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Why Can't I Add More USB-C Ports to my USB Type-C Host with a Hub?
Brendan Murphy

USB Type-C – One Cable to Rule Them All

USB Type-C was created to bring faster speeds and compatibility across all varieties of electronic devices. The idea was to create one cable and one specification that manufacturers would adopt for all new devices (you may have noticed every new phone being introduced to the market has a USB-C port on it). A uniform cable would allow for charging headphones, computers, and phones with a single adapter.  Additionally, devices like a hard drive or monitor would be plugged in with the same cable. Just a few years ago, all of this would likely require four separate cables and power bricks. This all can now be accomplished with a single USB Type-C cable as one of the many benefits of the USB-C standard.

As more and more USB-C accessories become available, the need for USB Type-C compatibility becomes an increasingly important issue. Today, external hard drives, power adapters, cables, and even headphones are widely available with a USB-C port.


Tangled cables Tangled cables; Image by: HighT3ch


A Shortage of USB Type-C Ports

Recently, tech giants, such as Apple and Google, have released devices that come with a single USB-C port, notably the new iPad Pro and MacBook Air. If the goal is to enable charging, device connectivity, and display with the same capabilities as older devices, problems begin to arise with the presence of only one port.


MacBook with single USB-C/Thunderbolt port. MacBook with single USB-C/Thunderbolt port; Image by: Cnet


It is common when using a computer, especially in an office environment, to have multiple external peripherals connected. The computer may have a backup USB hard drive, a keyboard and mouse, external displays, plus a power cable all plugged in. Most older laptops and computers are suited to this set up with most having at least one USB Standard-A port, an HDMI port, headphone jack, a power plug, and maybe even a Thunderbolt or mini DisplayPort port.  With newer laptop models offering only one USB Type-C port, questions begin to arise about how we connect all of our standard devices at a time.


Laptop with all IO ports being used Laptop with all IO ports being used; Image by: The Verge


As early adopters embrace USB-C connected computers and peripherals, they are being met with an interesting challenge: there are not enough USB-C ports on the computer to connect all of their peripherals at once.  In traditional laptops, when USB ports ran short, users simply reached for a hub to add more ports. However, a USB-C port expander hub does not yet exist.

Although USB-C stays consistent with the theme of cutting down clutter and simplifying the equipment needed to keep all your devices connected, the majority of USB-C enabled computers simply do not have enough USB-C ports to meet the needs of daily use.


USB-C port expander USB-C port expander; Image by: BestBuy


[Note: There are a plethora of USB-C hubs on the market that provide HDMI, USB-A, Micro SD card readers, DisplayPort, etc. For devices using these legacy ports, it is possible to find a hub to expand a USB-C enabled computer. The issue arises when trying to connect multiple USB-C devices to a USB-C computer as a USB-C port expander that provides more USB-C ports does not exist.]


The Solution is USB4

The current USB specification has not defined how to develop USB Type-C hubs. Without clear direction on the technology future for Type-C hubs, developers have not moved forward in designing a solution to this issue facing consumers.  Fortunately, the USB-IF and USB developers have recognized this challenge.  With the upcoming release of the USB4 specification, developers will begin to have guidance on how to move forward with this enabling technology.

The USB4 specification was announced in 2019. The latest revision of the USB specification features increased data transfer rates, increased video resource allocation, and better Thunderbolt compatibility.


Total Phase Supports USB Type-C

USB Type-C and Thunderbolt are no doubt the future of device connectivity. The ability to use a uniform standard across all devices is not a far-fetched vision of the future. However, a single standard for all connections, as the industry is finding out, is a rather complicated task to tackle. USB Type-C and Thunderbolt have gotten us closer to this vision of the future and with the introduction and implementation of USB4 we may even be able to accomplish this noble goal.

To learn more about how Total Phase has contributed to accelerating progress in reaching this goal check out these blog posts about our Advanced Cable Tester v2 and USB Power Delivery Analyzer:

Want to learn what leaders in the cable market have to say about USB-C? Check out what Cable Matters has to say in the blog posts below: