As members of both the Wi-Fi and LTE communities, Qualcomm is constantly collaborating and working very closely with all key stakeholders to ensure that LTE-U and Wi-Fi will coexist very well. Along with other members of the LTE-U Forum, we are working together to address technical concerns and answer technical questions in great detail. We are cooperating openly with the Wi-Fi industry and will support the test development effort jointly with Wi-Fi Alliance, who agrees with us on focusing on LTE-U behavior as much as possible rather than Wi-Fi performance.
In another example of the close collaboration on fair use of unlicensed spectrum, Qualcomm Technologies released today the results of a new set of tests that analyzes LTE-U and Wi-Fi coexistence. Using a test plan developed in collaboration with CableLabs, the R&D consortium for the cable industry, the two parties performed testing over a three-week long period. While time only allowed for the completion of a subset of the agreed–upon test cases, the results demonstrate that LTE-U shares spectrum fairly with Wi-Fi.
Qualcomm Technologies followed the guidance of CableLabs in terms of what scenarios to test, the density of nodes, the types and location of test devices, and what Wi-Fi equipment vendors to include. Since Wi-Fi equipment performance varies across brands and models, as each is designed for different types of customers and environment, the principles used for the coexistence tests focused on the impact of the LTE-U equipment. The results show excellent coexistence performance for the studied test cases. The performance of Wi-Fi in the presence of LTE-U was comparable to if not better than the examined Wi-Fi to Wi-Fi baseline scenario, demonstrating the effectiveness of LTE-U coexistence protocols.
The tests, which used a large collection of user devices connected to the test Wi-Fi Access Point (“AP”), showed that Wi-Fi throughput improves when a second interfering Wi-Fi AP is replaced by LTE-U equipment. The example above uses the same Wi-Fi vendor for both the test AP and the interfering AP. The 15 user devices were distributed over three different locations and had a mix of Data and VoIP services to assess both throughput and delay.
The testing also showed that the average one-way delay is substantially reduced when the second Wi-Fi AP is replaced by an LTE-U small cell. These latest test results are thus fully consistent with all prior tests that were performed in accordance with the LTE-U specifications.
Download a detailed summary of the test results here.