A study of in-building coverage for small cells using ray techniques

The increasing use of handportable mobile telephones, which are operated frequently within buildings, requires the current and the future operators to dimension their networks to provide reliable service in these locations. Initially buildings will be served mainly from external base stations, and so there is a need to understand the penetration losses into a wide range of building types for any orientation of the building relative to the incident field. As demand increases it will be necessary to deploy small cells within buildings, and the key issues here will be the coverage within a room, into adjacent rooms and between floors. Leakage from the building which may cause interference to co-frequency external cells, or co-frequency cells in nearby buildings is also of concern. In buildings with particularly high traffic density it may become necessary to deploy many base stations, some of which may be required to operate co-frequency with one another, and so isolation within a building is also an important issue. Key to the successful control of these demanding requirements is an reliable model for predicting coverage into-and within a wide range of building types