What Is Low Latency?
Latency refers to the time required for a data unit to be transmitted from one point to another on a network. If the network transmits data with the minimum delay, it is called low latency. Low latency is typically measured in milliseconds or microseconds. However, the specific low latency indicator depends on the specific application, user expectation, and industry standard.
The ability to build low-latency networks has become one of the important competitive features of network products. Huawei's intelligent lossless network solution can build high-quality and low-latency networks.
What Is Latency?
Latency refers to the time taken to transmit data from one point to another on a network. Low latency is the capability of a network to transmit data with the minimum latency. Low latency is typically measured in milliseconds or microseconds. However, the specific low latency indicator depends on the specific application, user expectation, and industry standard.
A low-latency network is one that has been designed and optimized to reduce latency as much as possible. However, such a network cannot reduce the latency caused by factors outside the network.
What Causes Latency?
Latency is inevitable when service signals are transmitted over the network. From the time when a user sends a request to the time when the user receives a response, each process of data transmission on the network generates a certain amount of latency, which can add up to discernible wait times for the user.
Generally, the following factors affect the latency, which in turn affects the response capability and efficiency of the system and network during data processing and operation execution.
- Network bandwidth: Higher bandwidth allows more data to be transmitted over the network within a given time range. Lower bandwidth will increase latency because it reduces the amount of data that can be transmitted in the network in a given period of time. However, high bandwidth does not guarantee low latency because the actual transmission time of data also depends on other factors.
- Transmission distance: The distance over which data needs to be transmitted is also one of the main factors affecting latency. A longer distance between communications devices results in higher latency.
- Transmission media: The transmission medium, such as optical fiber, copper cable, or wireless signal, also plays an important role. The transmission speed and sensitivity to interference that are inherent to each medium may affect the transmission time of signals. For example, fiber optic cables typically generate lower latency than copper cables because of the higher speed of light through glass or plastic compared to electrical signals through copper.
- Network device: Data needs to be transmitted through different network devices on the network, such as routers and switches. The processing time of such devices also affects the latency. This is because it takes time for each device to process and forward signals. The number of hops or intermediate devices between the source and target as well as the processing speed of each device also affect the overall latency.
- Network packet loss: Packet loss caused by network congestion also increases the application latency and decreases the throughput. On a congested network, multiple data packets compete for limited transmission resources, which may cause message delay or data loss on the network.
Why Do We Need Low Latency?
Low latency is critical to user experience. With the in-depth development and explosive growth of mobile Internet, cloud computing, and private line services, as well as the emergence of services such as the Internet of Things (IoT), 5G, Augmented Reality (AR), Virtual Reality (VR), and big video, the requirements for network latency become increasingly stringent. Millisecond-level and even microsecond-level differences can have a huge impact on these services.
The following are four types of services that are being developed and have low latency requirements:
- Financial/Transaction services, including services that have high real-time requirements, such as high-frequency transactions, stock transactions, and futures transactions
- Interactive entertainment services, including 4K/8K HD video, VR, AR, and other high-throughput services
- IoT and real-time cloud services, especially data hot backup, cloud desktop, and intra-city disaster recovery
- 5G mobile transport services
Low-latency networks are critical for both enterprises and individuals. The ability to build low-latency networks has become one of the important competitive features of network products. Huawei's intelligent lossless network solution can build high-quality and low-latency networks.
How Can We Achieve Low Latency?
Reducing latency involves optimizing all aspects of network communication and system performance. We can implement the following policies to achieve low network latency:
- Using wired connections: Compared with wireless connections, wired connections usually provide lower latency, thanks to the lower interference and better signal strength.
- Optimizing network configuration: Ensure that your network devices (such as routers and switches) are correctly configured and can process the required traffic without creating bottlenecks.
- Reducing network congestion: Minimize the number of devices that share a network and prioritize key traffic to reduce congestion and latency.
- Using Content Delivery Network (CDN) technology: Users can obtain required data files from the nearest CDN server, thereby reducing the distance required for data transmission, improving the response to network resource access, and shortening the latency of content access.
- Caching: Caching frequently accessed data locally reduces the need to obtain data from remote servers, thereby reducing latency.
- Optimizing protocol efficiency: Select communication protocols that minimize overhead and latency. For example, use UDP instead of TCP for real-time applications.
- Using Quality of Service (QoS) technology: Implement QoS mechanisms to prioritize key traffic over time-insensitive data, ensuring that latency-sensitive applications obtain sufficient bandwidth and resources.
- Optimizing application design: Design applications to minimize round-trip and unnecessary data transmission and optimize data transmission.
- Deploying edge computing resources: Use edge computing resources to process data closer to users, reducing the data transmission distance.
- Monitoring and analyzing performance: Continuously monitor network performance and latency indicators to identify bottlenecks and areas to be improved, thereby implementing proactive optimization.
Application Scenarios of Low-Latency Networks
Low latency is critical to any scenario involving a large amount of traffic on the network. The following lists the main application scenarios of low-latency networks:
- Audio and video streams:
For audio and video live streaming, a low latency of 1 to 5 seconds can maintain synchronization between audio and video tracks, ensuring real-time interaction between content creators and audiences. High latency causes content delivery delay, which adversely affects user experience. This level of low latency is particularly important for onsite activities, as audiences expect real-time interaction and participation.
- Instant communication:
For audio and video calls, the one-way latency must be kept below 150 ms to ensure smooth and natural conversations. High latency causes awkward pauses and crosstalk, which severely affects the communication experience. This level of low latency is critical to maintaining smooth conversations and ensuring clear and coherent communication, especially in professional environments where clarity and timeliness are critical.
- Telemedicine:
Telemedicine requires low latency to ensure timely and effective patient care. All types of care, including simple consultation, remote monitoring, or robot-assisted surgery, require minimum latency. For example, low-latency networks help ensure that surgeons maintain precise control of the surgical system while operating. High latency in telemedicine applications may lead to incorrect delivery of doctor's instructions, inaccurate medical evaluation, and even medical accidents.
- Online gaming:
For online games, a low latency of less than 100 ms can ensure fair and quick game response. High latency leads to delayed input and differences between player operations and game responses, resulting in unfair advantages and affecting the game experience. Especially in competitive games, even a slight delay can have a significant impact on player performance and game results.
- Web page browsing:
When a user browses a web page, a low latency of less than 100 ms can ensure quick page loading and quick response to user actions. High latency slows down the website rendering speed and delays the response to user input. As a result, user experience deteriorates and in some cases users may even leave the website entirely. Quick response of web pages is critical to user satisfaction.
- AR and VR:
To achieve quick response and create an immersive experience, AR and VR applications require a low latency of less than 20 ms. High latency in AR and VR applications may lead to user dizziness or other discomfort, due to the large difference between users' actions and the visual feedback they receive.
- Financial transaction:
In financial transactions, especially high-frequency transactions, ultra-low latency is critical because even a latency of microseconds may cause huge financial losses due to price fluctuations. Traders in financial markets rely on receiving and processing market data and executing transactions faster than competitors to gain an advantage. In such an environment, even a slight reduction in latency can lead to significant improvements in transaction performance and profitability.
- Industrial automation and IoT:
In the real-time manufacturing process, low latency is critical to controlling robots. In smart home, smart city, and industrial and home IoT devices, quick responses to sensor data can ensure IoT devices run properly.
- Emergency response system:
Emergency services, such as firefighting, police, and ambulance services, rely on low-latency connections. Ensuring reliable and real-time communication is critical to coordinating emergency responses.
Generally, lower latency brings better user experience and system performance. However, implementing ultra-low latency may bring higher complexity and costs.
- Author: Zhu Chunrong
- Updated on: 2024-08-30
- Views: 1872
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