What is dBm

Sometimes identified as dBmW, dBm has to do with the degree of power measured in decibels as it relates to one millwatt. The calculation of dBm is helpful in several different types of applications, and can be used to calculate any size power ratio. In most cases, dBm is used to measure absolute power in a given setting. What Types of Systems Make Use of dBm? Three basic types of networks will make use of a dBm calculation on a regular basis. Radio, microwave, and fiber optic networks all employ the use of dBm. In each case, the measurement helps to ensure that the amount of wattage employed by the network remains within proscribed limits, but is sufficient to generate the energy required for operation.

How Is dBm Calculated? It is important to note that dBm is referenced to the watt. This means that dBm represents an absolute unit, which is essential to the task of defining absolute power. Essentially, a zero dBm is the equivalent of one milliwatt.

This means that in the event of the occurrence of 3 milliwatts, the dBm would come to 4. If the millwatts were less than one, such as a half millwatt, that would make the dBm roughly a -3, since the power is reduced by half. How Widespread is the use of dBm as a Calculation? The use of dBm is common in the United States, where unweighted measurement is employed in many different applications.

This is especially true when it is necessary to ascertain the wattage involved in order to maintain transmissions within a certain bandwidth. Do Consumers Make Use of dBm? While consumers tend to reap the rewards of the use of dBm by various networks that deliver signaling, the average consumer has no real need for the use of dBm. The measurement tool is mainly used by professionals who are responsible for maintaining proper bandwidth in accordance with federal regulations and guidelines. Still, it must be noted that just about every consumer will benefit from the use of dBm in some way.

Everything from telephone calls to bandwidth on home computers, radio to television broadcasts, and a number of other related transmissions are monitored and measured with the use of dBm.

Tom Paine writes for The Tech FAQ and is the author of articles such as dBm, Satellite Television, and LNB Tester.