Redes Locais - LAN - Aula 03 - Sistemas de Cabos - 1ª parte - Meios Físicos

Summary

This educational video script from Professor Badaró's channel focuses on cable systems, crucial for computer networking. It's divided into three parts: physical media, network cards, and structured cabling. The script explains various physical mediums like UTP, coaxial cables, and fiber optics, detailing their characteristics, limitations, and maximum transmission distances. It also covers wireless transmission, emphasizing the 2.4 GHz and 5 GHz bands used in Wi-Fi. The video aims to educate viewers on the importance of choosing the right physical medium to support network speed and connectivity.

Takeaways

• 😀 The video series focuses on studying cable systems, divided into three parts: physical media, network cards, and structured cabling.
• 🔧 Physical media are crucial for the functioning of a network, including cables and electromagnetic waves.
• 🌐 The maximum cable length and transmission speed are determined by the material characteristics and the access method specified in OSI layer 2.
• 📡 Guided transmission media include twisted pair (UTP/STP), coaxial cables, and fiber optics, which are wired connections.
• 📻 Coaxial cables consist of a copper core, an insulating layer (PVC or Teflon), a shielding layer (copper or aluminum mesh), and an outer protective plastic layer.
• 🔌 Coaxial cables are used in cable TV and for connecting certain peripherals to a network, with two types: thick (RG-8) and thin (RG-58).
• 💻 Twisted pair cables are commonly used in daily work, with categories like Cat 5e, Cat 6, Cat 6a, Cat 7, and Cat 7a, each with different bandwidth and speed capabilities.
• 🌟 Fiber optic cables are made of glass filaments coated with a substance that reflects light internally, minimizing signal loss, and are covered by a protective plastic layer.
• 🌐 There are two types of fiber optics: multimode, which uses LEDs and can transmit up to 2 km, and single-mode, which uses lasers and can transmit up to 5 km.
• 📶 Wireless communication is based on the transmission of electromagnetic waves through the air via antennas, with common frequencies being 2.4 GHz and 5 GHz.

Q & A

What is the main topic of the video series?

The main topic of the video series is the study of cable systems, specifically focusing on physical media, network cards, and structured cabling.

What are the three main videos planned in the series?

The series is divided into three videos: one about physical media, another about network cards, and the third about structured cabling.

What is the importance of physical resources in a network?

Physical resources are crucial for the functioning of a network, as they determine the maximum cable length and the type of signal transmission, which in turn affects the network's speed and performance.

What are the different types of guided transmission media mentioned in the script?

The guided transmission media mentioned are twisted pair (UTP), coaxial cable, and fiber optic.

What is the difference between coaxial cable and twisted pair cable?

Coaxial cable has a copper core with an insulating layer of PVC or Teflon and a shielding layer of copper or aluminum mesh. Twisted pair cable consists of two insulated copper wires twisted together, which can be shielded (STP) or unshielded (UTP).

What are the two types of coaxial cables discussed and their uses?

The two types of coaxial cables are thick coaxial (RG-8) and thin coaxial (RG-58). Thick coaxial is rigid and difficult to handle, used for connections up to 500 meters, while thin coaxial is more flexible and can carry a signal up to 185 meters.

What is the maximum distance that a Category 5e UTP cable can support?

A Category 5e UTP cable can support a signal up to 100 meters in length.

What is the difference between Category 5e and Category 6 cables?

Category 5e has a bandwidth of 100 MHz and operates at a speed of 100 megabits per second, while Category 6 has a bandwidth of up to 250 MHz or 500 MHz and operates at a speed of 1 gigabit per second.

What is the main advantage of fiber optic cables over copper cables?

Fiber optic cables have less signal loss and can transmit signals over longer distances compared to copper cables, and they are immune to electromagnetic interference.

What are the two types of fiber optic cables and their main characteristics?

There are two types of fiber optic cables: multimode and single-mode. Multimode cables use LEDs for lower cost and have a larger core diameter, suitable for shorter distances. Single-mode cables use lasers for higher bandwidth and have a smaller core diameter, suitable for longer distances.

What are the two main frequency bands used for wireless networks and their characteristics?

The two main frequency bands used for wireless networks are 2.4 GHz and 5 GHz. The 2.4 GHz band has a longer range but is more susceptible to interference, while the 5 GHz band offers higher speeds but has a shorter range and is more easily obstructed by physical barriers.