scholarly journals Battery Lifetime Estimation for LoRaWAN Communications

2020 ◽  
Vol 9 (11) ◽  
pp. 306-310
Keyword(s):  
Power Consumption ◽  
Smart Cities ◽  
Building Blocks ◽  
Wide Area Networks ◽  
Lifetime Estimation ◽  
Battery Lifetime ◽  
Global Power ◽  
Simulation Results ◽  
Microcontroller Unit ◽  
Time Acquisition

Smart Cities concept increased the number of end devices (ED) which allow the acquisition of parameters for further analysis and processing. The actual technologies based on Internet of Things (IoT) enable sensors connectivity to Internet. This feature allows real time acquisition of several physical data important for smart cities monitoring. In order to minimize the power consumption, Low Power Wide Area Networks (LPWAN) assumes an important role on the evolution and growing of wireless network sensors. In this particular type of network, LoRaWAN has taken the lead, among other technologies. Typically most end devices need to be powered with batteries, since they are in remote zones. Therefore one important issue to consider is the global power consumption of the end device building blocks: LoRa transceiver, microcontroller unit and sensor unit. This paper presents the study and simulation results supported on LoRa modulation parameters, in order to estimate the battery lifetime, which is useful for IoT remote sensing units. The achieved results denote it is possible to configure LoRa transceiver with similar parameters and different payloads, reaching the same battery lifetime.

scholarly journals A Novel Cross-Latch Shift Register Scheme for Low Power Applications

2020 ◽  
Vol 11 (1) ◽  
pp. 129
Author(s):  
Po-Yu Kuo ◽  
Ming-Hwa Sheu ◽  
Chang-Ming Tsai ◽  
Ming-Yan Tsai ◽  
Jin-Fa Lin
Keyword(s):  
Power Consumption ◽  
Supply Voltage ◽  
Electrical Power ◽  
Average Power ◽  
Leakage Power ◽  
Shift Register ◽  
Cmos Process ◽  
Average Power Consumption ◽  
Simulation Results ◽  
Layout Area

The conventional shift register consists of master and slave (MS) latches with each latch receiving the data from the previous stage. Therefore, the same data are stored in two latches separately. It leads to consuming more electrical power and occupying more layout area, which is not satisfactory to most circuit designers. To solve this issue, a novel cross-latch shift register (CLSR) scheme is proposed. It significantly reduced the number of transistors needed for a 256-bit shifter register by 48.33% as compared with the conventional MS latch design. To further verify its functions, this CLSR was implemented by using TSMC 40 nm CMOS process standard technology. The simulation results reveal that the proposed CLSR reduced the average power consumption by 36%, cut the leakage power by 60.53%, and eliminated layout area by 34.76% at a supply voltage of 0.9 V with an operating frequency of 250 MHz, as compared with the MS latch.

scholarly journals Reliability Improvement of LoRa with ARQ and Relay Node

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 552 ◽  
Author(s):  
Rocksan Choi ◽  
SeungGwan Lee ◽  
Sungwon Lee
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Smart Cities ◽  
Wide Area ◽  
Forward Rate ◽  
Low Power Consumption ◽  
Modern World ◽  
Automatic Repeat Request ◽  
Actual Performance ◽  
Iot Devices

In our modern world, many Internet of Things (IoT) technologies are being researched and developed. IoT devices are currently being used in many fields. IoT devices use Wi-Fi and Bluetooth, however, communication distance is short and battery consumption is high. In areas such as smart cities and smart farms, IoT technology is needed to support a wide coverage with low power consumption. Low Power Wide Area (LPWA), which is a transmission used in IoT supporting a wide area with low power consumption, has evolved. LPWA includes Long Range (LoRa), Narrowband (NB-IoT), and Sigfox. LoRa offers many benefits as it communicates the longest distances, is cheap and consumes less battery. LoRa is used in many countries and covers a range of hundreds of square kilometers (km2) with a single gateway. However, if there are many obstacles to smart cities and smart farms, it causes communication problems. This paper proposes two (2) solutions to this problem: the relay method which is a multi-hop method and the Automatic Repeat Request (ARQ) system that detects packet loss in real-time and requests retransmission for LoRa. In this study, the actual performance of LoRa in the problematic environment was measured and the proposed method was applied. It was confirmed that the transmission rate of LoRa dropped when there were many obstacles such as trees. To use LoRa in a smart farm with a lot of space, multi-hop was observed to be better. An ARQ system is needed to compensate for the unexpected drop in the forward rate due to the increase in IoT devices. This research focused on reliability, however, additional network methods and automatic repeat request (ARQ) systems considering battery time should be researched in symmetry. This study covers the interdisciplinary field of computer science and wireless low power communication engineering. We have analyzed the LoRa/LoRaWAN technology in an experimental approach, which has been somewhat less studied than cellular network or WiFi technology. In addition, we presented and improved the performance evaluation results in consideration of various local and climatic environments.

A LOW-POWER AND HIGH-SPEED D FLIP-FLOP USING A SINGLE LATCH

2002 ◽  
Vol 11 (01) ◽  
pp. 51-55
Author(s):  
ROBERT C. CHANG ◽  
L.-C. HSU ◽  
M.-C. SUN
Keyword(s):  
Power Consumption ◽  
Low Power ◽  
Power Dissipation ◽  
High Speed ◽  
Operating Frequency ◽  
Flip Flop ◽  
Lower Power ◽  
Simulation Results ◽  
Hspice Simulation

A novel low-power and high-speed D flip-flop is presented in this letter. The flip-flop consists of a single low-power latch, which is controlled by a positive narrow pulse. Hence, fewer transistors are used and lower power consumption is achieved. HSPICE simulation results show that power dissipation of the proposed D flip-flop has been reduced up to 76%. The operating frequency of the flip-flop is also greatly increased.

scholarly journals Massive MIMO: Achievable Energy Efficiency for 5G systems with Multi-user Environment

2019 ◽  
Vol 8 (2) ◽  
pp. 6527-6534
Keyword(s):  
Energy Efficiency ◽  
Power Consumption ◽  
Path Loss ◽  
Antenna System ◽  
Base Station ◽  
Small Cells ◽  
Limiting Factors ◽  
Improve Energy Efficiency ◽  
User Terminal ◽  
Simulation Results

Massive Multi-Input and Multi-Output (MIMO) antenna system potentially provides a promising solution to improve energy efficiency (EE) for 5G wireless systems. The aim of this paper is to enhance EE and its limiting factors are explored. The maximum EE of 48 Mbit/Joule was achieved with 15 user terminal (UT)s. This problem is related to the uplink spectral efficiency with upper bound for future wireless networks. The maximal EE is obtained by optimizing a number of base station (BS) antennas, pilot reuse factor, and BSs density. We presented a power consumption model by deriving Shannon capacity calculations with closed-form expressions. The simulation result highlights the EE maximization with optimizing variables of circuit power consumption, hardware impairments, and path-loss exponent. Small cells achieve high EE and saturate to a constant value with BSs density. The MRC scheme achieves maximum EE of 36 Mbit/Joule with 12 UTs. The simulation results show that peak EE is obtained by deploying massive BS antennas, where the interference and pilot contamination are mitigated by coherent processing. The simulation results were implemented by using MATLAB 2018b.

scholarly journals Remote Microgrids for Energy Access in Indonesia—Part II: PV Microgrids and A Technology Outlook

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6901
Author(s):  
Desmon Simatupang ◽  
Ilman Sulaeman ◽  
Niek Moonen ◽  
Rinaldi Maulana ◽  
Safitri Baharuddin ◽  
...  
Keyword(s):  
Companion Paper ◽  
Monitoring Systems ◽  
Energy Access ◽  
Lifetime Estimation ◽  
Battery Lifetime ◽  
Utility Company ◽  
Pv Systems ◽  
Grid Connection ◽  
Advanced Technologies ◽  
Sustainability Challenges

This paper is the companion paper of Remote Microgrids for Energy Access in Indonesia “Part I: scaling and sustainability challenges and a technology outlook”. This part II investigates the issues of photovoltaic (PV) systems with respect to the planning, design, and operation, and maintenance phases in microgrids in Indonesia. The technology outlooks are also included as PV has an important role in providing electricity in the underdeveloped, isolated, and border areas. The data in this paper are from PV microgrids located in Maluku and North Maluku, which are two provinces where there is barely any grid connection available and thus very dependent on remote microgrids. The data are obtained from interviews with Perusahaan Listrik Negara (PLN) and NZMATES, which are an Indonesian utility company and a program for supporting role for the PV systems in Maluku funded by New Zealand respectively. Common issues with respect to reliability and sustainability are identified based on the provided data. Advanced technologies to increase reliability and sustainability are also presented in this paper as a technology outlook. Among these solutions are online monitoring systems, PV and battery lifetime estimation, load forecasting strategies, and PV inverters technology.

scholarly journals Wireless Technologies for IoT in Smart Cities

2018 ◽  
Vol 10 (1) ◽  
pp. 23 ◽  
Author(s):  
Laura Garcia ◽  
Jose Miguel Jiménez ◽  
Miran Taha ◽  
Jaime Lloret
Keyword(s):  
Power Consumption ◽  
Smart City ◽  
Smart Cities ◽  
Unlicensed Spectrum ◽  
Wireless Technologies ◽  
Unlicensed Bands ◽  
Communication Needs

As cities continue to grow, numerous initiatives for Smart Cities are being conducted. The concept of Smart City encompasses several concepts being governance, economy, management, infrastructure, technology and people. This means that a Smart City can have different communication needs. Wireless technologies such as WiFi, ZigBee, Bluetooth, WiMax, 4G or LTE have presented themselves as solutions to the communication needs of Smart City initiatives. However, as most of them employ unlicensed bands, interference and coexistence problems are increasing. In this paper, the wireless technologies available nowadays for IoT in Smart Cities are reviewed. Their characteristics and their adequacy to each domain is considered. The problems derived of over-crowded unlicensed spectrum and coexistence difficulties among each technology are discussed as well. Finally, power consumption concerns are addressed.

Battery Lifetime Estimation Based on Usage Pattern

2021 ◽  
pp. 353-365
Author(s):  
Manu Gupta ◽  
Shruti Mary ◽  
Jay Trivedi ◽  
Jai Goyal ◽  
Priyanka Maan ◽  
...  
Keyword(s):  
Usage Pattern ◽  
Lifetime Estimation ◽  
Battery Lifetime

IBCube

2018 ◽  
Vol 15 (1) ◽  
pp. 27-46
Author(s):  
Qiong Hu ◽  
Hanhua Chen ◽  
Hai Jin ◽  
Chen Tian ◽  
Aobing Sun ◽  
...  
Keyword(s):  
Low Cost ◽  
Packet Delay ◽  
Building Blocks ◽  
Network Interface ◽  
Allocation Scheme ◽  
The Past ◽  
Datacenter Networks ◽  
Construction Scheme ◽  
Economical Design ◽  
Simulation Results

Datacenter networks have attracted a lot of research interest in the past few years. BCube is proved to be a promising scheme due to its low cost. By using a recursive construction scheme, BCube can exponentially scale a datacenter. Industry experiences, however, articulate the importance of incremental expansion of datacenter. In this article, the authors show that BCube's expanding scheme suffers low utilization of switch ports. They propose IBCube, a novel economical design for incrementally building datacenter networks. The insight is that: by letting the number of switches in each BCube layer equal the number of the building blocks, the authors can enable the switch ports to be fully utilized to support the total number of network interface cards of the deployed servers in the datacenters. Accordingly, their IBCube designs a novel automatic port allocation scheme. Simulation results show that the IBCube design reduces the budget for the datacenter networks by 94% as well as improves the packet delay and throughput by 10.3% and 11.5%, respectively, compared to the previous partial BCube design.

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