Computer Network Tutorial

Introduction of Computer Network Types of Computer Network Network Topology Computer Networking Architecture Transmission Modes (Data Flow) Basic Networking Devices Integrate Services Digital Network (ISDN)


OSI Model TCP/IP Model

Physical Layer

Digital Transmission Analog Transmission Transmission Media Switching

Data Link Layer

Error detection and Error correction Data Link Control Multiple Access Aloha

Network Layer

Network Layer - Logical Address Address Mapping Unicast Routing Protocol

Transport Layer

Process to Process Delivery User Datagram Protocol Transmission Control Protocol Stream Control Transmission Protocol Session Layer and Presentation Layer

Application Layer

Domain Name System Application Protocol E-mail Cryptography


Classes of Routing Protocols Classification of Routing Algorithms Controlled Access Protocols in Computer Networks Differences between IPv4 and IPv6 Fixed and Flooding Routing Algorithms Advantages and Disadvantages of Fibre Optics Cable APIPA Difference between Active and Passive FTP Fiber Optics and its Types Method of Joining and Fusion of Fiber Optic Cable Define Framing in Computer Network Disadvantages of Computer Network Mesh Topology Diagram in Computer Network Ring Topology in Computer Network Star Topology in Computer Networks 4G Mobile Communication Technology Advantages and Disadvantages of LAN Advantages and Disadvantages of MAN Advantages and Disadvantages of WAN Application Layer in OSI Model Cyclic Redundancy Check Example Data link layer in OSI model Difference between Transport and Network Layer Hamming Code Example Network Layer in OSI Model Session Layer in OSI Model Transport Layer in OSI Model Two Port Network in Computer Networks Uses of Computer Networks What is Computer Network What is Framing in a Computer Network Advantages and Disadvantages of Bus Topology Difference between Star Topology and Bus Topology Subnetting in Computer Network Subnetting Questions and Answers What is Bus Topology What is Network Topology and Types in Computer Networks Access Control in Networking Basic Characteristics of Computer Network Benefits of SOCKS5 Proxy in Computer Networks Computer Network viva Questions Difference between BOOTP and RARP Difference Between Network Topologies and Network Protocols Difference between NFC and RFID Difference Between Point-to-Point Link and star Topology Network Differences Between MSS and MTU Differences Between Trunk Port and Access Port Different Modes of Communication in Computer Networks MIME Protocol in Computer Networks Modes of Communication in Computer Networks Network Attack in Computer Network Port Address in Networking Simplest Protocol in Computer Network Sliding Window Protocol in Computer Network Stop And Wait Protocol in Computer Networks TCP 3-Way Handshake Process in Computer Networks What is a Proxy Server What is APPN What is ICMP Protocol What is Point-to-Point Protocol What is Port Address in Networking What is the HDLC Protocol What is VRRP Protocol Difference Between Analog and Digital Signals Difference Between Hub and Repeater Difference between Repeater and Switch Difference Between Transparent Bridge and Source Routing Bridge Source Routing Bridge in Computer Networks Transparent Bridge in Computer Networks Transport Protocol in Computer Networks Types of CSMA in Computer Networks What is Wired and Wireless Networking Network Security in Computer Network Disadvantages of Extranet Difference Between TELNET and FTP Define Protocol in Computer Networks Guided Transmission Media in Computer Network What is a Gateway in a Computer Network IGMP in Computer Networks LAN Protocols in Computer Networks MAN Meaning in Computer Modulation Techniques in Computer Networks Switching in DCN TCP/IP Applications What is IGMP? What is Modem in Networking What is Non-Persistent CSMA Difference between Cell Splitting and Cell Sectoring Forouzen Computer Network Open Loop and Closed Loop Congestion Control Types of Cluster Computing WAP-Wireless Access Point What are the elements of the Transport Protocol Difference between Gateway and Switch Flow Control in Data Link Layer Body Area Network Flooding in Computer Network Token Ring in Computer Networks VoIP in Computer Networks What is Infrared Transmission Congestion Control Techniques Forward Error Correction (FEC) Switching Techniques What is Telnet in Computer Network What are the Types of IPv4 Addresses IEEE 802.6 (DQDB) IEEE 802.15.4 Technology What is HDLC (High-level Data Link Control)? What is SMS Hubbing in Telecom? Circuit Switching in Computer Networks Communication Satellites in Computer Networks Features of HTTP Protocol IMAP4 (Internet Message Access Protocol) Internet Services How to Set up a Wireless Router Internetwork Routing in Computer Networks Distributed Computing System Features of GSM The 802.11 MAC Sublayer Protocol What is IEEE 802.3? What are Hubs and Switches in Computer Networks? What is Modem in a Computer Network? What is multicasting in Computer Networks? GSM -The Mobile Station What is Network Server? Slotted Aloha in Computer Network What is Ethernet in Computer Networks What is Arpanet? Radio Access Network (RAN) TCP 3-Way Handshake Process PING SWEEP (ICMP SWEEP) Print Server Private IP Address Security Services in Computer Networks Protocol Data Unit (PDU) CSMA with Collision Avoidance (CSMA/CA) What is Gateway in Computer Network? Advantages of Networking Data Link Layer Design Issues DHCP in Computer Networks Internet Security Association and Key Management Protocol (ISAKMP) What is Switch Hub? Telnet Full form in Networking Multimedia Systems Quality of Service in Computer Networks What is Carrier Sense Multiple Access (CSMA)? What is Circuit Switching What is Duplex Network? What is Web Protocol Network LAN Technologies Classes in Computer Network Low-Density Parity Check (LDPC) Wireless Internet Service Providers(Wisps) What is Handshaking?

What is Infrared Transmission


For a long time, the only devices that could employ infrared light transmissions were wireless slide projector remote controls and TV remote controls. They are, nevertheless, beginning to hold a rather significant, although still limited, role. Similar to microwave systems, infrared systems use the infrared light spectrum to direct a concentrated light beam toward a receiver; however, they do not require a reflecting dish. Instead, as illustrated in Figure, a pair of lenses is utilized, with a focused lens being used in the transmitting device and a collective lens in the receiving device. Rather than being a conducted communication system, infrared is an airwave. They do give a sizable bandwidth despite being mostly used for short-haul transmission; however, there is a chance of interference.

What is Infrared Transmission

Benefits include quick deployment, particularly as there are no license requirements, unlike what is usually the case with microwaves. Furthermore, infrared provides a big bandwidth at a comparatively low cost. However, just like microwave systems, infrared systems also suffer from environmental interference and need line-of-sight. Additionally, error performance is acceptable. Furthermore, infrared has a distance restriction. Nonetheless, for buildings, infrared is frequently a desirable substitute for private cabled networks or leased lines.

Frequencies used by the preceding cell can be reused by the forward cell. Sharing the same frequency band is aided by this. One frequency can accommodate a large number of calls, particularly when digital phones are being used.

Applications and Implications

  • Communication: Data Exchange and Remote Controls

In the world of communication, infrared is still widely used, especially in consumer devices. One common example is the infrared remote control, which is highly valued for its dependability and simplicity. Beyond this, infrared data exchange is still useful for secure transactions and in places like some hospitals or secure government buildings where radio frequency communication can be harmful or forbidden.

  • Medicine: Using Infrared for Treatment and Diagnostics

The application of infrared technology in medicine is very beneficial. Infrared imaging has therapeutic uses, such as photobiomodulation therapy for pain management and inflammation reduction, and diagnostic uses, such as non-invasive temperature readings and vascular inspection. Early illness identification is aided by the comprehensive tissue sample analysis provided by infrared spectroscopy.

Applications in Industry and Defence

 Because they can identify heat patterns and energy loss, infrared sensors play a critical role in the industrial sector for quality control, maintenance, and process monitoring. The military still uses infrared technology for night vision, target acquisition, and surveillance. Rangefinders and missile guidance systems now rely heavily on infrared lasers.


The following are the requirements for infrared transmissions:

  • For an infrared data link, several standards have been created (IRDA).
  • The bidirectional communications protocols used in cordless devices including mouse, keyboards, joysticks, and handheld computers are provided by the IRDA-C standard.
  • The bit rate and distance area of the IRDA-0 standard are 75k bits/sec and 8 meters, respectively.
  • A further standard exists, referred to as IRDA-1. It can support data rates ranging from 115 kb/s to 4 Mb/s across a maximum distance of 1 meter. As a wireless substitute for connecting devices, including PCs, to printers, the infrared data link was developed.

Benefits of Infrared

  • The primary benefit of infrared technology is its ease of use and incredibly low-cost senders and receivers, which are built into almost all current mobile devices.
  • Infrared radiation doesn't require any licensing, and shielding is quite easy.
  • Infrared data association, or IrDA, is an interface found on PDAs, laptops, notebooks, mobile phones, and other devices.
  • The transmission of infrared cannot be interfered with by electrical devices.

The drawbacks of infrared

  • The reduced bandwidth of infrared transmission in comparison to other LAN technologies is one of its drawbacks.
  • Restricted transfer rates to 115 Kbit/s; yet, even 4 Mbit/s is a relatively low data rate, as we all know.
  • The fact that infrared can be easily insulated is their primary drawback.
  • Barricades and other obstructions are in the way of infrared transmission.
  • Generally, a direct link, or line of sight (LOS), is required for high data rates and good transmission quality.

Characteristics of Infrared Transmission

Special infrared emitters and detectors are required for infrared systems. There are two methods for transmitting infrared data. While carrier modulation is used in the second way, direct modulation is used in the first. Since wireless local area networks (WLANs) exclusively employ the direct modulation approach, it is explained below.

Direct Modulation

In optical Fiber systems, direct modulation—also known as on-off keying—is frequently employed. A binary 1 turns on a light source, often an LED, and a binary 0 turns it off. The system depicted in Figure is comparable to the direct modulation system. Before modulation, the source bit stream is encoded using a common encoding method. Next, a modulator is used to modify the encoded data. To lower the power needs, pulse position modulation or a related modulation technology is used. The LED gadget is then fed a modulated signal. An optical band-pass filter is used at the receiving end to pick the necessary band that has the transmitted signal component in it. A photodetector produces a modulated electrical signal. From here, the encoded data is extracted by a demodulator, and a decoder recovers the original data. In a room or small space where the transmitter and the receiver are in the line of sight, direct modulation is frequently utilized.

Operating Modes

There are two ways to use infrared connections. There are two types of modes: diffuse (omnidirectional) and direct (point-to-point). The light emitter is pointed straight at the detector when using the point-to-point mode. Therefore, photodetectors with lower sensitivity or low-power emitters can be employed. It is sufficient for this style of operation to establish a direct wireless link between two portable devices. Directed systems can be used outside and have a good range of many km. It provides the maximum throughput and bandwidth as well. High-performance directed IR is limited to the implementation of stationary sub-networks, as it is not practicable for mobile users.

When operating in the diffuse mode, the source's infrared light is visually dispersed over a large region. Consequently, broadcast operation is appropriate for this mode. Omni-directional infrared systems have a relatively short coverage range, usually only covering 30 to 60 feet. They are sporadically employed in particular wireless local area networks. One transmitter can send out a signal to all of the room's detectors, each of which has a different phase. The differences in the travel length between the transmitter and receiver are what cause the phase variation. Numerous light reflections also bring on these phase variations. Multipath dispersion is the name given to this phenomenon. In a typical room setting, this issue will have little impact on communication. It is possible to achieve a satisfactory signal rate of up to 1Mbps. Inter Symbol Interference is the main issue after this rate.


Consumer electronics frequently use infrared transmission for short-range data transfer and remote controls. It is appropriate for some applications, like security systems and medical devices, because of its energy efficiency and line-of-sight feature. However, more adaptable wireless technologies like Bluetooth and Wi-Fi have become competitors due to drawbacks like the requirement for direct visibility and a low effective range. In spite of this, infrared technology still has a few specialized uses and can be useful in some situations.