GenXComm gets $20 million to maximise 5G speeds with full duplex

Start up uses legacy networking technique to save precious spectrum for private 4G LTE and 5G networks

US start up GenXComm has been awarded $20 million by to coax the best performance from the private 4G LTE and 5G networks using a legacy technology – Full Duplex.

Investors led by BMW iVentures were impressed by performance hikes that are created by this ancient technology. To many full Duplex invokes memories of the smell of soldering irons hovering over RS232 cabling connectors. However, this technology from a bygone era is back and could give vital boost to the performance of 5G networks.   

GenXComm launched in 2016 out of a research and development effort at the University of Texas at Austin around dynamic filtering and Radio Frequency (RF) photonics systems. In 2017, the company scored $7 million in funding from Intel and others with the goal of enabling full duplex communications for 5G, cable systems and other possible uses.

Its mission has been refined to help mobile operators to make use of their most precious asset – spectrum. So now it’s being directed to optimise communication by allowing wireless channels to transmit and receive simultaneously. Which is why GenXComm is angling its technology into the private wireless networking space, according to Light Reading reports.

Save our spectrum with FD

Old fashioned Full Duplex succeeds where 5G’s frequency division duplexing (FDD) and time division duplex (TDD) have shortcomings. FDD transmits and receives signals in different spectrum bands while TDD uses different time slots in the same frequency band, so uplink signals must alternate, with uplinks connecting for a few seconds then handing over to downlink signals for their few seconds.

Full duplex shows the new methods how it’s done. It allows wireless networks to simultaneously transmit and receive wireless signals over a single spectrum channel at the same time.

The challenge, for wireless equipment makers, is to eliminate any possible interference between the uplink and downlink signals.

This differentiates Full Duplex from dynamic spectrum sharing (DSS), which uses the same spectrum band to transmit both 4G and 5G signals, which cannot run simultaneously but in 1 ms increments over the same spectrum.

Another FD start up Kumu Networks is working to filter out interference using special cancellation technology with the backing of Verizon Ventures and Cisco Investments. It’s now part of the 3GPP Release 16. IAB makes it possible for operators to use their existing 5G spectrum for backhaul as well as for customer access.

Full Duplex will be essential to integrated access backhaul (IAB) for 5G network operators that use millimeter wave (mmWave) spectrum, said Joel Brand, vice president of product management at Kumu Networks.

“What makes full duplex important now is that the mmWave signal doesn’t propagate very far and operators do not have access to backhaul for every mmWave cell site,” said Brand.

European operators will want to use IAB in conjunction with full duplex to make their backhaul more spectrally efficient. “No one wants to spend billions of dollars on spectrum and then use it for backhaul,” said Brand.

Full duplex technology say has come back into fashion because with 5G mobile operators have discovered that spectrum is a much more rare and precious asset.

Another FD start up, Lextrum, says it can suppress interference and dramatically improve throughput for LTE. Fine tuning LTE will be a priority for fixed wireless equipment makers, such as Nokia, Ericsson and Huawei, that produce both base station equipment and the end user device. 

Lextrum’s experimental license covers both 4G and 5G. Full Duplex may be covering a lot of European base stations in 2022.