![Lenovo A369i Dual SIM slots](https://upload.wikimedia.org/wikipedia/commons/6/67/Lenovo_A369i_Dual_SIM_slots.jpg)
Some
mobile phone
A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whil ...
s support use of two
SIM card
file:SIM-Karte von Telefónica O2 Europe - Standard und Micro.jpg, A typical SIM card (mini-SIM with micro-SIM cutout)
file:Sim card.png, A smart card taken from a Global System for Mobile Communications, GSM mobile phone
file:Simkarte NFC SecureE ...
s, described as dual SIM operation. When a second SIM card is installed, the phone either allows users to switch between two separate
mobile network
A cellular network or mobile network is a communication network where the link to and from end nodes is wireless. The network is distributed over land areas called "cells", each served by at least one fixed-location transceiver (typically thre ...
services manually, has hardware support for keeping both connections in a "standby" state for automatic switching, or has individual
transceiver
In radio communication, a transceiver is an electronic device which is a combination of a radio ''trans''mitter and a re''ceiver'', hence the name. It can both transmit and receive radio waves using an antenna, for communication purposes. The ...
s for maintaining both network connections at once.
Dual SIM phones are mainstream in many countries where phones are normally sold unlocked. Dual SIMs are popular for separating personal and business calls, in locations where lower prices apply to calls between clients of the same provider, where a single network may lack comprehensive coverage, and for travel across national and regional borders.
In countries where dual SIM phones are the norm, people who require only one SIM simply leave the second SIM slot empty. Dual SIM phones will usually have two unique
IMEI
The International Mobile Equipment Identity (IMEI) is a numeric identifier, usually unique, for 3GPP and iDEN mobile phones, as well as some satellite phones. It is usually found printed inside the battery compartment of the phone but can also ...
numbers, one for each SIM slot.
Devices that use more than two SIM cards have also been developed and released, notably the LG A290 triple SIM phone,
and even handsets that support four SIMs,
such as the
Cherry Mobile Quad Q70.
History
![Dual-SIM-eSIM](https://upload.wikimedia.org/wikipedia/commons/e/ec/Dual-SIM-eSIM.jpg)
The first phone to include dual SIM functionality was the Benefon Twin, released by
Benefon in 2000.
It wasn't until the late 2000s, however, when more dual SIM phones entered the marketplace and started to attract mainstream attention, most of them coming from small Chinese firms producing phones using
Mediatek
MediaTek Inc. () is a Taiwanese fabless semiconductor company that provides chips for wireless communications, high-definition television, handheld mobile devices like smartphones and tablet computers, navigation systems, consumer multimedia pr ...
systems-on-a-chip.
Such phones were initially eschewed by major manufacturers due to potential pressure from telecommunications companies,
but in the early 2010s
Nokia
Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational corporation, multinational telecommunications industry, telecommunications, technology company, information technology, and consumer electronics corporatio ...
,
Samsung
The Samsung Group (or simply Samsung) ( ko, 삼성 ) is a South Korean multinational manufacturing conglomerate headquartered in Samsung Town, Seoul, South Korea. It comprises numerous affiliated businesses, most of them united under the ...
,
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
and several others followed suit, with the
Nokia C2-00
The Nokia C2-00 is a mobile telephone handset produced by Nokia. It is the first mobile handset released by Nokia that supports dual SIM functionality. It was announced in June 2010 and was first released in July 2011, over a year after its annou ...
,
Nokia C1-00
Nokia's strategic nomenclature can be traced back in 2005 when the Nseries line was launched, offering devices with flagship specifications and premium hardware at various price points. These devices were considered the "bread and butter" of the ...
and
Nokia C2-03
Nokia Corporation (natively Nokia Oyj, referred to as Nokia) is a Finnish multinational telecommunications, information technology, and consumer electronics corporation, established in 1865. Nokia's main headquarters are in Espoo, Finland, i ...
and most notably the
Nokia X
The Nokia X was a mid-tier smartphone announced as part of the Nokia X family in February 2014, running on the Nokia X platform. The device shipped on the same day as the unveiling, with Nokia targeting the product for emerging markets, and was ...
,
phones from
Samsung's Duos series,
and the
Sony Xperia Z3 Dual,
Sony Xperia C
The Sony Xperia C is a touchscreen enabled Android smartphone designed, developed and manufactured by Sony Mobile Communications. Unveiled at the Mobile Asia Expo held in Shanghai, China in June 2013, the phone was targeted at the Chinese marke ...
and
tipo dual.
Apple
An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...
added dual SIM support in its 2018
iPhone XS models, with models sold in
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
containing two physical SIM slots, and models sold elsewhere supporting dual SIM by means of
(Embedded) eSIM alongside a single physical SIM.
Types
Adapters
Prior to the introduction of dual SIM phones, adapters were made for phones to accommodate two SIMs, and to switch between them when required.
Passive
Dual SIM switch phones, such as the
Nokia C1-00
Nokia's strategic nomenclature can be traced back in 2005 when the Nseries line was launched, offering devices with flagship specifications and premium hardware at various price points. These devices were considered the "bread and butter" of the ...
, are effectively a single SIM device as both SIMs share the same radio, and thus are only able to place or receive calls and messages on one SIM at the time. They do, however, have the added benefit of alternating between cards when necessary.
Standby
Dual standby phones, such as those running on Mediatek chipsets, allows both SIMs to be accessed through
time multiplexing. When making or receiving calls, the modem locks to the active channel; the other channel would be ignored and thus unavailable during the duration of the call. Examples of Dual-SIM Standby smartphones include the
Samsung Galaxy S Duos,
the
Sony Xperia M2 Dual,
and the
iPhone XS,
XS Max and
iPhone XR
The iPhone XR (stylized and marketed as iPhone Xʀ; Roman numeral "X" pronounced "ten") is a smartphone designed and manufactured by Apple Inc. It is part of the twelfth generation of the iPhone. Pre-orders began on October 19, 2018, with an ...
.
Active
Dual SIM active phones or dual active (DSDA) phones, however, come with two transceivers, and are capable of receiving calls on both SIM cards, at the cost of increased battery consumption.
One example is the
HTC Desire 600.
Unequal connectors
![Galaxy S7 clone dual-SIM tray](https://upload.wikimedia.org/wikipedia/commons/7/75/Galaxy_S7_clone_dual-SIM_tray.jpg)
Some telephones distinguish a primary SIM slot that allows for
4G/
3G connectivity and a secondary slot limited to
3G/
2G connectivity.
However, selecting either of the SIMs as primary is usually possible without physically swapping the SIMs.
Some phone models utilize a "hybrid" SIM tray, which allows two SIM cards or one SIM card and one
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 SanDis ...
memory card.
Huawei
Huawei Technologies Co., Ltd. ( ; ) is a Chinese multinational technology corporation headquartered in Shenzhen, Guangdong, China. It designs, develops, produces and sells telecommunications equipment, consumer electronics and various smar ...
's
Mate 20
Huawei Mate 20 is a line of Android phablets produced by Huawei, which collectively succeed the Mate 10 as part of the Huawei Mate series. The flagship models, the Mate 20 and Mate 20 Pro, were unveiled on 20 July 2018 at a press conference in ...
range introduced a proprietary memory card format called
Nano Memory, which exactly matches the dimensions of a nano SIM card.
Some devices accept dual SIMs of different form factors. The Xiaomi Redmi Note 4 has a hybrid dual SIM tray that accepts one micro SIM card and one nano SIM card, the latter of which can be swapped for a MicroSD card.
Market
Dual SIM phones have become popular especially with business users
due to reduced costs by being able to use two different networks, with one possibly for personal use or based on signal strength or cost, without requiring several phones.
Availability
Some sub-contract Chinese companies supply inexpensive dual SIM handsets, mainly in
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
n countries. The phones, which also usually include
touch screen
A touchscreen or touch screen is the assembly of both an input ('touch panel') and output ('display') device. The touch panel is normally layered on the top of an electronic visual display of an information processing system. The display is often ...
interfaces and other modern features, typically retail for a much lower price than branded models. While some such phones are sold under generic names or are
rebadged
In the automotive industry, rebadging is a form of market segmentation used by automobile manufacturers around the world. To allow for product differentiation without designing or engineering a new model or brand (at high cost or risk), a man ...
by smaller companies under their own brand,
numerous manufacturers, especially in China, produce phones, including dual SIM models, under
counterfeit
To counterfeit means to imitate something authentic, with the intent to steal, destroy, or replace the original, for use in illegal transactions, or otherwise to deceive individuals into believing that the fake is of equal or greater value tha ...
trademarks such as those of Nokia or Samsung,
either as cosmetically-identical clones of the originals, or in completely different designs, with the logo of a notable manufacturer present in order to take advantage of brand recognition or brand image.
Dual SIM phones are common in
developing countries
A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...
, especially in
Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
and the Indian subcontinent, with local firms like
Karbonn Mobiles
Karbonn Mobiles is an Indian smartphone manufacturing company, founded in March 2009. It is a vendor of feature phones, smartphones, tablets and mobile phone accessories.
Karbonn is a joint venture between United Telelinks Ltd., a Bangalore- ...
,
LYF
LYF (pronounced "life"), also known as Jio LYF, is an Indian brand of smartphones, laptops, consumer electronics developed by Jio and headquartered in Mumbai, Maharashtra, India. It manufactures 4G-enabled VoLTE smartphones which run on An ...
,
Micromax
Micromax (Scott Wright) is a fictional character, a mutant superhero appearing in American comic books published by Marvel Comics.
Publication history
Micromax was created by Alan Davis and first appeared in ''Excalibur'' #44 (Dec. 1991).
Fi ...
and
Cherry Mobile
Cherry Mobile is a Philippine mobile phone and electronics brand by Cosmic Technologies, established by Maynard Ngu in 2009. In 2010, barely two years after it started, Cherry Mobile was voted IT Company of the Year in the 3rd CyberPress Awards, ...
releasing
feature phone
A feature phone (also spelled featurephone) is a type or class of mobile phone that retains the form factor of earlier generations of mobile telephones, typically with press-button based inputs and a small non-touch display. They tend to use an ...
s and
smartphone
A smartphone is a portable computer device that combines mobile telephone and computing functions into one unit. They are distinguished from feature phones by their stronger hardware capabilities and extensive mobile operating systems, whic ...
s incorporating multiple SIM slots.
The French
Wiko
Wiko ( ) is a French company, fully owned subsidiary of Chinese mobile phone manufacturer Tinno Mobile.
History
Wiko was established in February 2011 by French businessman Laurent Dahan. Its head office, design and marketing teams are based in Ma ...
Mobile is also an example of rebadged Chinese Dual-SIM phones sold in few European countries as well as in North-West Africa.
Usage
Dual SIM phones have been rare in countries where phones have been usually sold on contract, as the carriers selling those phones prevent SIMs from competing carriers from being used with the phones. However, dual SIMs have been popular in locations where people normally buy phones directly from manufacturers. In such places there is little lock-in to carrier networks, and the costs of having two phone numbers are much lower.
Dual SIM phones allow separate numbers for personal and business calls on the same handset. Access to multiple networks is useful for people living in places where a single network's coverage may prove inadequate or unreliable. They are also useful in places where lower prices apply to calls between clients of the same provider.
Dual SIM phones allow users to keep separate contact lists on each SIM, and allow easier roaming by being able to access a foreign network while keeping the existing local card.
Vendors of foreign SIMs for travel often promote dual-SIM operation, with a home country and local SIM in the same handset.
See also
*
Dual mode mobile {{Unreferenced, date=April 2016
Dual-mode mobiles refer to mobile phones that are compatible with more than one form of data transmission or network.
Dual-Mode Phone
A dual-mode phone is a telephone which uses more than one technique for sending an ...
*
Subscriber Identity Module
A typical SIM card (mini-SIM with micro-SIM cutout)
A GSM mobile phone
file:Simkarte NFC SecureElement.jpg, T-Mobile nano-SIM card with NFC capabilities in the SIM tray of an iPhone 6s
file:Tf sim both sides.png, A TracFone Wireless SIM card ha ...
*
SIM cloning
Phone cloning is the copying of identity from one cellular device to another.
AMPS cloning
Analogue mobile telephones were notorious for their lack of security. Casual listeners easily heard conversations as plain narrowband FM; eavesdropper ...
*
Shanzhai
''Shanzhai'' () is a Chinese term literally meaning "mountain fortress" or "mountain camp", whose contemporary use usually encompasses counterfeit, imitation, or parody products and events and the subculture surrounding them. ''Shanzhai'' produc ...
References
{{Mobile phones
Mobile phones
Mobile telecommunications