Coverage and Deployment Analysis of Narrowband Internet of Things in the Wild

Narrowband Internet of Things (NB-IoT) is gaining momentum as a promising technology for massive Machine Type Communication (mMTC). Given that its deployment is rapidly progressing worldwide, measurement campaigns and performance analyses are needed to better understand the system and move toward its enhancement. With this aim, this paper presents a large scale measurement campaign and empirical analysis of NB-IoT on operational networks, and discloses valuable insights in terms of deployment strategies and radio coverage performance. The reported results also serve as examples showing the potential usage of the collected dataset, which we make open-source along with a lightweight data visualization platform.Comment: Accepted for publication in IEEE Communications Magazine (Internet of Things and Sensor Networks Series

LTE in Unlicensed Bands is neither Friend nor Foe to Wi-Fi

Proponents of deploying LTE in the 5 GHz band for providing additional cellular network capacity have claimed that LTE would be a better neighbour to Wi-Fi in the unlicensed band, than Wi-Fi is to itself. On the other side of the debate, the Wi-Fi community has objected that LTE would be highly detrimental to Wi-Fi network performance. However, there is a lack of transparent and systematic engineering evidence supporting the contradicting claims of the two camps, which is essential for ascertaining whether regulatory intervention is in fact required to protect the Wi-Fi incumbent from the new LTE entrant. To this end, we present a comprehensive coexistence study of Wi-Fi and LTE-in-unlicensed, surveying a large parameter space of coexistence mechanisms and a range of representative network densities and deployment scenarios. Our results show that, typically, harmonious coexistence between Wi-Fi and LTE is ensured by the large number of 5 GHz channels. For the worst-case scenario of forced co-channel operation, LTE is sometimes a better neighbour to Wi-Fi - when effective node density is low - but sometimes worse - when density is high. We find that distributed interference coordination is only necessary to prevent a "tragedy of the commons" in regimes where interference is very likely. We also show that in practice it does not make a difference to the incumbent what kind of coexistence mechanism is added to LTE-in-unlicensed, as long as one is in place. We therefore conclude that LTE is neither friend nor foe to Wi-Fi in the unlicensed bands in general. We submit that the systematic engineering analysis exemplified by our case study is a best-practice approach for supporting evidence-based rulemaking by the regulator.Comment: accepted for publication in IEEE Acces

A General Framework for Analyzing, Characterizing, and Implementing Spectrally Modulated, Spectrally Encoded Signals

Fourth generation (4G) communications will support many capabilities while providing universal, high speed access. One potential enabler for these capabilities is software defined radio (SDR). When controlled by cognitive radio (CR) principles, the required waveform diversity is achieved via a synergistic union called CR-based SDR. Research is rapidly progressing in SDR hardware and software venues, but current CR-based SDR research lacks the theoretical foundation and analytic framework to permit efficient implementation. This limitation is addressed here by introducing a general framework for analyzing, characterizing, and implementing spectrally modulated, spectrally encoded (SMSE) signals within CR-based SDR architectures. Given orthogonal frequency division multiplexing (OFDM) is a 4G candidate signal, OFDM-based signals are collectively classified as SMSE since modulation and encoding are spectrally applied. The proposed framework provides analytic commonality and unification of SMSE signals. Applicability is first shown for candidate 4G signals, and resultant analytic expressions agree with published results. Implementability is then demonstrated in multiple coexistence scenarios via modeling and simulation to reinforce practical utility

Risk-Informed Interference Assessment for Shared Spectrum Bands: A Wi-Fi/LTE Coexistence Case Study

Interference evaluation is crucial when deciding whether and how wireless technologies should operate. In this paper we demonstrate the benefit of risk-informed interference assessment to aid spectrum regulators in making decisions, and to readily convey engineering insight. Our contributions are: we apply, for the first time, risk assessment to a problem of inter-technology spectrum sharing, i.e. Wi-Fi/LTE in the 5 GHz unlicensed band, and we demonstrate that this method comprehensively quantifies the interference impact. We perform simulations with our newly publicly-available tool and we consider throughput degradation and fairness metrics to assess the risk for different network densities, numbers of channels, and deployment scenarios. Our results show that no regulatory intervention is needed to ensure harmonious technical Wi-Fi/LTE coexistence: for the typically large number of channels available in the 5 GHz band, the risk for Wi-Fi from LTE is negligible, rendering policy and engineering concerns largely moot. As an engineering insight, Wi-Fi coexists better with itself in dense, but better with LTE, in sparse deployments. Also, both main LTE-in-unlicensed variants coexist well with Wi-Fi in general. For LTE intra-technology inter-operator coexistence, both variants typically coexist well in the 5 GHz band, but for dense deployments, implementing listen-before-talk causes less interference

LTE/NR V2X Communication Modes and Future Requirements of Intelligent Transportation Systems Based on MR-DC Architectures

[EN] This paper deals with the potential of Third Generation Partnership (3GPP) Project mobile cellular standards to enable vehicular communications. Starting from 3GPP Release 15, and Release 16 specifications for Vehicle-to-Everything (V2X) communications, the different communication modes, interfaces and use cases for V2X based on Long Term Evolution (LTE) and New Radio (NR) are analyzed. This research also studies the potential beneficial impact on V2X of a network that is aware of the underlying Multi-RAT Dual Connectivity (MR-DC) architecture. The methodology followed in this work consists of a review of 3GPP standards for vehicular communications based on mobile networks. The performance evaluation of the communication modes was performed through simulations taking into account resource allocation schemes, packet transmission frequencies, packet size, vehicle density and other parameters defined in the standard. In order to perform simulations of the decentralized communication mode (mode 4), a simulator based on OMNeT++ was configured. For the centralized mode (mode 3), an analytical model in MATLAB was used to configure different simulation scenarios. The results obtained indicate that LTE networks can only support basic V2X use cases because they do not demand strict potential requirements. Simulations showed that the centralized mode offers better performance than mode 4; however, it requires cellular network coverage. More advanced use cases are key for a future Intelligent Transport System (ITS), high-performance networks (i.e., Fifth Generation (5G), NR) are expected to coexist gradually with LTE in the V2X landscape. Therefore, in order to meet the strict requirements for latency, transmission speed and reliability, MR-DC architectures combining different radio access technologies, communication modes and connection interfaces should be deployed. In addition, operation in multi-operator and cross-border scenarios must be guaranteed.This research was supported by the European Union's H2020-ICT-18-2018 action "5G for cooperative, connected and automated mobility", for project "5G for Connected and Automated Road Mobility in the European unioN (5G-CARMEN)" under grant agreement no. 825012.González, EE.; Garcia-Roger, D.; Monserrat Del Río, JF. (2022). LTE/NR V2X Communication Modes and Future Requirements of Intelligent Transportation Systems Based on MR-DC Architectures. Sustainability. 14(7):1-19. https://doi.org/10.3390/su1407387911914

Analisis Koeksistensi Jaringan LTE Non Lisensi dan Wi-Fi Pada Frekuensi 5GHz

Untuk memenuhi permintaan kebutuhan trafik layanan internet yang akan terjadi pada 2020, penggunaan spektrum harus dilakukan secara maksimal. Pemanfaatan spektrum frekuensi non-lisensi oleh teknologi LTE-Unlicensed atau LTE Non-Lisensi dapat memenuhi permintaan kebutuhan trafik. Tetapi spektrum frekuensi non-lisensi sudah terlebih dahulu digunakan oleh teknologi Wi-Fi, maka teknologi LTE Non-Lisensi harus dapat beradapatasi dan berkoeksistensi dengan Wi-Fi. Penelitian ini akan membahas jarak minimum yang dibutuhkan oleh eNodeB LTE Non-Lisensi dan Access Point Wi-Fi agar kedua teknologi ini dapat berkoeksistensi dengan kondisi indoor LOS dan NLOS serta outdoor LOS dan NLOS. Koeksistensi ditinjau dari nilai ACIR antara kedua teknologi tersebut. Berdasarkan hasil penelitian, jarak minimum untuk indoor adalah 16m-35m dengan kondisi LOS dan outdoor adalah 51m-199m dengan kondisi LOS. Nilai SINR threshold adalah 22dB untuk LTE Non-Lisensi dan 19,7dB untuk Wi-Fi. Dari hasil simulasi didapatkan nilai rata-rata CINR untuk outdoor adalah 15dB sedangkan untuk indoor nilai SIR rata-rata adalah 0,62dB.By the 2020 the traffic internet demand will be increasing, so that the utilization of spectrum frequency should be maximize and use wisely. LTE-U which is using unlicensed spectrum frequency may be option to fulfil the demand of the internet traffic. Unfortunately it has to adapt and coexistence with Wi-Fi which already exist in unlicensed spectrum frequency. In this research, will talk about the minimum distance needed so that LTE-U eNodeB and Wi-Fi can be coexistence in indoor and outdoor deployment LOS and NLOS condition. The coexistence analyze in ACIR value. The result, minimum distance needed is in range 16 m-35 m for indoor deployment. In the other hand 51 m-199 m for outdoor deployment. With software simulation in 51 m distance the mean CINR value is 15 dB, and for 16 m distance the mean SIR value is 0.62 dB

Models of Control Channels in the LTE System

Dizertační práce se zabývá zpracováním signálu fyzických řídicích kanálů systému LTE a vyšetřováním bitové chybovosti při přenosu řídicí informace z vysílače do přijímače v závislosti na podmínkách příjmu. Práce je rozdělena do dvou hlavních částí. První část práce je zaměřena na simulaci přenosu řídicí informace LTE v základním pásmu. Jsou zde prezentovány vytvořené simulátory řídicích kanálů ve směru uplink i downlink. Simulace jsou provedeny pro všechny druhy nastavení systému a základní modely přenosového prostředí. Jsou zde popsány výsledky vlivu použití MIMO technologií na kvalitu příjmu řídicí informace především v únikových kanálech. Druhá část práce je zaměřena na možnost nasazení systému LTE ve sdíleném pásmu ISM (2.4 GHz). Jsou zde představeny základní koncepce použití, na jejichž základě je vytvořen scénář simulací. Kapitola dále popisuje tvorbu simulátoru koexistence LTE a systému Wi-Fi v přeneseném pásmu ISM 2.4GHz. Jsou zde uvedeny výsledky simulací koexistence LTE a rušivého systému Wi-Fi provedených dle vytvořeného scénáře. Výsledky simulací koexistence LTE a Wi-Fi jsou ověřeny měřením v laboratorních podmínkách. Toto porovnání je důležité z hlediska optimalizace simulátoru koexistence. Dle výsledků obou typů simulací a měření jsou stanovena provozní doporučení, která mají přispět k bezpečnému a spolehlivému vysílání a příjmu řídicích informací LTE i při nepříznivých podmínkách příjmu.The doctoral thesis is focused on a signal processing in the LTE physical control channels and performance analysis of control information transmission according to receiving conditions. The thesis is divided into two parts. The first part deals with simulation of the transmission of control information in baseband. The created simulators for uplink and downlink are presented. The simulations are performed for all possible system settings and various channel models. The MIMO influence on a quality of control information reception under fading channels is also presented. The second part of the thesis is focused on LTE utilization in shared channel ISM (2.4 GHz). The basic LTE application concept for ISM band is presented. This concept is fundamental to created simulation scenario. The chapter also presents the LTE and Wi-Fi coexistence simulator in 2.4 GHz ISM passband. The coexistence simulation are presented according to simulation scenario and the results are shown. The simulated coexistence analysis results are verified in laboratory environment. The comparison of the simulated and the measured coexistence analysis results is crucial for further optimization of the coexistence simulator. Recommendations for optimal and reliable operation of LTE are specified according to the simulated and the measured results. Recommendations should be useful to the reliable transmission of LTE control information in bad receiving conditions.

Analisis Interferensi T-DAB Dan TV Analog Pada Pita Very High Frequency (VHF)

Kehadiran teknologi digital telah membawa Perubahan di dalam berbagai aspek kehidupan, tak terkecuali di dunia penyiaran. Digitalisasi dibidang penyiaran diyakini dapat memberikan manfaat dalam hal efisiensi spektrum frekuensi radio. Berkaitan dengan penyiaran radio, Menteri Komunikasi dan Informatika telah menetapkan DAB family sebagai standard penyiaran radio digital di Indonesia. Kajian dilakukan untuk mendapatkan jarak minimum yang diperlukan antara sistem T-DAB dan TV analog sebagai solusi terhadap kemungkinan interferensi. Analisis dilakukan dengan bantuan SEAMCAT. Berdasarkan hasil analisis disimpulkan bahwa kanal A T-DAB merupakan kanal yang paling rentan terhadap interferensi; Untuk mencapai probabilitas interferensi maksimum 5%, separasi geograpis minimum antara cakupan terluar TV analog kanal n dan transmitter terluar pada jaringan SFN T-DAB untuk kanal (n- 1)D, nA, nB, nC berturut-turut adalah 220 Km, 290 Km, 145 Km dan 40 Km. Sedangkan untuk kanal nD dan (n+1)A dapat dioperasikan tanpa separasi geograpis dengan TV analog

ANALISA INTERFERENSI LONG TERM EVOLUTION TERHADAP WIFI PADA FREKUENSI UNLICENSED

Long term evolution (LTE) merupakan bagian teknologi nirkabel dengan rentang frekuensi 2300-2400 MHz pada E-UTRA yang beroperasi di band 40 dengan mode transmisi time division duplex (TDD). Salah satu perangkat wireless yang frekuensi kerjanya mendekati sistem tersebut adalah WLAN (Wifi) dengan standar IEEE 802.11 b/g di frekuensi 2400 MHz. Interferensi dapat terjadi apabila pita frekuensi pada 2 sistem perangkat wireless yang berbeda mempunyai frekuensi yang sama atau berdekatan. Untuk melindungi Wifi dari interferensi yang disebabkan oleh perangkat LTE, perlu dilakukan kajian yang menganalisis interferensi LTE terhadap wifi 802.11 b/g. Penelitian ini bertujuan untuk menganalisis interferensi dari pengirim LTE band 40 terhadap penerima wi-fi 802.11 b/g menggunakan Spectrum Engineering Advanced Monte-Carlo Analysis Tool (SEAMCAT), yaitu model simulasi statistik yang menggunakan metode analisis yang disebut monte carlo dengan propagasi outdoor-indoor dengan melihat faktor jarak yang bervariasi antara pengirim pengganggu LTE terhadap penerima terganggu wi-fi. Dari hasil simulasi didapatkan desired Received Signal Strength (dRSS) menurun seiring jarak wanted transmitter (AP wifi) ke victim receiver (MS wifi) dijauhkan dengan jarak IT-VR minimum 50 meter, dRSS memiliki nilai sebesar -82.15 dBm dimana nilai ini dibawah nilai sensitivitas penerima yang ditetapkan. Sisi lain nilai C/I pada jarak IT-VR minimum 50 meter dengan jarak WT-VR maksimum 30 meter sebesar 13.01 dB mendekati nilai C/I yang ditetapkan dan probabilitas interferensi sebesar 16.79 %. Dengan mengetahui pengaruh interferensi LTE band 40 terhadap wifi 802.11 b/g pada band unlicensed dapat dilihat dari nilai C/I yang dihasilkan. Semakin dekat jarak pengganggu LTE maka semakin besar probabilitas interferensi yang dialami penerima wifi 802.11 b/g, sementara nilai C/I nya semakin kecil