U.S. Cellular CTO expects 5G will require new OFDM-based air interface

U.S. Cellular (NYSE:USM), which is still deploying its LTE network, is unsure of how quickly 5G networks will take hold but its CTO thinks it will require a new waveform for the 5G air interface.

U.S. Cellular CTO Michael Irizarry thinks the waveform for 5G networks will be based on OFDM (Orthogonal Frequency-Division Multiplexing), a technology that underpins LTE.

Speaking at the ATIS 5G Symposium in Chicago, Irizarry, CTO of Engineering and Information Services, said Universal Filtered OFDM (UF-OFDM) would likely be the waveform for 5G, according to Light Reading.

5G network standards are still being contemplated and are not even formally hashed out as network equipment vendors provide their own ideas and the debate takes shape ahead of a long standards-setting process that will likely begin next year. Most industry experts expect 5G networks to be commercialized starting in 2020 as LTE evolves until then.

Alcatel-Lucent (NYSE: ALU) has been a major proponent of UF-OFDM, a new radio access technology that can support a wide range of bandwidths for everything from low-powered connected devices to high-definition video.

In March at Mobile World Congress, Huawei proposed a new air interface for self-adaptive and software-defined air interface designs. Huawei favors the non-orthogonal access technology based on Sparse Code Multiple Access (SCMA), as well as Filtered-Orthogonal Frequency Division Multiplexing (F-OFDM).

Irizarry thinks whatever the 5G waveform is, it should be some type of OFDM. "The distinction between these waveforms considered for 5G and OFDM we use today is the new type of OFDM allows filtering down to the sub-carrier level, down to the resource block level, which allows for greater flexibility and coexistence with today's technologies," Irizarry said, according to Light Reading.

"I believe there will be a new waveform, and the new waveform will be required to support the extreme throughput demands of some of the use cases and the very low latency other use cases will require," he said. "The key question around the new waveform is whether or not it will work its way down to low-band spectrum."

Manish Jindal, CTO, Broadband and Media, at Ericsson (NASDAQ: ERIC), said at the ATIS event that UF-OFDM will likely cost about four times as much to deploy as traditional OFDM. Ericsson hasn't yet taken a stand in the debate but clearly wants to play a role, he said, according to Light Reading.

Nokia Networks (NYSE:NOK) CTO Hossein Moiin said in late March at the Next Generation Mobile Networks Alliance's industry event in Frankfurt that that "we can safely assume there will be" a new air interface with 5G because the current models will not deal with some of the requirements expected for 5G and as NGMN has outlined, such as very high capacity and extremely low latency of 1 millisecond. The new interface would also coexist with existing interfaces such as LTE and include components such as massive MIMO and beam forming, Moiin added. However, he did not take a stand on the wave form.

For more:
- see this Light Reading article

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