/doc/5-STD-27_L-2p3-E.pdf ARIB RCR STD-27L, Personal Digital Cellular Telecommunication System RCR Standard] 5.2 Half-rate speech CODEC</ref>

==Operators of PDC service==
* [[NTT DoCoMo]] (''mova'' brand): Service terminated on March 31, 2012
* [[SoftBank Mobile]] (''SoftBank 6-2'' brand): Service terminated on March 31, 2010
* [[KDDI]]
** [[au (mobile phone operator)|au]]: Service terminated on March 31, 2003
** [[TU-KA]]: Service terminated on March 31, 2008

==Standardization organizations==
* [[Association of Radio Industries and Businesses]] (ARIB)
* [[Telecommunication Technology Committee]] (TTC)

==See also==
* [[Adaptive multi-rate compression|AMR]]
* [[PDC-FR]] - [[Vector sum excited linear prediction|VSELP]]-based old full-rate codec

==References==
{{reflist}}

{{Mobile telecommunications standards}}

[[Category:Mobile telecommunications standards]]
[[Category:Japanese inventions]]