Rated carrier output power

Description

Rated carrier output power is a fundamental parameter in 3GPP specifications that defines the mean power level per carrier that a base station manufacturer declares to be available at a specified interface. This parameter is critical for ensuring that base stations operate within regulatory limits and for verifying their RF performance. It is applicable to various base station types, including those operating in single-carrier, multi-carrier, and carrier aggregation configurations. The parameter is measured during the transmitter ON period under specified reference conditions, which ensures consistency across different testing scenarios.

The concept of rated carrier output power is closely related to the conducted power at the antenna connector or the radiated power at the radiated interface boundary (RIB), depending on the base station architecture. For traditional base stations with external antennas, the power is declared at the antenna connector. For active antenna systems (AAS) where the antenna is integrated with the radio, the power is declared at the RIB. This distinction is important because it affects how the power is measured and what test methodologies are used. The parameter is specified in a number of 3GPP technical specifications, including 36.108 (LTE BS), 37.141 (LTE AAS BS), 38.104 (NR BS), 38.108 (NR AAS BS), 38.141 (NR BS conformance testing), and 38.174 (NR IAB BS).

In practice, the rated carrier output power is used by manufacturers to declare the maximum mean power that the base station can output per carrier. This declaration is then used in conformance testing to ensure that the base station does not exceed this power level, which could cause interference to other systems or violate regulatory requirements. The parameter also plays a role in network planning, as it determines the coverage and capacity of the base station. For multi-carrier and carrier aggregation configurations, the rated carrier output power is declared for each carrier, and the total power may be subject to additional limits.

The measurement of rated carrier output power is typically performed using a power meter or spectrum analyzer connected to the antenna connector or using over-the-air (OTA) methods for AAS. The transmitter ON period is the time when the transmitter is actively transmitting, and the measurement is averaged over this period to obtain the mean power. The specified reference conditions include parameters such as temperature, voltage, and modulation, which are defined in the relevant specifications to ensure repeatability.

Overall, rated carrier output power is a key parameter for the design, testing, and deployment of base stations. It provides a standardized way to declare and verify the output power per carrier, which is essential for ensuring coexistence, regulatory compliance, and efficient use of the spectrum. As base station technology evolves towards higher integration and more advanced antenna systems, the accurate declaration and measurement of rated carrier output power will remain essential.

Purpose & Motivation

The rated carrier output power parameter was introduced to provide a standardized way for manufacturers to declare the mean output power per carrier of a base station. Before its introduction, there was no consistent metric for declaring the power available at the antenna connector, which led to ambiguities in testing and regulatory compliance. The parameter solves this problem by defining a clear, measurable quantity that can be used in conformance tests and for network planning.

With the evolution of base station technology from single-carrier to multi-carrier and carrier aggregation, the need for a per-carrier power declaration became evident. The rated carrier output power allows manufacturers to specify the power for each carrier independently, which is essential for ensuring that the total power does not exceed regulatory limits and that the base station operates efficiently. It also supports the deployment of advanced features such as carrier aggregation, where multiple carriers are combined to increase bandwidth and throughput.

Furthermore, the introduction of active antenna systems (AAS) required a shift from conducted power at the antenna connector to radiated power at the RIB. The rated carrier output power was adapted to this new paradigm by allowing declaration at the indicated interface, which could be either the antenna connector or the RIB. This flexibility ensures that the parameter remains relevant across different base station architectures and technologies.