Online retailer Ocado has released details of the 4G-based protocol it is using to communicate with the 1000 robots powering its automated distribution centre in Andover that opened earlier this year. The protocol is the first deployment in the world to use unlicensed 4G spectrum for warehouse automation and is now being offered as an off-the-shelf solution to other online retailers.

The highly-automated warehouse is managed by a service called the Ocado Smart Platform. It controls the 1,000-plus robots roaming around the building on rails above hundred of thousands of crates containing the 47,000 items Ocado stocks, picking the items for delivery. Since the robots are all working within a 150-metre radius, the chance of collisions is not insignificant. The private 4G mobile network deployed inside the warehouse guarantees a connection ten times per second to each of the robots in order to eliminate this risk.

The company is now pitching the platform to retailers internationally, with the promise that it will enable them to build profitable and sustainable online retail businesses. The move comes after it realised when it was building the hardware architecture of the Andover facility, that it had “developed a world first in radio design”.

The company initially considered using wi-fi as the communications protocol, but dismissed it on the grounds of latency, speed and scale. So, working with Cambridge Consultants, Ocado came up with a system that takes advantage of modern wireless communication principles, but also has elements tailored to Ocado’s environment. One of these is the fact that it works in license-free spectrum, so can be rapidly deployed.

By making the system private, Ocado was able to improve the performance and simplify overall complexity by minimising handshake and eliminating roaming aspects, so achieving those impressive 10 times a second connections to each of the 1,000 client hosts per base station.

Wireless team leader at Ocado Adam Green said: “While building a robot can be a relatively straightforward task, creating a swarm of thousands of robots and making sure you can communicate with every single [one] in a tenth of a second is a whole different ball game.

“We have worked closely with Cambridge Consultants to develop an innovative system that takes advantage of modern wireless communications principles but has secret ingredients that tailor it to our specific environment. Since the protocol works in the license-free spectrum, we can also deploy it at a moments notice in any location around the world.”

Ocado suggests that the wireless protocol can be repurposed by other Internet of Things applications to create a reduced communications delay between devices, in areas such as vehicle-to-vehicle connectivity for smart cars, air traffic control systems and large scale industrial systems.