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Connection Methods, dropped image link, dropped image link, dropped image…
Connection Methods
Wireless
WiFi
Wi-Fi is a means of connecting nodes in a network without the use of cables. Data travels over the airwaves. This freedom from cables comes at a cost though:
Disadvantages of WiFi:
• WiFi is much slower at transferring data than using cables
• WiFi gets lots of interference from other electrical devices which can cause packets to become corrupted while they are being transmitted.
• WiFi is capable of traveling through walls, doors and windows, which means it is less secure than using cables.
• WiFi signals are best if there is clear line of sight between the transmitter device (often a router or a WAP) and the receiving node.
Advantages of WiFi:
• Users are able to move around more freely - not tied to a desk.
• The fact that cable are not needed for adding new users can save a lot of money.
• It is possible for WiFi to handle a large number of users because there is no need for lots of ports.
• It is much easier to set up a WiFi network.
Channels
WiFi makes use of channels - this is clusters of frequencies that signals are sent and received using. In some scenarios, these channels can become very noisy due to other nearby wireless transmissions. It is possible to move a WiFi transmitter from one channel to another which is quieter and has less interference.
Wireless Encryption
Wireless networks broadcast data. This means that all of the data that network users are sending and receiving is being passed through open airspace. Therefore, it is essential that these packets are encrypted. WiFi encryption is used for this. A handshaking protocol is used to ensure that the receiver is one who it should be.
SSID (Service Set Identifier) is the way the network is identified. You can set the name of the SSID. Make it hidden. And make the SSID password protected.
Bluetooth
Bluetooth is a short range wireless transmission technology which is often used to connect devices such as smartphones. It is possible to buy a Bluetooth USB device so that other computer systems can connect to devices using this technology.
Bluetooth devices need to be near each other to get good data transfer speed. At best, transmission of data will be about 2mbps.
Microwave connection
Traditionally, this connection type is often used to provide access to the internet for people who live in particular rural areas where there is no existing infrastructure for cabled connections. It has low latency, quick to install and uncontended connection. However, there must be a line of sight from an antenna to the dish and this connection type can be greatly effected by the weather.
Infrared connection
This connection method was primarily a feature of older mobile phones - although some smart phones still make use of it to transfer data over short distances. A clear line of sight is needed and any data interrupting would lead to data failing to be delivered. This connection allows 4mbps at best.
Infrared connection speed has been surpassed by Bluetooth as well as WiFi. Scientists have been using this te4chnology again and find ways for it to transmit data at very fast speeds.
Laser connection
Laser based internet connections are capable of transferring data at gbps over large distances, as long as each point has line of sight. This is a new and constantly developing option for connecting computer systems.
The use case for this technology is much the same as for microwave - but the maximum distance is potentially increased. In some countries, this technology is already being used.
Satellite connection
Satellite internet is designed for those who are in isolated, rural locations or who for some reason have no access to other connection methods. Satellite internet access is typically slower than other options because the data must be sent to an satellite dish that is in orbit before it is then bounced back to the head office of the ISP, where the data packets can be forwarded to the internet. This kind of connection suffers from higher latency because of the great distance the packets must travel.
GSM
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This is the protocol for how mobile phones could communicate using cellular networks. It was first set up as European wide standard and the rest of the world then also adopted it.
GSM allowed mobile phones to communicate using data as well as voice. Data transfer speeds were slow.
3G
3G = Third generation.
This is the third generation of wireless, mobile communication. 3G allowed data communication speeds through a cellular network of at least 144 kbps and in some case several mbps. This technology suppourted new generations of smartphones, which were able to access the World Wide Web and quickly download video and audio files as well as apps.
3G is still in use today in many places around the world. Many smartphones will switch to 2G, 3G, 4G and 5G depending on the connections available.
4G
4G = Fourth generation
This is the next step up after the 3G mobile internet connection. This technology makes it possible to download data at about 12-15mbps. It's 5 times faster than 3G and makes it possible to stream video at high resolution and take part in video conferencing.
Some home users may chose to use a 4G hotspot as their primary means of accessing the World Wide Web at home. Latency, Bandwidth and cost of 4G is usually low and can be comparable to traditional home broadband options.
Fibre Optic Cable
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Data is transmitted in light beams which bounce off the sides of the cable and are interpreted by the receiver.
The limiting factors of data transmission for this medium is the speed that the data can be read from the recipient as well as sent from the sender.
Copper cable
Copper wire has long been used to transmit data in computer networks. It has also been the most popular choice of material for transmitting voices on public phone networks.
The most common cabling standards are known as CAT-5 or CAT-6. This comprises of twisted cables. Twisted cables are less likely to conduct electricity from outside sources. It also suffers from less interference.
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