NTT DoCoMo, Huawei use IAB technology to boost mmWave coverage, capacity

DoCoMo IAB trial
The IAB trial system involved a 5G base station and a 5G relay station. (NTT DoCoMo)

NTT DoCoMo and Huawei recently conducted a trial using Integrated Access Backhaul (IAB) technology to significantly improve millimeter wave coverage and capacity in the 39 GHz band.

Conducted in Japan’s Minato Mirai 21 waterfront area of Yokohama, the field trial involved wireless backhauling functionality between a 5G base station and a 5G relay node using 39 GHz signals. Throughput exceeding 650 Mbps, with latency of 1.6 milliseconds, was achieved with user equipment that was outside the range of the base station. Both the relay node and user equipment were under mobility conditions during the tests, the operator reports.

According to DoCoMo, the 3GPP is considering IAB technology as part of the 5G New Radio (NR) standard.

The technology involves the use of a compact focal lens antenna made with metamaterials to achieve advanced beamforming (with a maximum gain of 31 dBi) that concentrates radio waves in a specified direction for long-distance transmission.

Beamforming mitigates interference between the wireless-backhaul and wireless-access links and enables simultaneous data transmissions over the same frequency. In addition, DoCoMo said, IAB nodes enable low-latency data transmissions through fast beam-switching for the uplink and downlink and they efficiently coordinate the radio resource scheduling between the backhaul and access links.

3GPP is meeting this week in Busan, South Korea, to finalize relevant standard technologies for 5G commercialization, with official ratification of the Standalone (SA) version of the 5G standard expected at a plenary in La Jolla, California, in June. The Non-Standalone (NSA) version, which uses LTE, was approved last December.

Huawei is one of the top contributors to the 3GPP standardization process, according to Signals Research Group (SRG). Ericsson and Nokia are the other two. Ericsson, Nokia and Huawei (in that order) account for up to 41% of total Technical Document (TDoc) submissions given to 3GPP for consideration during the standardization process, according to SRG.