There is such an interesting data transfer protocol - APRS. A lot has already been told about him on the Internet. There will be no in-depth theoretical material here. This article will describe how to create your own "pocket" AFSK modulator. In the following articles there will be instructions for going on the air and for creating a simple demodulator. Which will allow you to accept APRS packages and display information on the display right on the street. Everything will be implemented for Flipper Zero. If you don't have this gadget yet, then don't worry and try everything on the great and terrible Arduino. It is very interesting to transmit information at a distance "with your own hands".
Development of communication systems *
A hub about all that concerns the development of communication systems
Different navigation message protocols are used for different navigation signal type. This is true even for a single system like NAVSTAR GPS. For example, L1C/A signals have a LNAV protocol, while L2C and L5 signals utilize a CNAV protocol. The newest L1C signal will use CNAV-2.
The protocol defines a data distribution into frames, subframes, the subframes structure, transmission intervals, data resolution and so on.
A navigation receiver use the navigation message data flow for several purposes:
1. The data flow allows to resolve a code ambiguity and set the signal time.
2. Ephemeris and clock values are used for the satellite position calculation, pseudorange corrections and coordinates computation.
3. The received data flow and navigation message data can be used for navigation symbols prediction. As result, we can use the wipe-off technique, expand discriminators and significantly increase tracking sensitivity:
The potential of VoIP to your customers is simply phenomenal. Businesses are experiencing the advantages of VoIP’s cost-efficiency and reliability and now you can pass these benefits onto your own customers very easily. Cloud telecommunication is sophisticated and easily integrated. Confidence in this technology is growing fast. There has never been a better time to start talking to your customers about adopting this solution. It will deliver huge business benefits for them and has the potential to increase business income and profitability.
We used to think of Telegram as a reliable and secure transmission medium for messages of any sort. But under the hood it has a rather common combination of a- and symmetric encryptions. Where’s fun in that? And why would anyone trust their private messages to a third-party anyway?
TL;DR — inventing a private covert channel through users blacklisting each other.
Fiber-optic cables are a great way to bring high-speed Internet right to your home or office. But even in large cities not everyone can enjoy the benefits of it, since apartments far away from everyone, or low-population districts far from downtown, are very reluctantly served by ISPs.
And then there’s small towns and villages, far away from the main Internet “highways”. In poorer countries, Internet is often slow and expensive even in large population centers, while villages are often left without a connection for years. To connect them to the World Wide Web takes the resources of not just normal ISPs, but telecom giants. Solar-powered drones with networking equipment, weather balloons, satellites and other similar projects are not just science fiction, but a reality today (or in the near future). But who’s closer to launch and who’s lagging behind? Let’s find out.
The fault-resistance of an internet connection in any given region or country is tied to the number of alternate routes between ASes. Though, as we stated before in our Internet Segments Reliability reports, some paths are obviously more critical compared to the others (for example, the paths to the Tier-1 transit ISPs or autonomous systems hosting authoritative DNS servers), which means that having as many reachable routes as possible is the only viable way to ensure adequate system scalability, stability and robustness.
This time, we are going to have a closer look at the Russian Federation internet segment. There are reasons to keep an eye on that segment: according to the numbers provided by the RIPE database, there are 6183 autonomous systems in Russia, out of 88664 registered worldwide, which stands for 6.87% of total.
This percentage puts Russia on a second place in the world, right after the USA (30.08% of registered ASes) and before Brazil, owning 6.34% of all autonomous systems. Effects of changes in the Russian connectivity could be observed across many other countries dependant on or adjacent to that connectivity, and ultimately by almost any ISP in the world.