PDC (ICT in context) Flashcards
What is a firewall?
a network security system which can be software-based but, more likely for a large company such as PDC
What does firewall look like?
in the form of hardware device positioned between the network and the Internet connection.
What is the job of a firewall?
to keep the network secure from unauthorized access and hacking.
What is Wi-Fi?
a wireless communication technology that allows devices to connect to a Local Area Network
has a range of 15 meters
How does Wi-Fi work?
The technology works by providing Wireless Access Points (WAP) which send and receive signals from the wireless devices, such as the handheld scanners used by PDC
How is Wi-Fi different to a wireless router?
Wi-Fi provides wireless connectivity to an existing LAN – it does not route traffic between network
How does a Power over Ethernet (PoE) work?
by using pairs of copper wire inside the data cable that don’t use data to carry power to the WAP
How can PDC save money?
Using WAPs - they do not need to have separate power cables run to them This saves in costs and allows the units to be deployed more flexibly.
Give an example of Wi-Fi
Bluetooth
What does the IEEE stand for?
Institute of Electrical and Electronics Engineers
Who set the standards of IEEE?
all networking standards are set by the 802 committee, which first met in February 1980!
When was Wi-Fi first introduced?
1997
What is a legacy system?
an older system that might exist in some part of a company network infrastructure. A legacy system is likely to use an older communication technology.
What is a bar-code scanner?
a device that can read printed bar-codes and output the data contained in the bar-code to a computer.
What are bar-codes used for and why?
stock control as the codes can be read quickly and easily.
What does the inside of a bar-code look like?
Inside the scanner is a light source, a lens and a light sensor which translates optical impulses into electrical ones
What does most bar-codes contain?
decoder circuitry which analyses the barcode data and translates the data into an electronic output that can be understood by a computer system
How do you provide flexibility of bar-code scanners?
many bar-code scanners are portable and able to connect to, and communicate with, a wireless network.
How could flexibility of bar-code scanner use be useful to PDC?
it would give workers a greater range of physical movement than they would have if the scanner was tethered to a wire.
How do bar-codes work?
Each bar-code has a unique number that identifies the parcel.
The bar-code does not contain the sender or recipient’s address.
A bar-code is scanned so the computer systems can use the unique number to look up the details.
How are bar-codes read?
by an optical scanner
What were the dashes of bar-codes inspired by?
by the dots and dashes in Morse code extended into a line to make them easier to read
What is a check digit?
something that is calculated using a mathematical formula and based on the other values in the code
What does the scanner look for in a bar-code?
if the check digit in the bar-code corresponds to the check digit