Compare and contrast accessories & parts of mobile devices: CompTIA A+ 220-901 sub-objective 3.5

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Detailed (and official) description of CompTIA A+ sub-objective 3.5:

3.5 Compare and contrast accessories & parts of mobile devices.
> Connection types
– Proprietary vendor specific ports (communication /power)
– MicroUSB/miniUSB
– Bluetooth
– IR
– Hotspot/tethering
> Accessories
– Headsets
– Speakers
– Game pad
– Docking Station
– Extra battery pack/ battery charger
– Protective covers / waterproofing
– Credit card readers
– Memory/MicroSD

Welcome to ExamNotes by CertBlaster! This installment looks at the ports and accessories available on mobile devices. We’ll look at the connection types, the physical connection and any communication protocols that may be used. Enjoy!

Connection types


We’ll start today with the Connection types available for mobile devices and their accessories. We have already discussed Wi-Fi and Bluetooth in detail (in prior ExamNotes) but there is a third type that you need to be knowledgeable on is Near Field Communication (NFC). NFC is not a new technology, but it has experienced a resurgence through the proliferation of mobile devices and the main security feature of NFC, its transmission range which is roughly 10cm. Attackers have to be almost touching to be able to exchange data. This short proximity is seem as a feature on some devices such as tap and pay which exchanges payment information with a NFC capable reader at the cash register. Quick and easy. You can also exchange contact information with friends or clients by simply tapping compatible phones together. The ultimate business card!

Proprietary vendor specific ports (communication /power)

Each vendor introducing new technology will design proprietary connector types for power and data. As the technology becomes popular with users the manufacturers or the IEEE will agree upon and standardize a specific connection type that will used in the 2nd generation of devices.


Here are two connection types that became standard then one was phased out in favor of the other. The miniUSB connector was introduced as a digital camera or media player charger and data connector. It was only marginally smaller than the standard USB B connection and it wasn’t long before a replacement was designed and adopted, this was/is the microUSB. This connection was more durable and mobile device friendly. The micro USB was considerably smaller and was suitable to fit not only the media based devices but also the sleek thin Smart phones and Tablet PCs that were flooding the market.  The mass adoption of microUSB spelled deprecation for the miniUSB connector. You may see the miniUSB in the field but all new devices are considerably more likely to be microUSB than miniUSB.


The Bluetooth wireless connections were not as fast as its contemporaries (initially 2MBs) the ranges and speeds have been increasing fairly steadily as shown in the table. Special protocol features allow users to create Personal Area Networks (PAN).

Characteristics of different Bluetooth versions
Characteristics of different Bluetooth versions


Infrared transmissions use the invisible light spectrum to transmit low power signals to compatible devices. There are many applications that can utilize the technology, most notably remote control signaling for control of home theatre devices, garage door openers and any dedicated device that has an unobstructed line-of-sight between the devices. Some smart phones incorporate this technology to let users control their multi-media components.


a smartphone and a compatible USB cable is all that you need to connect your cellular internet connection to your laptop or tablet in a process called tethering, which allows the cellular device’s connection to be shared wirelessly to other devices. In this process the Internet connection is used to create a mobile hotspot, through which the other devices can access resources on the internet.


Practically any network capable and many device specific accessories can be connected used or shared. Here is the short list.


The diminutive size of most smartphones and even laptops makes sound reproduction a challenge. A good headset can be connected using a 1/8” headphone jack, USB or Bluetooth any of these connection types will provide high quality audio.

Speakers/Docking Station

Here again the device size and speaker quality will have the greatest impact on the sound quality. If you plan to use your mobile device for listening to music or watching movies the built in speakers in most mobile devices will not provide the most enjoyable experience.

photo of a tablet on its dock for comptia aplus
Tablet dock

Here the best choice would be a docking station containing stereo speakers and possibly a sub-woofer. There are many brand specific docks built exactly for your device.

Game pad – Here is where your computing horsepower display resolution and sound enhancements come together. You have a high speed computer high resolution display and superior sound. The last thing you will need is a superior game controller. It should have good response numbers. Here especially you do not want any missed actions poor response time. You can engineer a lot of problems out of your system. Right off the bat you want to avoid poor or bad connections by not using Bluetooth or IR controllers, the reason is simple. Since those devices nee a direct line of sight. Something as simple a your pet or a friend passing between your controller and the game console could get you killed in the game quickly

Extra battery pack/ battery charger

When you travel many airports train stations and hotel lobbies have charging stations for your devices. Just in case if you have the ability you should carry an extra battery and keep it charged.  It sounds simple but there are few things worse than having the foresight to have an extra battery and find that it’s dead! Also there is a handy power inverter that you can plug into a rental car’s cigarette lighter and charge your devices.

Credit card readers

If your business requires tanking payments, there is a very handy credit card readers that attach to your cell phone and validate credit cards over the internet.

Multi Smart card readers

For Memory/MicroSD carry a read/write USB adapter that will let your presentations or sales data to live on if your primary device fails.Keep the information on it up to date.

Protective covers / waterproofing

Lastly protect your devices from the elements using protective cases that will insulate it if dropped and keep it dry. Be smart and don’t blindly trust these protection past what common sense would indicate.

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That is all for Sub domain 3.5 and for Domain 3! Next up will be Domain 4. So be safe study hard and good luck on the test.


2 thoughts on “Compare and contrast accessories & parts of mobile devices CompTIA Aplus 220-901 sub-objective 3.5

  1. Thanks for providing the information about the accessories mobiles and laptops. nice blog and an informative blog good job.

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