scispace - formally typeset
Search or ask a question
Proceedings ArticleDOI

LTE UL Power Control for the Improvement of LTE/Wi-Fi Coexistence

TL;DR: The proposed LTE UL power control with interference aware power operating point is a flexible tool to deal with the trade-off between LTE and Wi-Fi performances in coexistence since it is able to set different LTE/Wi-Fi coexistence configurations with the choice of a single parameter.
Abstract: Spectrum sharing is a powerful alternative to deal with the exponential increase on the wireless communication capacity demand In this context, the coexistence of two of the most prominent wireless technologies today, Long Term Evolution (LTE) and Wi-Fi, is an important research topic In the most common Wi-Fi network operation, the Distributed Coordination Function (DCF), communication nodes access the channel only if the interference level is below a certain threshold Then, Wi-Fi operation is severely affected when in coexistence with LTE This paper proposes the use of LTE uplink (UL) power control to improve LTE/Wi-Fi coexistence With the introduction of an additional factor to the conventional LTE UL power control, a controlled decrease of LTE UL transmit powers is carried out according to interference measurements, giving opportunity to Wi-Fi transmissions The proposed LTE UL power control with interference aware power operating point is a flexible tool to deal with the trade-off between LTE and Wi-Fi performances in coexistence, since it is able to set different LTE/Wi-Fi coexistence configurations with the choice of a single parameter Simulation results show that the proposed approach can provide similar or better performance for both LTE and Wi-Fi networks than a previously proposed interference avoidance mechanism
Citations
More filters
Journal ArticleDOI
TL;DR: Simulation results demonstrate that LTE-U can provide better user experience to LTE users while well protecting the incumbent WiFi users' performance compared to two existing advanced technologies: cellular/WiFi interworking and licensed-only heterogeneous networks (Het-Nets).
Abstract: The phenomenal growth of mobile data demand has brought about increasing scarcity in available radio spectrum. Meanwhile, mobile customers pay more attention to their own experience, especially in communication reliability and service continuity on the move. To address these issues, LTE-Unlicensed, or LTEU, is considered one of the latest groundbreaking innovations to provide high performance and seamless user experience under a unified radio technology by extending LTE to the readily available unlicensed spectrum. In this article, we offer a comprehensive overview of the LTEU technology from both operator and user perspectives, and examine its impact on the incumbent unlicensed systems. Specifically, we first introduce the implementation regulations, principles, and typical deployment scenarios of LTE-U. Potential benefits for both operators and users are then discussed. We further identify three key challenges in bringing LTE-U into reality together with related research directions. In particular, the most critical issue of LTE-U is coexistence with other unlicensed systems, such as widely deployed WiFi. The LTE/WiFi coexistence mechanisms are elaborated in time, frequency, and power aspects, respectively. Simulation results demonstrate that LTE-U can provide better user experience to LTE users while well protecting the incumbent WiFi users’ performance compared to two existing advanced technologies: cellular/WiFi interworking and licensed-only heterogeneous networks (Het-Nets).

370 citations

Journal ArticleDOI
TL;DR: The issues that arise from the concurrent operation of LTE and Wi-Fi in the same unlicensed bands from the point of view of radio resource management are discussed and it is shown that Wi-fi is severely impacted by LTE transmissions.
Abstract: The expansion of wireless broadband access network deployments is resulting in increased scarcity of available radio spectrum. It is very likely that in the near future, cellular technologies and wireless local area networks will need to coexist in the same unlicensed bands. However, the two most prominent technologies, LTE and Wi-Fi, were designed to work in different bands and not to coexist in a shared band. In this article, we discuss the issues that arise from the concurrent operation of LTE and Wi-Fi in the same unlicensed bands from the point of view of radio resource management. We show that Wi-Fi is severely impacted by LTE transmissions; hence, the coexistence of LTE and Wi-Fi needs to be carefully investigated. We discuss some possible coexistence mechanisms and future research directions that may lead to successful joint deployment of LTE and Wi-Fi in the same unlicensed band.

247 citations

Journal ArticleDOI
TL;DR: This paper provides a comprehensive survey of the coexistence of LTE-LAA and Wi-Fi on 5 GHz with corresponding deployment scenarios, and explores a relatively smooth technical route for solving coexistence-related problems.
Abstract: Long term evolution (LTE) carrier aggregation with 5 GHz unlicensed national informational infrastructure band has been pointed out by the industry as a good solution to handle the rapidly increasing amounts of data traffic. To provide fair coexistence of LTE-licensed assisted access (LTE-LAA) and Wi-Fi on 5 GHz, several coexistence mechanisms have already been proposed. This paper provides a comprehensive survey of the coexistence of LTE-LAA and Wi-Fi on 5 GHz with corresponding deployment scenarios. We first analyze coexistence-related features of those two technologies, including motivation, LTE carrier aggregation with unlicensed band, LTE and Wi-Fi medium access control protocols comparison, coexistence challenges and enablers, performance difference between LTE-LAA and Wi-Fi, as well as co-channel interference. Second, we further extensively discuss current considerations about the coexistence of LTE-LAA and Wi-Fi. Third, influential factors for the classification of small cell scenarios, as well as four representative scenarios are investigated in detail. Then we explore a relatively smooth technical route for solving coexistence-related problems, which practically takes features of a specific scenario as the base for designing deployment mode of LTE-LAA and/or Wi-Fi. A scenario-oriented decision making procedure for the coexistence issue and the analysis on an example deployment scenario, including design and performance evaluation metrics focusing on the concept of the scenario-oriented coexistence are presented. We finally forecast further research trends on the basis of our conclusion.

201 citations


Cites background or methods from "LTE UL Power Control for the Improv..."

  • ...Both LTE-LAA and Wi-Fi have their own benefits and cannot be replaced by each other at the moment [9]....

    [...]

  • ...and network efficiency like what LTE offers [9]....

    [...]

  • ...An approach using LTE UL power control to solve the coexistence issue of LTE-LAA and Wi-Fi networks is studied in [9]....

    [...]

Proceedings ArticleDOI
11 May 2015
TL;DR: Using this framework, theoretical models based on Markov chains are established for both systems and downlink throughput can be calculated and numerical results show that the simple listen-before-talk scheme is very effective in LAA and LAA coexistence scenario and can improve WiFi performance substantially.
Abstract: Deployment of LTE in unlicensed bands is being considered in Rel-13 of LTE. This feature is called Licensed-Assisted Access (LAA) using LTE. Unlicensed band is attractive due to the large amount of available spectrum. However, in shared spectrum the coexistence between LAA and WiFi systems becomes a primary challenge. This paper presents an analytical framework to investigate the downlink coexistence performance between two systems with a simple listen-before-talk (LBT) mechanism enforced on LAA. Using this framework, theoretical models based on Markov chains are established for both systems and downlink throughput can be calculated. Numerical results from the models show that the simple listen-before-talk scheme is very effective in LAA and LAA coexistence scenario (i.e. two LAA systems sharing the same spectrum). In LAA and WiFi coexistence scenario, it can improve WiFi performance substantially.

150 citations


Cites background from "LTE UL Power Control for the Improv..."

  • ...In [7], another scheme which controls LTE uplink transmit powers is introduced to enable the coexistence between LTE and WiFi....

    [...]

Proceedings ArticleDOI
TL;DR: In this paper, the authors investigated the coexistence of Wi-Fi and LTE in emerging unlicensed frequency bands which are intended to accommodate multiple radio access technologies and showed that both networks cause significant interference to each other and that the degradation is dependent on power levels and physical topology.
Abstract: This paper investigates the co-existence of Wi-Fi and LTE in emerging unlicensed frequency bands which are intended to accommodate multiple radio access technologies. Wi-Fi and LTE are the two most prominent access technologies being deployed today, motivating further study of the inter-system interference arising in such shared spectrum scenarios as well as possible techniques for enabling improved co-existence. An analytical model for evaluating the baseline performance of co-existing Wi-Fi and LTE is developed and used to obtain baseline performance measures. The results show that both Wi-Fi and LTE networks cause significant interference to each other and that the degradation is dependent on a number of factors such as power levels and physical topology. The model-based results are partially validated via experimental evaluations using USRP based SDR platforms on the ORBIT testbed. Further, inter-network coordination with logically centralized radio resource management across Wi-Fi and LTE systems is proposed as a possible solution for improved co-existence. Numerical results are presented showing significant gains in both Wi-Fi and LTE performance with the proposed inter-network coordination approach.

123 citations

References
More filters
Journal ArticleDOI
TL;DR: An overview of the techniques being considered for LTE Release 10 (aka LTEAdvanced) is discussed, which includes bandwidth extension via carrier aggregation to support deployment bandwidths up to 100 MHz, downlink spatial multiplexing including single-cell multi-user multiple-input multiple-output transmission and coordinated multi point transmission, and heterogeneous networks with emphasis on Type 1 and Type 2 relays.
Abstract: LTE Release 8 is one of the primary broadband technologies based on OFDM, which is currently being commercialized. LTE Release 8, which is mainly deployed in a macro/microcell layout, provides improved system capacity and coverage, high peak data rates, low latency, reduced operating costs, multi-antenna support, flexible bandwidth operation and seamless integration with existing systems. LTE-Advanced (also known as LTE Release 10) significantly enhances the existing LTE Release 8 and supports much higher peak rates, higher throughput and coverage, and lower latencies, resulting in a better user experience. Additionally, LTE Release 10 will support heterogeneous deployments where low-power nodes comprising picocells, femtocells, relays, remote radio heads, and so on are placed in a macrocell layout. The LTE-Advanced features enable one to meet or exceed IMT-Advanced requirements. It may also be noted that LTE Release 9 provides some minor enhancement to LTE Release 8 with respect to the air interface, and includes features like dual-layer beamforming and time-difference- of-arrival-based location techniques. In this article an overview of the techniques being considered for LTE Release 10 (aka LTEAdvanced) is discussed. This includes bandwidth extension via carrier aggregation to support deployment bandwidths up to 100 MHz, downlink spatial multiplexing including single-cell multi-user multiple-input multiple-output transmission and coordinated multi point transmission, uplink spatial multiplexing including extension to four-layer MIMO, and heterogeneous networks with emphasis on Type 1 and Type 2 relays. Finally, the performance of LTEAdvanced using IMT-A scenarios is presented and compared against IMT-A targets for full buffer and bursty traffic model.

1,044 citations


"LTE UL Power Control for the Improv..." refers background in this paper

  • ...ABS is a subframe with reduced LTE DL power or activity with the purpose of coordinating transmissions on heterogeneous macro and pico eNodeB deployments....

    [...]

  • ...In [9], an approach inspired on the ABS feature is proposed and evaluated for LTE/Wi-Fi coexistence....

    [...]

  • ...4GHz band has been established [4], and features recently included on LTE standard [8] allow its usage on pico and femto cells, the coexistence of LTE-Advanced and Wi-Fi networks appears as a relevant research topic....

    [...]

  • ...LTE Release 10 introduces a key feature for enhanced Inter Cell Interference Coordination (eICIC): the Almost Blank Subframe (ABS) [8]....

    [...]

Journal ArticleDOI
TL;DR: Concepts underlying the "property" and "commons" debate are presented, options for spectrum reform are clarified, and the trade-offs of spectrum sharing are described.
Abstract: Many complain about severe spectrum shortage. The shortage comes from outdated spectrum policies that allows for little sharing. Regulators have granted licenses that offer exclusive access to the spectrum. When these licensees are not transmitting, the spectrum sits idle. A new technology regarding spectrum shortage enables more spectrum sharing that unleashes innovative products and services, provided that we adopt the appropriate spectrum policies. Two camps are pushing for extreme reform, one for "property rights" and the other for "spectrum commons". This article presents concepts underlying the "property" and "commons" debate, clarifies options for spectrum reform, and describes the trade-offs of spectrum sharing

592 citations


"LTE UL Power Control for the Improv..." refers background in this paper

  • ...While new licensed frequency bands become rare and expensive, the sharing of spectrum by different communication systems is considered by academia and industry as a powerful solution to provide additional capacity [1]....

    [...]

Proceedings ArticleDOI
09 Jun 2013
TL;DR: This paper considers two of the most prominent wireless technologies available today, namely Long Term Evolution (LTE), and WiFi, and addresses some problems that arise from their coexistence in the same band, and proposes a simple coexistence scheme that reuses the concept of almost blank subframes in LTE.
Abstract: The recent development of regulatory policies that permit the use of TV bands spectrum on a secondary basis has motivated discussion about coexistence of primary (e.g. TV broadcasts) and secondary users (e.g. WiFi users in TV spectrum). However, much less attention has been given to coexistence of different secondary wireless technologies in the TV white spaces. Lack of coordination between secondary networks may create severe interference situations, resulting in less efficient usage of the spectrum. In this paper, we consider two of the most prominent wireless technologies available today, namely Long Term Evolution (LTE), and WiFi, and address some problems that arise from their coexistence in the same band. We perform exhaustive system simulations and observe that WiFi is hampered much more significantly than LTE in coexistence scenarios. A simple coexistence scheme that reuses the concept of almost blank subframes in LTE is proposed, and it is observed that it can improve the WiFi throughput per user up to 50 times in the studied scenarios.

324 citations


"LTE UL Power Control for the Improv..." refers background or methods or result in this paper

  • ...The mean user throughput performance with the allocation of two LTE UL subframes as blank subframes, as proposed in [9], is also shown as reference....

    [...]

  • ...The general observations are similar to the ones given in [3], [9], where no LTE power control was considered: LTE is slightly affected by Wi-Fi interference, while Wi-Fi throughput can be hardly degraded according to the scenario....

    [...]

  • ...Interference avoidance approaches for LTE/Wi-Fi coexistence, as the allocation of LTE blank subframes for Wi-Fi transmission [9], may require significant signaling between the networks to define the agreement parameters and provide...

    [...]

  • ...One way to alleviate the degradation of Wi-Fi performance is to reserve LTE subframes for WiFi only transmission, as proposed in [9]....

    [...]

  • ...In order to overcome this problem, a mechanism for LTE/Wi-Fi coexistence is proposed and evaluated in [9], where LTE blank subframe allocation is used to improve Wi-Fi performance....

    [...]

Proceedings ArticleDOI
16 May 2005
TL;DR: In this article, the mutual effects of IEEE 802.15.4 and 802.11 in the 2.4 GHz ISM band are examined with real-life equipment, in order to quantify coexistence issues.
Abstract: Wireless systems continue to rapidly gain popularity. This is extremely true for data networks in the local and personal area, which are called WLAN and WPAN, respectively. However, most of those systems are working in the license-free industrial scientific medical (ISM) frequency bands, where neither resource planning nor bandwidth allocation can be guaranteed. To date, the most widespread systems in the 2.4 GHz ISM band are IEEE802.11 as stated in IEEE Std. 802-11 (1997) and Bluetooth, with ZigBee based in IEEE Std. 802.15.4 (2003) and IEEE802.15.4 as upcoming standards for short range wireless networks. In this paper we examine the mutual effects of these different communication standards. Measurements are performed with real-life equipment, in order to quantify coexistence issues

289 citations


"LTE UL Power Control for the Improv..." refers background in this paper

  • ...4GHz band has been established [4], and features recently included on LTE standard [8] allow its usage on pico and femto cells, the coexistence of LTE-Advanced and Wi-Fi networks appears as a relevant research topic....

    [...]

  • ...Several works on the coexistence of heterogeneous systems can be found in literature [4]–[7]....

    [...]

  • ...In [4], [5], the authors address the coexistence between IEEE 802....

    [...]

Proceedings ArticleDOI
02 Jun 2013
TL;DR: A simulator-based system- level analysis in order to assess the network performance in an office scenario shows that LTE system performance is slightly affected by coexistence whereas Wi-Fi is significantly impacted by LTE transmissions.
Abstract: The deployment of modern mobile systems has faced severe challenges due to the current spectrum scarcity. The situation has been further worsened by the development of different wireless technologies and standards that can be used in the same frequency band. Furthermore, the usage of smaller cells (e.g. pico, femto and wireless LAN), coexistence among heterogeneous networks (including amongst different wireless technologies such as LTE and Wi-Fi deployed in the same frequency band) has been a big field of research in the academy and industry. In this paper, we provide a performance evaluation of coexistence between LTE and Wi-Fi systems and show some of the challenges faced by the different technologies. We focus on a simulator-based system- level analysis in order to assess the network performance in an office scenario. Simulation results show that LTE system performance is slightly affected by coexistence whereas Wi-Fi is significantly impacted by LTE transmissions. In coexistence, the Wi-Fi channel is most often blocked by LTE interference, making the Wi-Fi nodes to stay on the LISTEN mode more than 96% of the time. This reflects directly on the Wi-Fi user throughput, that decreases from 70% to ≈100% depending on the scenario. Finally, some of the main issues that limit the LTE/Wi-Fi coexistence and some pointers on the mutual interference management of both the systems are provided.

270 citations


"LTE UL Power Control for the Improv..." refers background or methods or result in this paper

  • ...The general observations are similar to the ones given in [3], [9], where no LTE power control was considered: LTE is slightly affected by Wi-Fi interference, while Wi-Fi throughput can be hardly degraded according to the scenario....

    [...]

  • ...For the coexistence scenarios considered in [3], Wi-Fi nodes spend at least 96% of time in listen mode....

    [...]

  • ...However, it is known that the coexistence of distinct networks in the same frequency band may cause meaningful degradation on system performance, as shown in [3] and references therein....

    [...]

  • ...A general picture of the challenging coexistence between LTE and Wi-Fi in the same frequency bands is provided in [3]....

    [...]

  • ...A semi-static system level simulator is used, where standard-compliant LTE and WiFi networks are modeled, including network layout, nodes distribution, radio environment, physical layer (PHY), MAC layer, and traffic generation [3]....

    [...]

Trending Questions (1)
What is the difference between LTE Home Internet and FIOS?

Then, Wi-Fi operation is severely affected when in coexistence with LTE.