Qualcomm and SK Telecom have carried the first over-the-air technology demonstration of eLAA (Enhanced Licensed Assisted Access) and LAA (Licensed Assisted Access) utilising both licensed and unlicensed spectrum at SK Telecom's Corporate R&D Center in Bundang, Korea.
eLAA technology increases data speeds in both uplink and downlink by aggregating licensed and unlicensed spectrum to create a wider data pipe in both directions. eLAA is an evolution of LAA, which used the unlicensed spectrum to boost the data speed in the downlink direction only.
The demo uses 2.6GHz licensed spectrum and 5GHz unlicensed spectrum. When evaluating co-existence, a baseline was first established using only Wi-Fi users, of which some were then switched from Wi-Fi to LAA/eLAA, while others remained on Wi-Fi. The trial demonstrated that the users that remained on Wi-Fi were unaffected by those that switched to LAA/eLAA.
This effectively demonstrates that LAA/eLAA shares the unlicensed spectrum fairly with Wi-Fi – something that has been of major concern about the technology amongst the Wi-Fi community.
The sharing mechanism used by LAA/eLAA is called listen-before-talk (LBT). As for performance, LAA and eLAA were shown in multiple test cases to achieve 2X capacity in 5 GHz than the Wi-Fi only baseline.
In June 2015, SK Telecom launched "Band LTE Wi-Fi" service based on Multi-Path Transmission Control Protocol (MPTCP) technology that combines LTE and Wi-Fi traffic to enable downlink rates up to 1.17Gbps. This means that SK Telecom can now choose from two available technologies to combine unlicensed spectrum with existing LTE spectrum, eLAA and MPTCP.
In addition to MPTCP and eLAA, which use unlicensed spectrum in hotspots, SK Telecom is also concentrating on further LTE-Advanced Pro technology development based on new frequency bands to deliver faster data rate than competitors while mobile with wider coverage areas.
Eduardo Esteves, vice president, product management, Qualcomm Technologies, said: "This trial aims to demonstrate fair and harmonious coexistence of LAA with Wi-Fi in unlicensed spectrum. This is also a manifestation of Qualcomm Technologies' and SK Telecom's leadership in leveraging the latest technologies to improve user experience."
Jin Hyo Park, head of network technology at SK Telecom, said: "A flexible combination between licensed and unlicensed spectrum is necessary to enable high quality massive 5G service." He added: "We will lead the network innovation towards LTE-A Pro and 5G including combining licensed and unlicensed spectrum technologies such as eLAA and MPTCP."