Some devices have really small screens and it can be hard to see the information being displayed and people may have to squint to see small text or numbers or have to keep pinching the screen to zoom in on the text.
Resolution
Pixels are small boxes the more there is the smaller they are meaning that the screen looks much sharper and smoother. Having more pixels means that the boxes are smaller and with enough pixels you won’t even be able to notice them.
When a screen has a lower resolution screen everything will be really blocky and won’t look so nice especially images and videos and can even give people a headache.
Memory
Mobile phones have large amounts of memory to store all the applications, movies, games, pictures, videos etc. some even have memory card slots to extend the memory if the internal one runs out or to transfer data between devices.
Devices that don’t have extra slots for external memory will end up being full and meaning that the user will have to delete files to make room for anything new.
Cloud storage
Some phones have a feature to store data on cloud which can free up space on the internal memory and can be retrieved if your phone is lost or stolen by using the internet. The data is uploaded to the internet where it is stored.
Cloud storage can become costly and there is a limit on how much you can upload and sometimes the data can be lost or can be deleted which can be a concern.
Battery
The battery keeps the devices portable without having to be restricted by a wire with newer phones having big screens.
Higher resolution and faster processors mean that the batteries don’t last as long and need larger capacities which can raise the cost of replacing it.
Processor
The processor is the phone brain the more cores it has the faster it is and better at multitasking. The higher speed the core is the more it can handle e.g. 1 GHz has 1 billion cycles per second.
Sometimes the processor can get really hot, drain the battery life or turn the device off completely if it overheats.
Operating system
The operating system is the interface which you use to make use of the device there are four main ones: iOS, Android, Windows and blackberry which have different features.
Moving from different devices and OS’s can make it confusing for the user and some OS specific features may not be on that device.
App Stores
Each operating system has its own app store where you can browse what’s on offer, read user reviews and then download your chosen app. Smartphones can download programs which add features to it, there are many different types of apps including games, business apps, food apps, news apps etc.
People can add things onto the app store which doesn’t even work but will still charge you money wasting your time and having to make effort to get the money refunded.
Maps
Smartphones have an application which can track their location using GPS and help plan routes which can be useful when lost somewhere as phones also have 3g and 4g.
Maps on mobile devices can be unreliable at times especially when the signal is low or there is none at all sometimes the maps can think you are in a different location then what you’re actually in confusing you and making you think twice whether to follow the map or not.
Web browser
Phones have their own web browsers which use touch screens to make it easier to use and it works exactly the same as the ones on the computer with favourites, video streaming and multiple pages.
The web browser on mobile devices can have really small font making it hard to read and putting strain on the eyes or the browser can be really slow or lack a certain codec or program to stream videos or use other features.
Bluetooth
Bluetooth is used to connect to different devices without having to be in line of sight of each other and are useful for hands free kits like while driving, transferring data or even playing multiplayer games with nearby devices.
People can hack Bluetooth phones which would allow them to make calls using your credit. The signal can get interrupted with people moving by, the range of the signal isn’t long and it can cut out while in use, this can be annoying because it would force you to restart the download if you are downloading or reconnect the devices again.
4G and 3G
3G and 4G network is used to access high speed internet while on the go but it can cost lots of money especially if kept turned on because of different apps slowly using up data.
4G can become costly overtime especially if you download large files and if you go over your allowance the provider can charge you extra money if you are on a contract. The signal can be dropped at times like when going under a tunnel especially while using 3G. Some places do not even support 4G yet and still use 3G making 4G enabled phones useless.
Wi-Fi
This enables compatible devices to connect wirelessly to the internet either through your home network or via a Wi-Fi hotspot. This is usually much faster than connecting over a mobile network and won’t use up any data allowance you may have on your mobile contract.
Using Wi-Fi will drain the devices battery much more than if it was turned off because it keeps transferring data even if it is idle or constantly searching for new networks to join even while it is locked or there are none around wasting power.
Face recognition
The camera will be able to recognise the face and focus onto it for more detail and even be able to keep following it.
Facial recognition can fail and make the image look really fuzzy sometimes and you might not realise until you go back and view the image making you have to retake the picture if you still can.
Zoe shot
The HTC One has a feature which takes 20 still frames along with a 3 second video and also starts just before you fully press the button and also finishes 2 seconds after meaning that you are less likely to miss something that disappears.
Having this extra feature can take up extra space on the memory and over time may fill up the memory.
Retina display
Is a feature on the apple devices which had more pixel density so that the screen looks better and the pixels can’t be seen from normal distance. The iPhone 5 has an IPS screen meaning that it can be viewed from different angles without looking out of colour.
Gorilla glass
Gorilla glass makes the screen much stronger making it less likely to break from falls or knocks and also makes the screen less likely to have less deep scratches that don’t go away.
The disadvantage is that all glass is prone to breaking and being scratched easily.
Task 2
P3 – identify the protocols used by mobile communication devices, giving examples of their use.
802.11 protocols (Wi-Fi)
Wi-Fi transmits using 2.4 GHz or 5 GHz signals which is a lot higher than mobile phones so it can carry more data. For example it will be used when connecting a laptop to a router to access the internet. Wi-Fi uses 802.11 protocols which come in different types:
802.11a – transmits at 5 GHz and can send up to 54megabits of data per second.
802.11b– transmits at 2.4 GHz and can send up to 11 megabits of data per second making it the slowest but also the least expensive.
802.11g– transmits at 2.4 GHz and can handle 54megabits of data per second.
802.11n – can achieve speeds as high as 140megabits per second.
Wireless access protocol
Is used when accessing a mobile wireless network it would be used when accessing the browser, email and the internet in general while using a mobile device.
SMS protocol
Short message service is the delivery of short messages over the mobile networks. It is used to send messages to and from mobile phones. The message from the sending mobile is stored in a central short message centre which then forwards it to the mobile it was sent to. This means that in the case that the receiver is not available, the short message is stored and can be sent later. Each short message can be no longer than 160 characters.
P4 – Describe the technology used by a mobile communication device.
Infrared
Infrared is longer than visible light but shorter than radio waves and are also higher frequencies than microwave.
When devices are connected using infrared it is called beaming, the beam is invisible to humans and requires a clear line of sight to work so it can’t go through objects like walls etc. infrared is used with devices like remote controls and garage doors but is also used to send information from computers to mobile phones. Infrared communication requires something called a transceiver which is a receiver and a transmitter in both devices to communicate, sometimes will require software to synchronise the devices.
Bluetooth
Bluetooth transmits using low power radio waves using the frequency 2.45 GHz.
Bluetooth devices avoid interfering with each other because they send out very weak signals, the lower power limits the range to 10 meters lessening the change it will mess with other things like TV and computers. Bluetooth unlike infrared doesn’t require line of sight so it will work through objects. Up to eight devices can connect simultaneously but it’s unlikely that they would interfere with each other because they use technique called spread-spectrum frequency hopping which will make it rare for more than one device transmitting on the same frequency at the same time.
Wi-Fi
Wi-Fi uses radio waves. Computers use Wi-Fi by changing data into a radio signal and transmitting it using an antenna, the wireless router receives the signal and decodes it then the router sends the information to the internet. This is also works in reverse so the router receives the information from the internet changing it to a radio signal and sending it to the computers network adapter.
GSM
GSM is the most widely used cell phone technology it uses a SIM card which makes it easier to change phones while keeping the same number. There are different types of frequencies called single band, dual band, tri band and quad band some countries have different frequencies and require a different band quad band works in the most amount of places.
GPRS
GPRS is between GSM and 3G it offers speeds between 9.6kbits and 115kbits this allowed people to make phone calls and receive e-mails at the same time.
4G
4G is five times faster than a 3G network. 4G uses technology called Orthogonal Frequency-Division Multiplexing that is also used in Wi-Fi, it squeezes more data onto the frequency while reducing latency and interference, the data is split up and sent via small chunks in parallel. 4G also uses MIMO which uses both antenna arrays at both the transmitter and receiver to improve performance, this allows more data to be transferred without requiring more bandwidth or power. 4G may not work in different countries because of the different frequencies and will revert to 3G.
Task 3
M1 – Explain protection methods used to improve the security of data in mobile communications
Encryption
Encryption is needed so that people don’t have access to your network otherwise they can intercept your information.
WEP has two different encryption settings 64bit which is weak and 128bit which is better. WEP requires a password which is then generated into to a key. WEP is not the best because it can be easily cracked.
WPA is an improved version of WEP it has improved encryption methods like TKIP unlike WEP where people can create their own encryption key and access a secure network. With WPA all users have to use the same encryption and decryption key. WPA also implements EAP that authorises users instead of computers.
AES operates on 128 bits block ciphers, and comprises key lengths of 128, 192 and 256 bits. It is common to refer to the symmetric key AES encryption standard as AES-128, AES-192 and AES-256 depending on the key strength, it is used to protect networks from attack.
EAP is used in wireless networks. EAP protocol is not limited to wireless LAN networks and can be used for wired LAN authentication, EAP is more commonly used on wireless LAN networks because it would be hard for someone to plug in an Ethernet cable.
Passwords
Mobile devices like smartphones have passwords on their lock screens so that if it is lost or stolen your data is kept private, some phones have an option to erase the data if there are a certain amount of failed attempts at the password like on the iPhone.
Bio metric
This can scan for the owners eyes, check finger prints and motion. This feature on a device will only allow the owner to unlock the device, unlike passwords bio metric can’t be guessed.
Tracking
Smartphones like the iPhone have an app that will track the location of the device if it is stolen or lost using nearby Wi-Fi connections and mobile signals, it can be tracked by entering the same username and password that was on the device onto a computer or another apple product that will show the approximate location of the lost phone also an option to delete the data on it, make a large sound or display a message.
M2 – Compare different mobile transmission technologies.