## Fundamental Knowlegde for Wireless Communication
Day 3: July 21th, 2021

###### tags: `PNJ` `5G O-RAN` `ITB NTUST 5G course`

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### 3 Most Important Aspects
1. Wireless Communication
2. Wireless Data Communication
3. Huffman and Shannon Fano
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### Summary
- Wireless Communication
Wireless communications is a type of data communication that is performed and delivered wirelessly. This is a broad term that incorporates all procedures and forms of connecting and communicating between two or more devices using a wireless signal through wireless communication technologies and devices. There are 7 layers in the Open Systems Interconnection (OSI). Media Layer to define network transmission media, data synchronization bits, signaling methods, network architecture. Wireless technology is an implementation of the Physical layers and Data layers. The modes of wireless communication are Radio, Free-Space optical, Sonic, and Electromagnetic induction.

- Wireless Data Communication
Wireless data communication is a technology that uses the radio spectrum to transmit signals through the atmosphere. It may carry analog or digital signals and can be used on LANs or WANs in one- or two-way networks. Specific wireless data communication applications and technologies transmit signals through distinct segments of the radio spectrum (between the frequencies of 30 Hz and 300 GHz). Supporting technologies include Wi-Fi is a wireless local area network that enables portable computing devices to connect easily with other devices, peripheries, and the Internet; Cellular data service offers coverage within a range of 10-15 miles from the nearest cell site ; Mobile-satellite communications may be used where other wireless connections are unavailable, such as in largely rural areas or remote locations ; Wireless sensor networks are responsible for sensing noise, interference, and activity in data collection networks.

- Difference between Huffman and Shannon Fano Algorithm
Results produced by Huffman encoding are always optimal. Shannon Fano sometimes does not achieve the lowest possible expected code word length. The Huffman coding uses prefix code conditions while Shannon fano coding uses cumulative distribution function. However Shannon Fano algorithm also produces prefix codes.
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### Comment
Wireless data communications allows wireless networking between desktop computers, laptops, tablet computers, cell phones and other related devices. It has many benefit such as: speed, flexibility, and network efficiency. And more easy to implementation than wired technology.
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