Addressing Deep Indoor Coverage in Narrowband-5G

Ubiquitous connectivity is a common requirement of many services considered in Fifth Generation (5G) communication systems. However providing network coverage or wireless connectivity becomes very challenging in deep-indoor scenarios such as underground parking lots where the total channel loss can easily exceed the maximum coupling loss (MCL) of the communication technology. Particularly, new use-cases for machine type communications (MTC) in 5G pertaining to the automotive and utilities sectors demand deep coverage and ubiquitous connectivity without the need of deploying costly new infrastructure. We motivate the importance of deep coverage by conducting a representative site-specific realistic coverage analysis using ray tracing. The results show that existing cellular-based coverage-optimized technologies cannot achieve ubiquitous coverage in deep indoor/underground areas and highlight the need for dynamic multi-hop relaying in 5G MTC.