Improve Network Coverage Using Tower-Mounted Amplifiers

As cellular mobile networks continue to expand, operators keep trying to find cost-effective ways to improve network performance. Recent years have seen the introduction of remote radio head (RRH) modules as part of the base stations (BS). These provide the operator with the benefits of a less expensive solution by placing all the active radio frequency (RF) components at the top of the tower. However, this solution cannot be used in all situations. Tower loading, site access restrictions, or concerns with radio failures can in many instances restrict the installation of RRH at the top of the tower. Hence, the older generic site installation practice of using an RF feeder to go from the antenna to the base transceiver station (BTS) is still used in many applications. This scenario does introduce the potential need for tower-mounted amplifiers that can provide increased capacity and better coverage.

Achieving maximum coverage is often as easy as boosting the uplink signal from the network user’s handset at the BS, but this should not be confused with increasing the possible coverage from a site by boosting the downlink as well (increasing the link budget).

Appropriately installed low noise amplifiers (LNAs) in the BS uplink (receive channel) will significantly improve receiver system sensitivity when installed as close as possible to the receive antenna (particularly where cable losses are significant). LNAs located here are referred to as tower-mounted amplifiers (TMAs). This paper provides a general overview of BS receiver system sensitivity, and the benefits of installing a quality TMA.