New technology to build cellular networks

As you know, from time to time we do for you translations of interesting publications on new products and / or various discussion issues in the telecom industry. This time we bring to your attention a translation of an article on promising technology that can significantly increase the speed of wireless Internet in existing cellular networks.

In the middle of February of this year, the American startup Artemis Networks announced its plans to commercialize its own technology pCell. It is based on a new wireless communication scheme, which should relieve us from the overload of cellular networks and ensure faster and more reliable data transfer. And what is most interesting, ostensibly for this, we don’t even have to change our smartphones, pCell works on existing 4G devices.

If the possibility of scaling this technology is proved, then pCell can radically change the operation of wireless communication networks, replacing the existing cellular networks with new ones built on a completely different principle. They combine the signal from a variety of distributed antennas, which allows you to create around each subscriber device a kind of cocoon of stable communication. In such a cocoon will be available the full width of the spectrum of this network.
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PCell technology was first introduced in 2011 under the name DIDO (distributed input, distributed output). At that time, the idea looked like pure fantasy. And undoubtedly, Artemis will have to answer with reasoned criticism and numerous doubts before the major operators decide to give them attention. But there are several reasons why their technology can actually be implemented.

First, it is an elegant solution to the general problem of annual traffic doubling , which operators decide as they can . According to Artemis CEO Steve Perlman, the lack of spectrum width limits the ability of operators to introduce innovations. The reason is not a lack of ideas; in recent years, various solutions have been proposed to solve the problem of traffic growth. For example, small cells , interference coordination, as well as the use of the millimeter range, as we have already written ( part 1 , part 2 ). But Perlman believes that all these measures are crutches for the outdated cellular communication scheme. He argues that the main problem lies in the very principle of dividing the network into cells.

The main problem of cells is the interference of signals. Base stations and subscriber devices must precisely coordinate the power and spectrum of transmissions in order not to interfere with each other’s signals. This division of the available spectrum band between users was incorporated into cellular technology back in the 1980s. As a result, the throughput of each session is greatly reduced if there are many subscribers connected to the base station.

In Artemis decided to abandon this dynamic division of the range, instead, each subscriber device can use the entire available network band, regardless of the number of other users in the district. As if your smartphone is constantly connected to its personal base station. Hence the name pCell - personal cell, personal cell.

How exactly does this technology work? To deploy such a network, the operator needs to create a cloud data center that will take over all the main load of heavy calculations for the system. Then it is necessary to install antennas in places where subscribers are crowded: in residential and office buildings, shopping centers, on the streets. Although the antenna modules (the size of a box from under a hat) look like small cells, but they are not. These are not base stations, but rather simple devices that serve to redirect and decode signals. Each module connected to the data center can be installed anywhere.



Now suppose your smartphone is trying to connect to the pCell network. For this, a traditional request is sent, which is received by all antennas nearby (say, 10), which report this to the data center. Suppose you are viewing a YouTube video on a smartphone. The data center requests it from Google servers, and then the video is broadcast to your device through 10 antennas that have accepted your connection request. At the same time, none of them will broadcast the whole stream or even a part of it. Instead, the data center uses the location of the antennas relative to the subscriber device and the channel parameters, such as multipath and attenuation, to form 10 unique wave signals emitted by these antennas. Being meaningless by themselves, together these 10 waves form the desired signal. In fact, we are talking about deriving benefit from the interference of radiation from each antenna.

While you are moving in space, while other devices are disconnected from the network, the data center constantly recalculates the wave parameters for each antenna so that all subscriber devices receive the correct resultant signals. No competition for the base station resources, you can literally cover the entire city in the entire available spectrum.

On hand, pCell plays compatibility with existing 4G devices. This is done using software emulation of LTE stations, and the data center can use these virtual base stations to establish connections with unsuspecting smartphones and tablets. In addition, each gadget will assume that at the moment it is the only one connected to the BS. The same can be done in 3G and Wi-Fi networks.

Will pCell operators be adopted? It is unlikely that any of them will soon want to abandon the LTE networks created, even if the technology from Artemis really turns out to be so miraculous. But compatibility with LTE is the pCell trump card. For example, operators can deploy antennas in places where base stations are overloaded most often: at airports, at stadiums, in city centers. That is, where infrastructure has already been invested. And users can easily switch between networks without having to buy new smartphones.

Artemis wants to license its technology for use by cellular operators and Internet service providers. Large-scale field trials are also starting in San Francisco, and the technology may be commercially ready by the end of this year.



Of course, this technology can not be called a contender for the title of 5G. This is a different architecture - a self-optimizing cellular network. We are traditionally interested in the opinion of experts from the telecommunications industry: what do you think are the prospects for integrating the described technology into existing LTE networks without serious additional investments? How do you assess the feasibility of such a decision?