Archive for the ‘internet’ category: Page 25

Nov 25, 2022

Terabit FSO communication based on a soliton microcomb

Posted by in categories: computing, information science, internet, security, space

Large-capacity wireless data transmission systems are demanded along with the development of multimedia services, video-based interactions, and cloud computing in the era of big data. Compared with radio-frequency communication systems, free-space optical (FSO) signal transmission technology has the merits of high data rate, great flexibility, less power consumption, high security, and large license-free bandwidths [13], which has been widely applied in terrestrial transmission [4], last mile solutions [5], ground-to-satellite optical communication [6], disaster recovery [7], and so on. To date, up to 10 Gbit/s FSO communication system has been realized for transmission distance over 1,000 km of star-ground or inter-star communications [8], and 208 Gbit/s terrestrial communication is also reported at 55 m transmission distance [9]. Wavelength-division multiplexing (WDM) technology is commonly employed to improve data transmission capacity in fiber communication systems, which would be more effective in FSO communication systems benefitting from very weak non-linear cross talk between different frequency channels in free space. Based on a simulation platform, a WDM FSO communication system could boost the signal transmission capacity to 1.28 Tbit/s by modulating 32 optical channels with dual-polarization 16 quadrature amplitude modulation signals [10]. To date, beyond 10 Tbit/s FSO communication systems have been experimentally demonstrated recently using WDM technology [11,12]. However, a WDM communication system becomes power-hungry and bulky with the increase of transmission channels while traditional distributed feedback lasers are used as optical carriers. In addition, more rigorous requirement is imposed on the frequency tolerance of carrier lasers to avoid channel overlap with the decrease of channel frequency interval.

The invention of microresonator-based optical frequency combs provides novel integrated optical laser sources with the natural characteristic of equi-spaced frequency intervals which can overcome the challenge of massive parallel carrier generation [13 19]. In particular, the spontaneously organized solitons in continuous-wave (CW)-driven microresonators provide a route to low-noise ultra-short pulses with a repetition rate from 10 GHz to beyond terahertz. Soliton microcombs (SMCs) are typical stable laser sources where the double balances of non-linearity and dispersion as well as dissipation and gain are reached in microcavities. Meanwhile, the linewidth of the comb lines is similar with the pump laser, which enables low power consumption and costs multiwavelength narrow-linewidth carriers for a wide range of applications. Through designing the scale of microresonators, the repetition rate of SMCs could be compatible with dense wavelength-division multiplexing (DWDM) communication standard. To date, several experiments have demonstrated the potential capacity for ultra-high-speed fiber communication systems using SMCs as multiwavelength laser sources [20 30]. For instance, a coherent fiber communication system has improved the transmission capacity up to 55 Tbit/s using single bright SMCs as optical carriers and a local oscillator [20]. And dark solitons and soliton crystals are also employed as multiwavelength laser sources for WDM communication systems [27 30]. However, few studies have carried out massive parallel FSO communication systems using the integrated SMCs as laser sources.

In this paper, we experimentally demonstrate a massive parallel FSO communication system using an SMC as a multiple optical carrier generator. 102 comb lines are modulated by 10 Gbit/s differential phase shift keying (DPSK) signals to boost the FSO transmission rate up to beyond 1 Tbit/s. The transmitter and receiver terminals are installed in two buildings at a distance of ∼1 km, respectively. Using a CW laser as reference, the influence of optical signal-to-noise ratios (OSNRs) on the bit error rate (BER) performance is experimentally analyzed. Our results show an effective solution for large-capacity spatial signal transmission using an integrated SMC source which has potential applications in future satellite-to-ground communication systems.

Nov 24, 2022

Front 242 — Kampfbereit

Posted by in category: internet

Made using windows movie maker and the internet and kampfbereit because I was bored.

Nov 23, 2022

A simpler path to better computer vision

Posted by in categories: biotech/medical, internet, robotics/AI

Before a machine-learning model can complete a task, such as identifying cancer in medical images, the model must be trained. Training image classification models typically involves showing the model millions of example images gathered into a massive dataset.

However, using real image data can raise practical and : The images could run afoul of copyright laws, violate people’s privacy, or be biased against a certain racial or ethnic group. To avoid these pitfalls, researchers can use image generation programs to create for model training. But these techniques are limited because expert knowledge is often needed to hand-design an image generation program that can create effective training data.

Researchers from MIT, the MIT-IBM Watson AI Lab, and elsewhere took a different approach. Instead of designing customized image generation programs for a particular training task, they gathered a dataset of 21,000 publicly available programs from the internet. Then they used this large collection of basic image generation programs to train a computer vision model.

Nov 23, 2022

Hackers breach energy orgs via bugs in discontinued web server

Posted by in categories: cybercrime/malcode, energy, internet

Microsoft said today that security vulnerabilities found to impact a web server discontinued since 2005 have been used to target and compromise organizations in the energy sector.

As cybersecurity company Recorded Future revealed in a report published in April, state-backed Chinese hacking groups (including one traced as RedEcho) targeted multiple Indian electrical grid operators, compromising an Indian national emergency response system and the subsidiary of a multinational logistics company.

The attackers gained access to the internal networks of the hacked entities via Internet-exposed cameras on their networks as command-and-control servers.

Nov 22, 2022

Quantum city simulation shows how to make Paris-sized quantum internet

Posted by in categories: internet, quantum physics

A simulated version of Paris where universities and telecommunication hubs are connected by a quantum communication network suggests that existing technology is already nearing the ability to create functional “quantum cities”.

Nov 16, 2022

Reservations for new community of 3D homes in Georgetown to open in 2023

Posted by in categories: habitats, internet, security, solar power, sustainability

The community will offer eight different floor plans, ranging from three to four bedrooms and two to three bathrooms. Homes will be powered by rooftop solar panels, include a Ring Video Doorbell Pro, Schlage Encode Smart WiFi deadbolt, a Honeywell Home T6 Pro WiFi smart thermostat and a Wolf Ranch security package.

RELATED: The Georgetown gem that gleams rich with history: Southwestern University

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Nov 16, 2022

Cyber vulnerability discovered in networks used by spacecraft, aircraft and energy generation systems

Posted by in categories: cybercrime/malcode, energy, internet

A major vulnerability in a networking technology widely used in critical infrastructures such as spacecraft, aircraft, energy generation systems and industrial control systems was exposed by researchers at the University of Michigan and NASA.

It goes after a network protocol and hardware system called time-triggered ethernet, or TTE, which greatly reduces costs in high-risk settings by allowing mission-critical devices (like flight controls and ) and less important devices (like passenger WiFi or data collection) to coexist on the same network hardware. This blend of devices on a single network arose as part of a push by many industries to reduce network costs and boost efficiency.

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Nov 15, 2022

Meta Introduces ‘Tulip,’ A Binary Serialization Protocol That Assists With Data Schematization

Posted by in categories: internet, robotics/AI

Meta introduces ‘Tulip,’ a binary serialization protocol supporting schema evolution. This simultaneously addresses protocol reliability and other issues and assists us with data schematization. Tulip has multiple legacy formats. Hence, it is used in Meta’s data platform and has seen a considerable increase in performance and efficiency. Meta’s data platform is made up of numerous heterogeneous services, such as warehouse data storage and various real-time systems exchanging large amounts of data and communicating among themselves via service APIs. As the number of AI and machine learning ML-related workloads in Meta’s system increase that use data for training these ML models, it is necessary to continually work on making our data logging systems efficient. The schematization of data plays a huge role in creating a platform for data at Meta’s scale. These systems are designed based on the knowledge that every decision and trade-off impacts reliability, data preprocessing efficiency, performance, and the engineer’s developer experience. Changing serialization formats for the data infrastructure is a big bet but offers benefits in the long run that make the platform evolve over time.

The Data Analytics Logging Library is present in the web tier and the internal services, and this is also responsible for logging analytical and operational data using Scribe-a durable message queuing system used by Meta. Data is read and ingested from Scribe, which also includes a data platform ingestion service and real-time processing systems. The data analytics reading library helps deserialize data and rehydrate it into a structured payload. Logging schemas are created, updated, and deleted every month by thousands of engineers at Meta, and these logging schema data flows in petabytes range each and every day over Scribe.

Schematization is necessary to ensure that any message logged in the past, present, or future, depending on the (de) serializer’s version, can be reliably (de)serialized at any time with the utmost fidelity and no data loss. Safe schema evolution via backward and forward compatibility is the name given to this characteristic. The article’s main focus lies on the on-wire serialization format used to encode the data that is finally processed by the data platform. Compared to the two serialization formats previously utilized, Hive Text Delimited and JSON serialization, the new encoding format is more efficient, requiring 40 to 85 percent fewer bytes and 50 to 90 percent fewer CPU cycles to (de)serialize data.

Nov 15, 2022

A US company just deployed world’s largest communication satellite

Posted by in categories: internet, satellites

The 693-square-foot array is designed to provide 5G broadband connectivity directly with cellular devices via 3GPP standard frequencies.

Bluewalker 3 satellite, a test satellite by Texas-based firm AST SpaceMobile deployed its largest commercial communications array ever flow in space, in low Earth orbit, the company announced on Monday. The satellite was launched on a SpaceX Falcon 9 rocket in September, Interesting Engineering.

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Nov 15, 2022

SpaceX buys large Twitter ad campaign for Starlink as advertisers pause spending after Elon Musk’s takeover, report says

Posted by in categories: Elon Musk, internet

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