On home internet connections, file downloads can be fast while uploads often feel unusually slow. This happens because of how people use the internet and the structural characteristics of communications networks.

Engadget reported on Oct. 18 that internet service providers generally allocate more bandwidth to downloads than uploads. That is because most users use the internet more to download data than to upload it.

Some regional plans from U.S. telecom company Xfinity, for example, offer download speeds of 300 Mbps, 500 Mbps and 1 Gbps, but all have the same typical upload speed of 117 Mbps. Only its 2 Gbps download plan raises the upload speed to about 293 Mbps.

The difference comes from how the internet is used. Video streaming, game installation and software updates are mostly download-driven. By contrast, typical web browsing or posting comments sends relatively small amounts of data.

Network design also plays a role. Cable internet uses networks based on coaxial copper lines built in the past for cable TV transmission. Because downloads and uploads share limited frequency spectrum, providers have allocated more capacity to downloads, where demand is higher.

The next-generation cable internet standard DOCSIS 4.0 can sharply increase upload capacity and support symmetrical high-speed services. Actual deployment requires carriers to replace equipment and improve their networks.

Fiber internet can secure relatively wide bandwidth, so it often offers symmetrical services with the same download and upload speeds. Fiber internet can still slow down depending on network configuration and how heavily users concentrate on it.

How content is delivered also creates differences. Netflix and Google use content delivery networks (CDNs) that store content on servers close to users to improve download efficiency. Photos and videos uploaded by individuals are mostly unique data, making it difficult to apply the same method.

To raise upload speeds, it is important to check actual upload speeds and the type of communications network, rather than simply choosing a plan with fast download speeds.