Have you ever wondered what is so special about smartphones with two cards?
What benefits does Dual SIM technology have, how does it work and what benefits can it provide?
Maybe you already know these things, but are you wondering what is Dual SIM standby and how is it different from active?
If you want answers to these questions, or see a list of the best dual-card smartphones, read this article.
Why Dual SIM Smartphones Are Useful
For some people, Dual SIM devices can be extremely useful. For example, business people typically have one phone number for work and one for personal life.
An entrepreneur can either use two different smartphones, or use a phone with both active phone numbers on it. Having only one smartphone is, of course, easier than constantly carrying two at once.
Another common situation in which you might be interested in this technology is when one card is used for calls and the other for the Internet.
For example, some mobile operators have good plans for voice calls, but expensive ones for internet access.
Then having a Dual SIM smartphone, you can combine two different operators and get cheaper bills overall.
Types[edit]
Adapters[edit]
Prior to the introduction of dual SIM phones, adapters were made for phones to accommodate two SIMs, and to switch between them when required.[10][20]
Passive[edit]
Dual SIM switch phones, such as the Nokia C1-00, 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.[21]
Standby[edit]
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,[22] the Sony Xperia M2 Dual,[23] and the iPhone XS, XS Max and iPhone XR.[24]
Active[edit]
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.[25][26] One example is the HTC Desire 600.[27]
Unequal connectors[edit]
A dual SIM tray as shown on a Samsung Galaxy S7. Certain variants of the phone can accept either two nano SIMs or a nano SIM and a MicroSD card in place of the second SIM.
Some telephones distinguish a primary SIM slot that allows for 4G/3G connectivity and a secondary slot limited to 3G/2G connectivity.[28] 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 memory card.[29][30]Huawei's Mate 20 range introduced a proprietary memory card format known as “Nano Memory”, which exactly matches the dimensions of a nano SIM card.[31]
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.[28]
What Dual SIM smartphones are there?
If you decide to buy a Dual SIM smartphone, you should know that there are several types of implementations and some of them are better than others. The most common types are:
- Dual SIM passive is the weakest implementation and is used mainly on cheap phones, not smartphones. This passive mode is capable of using two different cards, but only one of them can be active. This means that if one works, then the other doesn’t. In order to use the second one, you need to activate it manually, and the first one will be automatically disabled.
- Dual SIM active - this implementation allows you to make phone calls from any card and receive calls from any card at the same time. Having this technology, you can conduct a conversation from one card, and the other can receive calls, messages and data from the Internet. For example, if you have a call on the first card, and receive another one on the second, you will be notified about this. These devices have two radio transmitters, one for each card. This means that they consume more power than Single technology smartphones and are more expensive, resulting in a higher purchase price.
- Dual SIM dual standby is a hybrid between two Standby and Dual SIM dual active. Dual standby mode can work with two cards active at the same time, but they are only active while the smartphone is in standby mode. Then you can make and receive calls to any number. When you make a phone call to one of the numbers, the other becomes inactive. This is not a perfect solution, but it is a less expensive option and very common.
Which dual SIM phone to choose?
Xiaomi Redmi 5A
Xiaomi Redmi 5A is a cheap, good phone with two SIM cards (in standby mode). In Russian stores it costs less than 10,000 rubles, but, despite the relatively low price, it has a fairly fast action compared to most competitors in this price segment.
It has a well-optimized Android system, a 5-inch HD IPS screen, 2 GB of RAM, 16 GB of main memory, two good cameras 13 and 5 Mpx, 4G LTE, dual SIM, microSD, Snapdragon 425 processor and a pretty good 3080 mAh battery. The downside is the lack of a fingerprint reader.
Main characteristics of Xiaomi Redmi 5A:
- Operating system: Android 7.0
- Display (diagonal): 5 inches
- Display (resolution): 720×1280 px
- Main processor (name): Qualcomm Snapdragon 425
- RAM: 2 GB
- Memory: 16 GB
- Camera (rear): 13 Mpx
Xiaomi Redmi 5
Redmi 5 is one of the new models from this manufacturer. Available in two versions - basic and most popular; with 2 GB of RAM and 16 GB of internal memory, less often 3/32 GB.
Both smartphones are good, but the second one is more noteworthy for its larger amount of RAM, which can improve the speed of the phone.
It has an HD+ display (720x1440 pixels) with an aspect ratio of 18:9 and a diagonal of 5.7 inches. The screen is surrounded by thin bezels and has rounded corners, making the smartphone look modern. Equipped with a pretty good Snapdragon 450 processor, a good 12 Mpx rear camera with Full HD recording, a 3300 mAh battery, hybrid dual SIM (standby), LTE and a fast fingerprint scanner.
Main characteristics of Xiaomi Redmi 5:
- Operating system: Android 7.1
- Display (diagonal): 5.7 inches
- Display (resolution): 720×1440 px
- Main processor (name): Qualcomm Snapdragon 450
- RAM: 2 GB
- Memory: 16 GB
- Camera (rear): 12 Mpx
Xiaomi Redmi 5 Plus
Xiaomi Redmi 5 Plus is an improved and slightly expanded version of the above presented Redmi 5. It also features an 18:9 display with rounded corners and thin frames, but it has a diagonal of 6 inches. Slightly improved Snapdragon 625 processor and 3/32 or 4/64 GB memory.
It uses a large 4000 mAh battery, thanks to which the smartphone can actually work for 2 days without recharging. The 12 Mpx rear camera can record video in 4K UHD format. Also available is dual SIM (standby), fast LTE mobile communications and a good fingerprint scanner. The downside is the lack of NFC.
Main characteristics of Xiaomi Redmi 5 Plus:
- Operating system: Android 7.1
- Display (diagonal): 5.9 inches
- Display (resolution): 1080×2160 px
- Main processor (name): Qualcomm Snapdragon 625
- RAM: 3 GB
- Memory: 32 GB
- Camera (rear): 12 Mpx
Xiaomi Mi A2 Lite
We had the pleasure of testing the Xiaomi Mi A2 Lite and we can confidently confirm that it is one of the most cost-effective smartphones under 20,000 rubles with dual SIM cards (standby mode).
It works quickly because it has pure Android without any clutter. In addition, it is included in the Android One program, so it will receive updates for at least 2 years from the release date. It is possible that it will receive Android 9.0.
It has 4/64 GB memory, a pretty good camera with Full HD recording and a large 4000 mAh battery (more than the more expensive Mi A2 model (without Lite)). NFC is missing.
Is it possible to use the Internet on both cards in a Dual SIM smartphone?
Answer: yes, but it depends on the manufacturer you choose. Manufacturers look at how much it will cost them and their profitability.
It is inexpensive to create devices that support fourth- and second-generation data connections.
4G + 2G modes can be combined and use the same spectrum.
However, if you want a Dual SIM smartphone that supports 4G on one card and 3G or 4G on the other, you'll need a processor powerful enough to handle two high-speed data connections simultaneously.
History[edit]
The first phone to include dual SIM functionality was the Benefon Twin, released by Benefon in 2000.[7] 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 Mediateksystems-on-a-chip.[8][9 ]
Such phones were initially eschewed by major manufacturers due to potential pressure from telecommunications companies,[10] but in the early 2010s Nokia, Samsung, Sony and several others followed suit, with the Nokia C2-00, Nokia C1-00 and Nokia C2- 03 and most notably the Nokia X,[11][12][13] phones from Samsung's Duos series,[14] and the Sony Xperia Z3 Dual, Sony Xperia C[15] and tipo dual.[16][17]Apple added dual SIM support in its 2022 iPhone XS models, with models sold in China containing two physical SIM slots, and models sold elsewhere supporting dual SIM by means of Embedded-SIM alongside a single physical SIM.[18][19]
Examples of smartphones Dual SIM double backup
A good balance between cost and features that they offer, most Dual SIM smartphones on the market today are dual standby.
If you want to buy such a device, here is a list of some good options: Samsung Galaxy S7, LG G5, Huawei Mate 8, Xiaomi Mi 5 Dual, ASUS Zenfone 2 Laser ZE550K, ASUS Zenfone Max ZC550KL, Lenovo Vibe X3, Huawei P8 Lite, OnePlus X and Lumia 650.
"Dual devices" can be very useful in some cases, and manufacturers have noticed that people want such devices. As a result, more and more of them are produced every year. However, as you've seen in this guide, not everything works alone, and some implementations are better than others.
Tell us what kind of experience you've had with this technology and what you think about it in the comments below. Good luck.
What is this
First, let’s figure out what the Dual button on the climate control means, because it takes a long time to find the necessary explanations in the instructions. Translated from English, this word means “double”. Consequently, when the driver presses the button, the driver activates the dual-zone climate control system.
In simple words, Dual in climate control allows you to enable or disable single-zone operating mode. In some cars you can find another designation on such keys (Sync), which means “synchronization”. When you click on it, on the contrary, a transition to single-zone operation occurs.
In the case of the Dual button, the opposite is true. When pressed, the ability to regulate in two zones is activated, and when activated again, this option is turned off. In this case, the correct use of the function is confirmed by the lighting of a special LED. By its glow, the driver can understand whether his climate control is operating in single- or dual-zone mode.
Market[edit]
Dual SIM phones have become popular especially with business users[10][32] 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[edit]
Some sub-contract Chinese companies supply inexpensive dual SIM handsets, mainly in Asian countries. The phones, which also usually include touch screen 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 by smaller companies under their own brand,[9] numerous manufacturers, especially in China, produce phones, including dual SIM models, under counterfeit trademarks such as those of Nokia or Samsung,[ 33] 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.[8]
Dual SIM phones are common in developing countries, especially in Southeast Asia and the Indian subcontinent, with local firms like Karbonn Mobiles, LYF, Micromax and Cherry Mobile releasing feature phones and smartphones incorporating multiple SIM slots.[34][35]
The French Wiko Mobile is also an example of rebadged Chinese Dual-SIM phones sold in few European countries as well as in North-West Africa.
Usage[edit]
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.[36]
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.[37]
Vendors of foreign SIMs for travel often promote dual-SIM operation, with a home country and local SIM in the same handset.
Need more than one eSIM?
If you travel a lot for business or pleasure and often have to switch between plans and carriers, you may want to store more than one eSIM on your iPhone. However, you can only use one at a time.
And remember that each eSIM requires its own unique data plan.
How to switch between eSIMs?
- Tap Settings > Cellular > Cellular
- Select the plan you want to use now
- Click Enable this line
Enabling dual SIM access
To enable dual SIM access:
- Make sure both SIM cards are turned on.
- Find and select “Settings” → “Network & Internet” → “Advanced settings” → “Dual SIM” → “Dual SIM access” reachability)" .
- Move the slider next to “Dual SIM reachability” to the right. The telephone numbers of the two inserted SIM cards are entered automatically. If numbers are not added, you can enter them manually. You can also follow the on-screen instructions.
Quickly change your cell phone plan
- Go to Settings > Cellular
- Tap Cellular Data
- Click on the number you want to use cellular data
- Switch to cellular data to automatically switch cellular data lines when you're on a call
Read also: eSIM for Acer Swift 7: How to Connect and Set Up Internet
When you enable cellular data switching and receive a voice call to your voice number, that number automatically switches to voice and data usage. This way you use both voice and data during a call.
If you turn off Allow Cellular Data Switching when you are using a voice number that is not your assigned cellular number, cellular data will not work while you are on that call.
How to enable 4G LTE?
How to enable LTE on Android
- Launch the standard “Settings” application.
- Open the “More” section.
- Select “Mobile networks”.
- Click on the “Network Type” tab and select the “LTE (Recommended)” option from the drop-down list.
Oct 21
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