  Densification of the network deployment, for example by adding new sectors or
sites within an existing mobile communication network, has traditionally been
an efficient way to improve the system coverage and capacity. That will be the
case even for the ultra-reliable low-latency communication (URLLC) services,
but the overall situation and the feasibility of the different deployment
options will depend on the characteristics of the URLLC service in question.
URLLC services with relaxed latency requirements, allowing multiple
transmission attempts, can tolerate a decent level of inter-cell interference
while still being able to guarantee the desired quality-of-service for all
users, which makes it possible to improve the URLLC service capacity by adding
new gNodeBs with omnidirectional or directional antennas. However, when the
URLLC services require extremely low latency that do not allow for
retransmissions, the system performance becomes quite sensitive to the
inter-cell interference, which means that in practice the gNodeBs should be
equipped with beamformed antennas to reach high levels of URLLC service
capacity. Finally, an active distributed antenna system could be an efficient
way to secure good coverage throughout the desired service area.

Networking and Internet Architecture