Steering the antenna/e (electronically or otherwise) to point at the satellites, increases the strength of the transmitted/received signal. These steerable antennae are often called High Gain antennae.
Some Satcom systems have a Low Gain and a High Gain antenna (or two). The low gain antenna can be used for data transmission. IRS alignment is not required for Low Gain antennae. The High Gain Antenna can be used for data and voice comms.
Rgds
NSEU