T-Mobile US believes future mobile 5G deployments can coexist with existing radio astronomy (RAS) and Earth Exploration Satellite services (EESS) operating above 24GHz without much trouble.
The assertion is based on a report from T-Mobile which assessed the potential for coexistence between wireless 5G services at 32GHz, 47GHz and 50GHz and passive services operating in adjacent frequencies. T-Mobile determined “harmful interference” with existing radio and satellite operations could be avoided with the imposition of “modest operating constraints” on the new 5G services.
“For example, adopting geographic separation and coordination zone requirements can protect RAS operations with little effect on 5G deployments nationwide because RAS sites are limited in number and mostly located in remote areas,” T-Mobile wrote in a filing to the Federal Communications Commission (FCC).
“Similarly, technical innovations in 5G systems will substantially limit the aggregate amount of out-of-band emissions EESS will experience even under line-of-sight conditions,” it added.
The operator indicated the higher propagation range in the 32GHz band, coupled with the presence of a 500MHz allocation for RAS and EESS immediately below the band, will pose the biggest challenge to coexistence. But T-Mobile said the implementation of beamforming and other 5G technologies will ultimately make coexistence possible.
Satellite players weigh in
Satellite communications company ViaSat submitted its own report to the FCC this month which concluded satellite earth station receivers in the 37.5GHz to 40GHz band can coexist with 5G operations.
However, other satellite players including EchoStar and Hughes have argued the FCC should reserve the 48.2GHz to 50.2GHz uplink band and 40.0GHz to 42.0GHz downlink band as exclusive for deployments via fixed satellite service earth stations.
The comments come as part of an FCC’s exploration into whether spectrum bands above 24GHz can be used for 5G services. In 2016, the commission opened up nearly 11GHz of millimetre wave spectrum for mobile use, including 3.85GHz of licensed spectrum from 27.5GHz to 28.35GHz and 37GHz to 40GHz bands, and 7GHz of unlicensed spectrum from 64GHz to 71GHz.