It is convenient to add more USB ports to a device by using a USB hub. With USB hubs, all devices must share bandwidth and power supply from the computer’s USB port. It does not matter how many devices are connected to the computer’s port, the bandwidth and power remain constant.

There are, however, some limitations associated with the USB hub.  It is important to read the instructions before using devices that consume too much power, for example. Connecting devices that consume too much power can increase their instability.  The USB hub can meet the basic needs of users who wish to connect their phones, mice, and keyboards to power them. 

Typical Structure of a USB Hub

The program is installed as soon as the computer recognizes it, and there is no need to install a driver.

The device supports USB2.0 at speeds up to 480Mbps and is backwards compatible with USB1.1.

It is possible to divide a USB interface into multiple working USB interfaces.

The device is equipped with a USB HUB controller from the second generation.

A current protection device is also included.

The program is compatible with Windows 95/98/Me/2000/XP, Linux 2.4, and Mac OS 8.5 or later.

Simple to use, it does not require an external power supply and can be directly connected to the computer.

USB Hub Operation

USB hubs have one upstream port, which connects to the host, and several downstream ports, which connect to other hubs or peripheral devices.

In most systems, hubs are transparent and do not appear on any visible mapping of the system. The data received from the upstream port, i.e. the host, is broadcast to all devices connected to the downstream ports, whereas the data received from the downstream port is routed only to the upstream port and the host.

The USB 3 specification introduced a Point to Point routing capability, which allows the host to direct data to a single destination port by sending a routing string in the data packet header. As a result, data is reduced on the USB ‘network’, while power consumption is also reduced.

An additional benefit of using a USB hub is that it can increase the length of the system. In the case of USB 1.1 devices, for example, USB cables are limited to a length of three metres. It is possible to increase the length of a USB cable by up to five meters by using a hub as an active USB repeater.

Various Types of USB Hubs

Powered USB Hub

A powered or active USB hub uses an external power source to raise the energy level of each port to that of an on-board port. Typically, active USB hubs are powered by a wall outlet. USB hubs are not required to distribute power to all connected devices, but they do distribute data bandwidth.

A small amount of power is generated by the USB ports on your computer. The power is also divided among the additional ports when you split a port (by plugging in a hub). In addition, depending on the devices you plug into the hub, there may not be sufficient power for everything. That is why it is important to select a hub that comes with an AC adapter. Power-hungry devices can be plugged into every port without fear of running out of amps.

Unpowered USB Hub

A USB hub without an external power source relies solely on the USB port of the computer for power. When a hub is not powered, it has compatibility issues with devices that require more power than the hub can provide.

A USB flash drive, for example, may work perfectly fine when connected to the computer’s USB port or an active hub, but it may not work when connected to a passive hub. By enhancing power management capabilities over previous versions, USB 3.0 may be able to support higher power devices that are not compatible with older standards.

Advantages and Disadvantages

Powered USB Hub


High-voltage devices can be powered by this device

It is capable of simultaneously powering multiple devices


There is typically a higher price tag associated with unpowered USB hubs.

Access to a power outlet is required.

Unpowered USB Hub


Portable and small in size

Compared to powered USB hubs, they are less expensive

It is not necessary to look for an electrical outlet.


It is not possible to power high-voltage devices without causing performance problems.

Multiple devices cannot be powered simultaneously.

When is a USB Hub Necessary?

If you are considering purchasing a USB hub, you may wish to consider some essential factors.

Make sure that you have checked the connection options first. Four or five ports can be connected by the user.  

The second step is to determine if the correct hub has been purchased by checking the cable connection to the main device.  

In addition, you should purchase a USB device that supports the latest connection protocol in order to avoid slow transfers or incompatibility with older devices.  

Lastly, you should purchase USB devices that are appropriate for the user’s daily use situation, including size, portability, etc.