New LTE network is likely to be overlaying with customer’s existing radio networks. Hence, antenna selection would be a critical factor in the new LTE radio network design. Frequency band of the new LTE network will also be a critical factor in antenna selection. If Single RAN solution is already in place and new LTE network is built on frequency band covered by existing antennae, no additional loss will be incurred. However, this may come at the expense of limitation in tilting flexibility.
On the other hand, if the LTE network is to be overlay on other vendor’s network within the same frequency band, addition loss (e.g. combiners, splitters and jumper cables) needs to be included in the prediction design to ensure all the extra combining loss are included due to equipment co-sitting.
While use of separate and/or new antenna may incur additional project cost, radio planners need to evaluate the benefit of having this tilting and orientation flexibility carefully on a site by site basis. Existing radio networks are also likely to have additional down tilt for coverage control purposes so independent tilt for Greenfield LTE network may help to reduce the final site count required.
New multiband antennae now offered by some vendor can provide independent electrical tilt for different band which may be useful for some situations. However, certain network requirements may demand new antennae altogether due to different network coverage requirement.
Finally, installation of new antennae in certain locations may not be possible due to local authority restriction, for example: inside shared antenna system in major shopping malls, tunnels and sporting stadium. Hence, radio engineers need to ensure project team or customer can provide appropriate installation feasibility for such locations. In general, engineers should not rely on tunnel coverage to be provided by radio signals coming from the base station located outside the tunnel premises.