While the goals and design targets specified above may be aggressive, options have been approved for consideration in the design that when used properly, will lead to a more efficient network compared to the existing 3G network. Therefore, in the quest to produce the best network possible in a cost-effective manner while meeting the goal to launch an excellent LTE network on schedule, the following design optimization options have been approved for consideration as part of the entire LTE design process.
Site Relocations: Relocations are allowed for a maximum of 10% of the final LTE sites when compared to their current UMTS site location.
LTE Overlay Site Sparsing: There is no limit on site sparsing of LTE sites on existing UMTS sites as long as the performance targets and goals of the LTE network are met and the forecasted demand is carried by the final network design. The key driver is that a quality design is done.
Radiation Center Changes: Radiation center changes are allowed for a maximum of 10% of the final LTE sites when compared to their current UMTS site radiation center.
Antenna Type: Antenna type changes are allowed. 100% of the antennas should come from the AT&T approved antenna list. The choice of antenna should not be limited by antenna size but by what will bring out the best LTE network performance.
Antenna Azimuth: 100% flexibility on antenna azimuth changes is allowed as long as the recommended minimum separation or isolation between sectors is maintained.
Antenna Tilts: 100% flexibility on antenna tilt optimization is allowed.
Shared Antenna Systems: No design sites should share antennas with UMTS or GSM unless pre-approved by A&P and HQ RAN.
"Remotely Located2" Radio Heads (RH): Remotely located RHs should be used as needed for distributed remote transmitter locations. This will bring the transmitter closer to the users to provide a uniform user experience and increased coverage and capacity. The number of RHs should not exceed the maximum allowed per MU.