SK Telecom (SK Telecom) developed the ‘4x transmission compression’ technology for the first time in the world. The ‘4x transmission compression’ technology is a technology for reducing the network data capacity transmitted between the digital unit (DU) and the radio unit (RU) of the LTE base station to 1/4. SK Telecom can now use this technology to design the next-generation base station for 5G mobile communication service.

As a result, it seems possible to implement the core technologies for 5G mobile communication, i.e. Massive MIMO and UWB (ultra wideband) frequency.

SK Telecom announced on December 25 that it developed the ‘4x transmission compression’ technology for the first time in the world and successfully demonstrated it. The mobile carrier efficiently changed the structure so that some of the functions performed by the DU can be performed by the RU, and added the compression technology to compress the network data capacity transmitted between the DU and the RU to 25%. The compression ratio of the currently commercially available technology is merely 25%. This technology increased the compression ratio from 25% to 75%.

If the transmission data capacity necessary for operating the base station is compressed to 25%, the extra capacity can be utilized to install additional base stations. Even if additional base stations are not installed, the existing two base stations can be installed so that different frequencies will be used, and the carrier aggregation (CA) technology can be used to double the speed. In particular, the number of antennas can be quadrupled to accommodate various technologies.

Currently, only two antennas can be installed in a single base station. The number of antennas that can be installed in a base station can be increased to 8. As users in areas with weak signals will connect to the good signal out of the 8 antenna signals, communication quality will be improved. As the signal processing capacity of the base station will be quadrupled, the base station operating efficiency will be raised.

It will be possible to implement MIMO in the future as well. MIMO, regarded as a core 5G technology, is a technology for improving the speed with tens of antennas in preparation for the explosive increase of wireless data. In the 5G era, far more antennas than now will be necessary for a speed faster than LTE. A technology for reducing the data transmission capacity, which increases in proportion to the number of antennas and the resulting frequency bandwidth, is essential.

The 4x transmission compression technology is the important first step toward implementing the new base station structure. SK Telecom confirmed that compressing transmission data capacity to 25% will not affect service quality. Accordingly, the technology for increasing the compression ration by more than 4x is expected to be developed soon.

“The core of the 4x transmission compression technology is to change the structure so that part of the signal processing of the DU will be handled by the RU,” an SK Telecom insider. “If this technology is commercialized, it will be possible to implement efficient base stations, and thus help enhance the quality of not only the LTE network, but also the 5G network.”

Earlier in May SK Telecom developed the 'CPRI I/Q data compression technology' for compressing the data transmitted between the DU and the RU to 50% and successfully demonstrated it. The 4x transmission compression technology upgrades this technology. ♦