The Density of Millimeter Wave Access Points in Dense Urban Areas and Its Effect on Link Availability in the Presence of Blocking

Radio access networks of the next generation (5G) are designed to be capable to handle the increasing demand for bandwidth and low latency as required for services like enhanced Mobile Broadband (eMBB), augmented reality or applications of the "tactile internet", that cannot be provided satisfactorily by today's radio access technologies. An extension of the used frequency bands towards millimeter wave bands with frequencies in the range of tens of Gigahertz that puts bandwidths of several hundreds of Megahertz to the operator's disposal is the most promising approach for the upcoming demands. Millimeter wave radio communications, however, implicate propagation conditions dominated by line-of-sight links with only few signal components contributed by reflections. Under such conditions blocking by physical obstacles within the signal path plays a major role for the availability and life time of a millimeter wave link. In this paper, we present our investigations showing the influence of the deployment density of mm-wave access points in a dense urban area on the availability and reliability of mm-wave links. We further show that, depending on access point density, in case of link blockage alternative paths with sufficient performance for a large part of the users are present.