The FCC last week conditionally granted a request from Ericsson so that now it can move forward with the manufacture of a single radio that supports both 3.45 GHz and 3.7 GHz/C-band.
Ericsson responded this week by thanking the commission and noting that the approval will allow it to make more energy efficient, climate friendly, smaller and easier-to-deploy radios for wireless providers with licenses in both bands. That includes AT&T, T-Mobile and UScellular, all of whom had given their blessings to the product ahead of the FCC’s approval.
The reason Ericsson sought a waiver had to do with out-of-band-energy (OOBE) emission levels. According to Ericsson, when operated in carrier aggregation mode, the 3.45 GHz-3.55 GHz waveform generated by its base station will exceed the 3.45 GHz OOBE limit in the 3.7-4.0 GHz range.
However, Ericsson said the emissions from these operations will not exceed the -13 dBm/MHz emission limit required for base stations operated by licensees in the 3.7 GHz service and, as such, will not increase the likelihood of harmful interference in the 3.7 GHz band.
Further, Ericsson said that operation of its proposed radio, in both carrier aggregation mode and standalone 3.7 GHz service mode, complies with the 3.45 GHz service OOBE limits across the 3.5 GHz band, as well as below the 3.45 GHz band edge.
In its approval, the FCC noted that none of the comments on the petition expressed concerns related to harmful interference with operations in the 3.45 GHz, 3.5 GHz, or 3.7 GHz bands.
Reduced interference potential
Ericsson isn’t saying when it expects its 3.45/C-band radios will be commercially available. It did say that the commission and commenters found that granting the waiver was in the public interest because it would make pairing of spectrum more feasible, thus supporting investment and minimized interference.
“The interference potential is reduced with this multiband design from a situation where a separate 3.45 GHz transmitter and 3.7 GHz transmitter are installed together at the same site,” Ericsson said in a statement provided to Fierce.
The multiband design has several desirable characteristics, including savings in size on towers, energy consumption, and savings in rack space needed for radio equipment on cell sites because the multiband radio combines the electronics for the two bands within common tower and remote infrastructure, without adverse impact to nearby bands, according to Ericsson.
“The proposed design supports state-of-the-art base station solutions with 64TR capability. For example, in high-rise urban settings, a 64TR solution supports roughly 60 percent higher capacity than a solution that uses 32 transmit and receive antennas. Low-rise urban environments can likewise be covered with 10-15 percent advantage in capacity,” the company stated.