Release Date：2020-01-09 Author：By Zhang Yu, Chief Engineer of ZTE CDN Products Click：
While video service is moving towards UHD and immersive experiences, 5G will be used to handle bandwidth-hungry and latency-sensitive services, such as AR, VR, and 4K/8K, which helps promote the further development of UHD live broadcasting and VoD.
By 2022, UHD-based IP VoD is believed to account for 22% of the global IP video traffic and UHD 35% of the global VoD IP traffic. To meet the ever-growing demand for user experience, operators are accelerating the deployment of CDN in the following aspects to achieve the distribution of UHD videos and new services.
CDN Nodes Closer to Users
For dense places with large video traffic, such as college campus, business center, metro, railway station, airport, residential district, and island, CDN edge nodes can be introduced to offer indiscriminate service to both internet content and video content for fixed and mobile users. This increases utilization of the CDN server, reduces pressure on network backhaul, and improves user experience. As HD and UHD video traffic surges, it is difficult to deploy CDNs in a centralized manner due to limited conditions of some BRAS offices. In this case, the built-in blade mode is preferred for CDN deployment.
ZTE's CDN sinking solution integrates CDN boards into the OLT/BRAS to move CDNs closer to the network edge. For example, video contents are pushed to the mobile network edge of traffic-heavy areas such as college campus, enabling a better user experience with large bandwidth and low latency. This also saves 10%–15% of transmission resources and reduces operator Capex. In the future, the built-in blades of OLT can be used as the NFVI infrastructure to be deployed in the access office.
The storage of a built-in CDN is usually limited. To improve the hit rate of edge nodes, ZTE adopts a decision support system to predict and analyze popular content of each area and each node. This enables intelligent distribution of popular content, reduced traffic load on backbone networks, and faster response times. The stuttering rate is reduced from 3.5% to 0.8%, the average latency of the first packet shortened from 109 ms to 20 ms and the byte hit rate increased from 70% to 93%.
Improving Performance of Streaming Devices
With a large-scale introduction of 4K, 8K, and VR services, the construction capacity of CDN will grow by 4–8 times, which significantly increases the construction costs of the CDN and bearer networks. Since costs will be huge if additional hardware is added to meet the growing service requirements, it becomes critical to develop a new CDN device with high throughput, low power consumption, and large storage.
This year, ZTE will launch its high-performance and high-throughput CDN streaming server VS3000T. The throughput of a single CDN server can reach 200 Gbps, capable of serving various new services in the 5G scenarios. For example, it can fulfill the distribution and service requirements of 8K UHD videos, 4K UHD broadcasting and 8K VR, saving investments for operators.
Optimizing Experience with Technologies
To continuously improve 5G video experience, the video transmission and service stages adopt optimization technologies like fast loading, fast first-frame delivery, FCC, FEC, M-ABR, and JITX. In addition, ZTE's industry-leading OTT low-latency multicast technology reduces the end-to-end latency to less than 1s by virtue of the CMAF and Chunk low-latency transmission technologies. Based on this, ZTE has launched the 5G Smart Stadium Live Broadcasting solution, aiming at large events such as sporting games. Harnessing 5G, this solution integrates multi-angle UHD live broadcast, MEC, 360-degree video stitching and rendering and AI recognition, delivering an innovative, multi-angle viewing experience to users.
Coordination of CDN and MEC in the Future
Operators have rich basic network resources, unique capabilities in edge connection and cloud-network integration, and well-reserved facilities such as access offices and hardware. With the improvement of edge computing in the 5G age, operators are accelerating the deployment of MEC CDN, considering the similarity between edge cloud and CDN in terms of service and deployment location.
ZTE and China Mobile have started to coordinate the layouts for edge cloud and CDN resources in a phased manner, in order to deploy the CDN on the network edge and use it as the MEC basic resource platform. Their coordinated development can be achieved through the following aspects.
Both the CDN and the edge cloud provide services for nearby users and have similar deployment locations; thus, they can be co-located to reuse the equipment room of the CDN service in the early phase.
The CDN and the edge cloud occupy different types of resources. Research shows it is feasible to use idle resources of the existing CDN, and the plan is to use the edge cloud to carry multiple types of services.
The CDN can open up functional modules/components of video applications (e.g. codec, content stitching, and transcoding) to the edge cloud platform. The edge cloud can provide CDN services with rich open capabilities and services, such as QoS, positioning, image recognition capability, and video quality enhancement, to meet new CDN service requirements.
With the rapid growth of 5G traffic in the future, the CDN serving mobile users will move closer to users as required. Since fixed-mobile convergence will be the trend for the edge cloud, the CDN will be capable of providing video services for both fixed and mobile users.
In these ways, ZTE deeply integrates the 5G network and the MEC CDN platform, and optimizes user experience with industry-leading technology.
The future of CDN will focus on providing more real and immersive video service experiences for more diverse scenarios. By virtue of cutting-edge technologies and MEC, the CDN will develop in a more intelligent and highly integrated manner, providing home and enterprise users with a better experience of 5G video.