Data Rate Selection Research Articles

Using ranging for collision-immune IEEE 802.11 rate selection with statistical learning

Appropriate data rate selection at the physical layer is crucial for Wi-Fi network performance: too high rates lead to loss of data frames, while too low rates cause increased latency and inefficient channel use. Most existing methods adopt a probing approach and empirically assess the transmission success probability for each available rate. However, a transmission failure can also be caused by frame collisions. Thus, each collision leads to an unnecessary decrease in the data rate. We avoid this issue by resorting to the fine timing measurement (FTM) procedure, part of IEEE 802.11, which allows stations to perform ranging, i.e., measure their spatial distance to the AP. Since distance is not affected by sporadic distortions such as internal and external channel interference, we use this knowledge for data rate selection. Specifically, we propose FTMRate, which applies statistical learning (a form of machine learning) to estimate the distance based on measurements, predicts channel quality from the distance, and selects data rates based on channel quality. We define three distinct estimation approaches: exponential smoothing, Kalman filter, and particle filter. Then, with a thorough performance evaluation using simulations and an experimental validation with real-world devices, we show that our approach has several positive features: it is resilient to collisions, provides near-instantaneous convergence, is compatible with commercial-off-the-shelf devices, and supports pedestrian mobility. Thanks to these features, FTMRate outperforms existing solutions in a variety of line-of-sight scenarios, providing close to optimal results. Additionally, we introduce Hybrid FTMRate, which can intelligently fall back to a probing-based approach to cover non-line-of-sight cases. Finally, we discuss the applicability of the method and its usefulness in various scenarios.

Towards Mass-Scale IoT with Energy-Autonomous LoRaWAN Sensor Nodes.

By 2030, it is expected that a trillion things will be connected. In such a scenario, the power required for the trillion nodes would necessitate using trillions of batteries, resulting in maintenance challenges and significant management costs. The objective of this research is to contribute to sustainable wireless sensor nodes through the introduction of an energy-autonomous wireless sensor node (EAWSN) designed to be an energy-autonomous, self-sufficient, and maintenance-free device, to be suitable for long-term mass-scale internet of things (IoT) applications in remote and inaccessible environments. The EAWSN utilizes Low-Power Wide Area Networks (LPWANs) via LoRaWAN connectivity, and it is powered by a commercial photovoltaic cell, which can also harvest ambient light in an indoor environment. Storage components include a capacitor of 2 mF, which allows EAWSN to successfully transmit 30-byte data packets up to 560 m, thanks to opportunistic LoRaWAN data rate selection that enables a significant trade-off between energy consumption and network coverage. The reliability of the designed platform is demonstrated through validation in an urban environment, showing exceptional performance over remarkable distances.

Enhanced Time Slotted LoRaWAN for Node Mobility: A Joint Selection of Data Rate, Time Slot and Channel

Enhanced Time Slotted LoRaWAN for Node Mobility: A Joint Selection of Data Rate, Time Slot and Channel

IEEE 802.11ba: Low-Power Wake-Up Radio for Green IoT

Low-power devices have manifested their crucial roles in manifold green Internet of Things (IoT) applications, including healthcare, smart home, industrial sensors, and wearable apparatuses. However, to prolong the operation time of these devices, significantly enhancing the battery capacity turns out to be an intractable challenge due to the mandatory constraint of limited form factors. Achieving this goal thus inevitably relies on new designs of physical-layer (PHY)and medium access control (MAC) schemes. This desire has driven IEEE 802.11 Task Group ba (TGba) to launch the normative work of wake-up radios (WURs) since 2017. To comprehend essential knowledge of this new technical feature, in this article, we consequently offer substantial insights of IEEE 802.11ba, including the deployment scenarios, PHY operations (waveform, modulation, data rate selection, and synchronization design), and MAC operations (radio wake-up procedure, WUR duty cycle, WUR mode, channel access scheme, and the format of a MAC packet data unit). The provided insights facilitate further research and implementation of IEEE 802.11ba WUR to empower the next generation green IoT.

A Rate Adaptation Scheme with Enhanced Loss Differentiation for LoRaWAN Communications

As an emerging technology for long-range communication, LoRaWAN provides several data rates for transmission and the choice of data rates will affect the communication distance and the link quality. So how to allocate this communication resource in a network with a large amount of devices is a challenge. In this paper, we classify the reasons of packets loss as channel attenuation and data collision and then propose a rate adaptation scheme with enhanced loss differentiation. The proposed scheme can estimate two packet loss rates according to the channel attenuation probability model and data collision probability model respectively. And the selection of communication data rate is given by the balance of probabilities. Simulation results indicate that the proposed scheme is better than ADR and EXPLoRa on Data Extraction Rate and Goodput.

A Hybrid Data Compression Scheme for Power Reduction in Wireless Sensors for IoT.

This paper presents a novel data compression and transmission scheme for power reduction in Internet-of-Things (IoT) enabled wireless sensors. In the proposed scheme, data is compressed with both lossy and lossless techniques, so as to enable hybrid transmission mode, support adaptive data rate selection and save power in wireless transmission. Applying the method to electrocardiogram (ECG), the data is first compressed using a lossy compression technique with a high compression ratio (CR). The residual error between the original data and the decompressed lossy data is preserved using entropy coding, enabling a lossless restoration of the original data when required. Average CR of 2.1 × and 7.8 × were achieved for lossless and lossy compression respectively with MIT/BIH database. The power reduction is demonstrated using a Bluetooth transceiver and is found to be reduced to 18% for lossy and 53% for lossless transmission respectively. Options for hybrid transmission mode, adaptive rate selection and system level power reduction make the proposed scheme attractive for IoT wireless sensors in healthcare applications.

Data rate, path length and network contention trade-off in IEEE 802.11s mesh networks: A dynamic data rate selection approach

Most of the commercially available wireless routers are equipped with multi-rate support to adopt physical data rates based on the channel condition fluctuations. The recent studies in multi-rate support have shown that low data rates are more effective when the channel error rate is high. Because of the physical layer modulation and signal decoding issues, low data rates are sustainable for long transmission ranges. Therefore, for multi-hop mesh networks, low data rates may scale down the end-to-end path length towards the destination in terms of number of hops, resulting in less end-to-end forwarding delay. However, for a network with high traffic load, long transmission ranges may increase contention for channel access among the contending neighbors. This paper uses the diffusion approximation method of queuing analysis to study the trade-off among data rate, end-to-end path length and network contention in a multi-rate mesh network built over the IEEE 802.11s specifications. From the observations of the theoretical analysis, a distributed and localized rate adaptation scheme is proposed for IEEE 802.11s mesh networks, by augmenting the standard peer selection, channel access and forwarding protocols. The performance of the proposed rate adaptation protocol is evaluated and compared with existing rate adaptation protocols using simulation results.

Coded MIMO With Asymmetric Constellation Sizes

An asymmetric constellation scheme for coded multiple-input–multiple-output (MIMO) transmission is proposed, which applies different constellation mappings to different transmit streams and carefully selects the coding rates for different transmit streams. An improved power allocation is derived to naturally incorporate with the coding rate selection and to further enhance the achievable performance. The proposed scheme provides more flexible choices of data rate selection, and by employing fixed-complexity sphere decoding (FSD) detection, it achieves better performance with reduced detection complexity in comparison with the conventional MIMO using the FSD-based detection with the same constellation set for all streams.

Critical Analysis of Dispersion Compensated Optical Communication System

generation communication systems need to dispense higher data rate in the efficient manner with capability to customize according to the dynamic data transfer framework in an economically dominant approach. The optical fiber communication networks fulfill these requirements along with small attenuation loss and better quality of services. In the last a few years the rapid progress of the data rate transmission over the existing optical transmission networks accentuated the need of more worthwhile usage of the transmission capacity of the prevailing networks. The forthcoming optical communication systems needs to support 10 Gbps and above over the single wavelength in the optical fiber channel.The Inter-Symbol Interference (ISI) due to dispersion limits the repeater less maximum transmission data rate and maximum transmission distance for the optical fiber channel (1). Various endeavors have been taken for the advancement of the schemes and dispersion compensation devices to mitigate the effect of the dispersion causing inter-symbol interference.The primary instrument to achieve this objective is to use an equalizer. Orthogonal Frequency Division Multiplexing (OFDM) is a very favorable scheme for the high data rate data transmission because of its ability to overcome the effect of the dispersion, tolerance to the dispersive channel, high spectrum efficiency and better flexibility of operation. For mitigating dispersion impact OFDM transmits a large number of modulated sub-carriers at the same time operating at low data rate. These cause the symbol period relatively longer than the channel impulse response, hence mitigating the impact of inter-symbol interference. OFDM is a multicarrier modulation scheme, extensively investigated and deployed in wireless as well as wire line communication. It is getting increased interest in the fiber optic research community for its robustness against dispersion causing inter-symbol interference. It utilizes the spectrum efficiently and dynamically controls the dispersion. This suggest that OFDM can be the best method for the mitigating the dispersion for the long distance high data rate optical fiber communication systems. Therefore, the integration of OFDM with the optical fiber can be the excellent scheme for providing long distance high data rate efficiently. A comparative performance analysis of the dispersion compensated optical system carried out for examining the impact of the OFDM to mitigate the dispersion at 10 Gbps and above. The systems with and without using OFDM has been configured and its performance has been investigated,various results obtained exhibited that transmission performance is entirely dependent upon a proper selection of data rate, transmission length, and modulation schemes etc. For evaluating the systems performance, constellation and bit error rate are evaluated for system with and without using OFDM and subsequently compared.The various results of the investigation depicts that for high data capacity transmission for the long distance the systems with using OFDM shows better results, and having better spectrum utilization than the systems without using the OFDM.The use of a large number of sub-carriers has been observed to be more effective in overcoming the fibre dispersion.

Data rate selection for efficient broadcasting in ad hoc networks

The required transmission time decreases as the data rate increases on a single link. When broad-casting in an ad hoc radio network, this may not be so, as the number of retransmissions may grow as the data rate increases because of decreased transmission range. Moreover, there is often a non-trivial optimum. To resolve the problem of selecting an appropriate rate in such a network, the authors propose a novel method that is theoretically optimal under certain simplifying conditions. When compared with other rate selection methods under more realistic assumptions, the authors have found it to perform better. It is also easy to implement in a real system.

An Optimal Rate Adjustment Algorithm for Medium Access Control Protocol in 802.11 Multi Hop Ad Hoc Networks

Problem statement: Medium Access Control (MAC) protocol plays an important role in providing a fair and efficient allocation of limite d bandwidth in wireless LANs. In IEEE 802.11 standard protocol, data rate selection is not speci fied. Rate control is the process of switching data rates dynamically based on channel conditions, with the t arget of selecting the rate that will provide the maximum throughput feasible for a given channel condition. The two major components of the rate control process are Channel estimation and rate sel ection. Although rate control has been studied extensively for wired networks, these results canno t be directly applied to multihop wireless networks . Approach: In this study, we propose to develop an Optimal Ra te Adjustment Algorithm (ORAA) which is based on the channel state conditions. We also follow a two level channel estimation one at the receiver end and another at each intermediate n ode along the path. Results: By simulation results we show that our proposed ORAA achieves high throughput and fairness, when compared with the standard IEEE 802.11 MAC protocol. Conclusion: In ad hoc networks, where the channel conditions are dynamic, our proposed ORAA provides the accurate data rate most suitable for the current changes in the network.

Bandwidth‐satisfied routing in multi‐rate MANETs by cross‐layer approach

AbstractPrevious quality‐of‐service (QoS) routing protocols in mobile ad hoc networks (MANETs) determined bandwidth‐satisfied routes for QoS applications. Since the multi‐rate enhancements have been implemented in MANETs, QoS routing protocols should be adapted to exploit them fully. However, existing works suffer from one bandwidth‐violation problem, named the hidden route problem (HRP), which may arise when a new flow is permitted and only the bandwidth consumption of the hosts in the neighborhood of the route is computed. Without considering the bandwidth consumption to ongoing flows is the reason the problem is introduced. This work proposes a routing protocol that can avoid HRP for data rate selection and bandwidth‐satisfied route determination with an efficient cross‐layer design based on the integration of PHY and MAC layers into the network layer. To use bandwidth efficiently, we aim to select the combination of data rates and a route with minimal bandwidth consumption to the network, instead of the strategy adopted in the most previous works by selecting the combination with the shortest total transmission time. Using bandwidth efficiently can increase the number of flows supported by a network. Copyright 2010 John Wiley & Sons, Ltd.

Efficient cross-layer protocol for bandwidth-satisfied multicast in multi-rate MANETs

Since the multi-rate enhancements have been implemented in 802.11 wireless networks, QoS-constrained multicast protocols for multimedia communication should be adapted to exploit them fully. This work proposes a multicast protocol for data rate selection and bandwidth-satisfied multicast tree determination with an efficient cross-layer design based on the integration of PHY and MAC layers into the network layer. To use bandwidth efficiently and increase network capacity (which is the number of multicast flows supported by the network), we aim to select the combination of data rates and a multicast tree whose total amount of bandwidth consumption to the network is minimal in order to maximize the network capacity. The performance of the proposed protocol is compared with two existing protocols. Simulation results indicate that the proposed protocol has the ability to admit more multicast flows.

Toward network coding-based protocols for data broadcasting in wireless Ad Hoc networks

In this paper we consider practical dissemination algorithms exploiting network coding for data broadcasting in ad hoc wireless networks. For an efficient design, we analyze issues related to the use of network coding in realistic network scenarios. In detail, we quantify the impact of random access schemes, as used by IEEE 802.11, on the performance of network coding. In such scenarios, deadlock situations may occur where the delivery process stops and some of the nodes never gather the required packets. To tackle this problem, we propose a proactive mechanism (called proactive network coding) which adapts its transmission schedule according to the decoding status of neighboring nodes. This scheme can detect when nodes need additional packets in order to decode and acts accordingly. We finally investigate the behavior of network coding schemes in multi-rate environments, where we propose a distributed heuristic approach for the selection of data rates.

A 5.75 to 44 Gb/s Quarter Rate CDR With Data Rate Selection in 90 nm Bulk CMOS

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents a quarter-rate clock and data recovery (CDR) circuit for plesiochronous serial I/O-links. The 2<formula formulatype="inline"><tex Notation="TeX">$\times$</tex></formula>-oversampling phase-tracking CDR, implemented in 90<formula formulatype="inline"><tex Notation="TeX">$\,$</tex></formula>nm bulk CMOS technology, covers the whole range of data rates from 5.75 to 44 Gb/s realized in a single IC by the novel feature of a data rate selection logic. Input data are sampled with eight parallel differential master-slave flip-flops, where bandwidth enhancement techniques were necessary for 90 nm CMOS. Precise and low-jitter local clock phases are generated by an analog delay-locked loop. These clock phases are aligned to the incoming data by four parallel phase rotators. The phase-tracking loop of the CDR is realized as a digital delay-locked loop and is therefore immune against process tolerances. The CDR is able to track a maximum frequency deviation of <formula formulatype="inline"> <tex Notation="TeX">${\pm }{\hbox{615~ppm}}$</tex></formula> between incoming data and a local reference clock and fulfills the extended XAUI jitter tolerance mask. A bit error rate <formula formulatype="inline"><tex Notation="TeX">${≪} \hbox{10}^{-12}$</tex></formula> was verified up to 38 Gb/s using a 2<formula formulatype="inline"><tex Notation="TeX">$ ^{7} -$</tex></formula>1 PRBS pattern. With a low power consumption per data rate of only 5.74 mW/(Gb/s) the CDR meets the specifications of the International Technology Roadmap for Semiconductors for 90<formula formulatype="inline"><tex Notation="TeX">$~$</tex></formula>nm CMOS serial I/O-links at the maximal data rate of 44 Gb/s. The CDR occupies a chip area of 0.2 <formula formulatype="inline"><tex Notation="TeX">${\hbox{mm}}^{2}$</tex> </formula>. </para>

A seamless mobile VPN data solution for CDMA2000,* UMTS, and WLAN users

Mobile virtual private networks (MVPNs) can provide remote users with easy, secure high-speed access to their enterprise network resources. There is a tremendous market opportunity for operators who can meet the needs of these users. Third-generation (3G) systems, such as code division multiple access (CDMA) (3G-1X and 1xEV-DO) or universal mobile telecommunications system (UMTS), and IEEE 802.11b wireless local area network (WLAN) systems have complementary strengths. For end users, integrating these systems provides ubiquitous high-speed data coverage, continuous selection of the highest possible data rates, and seamlessly maintained user VPN sessions when moving between air interface technologies. For operators, they enable integrated billing and offload 3G network capacity for higher revenue voice subscribers. This paper shows how Lucent Technologies uses IETF mobile IP (MIP), IP security (IPSec), and multiple tunneling protocol standards to offer a comprehensive transport layer solution across 3G and WLAN air interface technologies. Shared requirements for accounting, authentication, security, and confidentiality in 3G and WLAN core data networks are also addressed.

A communication protocol for mobile satellite systems affected by rain attenuation

A protocol that supports real-time data rate selection and change during rain events is presented. The protocol is developed with emphasis on being efficient yet robust to the primary channel impairment in such mobile satellite systems. The system architecture is briefly presented and the analytical framework from which the protocol originates is pointed out. Link, connection, and packet types are introduced, and the protocol procedures and design rationale are discussed. The detailed presentation focuses on link setup with the appropriate data rate(s) and the real-time switching of data rates during a voice conversation to either preserve the link or enhance its quality during rain attenuation events.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A One‐bit VLBI Recording and Playback System Using Videotape Recorders

A flexible, hybrid very long baseline interferometry (VLBI) instrumentation system, which uses videotape recorders for recording digitized data, has been developed for making routine observations for geodetic and geophysical measurements. The system records data on videotape in the field and later generates conventional digital magnetic tapes for programed correlation in a high‐speed, general‐purpose computer. By selection of an appropriate data rate, these tapes can be made compatible with the present National Radio Astronomy Observatory‐Arecibo Ionospheric Observatory (NRAO‐AIO) Mk 1 format. In addition, the major components have been designed and chosen so that they can be incorporated into the Mk 2 system now being developed at NRAO. This is a high‐density, wide‐bandwidth system that uses direct videotape correlation. Other more immediate advantages of using videotape recorders are: low initial cost, low cost per bit, long recording time, portability, and minimization of the field installation. This paper describes the entire instrumentation back end, including the video converter, recording system, and computer‐compatible reformatting units. Station timekeeping, which is integral with the recording format, is also discussed.

Optimization of Subchannel Data Rate in FDM-SSB Transmission over Selectively Fading Media

In radio channels both time-selective and frequencyselective fading effects distort the transmitted signal. The present paper determines the effect of time and frequency selective fading upon the binary error probabilities of incoherent matched filter receivers employing postdetection diversity combining. General analytical results are specialized to the case of phase-continuous FSK and a Gaussian distribution of scattered power vs delay and Doppler shift. For this case families of curves of error probability are presented as a function of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SNR</tex> and data rate with the spread factor and order of diversity as family parameters. It is shown that an optimum data rate exists at which the binary error probability is minimized. For a wide range of cases of interest this optimum data rate is approximately two to four times the geometric mean of the fading bandwidth and correlation bandwidth of the channel. In the frequency division multiplex of a number of binary data streams on an SSB carrier, the selection of the above optimum data rate for each stream will result in a minimum over-all binary error probability for a specified bandwidth occupancy of the multiplex group.

An Approach to the Evaluation of Vocoded Speech

Distortions peculiar to speech analysis-synthesis devices, such as the vocoder, introduce new problems in the determination of performance standards. Intelligibility can be determined in the laboratory, but standardized methods for the measurement of the characteristics of speech quality and talker recognition have not yet been established. The researcher or engineer has little to guide him in the inevitable compromises involved in the development and design of such devices and in the selection of optimum data rates. In an effort to provide such guidance, a survey was first made of certain potential military users. Speech samples obtained by filtering, telephone transmission, and vocoder processing were presented for judgments regarding intelligibility, speech quality, talker recognition, and adequacy for normal use. This paper presents the results of these surveys, along with data regarding intelligibility and talker recognition obtained in the laboratory. The speech samples used in the survey will serve as a basis for comparison in laboratory judgments to determine approximate boundaries for those parameters affecting the characteristics considered.