2019-09-04 (Wednesday)

Today, I learned that:

There is finally something really BIG happening in the world of serial communication between electronic devices. Last Thursday, 2019-08-29, was officialized the release of a new version of the popular USB interface, version 4, USB4 to be short, with a maximum data rate of 40 Gbit/s. See also reference #1 below.

From RS-232 to USB4

So, what is so special with this version then? Well, it seems that we now, almost 60 years after the RS-232 serial protocol was introduced, have returned to only one standard, regardless of the brand of the device.

It all started in 1960, when the American industry organisation EIA (Electronic Industries Association) introduced the RS-232 standard, initially to be used between electromechanical teletypewriters as DTEs (data terminal equipment) and modems as DCEs (data circuit-terminating/communication equipment). According to today’s standards, it was extremely slow, maximum 20 kbits/s.

RS-232 had some successors, such as RS-422 and RS-485, where both the speed and maximum cable length had been improved. For example, RS-422 is specified for a maximum bitrate of 10 Mbits/s and a maximum cable length of 1500 m.

We now jump to the 1990s, when the emerging personal computer (PC) industry found that maintaining the RS-232 communication was not feasible. There were then started two different initiatives to make communication between a PC and its peripherals much easier and faster. On January 1, 1996, was released the first version of the universal serial bus (USB). It had been developed by a consortium of companies such as Compaq, DEC, IBM, Intel, Microsoft, NEC, and Nortel. The data rate of USB 1.0 was 12 Mbits/s, which was improved to 480 Mbits/s with version 2.0 in 2001 and 5 Gbits/s through USB 3.0 in 2014, 10 Gbits/s by USB 3.1 in 2014, and 20 Gbits/s specified by USB 3.2 in 2017.

As you can see above, Apple did not participate in the USB consortium. Instead they had decided to develop their own communication interface, and attracted other companies such as Sony, Panasonic, Philips, LG, Toshiba, Hitachi, Canon, Thomson, and Texas Instruments. This group developed what came to be known as FireWire 400, aka standard IEEE 1394-1995. The data rate of this version was a maximum of 400 Mbits/s in half-duplex mode. It was followed by FireWire 800, which reached the speed of its name in 2006. However, Steve Jobs declared that FireWire was dead in 2008 when many camcorders were still using USB 2.0, instead of the faster FireWire.

Intel, which as you saw before already was a leading force in the USB consortium, now started to develop a new hardware interface together with Apple. It was dubbed Thunderbolt, and the first version appeared on MacBook Pro computers in 2011. Sony also used it in a Vaio line of notebooks in 2011. It was later followed by Thunderbolt 2 in 2013, with a maximum data rate of 20 Gbits/s.

And then, in 2016, Thunderbolt 3 was introduced, and as of now we can see that both standards are coming closer to each other, because they share the same USB-C connector. Intel decided in April 2019 to release the Thunderbolt without charging royalties from the companies who would use it, and that was the signal to finally use Thunderbolt 3 as a starting point for the specification of USB 4.

Will this mean that there is now unanimity in the electronics industry to start using only USB 4? Let us hope so, and that we will see the concrete result starting to appear in about a year or so.

There is much more to be said about this interesting topic of data communication, please see references # 2 through 7 below for details.

If you can’t beat them, join them!

A big problem in the crazy traffic in major cities around the world is of course that so many different categories of people on the move need to share the same physical space. Maybe the most troublesome is when motorbikes try to squeeze their way through in the small corridors between the cars. In 1997, when the most recent Brazilian Code for traffic was published, it permitted that they could do so, contrary to safety measures. And as a consequence, every day quite a few of those bikers are involved in severe accidents, even deaths.

However, one of the ways to mitigate somewhat this conflict was created in 2013 in São Paulo. You can see it in today’s header photo, taken downtown on 2019-08-09 at Avenida Ipiranga. It shows that motorbikers and other bikers, as well, have a privileged zone in front of the cars, when they need to stop for a red light. That way, when the light turns into green, they can speed away without needing to negotiate space with the car drivers. This method is called “Frente segura”, which means ‘Safe front’. More about it can be seen in reference #8 below (in Portuguese).

That’s what I learned in school !

Refs.:

1: USB4 Specification merges Thunderbolt 3 and USB with transfer speeds up to 40 Gb/s

2: RS-232

3: RS-422

4: RS-485

5: USB

6: IEEE 1394

7: Thunderbolt

8: Frente segura

*: What did you learn in school today ?

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2016-01-24 (Sunday)

Today, I learned that:

The largest prime number ever found was announced last Wednesday, January 20, 2016. So, what is a prime number and what is it good for?

A prime number is defined as a natural number (a positive integer) greather than 1, which cannot be evenly divided by any other natural number than 1 and itself. Examples of such numbers are 2, 3, 5, 7, 11, etc. It has been proven that there are an infinite quantity of prime numbers.

Prime numbers have been known for a long time, e.g. Euclid’s Elements (300 years BC) already mentions them, and in the beginning of the 17th century, a French monk named Marin Mersenne devised a formula, of the form 2p – 1, where p=1 is a prime number, to be used to check for unknown prime numbers. In fact, the largest prime number, which is exactly 274.207.281 − 1, consists of more than 22 million digits, and the search for bigger numbers continue. Please see the three references below for more information about prime numbers in general and also about the discovery of the currently biggest prime number, including an interview with Curtis Cooper, the leader of the project that discovered it.

One of the practical usages of prime numbers is in public-key cryptography, where two large prime numbers are multiplied to obtain a product that it is extremely difficult to factorize and thus break the code. But the search for these very big numbers does not seem to have any major practical use today, although they are very well fitted to test the speed performance of computer hardware.

And speaking about cryptography, having means of obtaining secure data streams is of course essential when we want to communicate data from one point to another. The current standard for data communication in the world is based upon what is called fourth-generation (4G) technology, and although it offers very fast rates of data communication, there are applications that demand even faster data transmission speeds. Examples of such applications are some components of the ‘Internet of Things’ (e.g. driver-less cars), and also in remote surgery, when the patient is in a hospital somewhere in the world, and at the same time the head surgeon is in a totally different place, performing the surgery via advanced, fast video and manipulation technologies.

For that and other purposes, last Friday, January 22, 2016, TeliaSonera and Ericsson announced that in 2018, they will start 5G networks in Stockholm and Tallinn. The rest of Sweden should see 5G in use in 2020.

Update on 2016-01-27: Today’s program of ‘Vetenskapens värld’ on Radio Sweden’s domestic channel P1 penetrates into the 5G technology. It will be a standard mostly used for machine to machine communication, and there are good hopes that one standard will be used everywhere on Earth, with speeds 100 times higher than the current 4G standard. See reference 7 below.

… That’s what I learned in school!

Refs.:

1: https://en.wikipedia.org/wiki/Prime_number

2: http://www.mersenne.org/primes/?press=M74207281

3: https://www.youtube.com/watch?v=q5ozBnrd5Zc

4: https://en.wikipedia.org/wiki/Public-key_cryptography

5: http://news.err.ee/v/scitech/fd66b9ee-1a44-4d13-aa6c-1f687812b2b8/

6: https://en.wikipedia.org/wiki/List_of_mobile_phone_generations

7: http://sverigesradio.se/sida/avsnitt/668029?programid=412

+: https://www.youtube.com/watch?v=VucczIg98Gw