Disappearing without a trace is nearly impossible today. Although this is not the case with burglars, it’s virtually impossible to move through the digital world without leaving evidence of one’s presence there. A new Facebook posting, the perusal of an online newspaper, or a leisurely drive in your car whose navigation device transmits a positioning signal — regardless of what people do, and whether they do it unintentionally or on purpose, they now leave behind traces of themselves in the form of data.
From Big Data to Smart Data: Multichannel systems
Efficient Data Transfer “Squared”
The amount of data generated in all areas of life is growing at an incredibly fast pace. The challenge here is to be able to wirelessly transmit and store such high data volumes even more quickly and securely. Siemens researchers are therefore linking many channels for the simultaneous transmission and reception of data. The multichannel approach can also improve other types of high-frequency applications, such as pivoted radar beams, precise angle measurements in radar systems, and local optimization of the wireless energy supply in RFID systems.
A study conducted by the International Data Corporation (IDC) market research firm in the U.S. predicts that by 2020, the number of bits of data stored worldwide will be nearly as high as the number of stars in the universe: Total data volume is expected to reach 44 zettabytes, or 44 billion terabytes, by 2020. If this prediction proves correct, it will mean a ten-fold increase in global data volume by that time as compared to 2013. A notebook hard disk (3.5 inches) can store a maximum of three terabytes these days, which means it would take 14.7 billion of these disks to store the volume of data anticipated for 2020.
There are many reasons for this data explosion. IDC cites the booming market for PCs and smartphones with mobile Internet access and — more importantly — the rapid expansion of Internet use in emerging markets.
The growth in data is also increasing the need to transfer ever-larger amounts of information more quickly. We’re all familiar with the fact that downloading speeds decrease significantly in proportion to file size and the number of computers using the same Internet connection, and thus “stealing” transmission capacity from other users. If data volumes continue to rise, the data-transfer rate problem will become even more acute. Why is this the case? Consider the following: Today’s laptops are equipped with only one antenna, which sends data to another antenna and disrupts many other antennas in the process. This places limitations on global data-transfer capacities and speeds.
The solution here is to be found in multichannel systems equipped with a large number of antennas that exchange electrical signals with one another simultaneously. This setup works because each of the antennas consists of up to 100 small antennas, which means multichannel systems can generate and direct their radio beams very precisely. This in turn enables data connections that display very low losses and are extremely resistant to interference. In other words, the frequency spectrum in a room can theoretically be used simultaneously by several different devices without the data-transfer rate decreasing. What’s more, the individual antennas make it possible to generate different beams in different directions to different users at the same time.
Siemens is also making use of multichannel systems. A total of 40 high-frequency technology experts in Munich, Erlangen, and Vienna are conducting research into such systems and are also optimizing them in line with the needs of the company. Among other things, they’re testing applications for communication, wireless energy transmission, and sensor systems. “The effect here is similar to that of an apple being illuminated from different directions by ten flashlights in a dark room,” says Andreas Ziroff, Head of the RF Technologies Germany research unit at Siemens AG Corporate Technology (CT). Each lamp emits only a weak beam by itself; it’s only after the many different beams converge on the apple that it becomes very bright. The same simple principle enables multichannel systems to increase data volumes and transfer speeds through the use of numerous individual transmission channels.
There is one difference, however: Whereas the brightness of ten flashlights is simply added together in the above example, the multichannel effect squares the capacity of a single transmission channel. That’s because several channels per user are linked with one another in such a manner that each individual signal no longer spreads out across a whole room but instead travels via the most direct — and thus most efficient — path from the transmitting to the receiving device.
Multichannel systems can be used for many applications, one being communication technology. “Wireless communication systems have reached the limits of their capacities,” says Stefan Schwarzer, a high-frequency technology engineer at CT. That’s why the wireless systems of the future will rely on the 5G multichannel standard to ensure data can be transmitted at lightning speed. The Siemens experts believe the transfer of several gigabits per second via up to 100 parallel channels is a realistic possibility for 2020. Today’s optimum data-transfer rate is around 300 megabits per second, although this speed is rarely reached in daily life.
What is certain today is that mobile communication will change dramatically in the future. “The goal is no longer to simply send data from one location to another,” says Prof. Gerhard Fettweis, Chairman of the Department of Mobile Communication Systems at Technical University of Dresden. “What’s more important now is to network a broad range of objects in real-time with only a low degree of human influence. We will therefore have to rethink wireless communication, especially in terms of data-transfer rates, waiting times, and Internet protocols.” Multichannel systems thus also hold great significance for the Internet of Things, as the rapid increase of networked and communicating devices can only be managed if many different and spatially separate channels can enable the exchange of huge amounts of data.
Normal everyday people will notice the advantages of multichannel systems when they use their smartphones, for example. Phones that can make use of several data channels simultaneously will be able to send and receive much more data than is now the case. “Multichannel systems can increase today’s data-transfer speeds many times over,” says Schwarzer. This will significantly reduce lag times — i.e. the interval between the time data is sent and received. “Today’s single-channel mobile devices have a lag time of milliseconds; our goal is a lag time in the double-digit microsecond range,” Schwarzer explains.
Humans tend not to greatly notice lag times of less than 50 milliseconds when viewing a video on a smartphone, for example. However, reducing lag times to the microsecond range is crucial for the optimal operation of industrial equipment, for example. If such equipment is to be remotely controlled and synchronized wirelessly, then data has to be transmitted in microsecond intervals.
The Siemens technicians are also examining ways to use multichannel systems for wireless energy transmission. An RFID chip base station that utilizes such a concept would be able to supply chips with electrical energy in a targeted manner. “Electromagnetic wave field synthesis can be used to generate energy at a single point without filling up the whole room, which would be inefficient,” Schwarzer explains. RFID chips can be used in many ways — for example, to track individual products in a manufacturing process or to grant authorization to open locking systems.
However, these examples by no means cover the entire range of potential applications for multichannel systems, as Siemens engineers are also optimizing multichannel radar sensors for monitoring parking lots and garages. Multichannel systems are being used in a similar manner in open-pit mining operations, where machines 100 meters long have to be exactly positioned down to the last centimeter when transporting spoil. This is done with the help of multichannel radar sensors that are able to measure angles precisely. Public transportation systems also offer a good example of the broad range of applications for multichannel systems, particularly in conjunction with electronic tickets. RFID chips could be used here in the future to help with searches for available seats and with automatic ticket invoicing across different modes of transport. Multichannel systems can also play a key role in medical applications, as Schwarzer explains: “Ultimately, even an MRI machine is ‘nothing more’ than a receiver in which multichannel transmission enables high-quality images.”