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TCH/FS Traffic Channel using Full Rate Speech

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TCH/FS (Traffic Channel using Full Rate Speech) is a dedicated communication channel in mobile networks that is used for carrying voice calls using full-rate speech transmission. It employs coding techniques that preserve the original quality of the speech signal, providing clear and natural voice reproduction during mobile calls.

Here are the key aspects and features of TCH/FS:

  1. Traffic Channel: TCH/FS is a dedicated channel within a mobile network that is specifically allocated for carrying voice traffic. It is used to establish a connection between a mobile device (UE) and the base station (NodeB in 3G or eNodeB in 4G/5G) for voice communication.
  2. Full Rate Speech: TCH/FS is designed to transmit speech signals without significant compression or loss of quality. It supports full-rate speech, which means that it can transmit speech at the original rate without excessive compression or distortion. This ensures a high level of voice fidelity and clarity, offering a satisfactory user experience during mobile calls.
  3. Speech Coding and Decoding: TCH/FS employs speech coding techniques to compress and decompress speech signals. The speech coding algorithm used in TCH/FS maintains the quality of the speech by minimizing the loss of information during the encoding process. At the receiving end, the decoding process reconstructs the original speech signal for the listener.
  4. Codecs for Speech Compression: Various speech codecs can be used in TCH/FS, depending on the specific mobile network technology. For example, in GSM (2G) networks, the Full Rate (FR) codec is commonly used, which provides a speech sampling rate of 8 kHz and a bit rate of 13 kbps. Other codecs like Enhanced Full Rate (EFR) and Adaptive Multi-Rate (AMR) are used in newer generation networks.
  5. Speech Quality and Fidelity: TCH/FS aims to provide high-quality voice transmission by preserving the original characteristics of the speech signal. The coding algorithm used in TCH/FS ensures minimal distortion and loss of speech information, resulting in clear and natural voice reproduction at the receiver's end.
  6. Efficient Bandwidth Utilization: While TCH/FS prioritizes maintaining speech quality, it also considers efficient bandwidth utilization. The coding algorithms strive to strike a balance between speech quality and the efficient use of network resources. By carefully selecting the appropriate codec and bit rate, TCH/FS optimizes the use of available bandwidth.
  7. Interoperability and Standardization: TCH/FS is standardized and widely adopted across different mobile network technologies, including GSM, UMTS (3G), LTE (4G), and 5G NR (5G). The standardization ensures interoperability between different network equipment and mobile devices, allowing seamless voice communication across various networks.
  8. Integration with Other Services: TCH/FS is primarily used for voice calls in mobile networks. However, it can also be integrated with other services such as circuit-switched data transmission, supplementary services like call waiting and call forwarding, and other voice-related features supported by the mobile network.

TCH/FS (Traffic Channel using Full Rate Speech) is a dedicated communication channel in mobile networks that provides high-quality voice transmission without significant compression or loss of speech quality. By employing coding techniques that preserve the original speech signal, TCH/FS ensures clear and natural voice reproduction during mobile calls, delivering a satisfying user experience.