During a wireless site survey for a hospital, the client requires seamless roaming for VoWi-Fi handsets. Which design factor is most critical to ensure high-quality voice roaming?

Omnidirectional antennas radiate RF energy equally in all horizontal directions, which is critical in a hospital where staff move through rooms, corridors, and open areas from unpredictable angles. This uniform pattern ensures VoWi-Fi handsets consistently detect overlapping AP signals needed to trigger seamless roaming handoffs before calls drop. Using omni antennas as the foundational antenna type prevents the directional coverage gaps that would cause voice quality degradation during cell transitions.

While cell overlap percentage and minimum signal thresholds are important VoWi-Fi design parameters, this option as presented contains encoding artifacts that make it unreadable, and proper antenna type selection first establishes the uniform coverage foundation that all overlap planning depends on.

Restricting deployment to the 2.4 GHz band alone reduces available capacity, increases co-channel interference in dense environments, and does not inherently improve roaming continuity for VoWi-Fi handsets.

High-gain directional antennas in hallways create elongated, narrow coverage cells that leave adjacent rooms and perpendicular corridors with insufficient signal, increasing the likelihood of dropped voice calls during handoffs.