CS (Circuit-switched)

Circuit-switched (CS) is a type of telecommunications network technology that establishes a dedicated physical connection or "circuit" between two communicating devices for the duration of the conversation or data transfer. This means that during the entire communication session, the network allocates a fixed amount of bandwidth and resources to the two communicating devices, which are exclusively available to them.

In a circuit-switched network, communication sessions are established by setting up a dedicated path or circuit through the network. The circuit is typically made up of multiple links or segments that are connected end-to-end, forming a continuous path for the transmission of data. The circuit remains in place until the communication session is terminated, at which point the resources are released and made available for use by other devices.

CS technology has been around since the early days of telecommunication networks, when voice calls were the primary mode of communication. CS networks were originally implemented using analog technology, but with the advent of digital technology, digital circuit-switched networks were developed. Digital CS networks provide better call quality, greater capacity, and more advanced features than analog networks.

Circuit-switched networks can be classified into two types: circuit-switched voice networks and circuit-switched data networks. In voice networks, the circuit is used exclusively for voice communication. In data networks, the circuit is used for the transmission of digital data, including email, web browsing, and file transfer.

One of the main advantages of CS networks is the high level of reliability they offer. Since the circuit is dedicated to a single communication session, there is very little chance of data loss or network congestion. The connection is also highly secure, since the circuit is not shared with any other devices.

Another advantage of CS networks is that they are highly efficient in terms of bandwidth usage. Since the circuit is dedicated to a single communication session, there is no need for overhead or control data to be sent along with the actual data being transmitted. This means that the entire bandwidth of the circuit can be used for the transmission of user data.

However, CS networks also have some disadvantages. One of the main drawbacks is that they are not very flexible. Once the circuit is established, it cannot be used for any other purpose until the communication session is terminated. This means that if the circuit is not being used, the resources allocated to it are wasted.

CS networks are also not very scalable. Adding additional capacity to the network requires the installation of additional physical circuits, which can be expensive and time-consuming. This makes it difficult for CS networks to keep up with the ever-increasing demand for bandwidth and capacity.

In addition, CS networks are not well-suited for handling bursty traffic, such as internet traffic. Since the circuit is dedicated to a single communication session, there is no way to share the bandwidth with other devices. This can lead to network congestion and poor performance, especially during peak usage periods.

Despite these drawbacks, CS networks are still widely used today, especially in the telecommunications industry. They are often used for voice communication, as well as for data communication in certain applications where reliability and security are critical.

Examples of CS networks include the Public Switched Telephone Network (PSTN) and the Integrated Services Digital Network (ISDN). These networks are still in use today, although they are gradually being replaced by newer technologies, such as packet-switched networks.

In summary, circuit-switched networks are a type of telecommunications network technology that establishes a dedicated physical connection or "circuit" between two communicating devices for the duration of the conversation or data transfer. They offer high reliability and security, as well as efficient bandwidth usage. However, they are not very flexible, scalable, or well-suited for handling bursty traffic. Despite these limitations, circuit-switched networks are still widely used today, especially in the telecommunications industry.