In telecommunications and computer networking, CTS or “Clear to Send” is a control signal used in the RTS/CTS (Request to Send/Clear to Send) handshake. Here’s a brief overview of CTS:
Purpose: The main purpose of the RTS/CTS mechanism is to mitigate the Hidden Node Problem in wireless networks and to manage access to the shared communication medium, ensuring that only one device transmits data at a given time.
Functionality:
- A device wishing to send data first transmits an RTS (Request to Send) packet.
- If the receiving device or access point (in a Wi-Fi context) hears the RTS and determines that it’s okay for the sender to transmit its data, it replies with a CTS (Clear to Send) packet.
- Upon receiving the CTS, the sender knows it’s clear to begin data transmission without interference from other devices.
Benefits:
- Collision AvoidanceBy ensuring that only one device transmits at a time, RTS/CTS helps avoid data collisions in the wireless medium.
- Efficient Use of BandwidthWith fewer collisions, less bandwidth is wasted on retransmissions.
- Hidden Node ProblemIn wireless networks, two devices might be in range of a common access point but not in range of each other. Using RTS/CTS ensures that if one device is transmitting, another hidden device will know not to transmit at the same time, reducing interference.
Usage: While RTS/CTS can provide several benefits, especially in busy networks, it introduces additional overhead because of the RTS and CTS packets. As a result, it’s not always used by default and is typically configurable depending on the network’s needs.
The CTS signal, in its essence, is an acknowledgment signal given by a receiving entity, indicating it is ready to accept data from a transmitting entity.
Key terms in plain language
Open a term for a concise explanation of language used on this page.
Fiber Internet
Internet delivered through strands of glass using light. Fiber commonly supports high capacity, low latency, and strong upload performance, but availability must be confirmed for the exact address.
Bandwidth
The amount of data a connection can carry in a given time, usually measured in Mbps or Gbps. More bandwidth supports more users, devices, and simultaneous applications.
Broadband
A general term for always-on, high-speed Internet access. Broadband can be delivered over fiber, cable, DSL, fixed wireless, cellular, or satellite networks.
Latency
The time it takes data to travel between two points. Lower latency improves voice, video meetings, cloud applications, gaming, and other real-time services.
Dedicated Internet Access (DIA)
A business-grade Internet connection with capacity dedicated to the customer rather than shared in the same way as typical consumer broadband. It often includes symmetrical speeds and an SLA.
SD-WAN
Software-defined wide area networking. It manages multiple connections and chooses paths based on application needs, performance, and policy to improve resilience and control.