Suggest an editImprove this articleRefine the answer for “What is bit-level transmission?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**Bit-level transmission** is the process by which data is transmitted one bit at a time (0 or 1) as a physical signal over a communication channel. **Key point:** the physical layer transmits bits but does not understand data structure, does not check for errors, and does not understand addresses.Shown above the full answer for quick recall.Answer (EN)Image**Bit-level transmission** is the process by which data is transmitted **one bit at a time (0 or 1)** as a **physical signal** over a communication channel. Put simply: bit-level transmission is the **sequential sending of zeros and ones** from one device to another. --- ## What "bit" means in bit-level transmission A **bit** is the smallest unit of information: - `0` or `1` Example of a bit stream: ``` 10110010 ``` The physical layer **does not know** whether this is: - text - an image - video - an IP packet To it, this is simply **a set of bits**. --- ## How bit-level transmission happens 1. The device takes a stream of bits 2. Each bit is converted into a signal: - an electrical pulse - a light pulse - a radio signal 3. The signal is transmitted over the medium (cable, fiber, air) 4. The receiver converts the signal back into bits --- ## What bit-level transmission looks like in different media ### Copper cable - 1 is a high voltage level - 0 is a low voltage level ### Fiber optic - 1 means light is present - 0 means no light ### Wireless communication - 0 and 1 are encoded as changes in the radio wave (frequency, phase, amplitude) --- ## Important point for interviews **Bit-level transmission ≠ packet transmission** - bit-level transmission is the **physical layer** - frames are the **data link layer** - packets are the **network layer** The physical layer: - transmits bits - does not know the structure of the data - does not check for errors - does not understand addresses --- ## Simple analogy Morse code: - a short signal is 0 - a long signal is 1 What is transmitted is the **signal**; the meaning appears later. --- ## Briefly, for the interview > **Bit-level transmission** is the transmission of data as a sequence of bits (0 and 1), converted into physical signals, without any understanding of their structure or meaning.For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.