Embedding LTE-U within Wi-Fi Bands for Spectrum Efficiency Improvement

Abstract

Driven by growing spectrum shortage, Long-term Evolution in unlicensed spectrum (LTE-U) has recently been proposed as a new paradigm to deliver better performance and experience for mobile users by extending the LTE protocol to unlicensed spectrum. In the paper, we first present a comprehensive overview of the LTE-U technology, and discuss the practical challenges it faces. We summarize the existing LTE-U operation modes and analyze several means for LTE-U coexistence with Wi-Fi medium access control protocols. We further propose a novel hyper access-point (HAP) that integrates the functionalities of LTE small cell base station and commercial Wi-Fi AP for deployment by cellular network operators. Our proposed LTE-U access embedding within the Wi-Fi protocol is non-disruptive to unlicensed Wi-Fi nodes and demonstrates performance benefits as a seamless and novel LTE and Wi-Fi coexistence technology in unlicensed band. We provide results to demonstrate the performances advantage of this novel LTE-U proposal.

Efficient LTE/Wi-Fi Coexistence in Unlicensed Spectrum Using Virtual Network Entity: Optimization and Performance Analysis

“…In this mechanism, each superframe consists of a contention-free period (CFP) followed by a contention period (CP). Thus, by activating the PCF, the CFP can be used by LTE users, while the CP can be assigned to the WiFi users [24].…”

“…Therefore, for a specific packet, the pmf of the packet delay (denoted by d) can be computed as (24) where P(d = n|E f ) and P(d = n|E c ) are conditional probabilities of delay given E f and E c [29].…”

“…To calculate P(d = n) based on (24), in the following, we first explain how to obtain p 0 (the probability of empty user queue), which facilitates computing P(d = n|E f ) and P(d = n|E c ), and finally we derive P(E f ) and P(E c ).…”

“…In this mechanism, each superframe consists of a contention-free period (CFP) followed by a contention period (CP). Thus, by activating the PCF, the CFP can be used by LTE users, while the CP can be assigned to the WiFi users [24].Each duty cycle has a fixed duration of T . Although the length of each duty cycle is fixed, the length of each phase assigned to WiFi or U-LTE network varies over different cycles.…”

IoT‐Based Management Platform for Real‐Time Spectrum and Energy Optimization of Broadcasting Networks

“…The TV Band spectrum allocations not in use at a certain location and time frame are known as TV White Spaces (TVWS). In the same way, to overcome the licensed spectrum shortage and its inefficient usage, Long-Term Evolution networks in the unlicensed spectrum (LTE-U) have been proposed and are under consideration by the Third Generation Partnership Project (3GPP) [6]. In [6], authors propose a novel wireless access point architecture (hyper-AP), which implements both Wi-Fi and LTE and jointly coordinates the spectrum allocation and interference management.…”