CDN, also known as content delivery network, is a cache mechanism that shares and loads content, usually video services, from a data center to users’ network edge. The worldwide popularity of the Internet has also resulted in the Internet carrying increasingly more services, especially the aforementioned video services. Users often watch Internet video content through platforms such as YouTube, STB, OTT, and smartphones. Traditionally, video content has been stored in a central data center, where global users flock to for video service requests. This creates massive data loads at the data center, as well as increased latency due to the distance between end users and the data center.

Viewer behavior patterns are often similar and occur at the same time, in the same area. For example, an area’s users may simultaneously watch a live baseball game. If the service provider places the game’s video content as close as possible to the area, this reduces transmission delay and loading from the data center. Only video content not provided by the local content server will be redirected to the data center.

This architecture is the so-called Content Delivery Network (CDN), which provides high quality video services and reduces latency and transmission. CDN is already quite popular in broadband, and the 5G mobile network will push CDNs to a new level of demand.