March 01, 2018

3GPP LTE-WLAN Aggregation Technologies: Functionalities and Performance Comparison

  • Henttonen T.
  • Laselva D.
  • Lopez-Perez D.
  • Rinne M.

The use of license exempt bands offers a promising opportunity to additionally enhance operator networks to meet the future traffic demand. The recent specification efforts in 3GPP has resulted in two major aggregation features that enable Long Term Evolution (LTE) networks to benefit of unlicensed spectrum via Wireless Local Area Network (WLAN). In this article, we provide a thorough overview of these features known as, LTE-WLAN Aggregation (LWA) and LTE-WLAN radio level integration with IP security tunnel (LWIP). The article presents and motivates the design choices of protocol architectures, procedures, mobility and security. It also proposes flow control algorithms suitable for both technologies, which aim at the best usage of licensed and unlicensed spectrum. Simulation results show the performance unveiling the potential gains of these features in different load conditions, also in a comparative manner, showing that LWA substantially outperforms LWIP.

View Original Article

Recent Publications

January 01, 2018

Fair Dynamic Spectrum Management for QRD-Based Precoding with User Encoding Ordering in Downstream Transmission

In next generation DSL networks such as, employing discrete multi-tone transmission in high frequencies up to 212 MHz, the crosstalk among lines reaches very high levels. To precompensate the crosstalk in downstream transmission, QRD-based precoding has been proposed as a near-optimal dynamic spectrum management (DSM) technique. However, the performance ...

January 01, 2018

Practical Mitigation of Passive Intermodulation in Microstrip Circuits

This paper presents new experimental evidence and a novel practical approach for mitigation of passive intermodulation (PIM) in microstrip circuits fabricated on commercial printed circuit board laminates. The mechanisms of distributed PIM in microstrip circuits are reviewed and a phenomenology of PIM generation due to locally enhanced electromagnetic fields at ...

January 01, 2018

Efficient Cooperative HARQ for Multi-Source Multi-Relay Wireless Networks

In this paper, we compare the performance of three different cooperative Hybrid Automatic Repeat reQuest (HARQ) protocols for slow-fading half-duplex orthogonal multiple access multiple relay channel. Channel State Information (CSI) is available at the receiving side of each link only. Time Division Multiplexing is assumed, where each orthogonal transmission occurs ...