Personal Handy-phone System
Encyclopedia
The Personal Handy-phone System (PHS), also marketed as the Personal Access System (PAS) and commercially branded as Xiaolingtong (小灵通) in China
, is a mobile network system operating in the 1880–1930 MHz frequency band, used mainly in Japan
, China
, Taiwan
, and some other Asia
n countries and regions.
PHS is essentially a cordless telephone
like DECT
, with the capability to handover from one cell
to another. PHS cells are small, with transmission power of base station
a maximum of 500 mW and range typically measures in tens or at most hundreds of meters (some can range up to about 2 kilometres in line-of-sight), contrary to the multi-kilometer ranges of CDMA and GSM. This makes PHS suitable for dense urban areas, but impractical for rural areas, and the small cell size also makes it difficult if not impossible to make calls from rapidly moving vehicles.
PHS uses TDMA
/TDD for its radio channel access method
, and 32 kbit/s ADPCM for its voice codec
. Modern PHS phone can also support many value-added service
s such as high speed wireless data
/ Internet
connection (64 kbit/s and higher), WWW
access, e-mail
ing, text messaging and even color image transfer.
PHS technology is also a popular option for providing a wireless local loop
, where it is used for bridging the "last mile
" gap between the POTS
network and the subscriber's home. Actually, it was developed under the concept of providing a wireless front-end of an ISDN
network.
Thus a base station of PHS is compatible with ISDN and is often connected directly to ISDN telephone exchange
equipment e.g. a digital switch.
In spite of its low-cost base station
, micro-cellular
system and "Dynamic Cell Assignment" system, PHS offers higher number-of-digits frequency
use efficiency with lower cost (throughput
per area basis), compared with typical 3G cellular telephone systems. It enables the flat-rate wireless service like AIR-EDGE throughout Japan.
The speed of AIR-EDGE data connection is accelerated by combining lines, each of which basically is 32 kbit/s. AIR-EDGE 1× or first version introduced in 2001 provide only 32 kbit/s service. In 2002, 128 kbit/s service (AIR-EDGE 4×) started. In 2005, 256 kbit/s (AIR-EDGE 8×) service started.
In 2006, the speed of each line was also up-graded to 1.6 times with the introduction of "W-OAM" technology. The speed of AIR-EDGE 8× is up to 402 kbit/s with the latest "W-OAM" capable instrument.
In April 2007, "W-OAM typeG" was introduced allowing data speeds of 512 kbit/s for AIR-EDGE 8x users. Furthermore, the "W-OAM typeG" AIR-EDGE 8× service is planned to be upgraded to a maximum throughput of 800 kbit/s, when the upgrading for access points (mainly switching lines from ISDN to fibre optic
) in its system are completed. And it may exceed the speeds of popular W-CDMA
3G service like NTT DoCoMo
's FOMA
in Japan.
Originally developed by NTT Laboratory
in Japan
in 1989 and far simpler to implement and deploy than competing systems like PDC or GSM, the commercial services has been started by three PHS operators (NTT-Personal, DDI-Pocket, and ASTEL) in Japan in 1995. However, the service has been pejoratively dubbed as the "poor man's cellular", due to its limited range and roaming abilities. Market share in Japan has been declining and NTT DoCoMo, which has absorbed NTT Personal, and ASTEL is going to terminate the PHS service. Some of other countries have already terminated offering PHS services and migrated to GSM.
Wireless local loop
(WLL) systems based on PHS technology are in use in some of the above-mentioned countries. In recent years, WILLCOM
, formerly DDI-Pocket, is introducing flat-rate wireless network
and flat-rate calling in Japan, which has reversed the local fate of PHS up to an extent. In China, there was seen an explosive expansion of subscribers until around 2005, but it has been calming down in 2006. In Chile
, Telefónica del Sur on March 2006 launched a PHS-based telephony service in some cities of the southern part of the country. In Brazil
, Suporte Tecnologia has a PHS-based telephony service in Betim
, state of Minas Gerais, and Transit Telecom has announced a rollout of a PHS network in 2007.
China Telecom
operates a PAS system in China, even though technically it was not regarded as allowed to provide mobile services, because of some particularities of the Chinese governance. China Netcom
, the other fixed-line operator in China, also provides Xiaolingtong service. The system was a runaway hit, with over 90 million subscribers signed up . The largest vendors of the system are UTStarcom
and ZTE
. However, low priced mobile phones are rapidly replacing PHS. The Ministry of Industry and Information Technology of the People's Republic of China issued notices on 13 February 2009 that both registration of new users and expansion of the network were to be discontinued with the service to be ended by the end of 2011.
A PHS global roaming service is available between Japan (WILLCOM), Taiwan, and Thailand.
}: 3,806,900 (April, 2011)
}: 75,200,000 (September, 2008)
}: 1,457,463 (3rd quarter 2008)
}: By Transit Telecom in use for WLL services, in southern region in Brazil.
}: PCT
, Asia wireless communication
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, is a mobile network system operating in the 1880–1930 MHz frequency band, used mainly in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, Taiwan
Taiwan
Taiwan , also known, especially in the past, as Formosa , is the largest island of the same-named island group of East Asia in the western Pacific Ocean and located off the southeastern coast of mainland China. The island forms over 99% of the current territory of the Republic of China following...
, and some other Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
n countries and regions.
Technology
Cordless telephone
A cordless telephone or portable telephone is a telephone with a wireless handset that communicates via radio waves with a base station connected to a fixed telephone line, usually within a limited range of its base station...
like DECT
Digital Enhanced Cordless Telecommunications
Digital Enhanced Cordless Telecommunications , usually known by the acronym DECT, is a digital communication standard, which is primarily used for creating cordless phone systems...
, with the capability to handover from one cell
Cellular network
A cellular network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver known as a cell site or base station. When joined together these cells provide radio coverage over a wide geographic area...
to another. PHS cells are small, with transmission power of base station
Base station
The term base station can be used in the context of land surveying and wireless communications.- Land surveying :In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS...
a maximum of 500 mW and range typically measures in tens or at most hundreds of meters (some can range up to about 2 kilometres in line-of-sight), contrary to the multi-kilometer ranges of CDMA and GSM. This makes PHS suitable for dense urban areas, but impractical for rural areas, and the small cell size also makes it difficult if not impossible to make calls from rapidly moving vehicles.
PHS uses TDMA
Time division multiple access
Time division multiple access is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This...
/TDD for its radio channel access method
Channel access method
In telecommunications and computer networks, a channel access method or multiple access method allows several terminals connected to the same multi-point transmission medium to transmit over it and to share its capacity...
, and 32 kbit/s ADPCM for its voice codec
Codec
A codec is a device or computer program capable of encoding or decoding a digital data stream or signal. The word codec is a portmanteau of "compressor-decompressor" or, more commonly, "coder-decoder"...
. Modern PHS phone can also support many value-added service
Value-added service
A value-added service is popular as a telecommunications industry term for non-core services, or in short, all services beyond standard voice calls and fax transmissions. However, it can be used in any service industry, for services available at little or no cost, to promote their primary business...
s such as high speed wireless data
Data
The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...
/ Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
connection (64 kbit/s and higher), WWW
World Wide Web
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet...
access, e-mail
E-mail
Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...
ing, text messaging and even color image transfer.
PHS technology is also a popular option for providing a wireless local loop
Wireless local loop
Wireless local loop , is a term for the use of a wireless communications link as the "last mile / first mile" connection for delivering plain old telephone service and/or broadband Internet to telecommunications customers....
, where it is used for bridging the "last mile
Last mile
The "last mile" or "last kilometer" is the final leg of delivering connectivity from a communications provider to a customer. The phrase is therefore often used by the telecommunications and cable television industries. The actual distance of this leg may be considerably more than a mile,...
" gap between the POTS
Plain old telephone service
Plain old telephone service is the voice-grade telephone service that remains the basic form of residential and small business service connection to the telephone network in many parts of the world....
network and the subscriber's home. Actually, it was developed under the concept of providing a wireless front-end of an ISDN
Integrated Services Digital Network
Integrated Services Digital Network is a set of communications standards for simultaneous digital transmission of voice, video, data, and other network services over the traditional circuits of the public switched telephone network...
network.
Thus a base station of PHS is compatible with ISDN and is often connected directly to ISDN telephone exchange
Telephone exchange
In the field of telecommunications, a telephone exchange or telephone switch is a system of electronic components that connects telephone calls...
equipment e.g. a digital switch.
In spite of its low-cost base station
Base station
The term base station can be used in the context of land surveying and wireless communications.- Land surveying :In the context of external land surveying, a base station is a GPS receiver at an accurately-known fixed location which is used to derive correction information for nearby portable GPS...
, micro-cellular
Microcell
A microcell is a cell in a mobile phone network served by a low power cellular base station , covering a limited area such as a mall, a hotel, or a transportation hub. A microcell is usually larger than a picocell, though the distinction is not always clear...
system and "Dynamic Cell Assignment" system, PHS offers higher number-of-digits frequency
Frequency
Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency.The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency...
use efficiency with lower cost (throughput
Throughput
In communication networks, such as Ethernet or packet radio, throughput or network throughput is the average rate of successful message delivery over a communication channel. This data may be delivered over a physical or logical link, or pass through a certain network node...
per area basis), compared with typical 3G cellular telephone systems. It enables the flat-rate wireless service like AIR-EDGE throughout Japan.
The speed of AIR-EDGE data connection is accelerated by combining lines, each of which basically is 32 kbit/s. AIR-EDGE 1× or first version introduced in 2001 provide only 32 kbit/s service. In 2002, 128 kbit/s service (AIR-EDGE 4×) started. In 2005, 256 kbit/s (AIR-EDGE 8×) service started.
In 2006, the speed of each line was also up-graded to 1.6 times with the introduction of "W-OAM" technology. The speed of AIR-EDGE 8× is up to 402 kbit/s with the latest "W-OAM" capable instrument.
In April 2007, "W-OAM typeG" was introduced allowing data speeds of 512 kbit/s for AIR-EDGE 8x users. Furthermore, the "W-OAM typeG" AIR-EDGE 8× service is planned to be upgraded to a maximum throughput of 800 kbit/s, when the upgrading for access points (mainly switching lines from ISDN to fibre optic
Optical fiber
An optical fiber is a flexible, transparent fiber made of a pure glass not much wider than a human hair. It functions as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. The field of applied science and engineering concerned with the design and application of...
) in its system are completed. And it may exceed the speeds of popular W-CDMA
W-CDMA
W-CDMA , UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface standard found in 3G mobile telecommunications networks. It is the basis of Japan's NTT DoCoMo's FOMA service and the most-commonly used member of the UMTS family and sometimes used as a synonym for UMTS...
3G service like NTT DoCoMo
NTT DoCoMo
is the predominant mobile phone operator in Japan. The name is officially an abbreviation of the phrase, "do communications over the mobile network", and is also from a compound word dokomo, meaning "everywhere" in Japanese. Docomo provides phone, video phone , i-mode , and mail services...
's FOMA
Foma
Foma may refer to:* FOMA , a Japanese mobile telecommunications service* Sergei Fomenko, nicknamed "Foma", Ukrainian musician...
in Japan.
Implementation
Nippon Telegraph and Telephone
, commonly known as NTT, is a Japanese telecommunications company headquartered in Tokyo, Japan. Ranked the 31st in Fortune Global 500, NTT is the largest telecommunications company in Asia, and the second-largest in the world in terms of revenue....
in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
in 1989 and far simpler to implement and deploy than competing systems like PDC or GSM, the commercial services has been started by three PHS operators (NTT-Personal, DDI-Pocket, and ASTEL) in Japan in 1995. However, the service has been pejoratively dubbed as the "poor man's cellular", due to its limited range and roaming abilities. Market share in Japan has been declining and NTT DoCoMo, which has absorbed NTT Personal, and ASTEL is going to terminate the PHS service. Some of other countries have already terminated offering PHS services and migrated to GSM.
Wireless local loop
Wireless local loop
Wireless local loop , is a term for the use of a wireless communications link as the "last mile / first mile" connection for delivering plain old telephone service and/or broadband Internet to telecommunications customers....
(WLL) systems based on PHS technology are in use in some of the above-mentioned countries. In recent years, WILLCOM
Willcom
is a Japanese PHS operator, offering flat-rate wireless network data transmission and flat-rate voice calls for its subscribers.The company was formerly known as DDI Pocket, a subsidiary of KDDI. In 2004, the Carlyle Group acquired a majority stake from KDDI and changed the name of the company in...
, formerly DDI-Pocket, is introducing flat-rate wireless network
Wireless network
Wireless network refers to any type of computer network that is not connected by cables of any kind. It is a method by which homes, telecommunications networks and enterprise installations avoid the costly process of introducing cables into a building, or as a connection between various equipment...
and flat-rate calling in Japan, which has reversed the local fate of PHS up to an extent. In China, there was seen an explosive expansion of subscribers until around 2005, but it has been calming down in 2006. In Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...
, Telefónica del Sur on March 2006 launched a PHS-based telephony service in some cities of the southern part of the country. In Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Suporte Tecnologia has a PHS-based telephony service in Betim
Betim
Betim is a city in Minas Gerais, Brazil. It is located at around . The city belongs to the mesoregion Metropolitan of Belo Horizonte and to the microregion of Belo Horizonte....
, state of Minas Gerais, and Transit Telecom has announced a rollout of a PHS network in 2007.
China Telecom
China Telecom
China Telecom Corp. Ltd. is a Chinese state-owned telecommunication company. It is the largest fixed line service and 3rd largest mobile telecommunication provider in the People's Republic of China.-Sectors:...
operates a PAS system in China, even though technically it was not regarded as allowed to provide mobile services, because of some particularities of the Chinese governance. China Netcom
China Netcom
China Netcom, full name China Netcom Group Corporation Limited , abbreviated CNC, was a former telecommunication service provider in People's Republic of China...
, the other fixed-line operator in China, also provides Xiaolingtong service. The system was a runaway hit, with over 90 million subscribers signed up . The largest vendors of the system are UTStarcom
UTStarcom
UTStarcom is a Fortune 1000 company that specializes in IP-based networking products for telecommunications companies and service providers. Its core markets are multimedia communications and broadband, including IP and entertainment , next generation broadband networks and optical network solutions...
and ZTE
ZTE
ZTE Corporation formerly Zhongxing Telecommunication Equipment Corporation is a Chinese multinational telecommunications equipment and systems company headquartered in Shenzhen, China...
. However, low priced mobile phones are rapidly replacing PHS. The Ministry of Industry and Information Technology of the People's Republic of China issued notices on 13 February 2009 that both registration of new users and expansion of the network were to be discontinued with the service to be ended by the end of 2011.
A PHS global roaming service is available between Japan (WILLCOM), Taiwan, and Thailand.
International development
- PHS's subscribers and major operators
}: 3,806,900 (April, 2011)
-
-
- WillcomWillcomis a Japanese PHS operator, offering flat-rate wireless network data transmission and flat-rate voice calls for its subscribers.The company was formerly known as DDI Pocket, a subsidiary of KDDI. In 2004, the Carlyle Group acquired a majority stake from KDDI and changed the name of the company in...
- Under the Japanese telephone numbering planJapanese telephone numbering planCountry Code: +81International Call Prefix: 010Trunk Prefix: 0-Dialing prefixes: 00 Carrier selection prefix 184 Prefix to withhold caller ID 186 Prefix to provide caller ID-Types of numbers:...
, use the 070 prefix.
- Willcom
-
}: 75,200,000 (September, 2008)
-
-
- PHS services (provided by UTStarcomUTStarcomUTStarcom is a Fortune 1000 company that specializes in IP-based networking products for telecommunications companies and service providers. Its core markets are multimedia communications and broadband, including IP and entertainment , next generation broadband networks and optical network solutions...
under the commercial name Little Smart ) of China TelecomChina TelecomChina Telecom Corp. Ltd. is a Chinese state-owned telecommunication company. It is the largest fixed line service and 3rd largest mobile telecommunication provider in the People's Republic of China.-Sectors:...
and China NetcomChina NetcomChina Netcom, full name China Netcom Group Corporation Limited , abbreviated CNC, was a former telecommunication service provider in People's Republic of China...
have been merged into China UnicomChina UnicomChina Unicom or China United Netcom Ltd , is a Chinese state-owned telecommunications operator in the People's Republic of China.-History:...
- PHS services (provided by UTStarcom
-
}: 1,457,463 (3rd quarter 2008)
-
-
- FITEL
-
}: By Transit Telecom in use for WLL services, in southern region in Brazil.
}: PCT
PCT
- Geography :* Pacific Crest Trail, a hiking trail that runs along the west coast of the United States, from Mexico to Canada* Princeton Airport - Science and technology :...
, Asia wireless communication
External links
- PHS MoU Group
- Article on Xiaolingtong
- PHS in Taiwan
- Telefonica del Sur in Chile