RUDN mathematicians have calculated how many 5G towers are needed depending on the network requirements

One of the technologies that the new 5G communication standard relies on is network slicing (NS). Several virtual networks — “layers” — are deployed on the same physical infrastructure (the same base stations) at once. Each layer is allocated to a separate group of users, devices, or applications. To split the network, NR (New Radio) technology is needed, which operates on millimeter waves. Most of the research in this area is aimed at creating an infrastructure of NR stations that would provide network slicing in each specific case. For the first time, RUDN mathematicians have developed a general theoretical method that helps to calculate the density with which NR base stations need to be installed to divide the network with the specified parameters of customer service quality.

“The concept of network slicing will greatly simplify the entry into the market for mobile virtual network operators and provide differentiated quality of network services. This is an important paradigm shift in the world of cellular communications, it will allow creating multi-level network structures similar to the structures of the modern Internet. Several users or services will be able to use resources at the same time,” says Ekaterina Lisovskaya, Candidate of Physical and Mathematical Sciences, junior researcher at the Scientific Center for Applied Probabilistic Analysis of the RUDN.

When constructing the algorithm, RUDN mathematicians used a model “city”. Base stations NR were distributed in it with some density. The stations had three antennas, each of which covered 120 degrees. Pedestrians were randomly distributed around the city — users of devices using a 5G cellular communication network operating in the millimeter frequency range (30-100 GHz). They moved and could block each other’s line of direct communication with the base station. Each antenna had an effective range — there were no problems with the connection inside it, even if the direct communication line was blocked. RUDN mathematicians have constructed the dependence of network characteristics on the density of station locations.

To check the accuracy of the constructed model, mathematicians used computer simulation. The results of theoretical and experimental calculations coincided. The developed model shows, for example, how the density of station locations affects the mode of dividing network resources from complete isolation to complete mixing. The first assumes that each layer has its own frequency range of fixed width, in the second variant, the frequencies of the layers are completely mixed with each other. The second option is more difficult from a technical point of view but increases the efficiency of using physical network resources. RUDN mathematicians have studied these modes as two “extreme” versions of the network implementation — in real problems, some intermediate implementation is usually required. It turned out that the difference in the frequency of towers between these extreme implementations is small — one tower per 10,000 square meters.

“The mode of complete isolation of layers can change dramatically until complete mixing, depending on the density of NR stations. However, you can change the required density by changing the system parameters. In practice, this means that at the initial stage of market penetration, full isolation mode can be used without compromising network performance. And in the future, new improved schemes will help to reduce the costs of operators for network deployment,” says Ekaterina Lisovskaya, Candidate of Physical and Mathematical Sciences, junior researcher at the Scientific Center for Applied Probabilistic Analysis of the RUDN.

The results are published in Computer Communications.