The transmission of JPEG 2000 images or video over wireless channels has to cope with the high probability and burstyness of errors introduced by Gaussian noise, linear distortions, and fading. At the receiver side, there is distortion due to the compression performed at the sender side, and to the errors introduced in the data stream by the channel. Progressive source coding can also be successfully exploited to protect different portions of the data stream with different channel code rates, based upon the relative importance that each portion has on the reconstructed image. Unequal Error Protection (UEP) schemes are generally adopted, which offer a close to the optimal solution. In this paper, we present a dichotomic technique for searching the optimal UEP strategy, which lends ideas from existing algorithms, for the transmission of JPEG 2000 images and video over a wireless channel. Moreover, we also adopt a method of virtual interleaving to be used for the transmission of high bit rate streams over packet loss channels, guaranteeing a large PSNR advantage over a plain transmission scheme. These two protection strategies can also be combined to maximize the error correction capabilities.

The Internet of Things (IoT) architecture is quickly becoming popular even outside of its originating scenario of home automation. This paper reports the design, implementation, and performance of an IoT hardware and software architecture conceived for the continuous monitoring of livestock located in barns and during grazing. We have adopted the LoRa low power wide area network (LPWAN) technology to cover the diverse environments, and a suitable configuration of web services to perform data storage, analysis, and visualization. Since the LoRa LPWAN (LoRaWAN) medium access control (MAC) layer does not provide a listen-before-talk (LBT) mechanism, we propose a custom MAC layer with LBT-based carrier-sense multiple access with collision avoidance (CSMA/CA). The devised system has been implemented using off-the-shelf hardware, and its performance has also been estimated with the help of a C++ event-based simulator. The preliminary results of our HW implementation on the field confirm the stability of the conceived system and its reliability. suburban or rural environments [15], making this technology viable for both small and medium-scale applications. It has also been shown that a single LoRa gateway can manage a large number of EDs with little maintenance and easy deployment [5].LoRa is a proprietary wireless communication standard developed by Semtech, based on a chirp spread spectrum (CSS) modulation [16,17]. The physical layer (PHY) uses chirp waveforms with different chirp rate, to maintain orthogonality among different classes of users, and with different initial frequency, to convey the actual information message [15]. Channel coding is also used, with interleaving and Hamming block codes. Although the details of the LoRa PHY are not public, several authors have tried and succeeded to reverse-engineer, almost completely, its PHY communication techniques [18].On the other side, LoRaWAN is an open MAC protocol, built on top of the LoRa PHY, that is specifically designed for low-powered devices operating over long-range wireless links. Even though LoRaWAN is commonly used in deploying LoRa networks [19], in this work we have decided to implement a custom MAC layer in order to have more control over the architectural design and to remove some features of the LoRaWAN layer [20] that are not used in our application, such as the large header size when short payloads have to be delivered, and the packet acknowledgments managed by a LoRa server. Continuous and near-real-time monitoring of livestock, in particular of dairy cattle, can help to provide information vital to study the animal behavior and to prevent pathological states that have a negative impact on livestock health [21,22].In particular, our proposed architecture aims at analyzing, almost in real-time, the status of dairy cattle in a cowshed or during grazing by means of sensors embedded in smart collars. By the way, this approach may be extended also to other kinds of livestock, such as beef cattle, swine, ovine, and even equine.In this paper we first de...

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This paper presents a feasibility study for a very high data rate receiver operating in the K/Ka-band suitable to future Moon exploration missions. The receiver specifications are outlined starting from the mission scenario and from a careful system analysis. The designed architecture uses a low noise front-end to down-convert the incoming K/Ka-band signal into a 3.7 GHz intermediate frequency (IF). For maximum flexibility, a software defined radio (SDR) is adopted for the I/Q demodulation and for the analog to digital conversion (ADC). The decoding operations and the data interface are carried out by a processor based on field programmable gate array (FPGA) circuits. To experimentally verify the above concepts, a preliminary front-end breadboard is implemented, operating between 27.5 and 30 GHz. The breadboard, which uses components off the shelf (COTS) and evaluation boards (EVBs), is characterized by a 46 dB gain, a 3.4 dB noise figure and a − 37 dBm input-referred 1 dB compression point. Finally, a 40 Msym / s quadrature phase shift keying (QPSK) signal is demodulated by means of a commercially available SDR, demonstrating the above concept. The importance of these results is that they have been obtained exploiting a class of miniaturized and low cost microwave integrated circuits currently available on the market, opening the way to a dense communication infrastructure on cislunar space.

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In this paper, we present an overview of the JPWL standardization activity. JPWL is an extension of JPEG 2000 for the efficient transmission of JPEG 2000 images over an error-prone wireless network. More specifically, JPWL supports a set of tools for error protection and correction, including Forward Error Correcting codes (FEC), Unequal Error Protection (UEP), data partitioning and interleaving.

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