We all use communication devices like mobile phones and other smart devices that depend on cellular signals and may have come across dB or dBm when reading the technical details of these devices. These two terms are very important and especially important when it is regarding cellular signal booster. So, you must be wondering what the difference between dB and dBm is, and their importance in cellular communication. The purpose of this article is to better understand this, read on to know more.
What Is dBm?
We will begin with dBm or decibel milliwatts, as it is the more prominent one of the two because it is used in microwave, radio and fibre optic communication networks. It denotes the power ratio in decibels (dB) of the measured power over one milliwatt power. This is very useful as it can express very large and small quantities, so it can be used to measure absolute power of communication devices or networks.
What Is The Use Of dBm And dB In Signal Boosters?
In cell phone signal boosters dBm is used to indicate the power generated by the antenna and the amplifier or the strength of the cellular signal at a place. The difference between dB and dBm is that the former is a relative measure of increase or quality in signal strength, the latter is an absolute measure. When it comes to determining the outside signal strength we use dBm, if it is -70 dBm it is considered to be good and -100 dBm it is poor or worse. Similarly, it is also used to calculate the coverage area of the cellular signal booster setup and -20 dBm is a fairly good value to cover an area of 3000 square feet.
As stated earlier, dB is used as a relative measure to calculate the gain i.e. improvement in signal strength in cellular signal booster systems. For example, if the outside signal strength is -90 dBm, the total gain of the amplifier is 70 dB, then the strength of signal broadcasted by the internal antenna is -20 dBm. You should also keep in mind that increase in strength or quality of signal calculated using dB and dBm are logarithmic in nature i.e. they are not linear. The signal strength increases 2 times for every 3 dB rise; for example, -30 dBm is two times more strong than -33 dBm, -84 dBm is four times more strong than -90 dB.
You can check cellular signal quality with a signal meter or use the phone in field tests mode. When the outside signal strength is within the range of -101 to 109 dBm for 3G networks and -111 to -119 dBm for 4G networks, it is considered to be of poor quality. In these situations you can use a cellular signal booster. We hope that the aforementioned details clarified your doubts about the importance of dBm and dB in mobile network booster systems.