What is network latency?
Network latency is the time that elapses between a request for information and its arrival. Because it takes time for a signal to pass through wire or fiber, some latency will always be present, but slow servers, inefficient data packing and excessive network hopping can increase delays. One of the main causes of high latency is the increasing demand for attention from various applications competing to use the network, which occurs when too many people are streaming, chatting and playing on their personal devices over the same network at the same time.
What requires low latency?
Whenever a “real-time” experience is important, very low latency for optimal performance is required. Examples of this are video conferencing, gaming and critical functions like remote surgery. If latency is even a few milliseconds too slow, users experience a noticeable and frustrating “lag” in their connection. The closer it is to zero, the better the user experience.
What problem are we solving?
Latency is one of the most important metrics of broadband performance. People begin to detect delays at about 20 milliseconds, so network latency must be decreased to near-zero in order to provide the “real-time” digital experiences users want. Latency is critical in areas like VR gaming and telesurgery where even a half-second delay is too long.
How will we get there?
Optimizing Traffic Flow
Our Low Latency DOCSIS technology decreases latency to just 1 millisecond for many applications by giving latency-sensitive applications a higher priority without slowing down all other data.
Low Latency DOCSISBuilding a Delay-free Wi-Fi
Even if a user’s modem has good latency, a poor Wi-Fi connection can still cause a significant “lag”—consecutive delays of varying length—that can ruin an online experience. CableLabs is working on applying some of the Low Latency DOCSIS technologies to Wi-Fi access points to reduce the latency and jitter of data traffic over Wi-Fi.
Low Latency Wi-Fi (Login required.)
Improving the Mobile Experience
Backhaul is a wireless cell tower connection to the internet, essential for LTE and 4G/5G small cell deployment. To meet mobile users’ increasing demand for more bandwidth, our Mobile Xhaul (formerly Mobile Backhaul) and vRAN Fronthaul solutions maximize mobile network performance connected to the cable DOCSIS-based wireline network.
Mobile Xhaul and Fronthaul vRANLatency Measurement
Understanding the latency characteristics in each portion of the network is vital for MSOs. The “Latency Measurement Metrics and Architecture” report recommends latency metrics to track and describes an architecture to implement in operator networks. The simple end-to-end latency measurement framework uses IETF’s STAMP and LMAP technologies. A measurement software prototype is available for use from the CableLabs Common Code Community (C3) program and contains session reflectors, measurement agents and controller/collector components. A specification of latency test definitions and STAMP extensions will be published soon.
Latency MeasurementFixing the Internet
The root cause of high latency is the design of Transmission Control Protocol (TCP) that governs how packets of data are sent over the internet. Designed in 1981, TCP was built for bulk delivery of information that tends to queue up packets of data and then send it all at once. And since queues often cause delays, this system is prone to latency. As part of the Internet Engineering Task Force, CableLabs is working on a new, 21-century version of TCP that maximizes capacity and eliminates latency at the same time.
L4S Technology
