The future of USB: next-gen connectivity revealed

The future of the Universal Serial Bus is approaching very, very quickly

USB 3 micro B

Just getting used to the USB 3 mini and micro B connections on the latest devices? The next connector is already being designed; we don't know what it will look like, as the standard hasn't got as far as prototypes, but we know it will be reversible.

"You don't have to worry about the orientation of the plug or the different ends of the cable; whichever way you plug it in, it will work and you don't have to worry about whether it's an A or B type cable," Jeff Ravencraft of the USB Implementers Forum told us.

It will be a similar size to the USB micro B connection, so the socket on your phone won't take up any more space, and Ravencraft said smartphone, tablet and PC makers are all preparing to use it on new devices.

Next gen USB
The USB 3 micro-B socket

It's also going to get picked up by the EU and China as one of the approved charging standards for phones; both have adopted USB micro B connectors as a charging standard so you don't need a new cable for every phone. Expect to see an adapter so you can use USB micro B and USB C together.

The good news is we won't have to go through more cable changes for a while because the plan is to make this a design that can be used for multiple generations of USB at higher speeds. "It will scale for performance as well as power," says Ravencraft. "The working group understands this will need to scale beyond 20Gbit per second data rates; the connector will support that." The connector will be rated for 100W. We don't expect to see higher power than that, both because of safety regulations and because newer laptops are using less power to charge.

Next gen USB
USB cables will soon deliver power too

There are some interesting ideas about what might be on the other end of the plug too. One researcher at the University of Berkeley is trying out connecting a solar panel by USB. Once they can take 100W, USB cables could power anything from a phone to a TV screen to a sewing machine, doing away with a host of custom power connectors.

20Gbps USB won't ship for a while, but we will see SuperSpeed 10Gbps connectors in devices shipping this year. That's twice the speed of the 5Gbps that's the USB maximum today, and the connection has less overhead; in tests, Ravencraft says the engineers are seeing 9.7Gbps throughput on a 10Gbps connection. These connectors will work with both 5Gbps and 10Gbps USB 3 devices and hubs (obviously at the slower speed for 5Gbps devices), and you'll even be able to plug in USB 2 devices as well.

Next gen USB
Benchmarking high-speed USB data transfers, using a USB connected hard drive and a USB host card

What would you want 10Gbps for? DisplayLink is going to use it for docking stations that can drive 4K screens, rather than the two 2560 x 1600 screens current USB docks can handle, as well as powering your device and transferring data – all over a single cable. DisplayLink is also working with Rohm to put 100W USB power into its chipset, which will make it easier for manufacturers like Targus, Dell and Lenovo who use DisplayLink chips in their docks to ship 100W USB3 SuperSpeed docks.

Displaylink
DisplayLink's latest chips deliver power and 2K video to multiple screens

The first SuperSpeed 10Gbps products will be storage, monitors using it to connect audio and video as well as being a fast USB hub you can plug other devices into and USB hubs that let you connect multiple 5Gbps devices at once without slowing down, Ravencraft predicts. "You can send audio and video from a notebook to a monitor and get power back from the dock to run your notebook," he suggested. "Today you can only draw 7.5w, and that's not enough for tablets and notebooks, but [when you plug it to a monitor] the user expects to be able to charge over USB too."

Virtual USB

The next USB connector after that might look like Ethernet, or be wireless, or anything else you can think of. That's because the 'media-agnostic' USB specification that's currently being developed is a way of having a USB connection without a USB cable. "It will allow wireless devices and docking stations to communicate over USB without a physical connection," Ravencraft explained. "You can have a device out on the cloud communicating over Wi-Fi or WiGig, but it looks like it's right here, connected by a USB cable." That could give you remote access USB connections to peripherals, or an encrypted connection to remote storage that looks like a USB drive to your PC.

WiGig, the wireless gigabit standard, has already moved to a new home with the USB Implementers Forum and has become that foundation of the media-agnostic USB spec. "We're working to make sure it's the real USB experience over 60Gbps radio," Ravencraft promises.

But once you've virtualised the connection, it could work over anything. "It's compatible with WiGig and Wi-Fi and wireless USB. It could run over Zigbee. If you had UWB radios you could support it. You could do USB over fibre." And that will make the U in USB really universal.