October Technical Tip

weBoost | October 1, 2013

This month for our Technical Tip, we’re talking about a thing called the ASU number. Keep reading to learn more!

Q. I am looking for my signal strength, and when my phone is in ‘test mode’, I notice the ASU number. What does this mean, and is it something I should pay attention to?

A. Great question. ASU or “Arbitrary Strength Unit” is an integer value proportional to the Reference Signal Received Power (RSRP) measured by the mobile phone. Basically the higher the number for ASU, the less interference you have between you and the towers. This interference, or noise, will range from too much to use –> to the ideal amount –> to so little that there is no signal.

In non-technical terms, ASU is a measurement of the quality of the signal. This measurement is in the range of 0 to 99. See the number line below for more detail:

Traditionally, the ideal ASU is somewhere between 20 and 33. However, because the connection type (GSM, CDMA, HSPA, etc.) determines the ideal number to aim for, the ASU is not an ideal measurement for signal. ASU measures the quality of the signal, whereas dB measures the strength of the signal.

When checking your signal strength for a booster, we still encourage you to focus on the dB signal strength, since this is what will be affected.

Got a technical question of your own? Feel free to contact us at 1-866-294-1660 or at  [email protected].

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