LTE-TDD, a technology that can be used by dividing the uplink and downlink ratio times

The Electronics and Telecommunications Research Institute (ETRI) is developing advanced small cell base station SW technology that can be used in buildings and sports stadiums and is preparing to commercialize it.

Following the successful development of LTE small cell base station SW in 2016, the company announced that it has succeeded in developing SW technology that supports LTE-TDD technology and dual connectivity.

The LTE-TDD technology developed by the research team is a technology that can be used by dividing the ratio of uplink and downlink by time. In LTE, the ratio of uplink and downlink can be changed in 7 ways. For example, the ratio of uplink and downlink data rates can be adjusted according to the situation for limited data.

In addition, SW technology that supports dual connectivity can be utilized in the future 5G. It is called LTE-A Pro technology, and it is a technology that allows users to simultaneously connect to two base stations to transmit and receive data. In 5G, it is also possible to connect to 4G and 5G base stations simultaneously.

In addition, the research team developed an enhanced interference control (eICI) function and an eMBMS function that additionally controls interference between base stations to increase the user's transmission speed at the edge of the cell. They also announced that they successfully developed a test environment technology to verify small cell base station SW.

The LTE-FDD/LTE-TDD SW developed by ETRI is a model that can be exported not only domestically but also overseas, and the research team has transferred four technologies. It is also expected that it will be possible to commercialize a backpack-type base station with a radius of several hundred meters to several kilometers to form a temporary LTE network.

The research team specifically increased the number of subscribers in small cells from about 8 in the past to 64, allowing simultaneous connections. Previously, only the FDD method could be used, but this has been expanded to include the TDD method.

This technology is suitable for places with a rapid increase in traffic such as stadiums, department stores, disaster areas, and military communications where many people gather in the future, and it seems that it can be used by attaching it to indoor and outdoor building walls, utility poles, and communication antennas like a wireless LAN AP or by carrying it around in a backpack. The research team explained that the size of the small cell has been minimized to the size of a wireless LAN AP for indoor use and a shoebox for outdoor use depending on the purpose, and if made into a backpack, it will weigh about 10 kg.

Lee Jae-hak, PM of Mobile Communications at the Information and Communications Technology Promotion Center (IITP), said, “Small cell base station SW technology is expected to be localized and effectively utilized by small and medium-sized businesses. We will work to ensure that this technological prowess can lead to 5G.”