Must know about Cellphones & before buying a New One

A lot gets attached to this discussion on Cellphones as it’s not only specification that plays a role in the selection, but also look, the size and thickness and also how you feel with the model in consideration. While the latter is more of a personal preference, here we’ll curtail the discussion to the crucial aspects you need to see before deciding on your next mobile phone. You may certainly like the look and feel, but do not miss out to check and compare the key buying considerations.

Camera in Cellphones


1. Processor & Cores in Cellphones

CPU in CellphonesGone are the days when mobile phones were only used for voice communication. This is the information age and all that you need to know fits in your palm, inside your pocket. Ranging from Voice communication, to high speed internet connection on the go, to HD multimedia content playback on the television, to some serious gaming, the need for faster processing and multi-tasking never subsides. The one small chip mounted on the mobile phone hardware has to take all that load, increasing the need for multi-processors and multi-cores like never before.

So how does all that functionality gets added to your mobile phone even when they keep becoming sleeker and slimmer? To a very granular level, it’s the nanometer size of the chip electronics that usually keeps on decreasing with every new generation. In layman terms, the processor is made of nanometer functional elements and higher these elements, more the functionality the chip can cater to. With a decrease in nanometer size, it’s certain that more of these elements can now be accommodated in a single chip, catering to more functionality and also making it faster. This also leads to an increase in Processor Cores and the frequency of processing. So higher the number of cores and higher the Core frequency, faster is your mobile phone when handling multiple applications. Simple thing that can be differentiated with a faster processor, is the time taken to say open an image file once you tap on the screen or the response time while gaming or any other day today tasks. Multi-Processors adds much fire power under intensive application environment.

2. Battery in Cellphones

BatteryThis is a key consideration when it comes to a mobile phone selection. Faster Processor and Input/Output Ports are good and all this is achievable because of the Power Supply running on your Mobile hardware. There are multiple voltages that the chips inside the Mobile need and all these voltages are down converted from One DC Voltage coming from your charger or the battery. While the Charger down converts AC to a specific DC Voltage, the battery is the store house of current at a specific voltage. The higher the current rating in Ampere-Hour (mAH), the more current the battery can supply for a longer time. For example a 5 Volt 6000mah battery lasts longer than a 5V 4000mah battery with same application environment. This depends on the number of cells the battery has. More cells correspond to more current driving capacity.

Mobile phone these days come with either a removable or a fixed battery both offering different use cases. A removable battery is helpful for a manual power off by battery removal in case the mobile hangs. Another advantage is the replaceable option in case the battery is in it’s End of Life. On the other hand, a fixed battery would make the mobile phone slimmer, sleeker and gives it a Unibody feel while also making it a bit more resistant to dust.


We’ll not discuss the scenario when the mobile phone gets drenched in water. It’s mainly the overall mobile phone design claimed by the manufacturer that can prevent a short in such scenarios and not only limited to battery itself. I am yet to see a mobile phone that will activate it’s sensors detecting water contact and shutting the mobile off thus preventing the short, saving the hardware.


3. Cellphone Display.

Cellphone DisplayThe principles in selecting the display remains same as mentioned in the Tablet section. Clarity of picture is the key. A 6 inch display with same clarity as a 5 inch Mobile display is better. Clarity depends on the Pixel count and the Resolution that is the proximity of the pixels from each other for a given display size. Pixel Density that is PPI or Pixel per Inch would provide this information. In general a 2048 X 1536 pixels is better resolution than 1920×1080 pixels and 1280 X 800 displays. Color combinations and quality can play their role in selection. Higher color combinations essentially means higher digital RGB combinations a display can support.

Contrast Ratio defines maximum whiteness to maximum blackness. The higher this ratio, the better it is in realizing whites whiter, grey grayer and black blacker.
The Mobile displays these days are usually Capacitive that provides multi-touch capability and can also be used outdoors under the sun. On the contrary, a Resistive Display would be a single touch and cannot be used under the sun.

4. Connectivity in Cellphones

Cellphone ConnectivityThe ports on the mobile phone connects to the outer would for charging the battery, data transfer, direct playback to a display or even a projection to the Screen. These ports are usually mini or micro ports with much lesser size than the normal ones. Serial Ports like Micro and Mini USB, Mini Display Port or Micro HDMI each with specific generations and transfer speeds are supported. We’ll have a generic discussion on the Ports at the end of this article.

Additional support for standards like Mobile High Definition Link (MHL) and USB Type C need to be checked. With MHL you may directly connect your Mobile with HD Television when playing multimedia. USB Type C is very versatile and allows direct charging of the Mobile by televisions or monitors. USB Type C has a reduced connector size and can connect to any host( PC USB Type A connector) supporting any USB standard. Prior to USB C standard, the devices usually had a USB Type B or AB connector.
USB C is one connector that would probably replace all existing USB connectors on your devices while keeping the underlying technology like USB2/USB3/USB3.1 intact.

The wireless connectivity standards viz 802.11 b/g/n and 802.11 ac let you connect to 2.4GHz band and 5GHz band respectively as supported by your home Router.
Then, there are wireless connectivity options for interfacing mobile directly with your television for watching multimedia. Support of 4G LTE would be necessary for a faster data access up to 400Mbps and higher during travel. Decide, based on the availability of Service Provider and the network.


5. Camera in Cellphones

Camera in CellphonesThe Primary camera is mainly used for Photos and video recording. The FNumber, Sensor type, Image Resolution, Video Resolution, Frames/second specification of the camera are the key specs that forms the Primary Camera.

One of the important considerations in camera selection is the F-Number range supported by the Lens. This number determines how well the camera is able to accumulate Light for a clear bright Picture and how close from the object the camera is able to resolve focus. The smaller the F-Number, the higher the aperture and higher the light entering into the camera for a brighter capture. A smaller F-Number would do really good for Portraits where the clear focus is on the subject. This would mean a good focus on the subject and a blurry background image. The reverse, that is a smaller aperture would leave less light in and would capture good background image like that needed for Landscapes.Image Resolution specification provide information on the number of pixels available for clicking photos and Video resolution provides the pixels available for videos.

A high resolution camera would provide more detailed Picture but also increasing the overall size of the picture for transfers. Information about the number of Frames per second for taking videos is important along with the Video Resolution. FHD resolution is now common and Cellphones with Cameras up to 4K Video recording are also available. Features like Digital Zoom, Scene Mode, Panoramic view and Auto-Focus can be looked at based on personal preference and the amount of Mobile Phone Camera Use.The secondary camera is for Video conferencing and gesture recognition and is provided with the same specifications as the Primary camera.

6. Sensors in Cellphones

Sensors in CellphonesThe different sensors available in the Mobiles are Gyroscope, Accelerometer, Ambient Light Sensor, Proximity Sensor, Barometer, Temperature Sensor and Finger Print Sensor. Each sensor serves a specific purpose, let’s discuss each one in short.

Gyroscope and Accelerometer

Have you noticed how Cellphones respond while gaming or while rotating the screen or taking certain actions when shaken. The responsible sensors for this purpose are Accelerometer and Gyroscope. Accelerometer provides sensing Linear acceleration based on vibration from a constant position and Gyroscope senses orientation based on rotation. While Accelerometer is commonly found in Mobiles, Gyroscope is a must for high end Gaming .

Ambient Light Sensor

Controls the brightness based on different light scenerios, the auto mode for brightness in Cellphones.

Proximity Sensor

Takes certain actions based on the proximity of the tablet from nearby objects.


This sensor helps you when there is a sudden change in the atmospheric pressure in certain scenerios, say when you are trekking to higher altitudes. Mobiles with GPS would just do that, but would keep your battery draining.

Finger Print Sensor

Enhances the security of Cellphones from unwanted accessibility.

7. Storage in Cellphones

Cellphones come with internal storage that is inclusive of the space taken by the mobile itself for firmware, and also with expandable SD Card Storage. Mobiles with up to 2 Tera Byte of SD Card options are available now a days providing a good option to store those large Video files taken from the inbuilt high resolution 4K camera.

The RAM in the mobile is permanently mounted on the PCB that is soldered down unlike a Laptop where the RAM is detachable and up-gradable. RAMs with 6GB size are available now a days supporting the Processor for an increased Fire-Power for intensive applications. We’ll have a discussion on how the RAM and Cache Size in general would improve the overall performance of Cellphones at the end of this article.

The Ports that matter. Also discussed in our connectivity Post earlier.




USB1 or Low Speed USB.

This is essentially a serial bus for connecting a mouse to the PC and runs at 1.5 Megabits per second that is about 1.5 Million bits/second.

USB1.1 or Full Speed USB.

This bus connects your keyboard to the PC and runs at 12Mbps.


Backward compatible with USB1 and USB1.1 runs at 480 Mbps and this bus is rightly termed as High Speed USB.
So what is backward compatibility? In simple terms the same USB2.0 port on your PC can connect to a pen drive running at 480Mbps, a keyboard at 12Mbps and a mouse at 1.5 Mbps.

Enter USB3.0

Backward compatible with USB2.0, USB1.1 and USB1 and running at 5 Gigabits per second, that’s about 10 times faster than USB2.0. So a USB3.0 port on your PC also known as a host port can be connected to a USB3.0 pen drive, USB2.0 Pen drive, USB1.1 Keyboard and USB1 Mouse. This backward compatibility is only true for host ports like that on a PC. However, a USB3.0 pen drive that is a device port would not connect with a USB2.0 Host port on the PC at 5Gbps.

Next comes USB3.1

Host Port is backward compatible and can be connected with USB3.0, USB2.0 and USB1.1 devices and has a data rate of 10Gbps. However a USB3.1 device might not connect with a USB3.0 port at 10Gbps.

And the ubiquitous USB C Port

The beauty of USB C is the small sized connector yet with higher number of pins in the connector with multiple serial lanes, resulting in an overall increase in speeds up to 10Gbps while also catering to providing a higher wattage of power up to 100 Watts at 20 Volts to devices. The multiple serial lanes can also carry HDMI and Display Port Signals and USB C is backward compatible with all USB standards with additional adapters making it truly ubiquitous.


Carry all video and audio on serial copper lanes. HDMI does exactly that. But what’s evolving the standard? The need of picture clarity and color has increased the pixel quantity and resolution of the display. Higher the Display (usually termed as HDMI Sink) pixels and higher the resolution, higher is the amount of data that need to be transferred from any HDMI Source to that Display sink. And why not? In practical terms, you would clearly see the difference between VGA and HDMI as HDMI carries much more Mbps per second compared to VGA making the picture quality much clear and crisper. Given an option to connect VGA or HDMI, always choose HDMI for a better visual experience.

How does HDMI do it?

HDMI carries three pairs of data lanes each at a specific frequency all adding up to a much higher rate and all synchronized to a single clock pair. So your HDMI connector has multiple serial data pairs and a clock pair along with Power and Ground pins connected to the Printed Circuit Board of the product in discussion.
So let’s look at different speeds, HDMI caters to and start with the minimum ones contained in any product now a days.

HDMI 1.4

The clock speed that we discussed above is driven at 340 MHz and 10 bits of data per serial lane is transferred at 340 MHz making the overall speed per lane at 3400Mbps. This multiplied by three pairs make it a total of 10.2 Gbps of data transfer between Source and Sink. This enables to carry 3D data and much deeper color bit per pixel as required by the sink Display. To make it simple, we’ve left out the 8b/10b encoding overhead applied to 10.2 Gbps, making the overall data at about 8Gbps.

HDMI 2.0

The clock speed now increases to 600 MHz and 10 bits of data per serial lane is transferred at 600 MHz making the overall speed per lane at 6000Mbps that is 6Gbps.
This multiplied by three pairs make it a total of 18 Gbps of data transfer between Source and Sink. This enables to carry 3D data at 60Hz and much deeper color bit per pixel as required by the sink Display.
Display that is Sink device specs need to be looked into before arriving at any conclusion. 4K X 2K display resolution at 60 Hz usually goes well with HDMI 2.0. It’s good to have
HDMI 2.0 on your Source Product, but does the Display device support HDMI 2.0 is what is to be addressed before arriving at a decision. Another key thing is the interface connector itself, that can range from HDMI-A to HDMI-E and can be a Micro or a Mini HDMI form factor.

HDMI 2.1

The new age gamers should look at the coming up standard HDMI2.1 that would enable 4K X 2K, 8K and higher resolution with higher refresh rates up to 120 Hz.

A Note on RAM and Cache Size.

L1,L2,L3 Cache are different chuck of memories accessible to the processor for speedy processing. Consider a scenario where you are sitting on the easy chair in you office cabin
and looking for a specific customer record. There is a small chunk of files lying on the table in front of you, you search but couldn’t find the records there. Next,you look into the drawers with relatively bigger chuck of files but the records won’t show up. You know that there is bigger chunk of files in the cupboard. So you get up, walk and search the files in the cupboard and still not able to find the records. You seem to be losing patience now and know that more work needs to be done to search the record in the big store room of records. so you walk to the store room, search the huge set of files and finally could locate the relevant record.

In analogy, You are the processor, the smaller chunk of files lying on the table is L1 Cache just very easily accessible to the processor with minimum latency. The drawer of the table is L2 Cache, the cupboard in the cabin is L3 Cache and the Store Room is the RAM (DDR) with maximum Latency. The higher the RAM & cache size, the faster the processing time. 


Inputs? Feedback? Please leave a comment..

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  1. Very help article! Usually when I buy a phone, I focus on the aspects of battery life, graphics, and the camera. It never occurred to me the importance of looking at mobile sensors specs and I will definitely pay more attention to that from now on. Other than that, keep up the good work with these insightful articles!

  2. Thanks Davide, What i have seen is it's common to go behind new released models without comparing specification and pros and cons..The fact is, this is not only limited to Smartphones 🙂

  3. I agree, a good article about a complicated decision we all take once in a while. Phone prices make them a big investment now so it's important to make an informed and educated decision.

    That being said, what phone would you reccomend if I were to purchase one next month? (no iPhone please)

  4. Thank you for the comment. It really depends on what is the main use. Say if you use it for frequent photography, you would need high Rear Camera pixel size and photo/video resolution. If you game a lot and run a lot of applications, look for multi-core high frequency processor, higher RAM Size and sensors. If you mainly use it for voice communication like i do, a basic model would suffice. It's really need based. .If you travel frequently, you would really need a very high mAH.. One input is to try the one drop down tool at that compares all specs for smartphones in one drop down you can quickly arrive at a decision..Note, you can always compromise on specs that will hardly be used:)..

  5. Thank you.. Xperia T2 Ultra is a fixed battery phone and with resolution of 720 x 1280 and RAM 1GB. A higher resolution and higher RAM would have been better though.. It's MHL enabled which is nice and let's to connect to a TV directly..

  6. Hey this is very helpful. I usually just consider the camera and graphics when I buy a phone, I don't even know about gyroscope and accelerometer. Thanks for the tips!

  7. Thanks for such a useful article. Especially with mobile phones we get dazzled by their marketing and video ads and influenced by peers and families. Good to know what we are actually getting for our money 🙂

  8. Wow there's so much more to consider than I usually think about. I'm not very techy so in the past I've focused on simple things like camera quality and phone size. This is a really helpful post for someone like me.

  9. There is so much more to think about when buying a new smartphone then I had thought. I typically just care about the camera and graphics like someone else said in the comments before. I also just tend to get the latest iPhone, when I'm up for my renewal, since I'm all about my iPhone.

  10. I really like how this post broke down a lot of stuff for me. I already know to check this stuff and like you said, depending on you needs, you pick the ones you want. However, what annoys me about phones is their cost, and being a student, it becomes hard to afford something good.

  11. So informative! I usually just take storage and camera since I take about a million photos of my kids. I never really thought about the other things. I will definitely have to refer back to this post the next time I need a new phone! Got to remember to look at the battery life too!

  12. I never much considered all the things on this list, I always wanted one I felt was good size, takes excellent pics and has enough space for taking pics of the little one. This is insightful.

  13. It is always such a big decision to buy a new phone. I always had an iPhone and just bought a Huawei p9 for the memory and camera qualities. Good article and thanks for sharing.

  14. I had no idea that a mobile phone that many different types of sensors. It seems like there is a lot I never took into consideration when buying a mobile phone and since I need a new one this guide would be perfect for me x

  15. Very helpful post for people who are in the market for a new cellphone. I made a mistake before when I bought a cellphone just because it was the "fad." Didn't even care to look at the specs. Ditched it after a few months. I am happy now with my new phone. It has all the features and specs that give me a great mobile experience.

  16. Gyroscope is so important to me. Pokemon go may or may not have taken over my life for a little while, so when I finally got a phone that was gyroscope compatible, it was like the world was made a new lol.

  17. I used to not care about the processors and the cores, I figured, who needs a quad core or more if it's just a phone. But you're definitely going to want something that can perform especially if you're going to use your phone for work.

  18. My husband is in the market for a new phone and I shared your post with him. He couldn't believe how many different things there were to think about! I know he's slightly obsessive about battery life and the camera is super important. Can't wait to see what he decides on!

  19. Thanks for this! So much information; this has helped me a lot as I'm about to get a new mobile phone, it's helped saved me stress and paying someone to help me with it; I'm so particular about the camera and storage but now, I know better. Thanks 🙂

  20. Wow! This is a very comprehensive and helpful guide. I wish I had this information before signing my latest mobile phone contract. My husband and I made a spur-of-the-moment decision when we should have slowed down and done our homework. Thank you for this super informative article.

  21. This is such great information. I always consider battery life. I have been with iPhone for a while now a really love it. It's so easy to use.

  22. Oh damn, buying a new phone is so stressful. I would always pic a couple of phones I like how they look and then give them to my hubby to look if they are good for what I need. Most of the times he denies all of them, and have to look for something else.

  23. I actually need to get a new phone so this the perfect guide for me to buy a phone that is right for me. Learning about the types of displays has been really helpful as I am looking for one that has good resolution and pixels x

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