Why is fiberglass antenna unsuitable for indoor use?

Why is fiberglass antenna unsuitable for indoor use?
Answer: Many people may notice that international brands such as Linksys or DLink typically only use 7dB, 5dB, or 2dB antennas on their devices, but rarely see their 9dB or higher gain indoor omnidirectional antennas on the market. Based on our understanding, indoor applications with 7dB antennas have fully met the requirements, while antennas with 7dB or above may not have the advantage due to their smaller angles. Therefore, indoor applications may have the opposite effect. So we propose that omnidirectional antennas with a power output of 9dB or above should be used outdoors. As for some people who say that indoor antennas have good wall penetration effects, this statement cannot be denied and there is no need to be overly confident.
Why is it called an omnidirectional antenna, and there is also the saying of vertical angle?
Answer: The commonly referred omnidirectional antenna refers to an antenna with a degree radiation angle of 360 degrees, which emits in a fan-shaped manner vertically. The angle is usually around 6-15 degrees, and the higher the gain, the smaller the vertical angle. For example, a 9dB antenna can achieve a radiation angle of around 14 degrees, while a fiberglass antenna can achieve around 8 degrees, which was once the limit.
Why is there a phenomenon where a 15dB antenna does not perform as well as a 9dB or lower gain antenna at the same position? The higher the gain, the smaller the vertical angle
4. After reading all the above questions, what is the suitable environment for using fiberglass?
Answer: Due to the small vertical angle, fiberglass antennas can only transmit signals at a degree of 6-8 degrees. Therefore, fiberglass antennas are commonly used for wireless masking in plain areas, as well as in environments at the same level of location. If mounted at a higher position, signals can only be transmitted to a farther position, while nearby or centers with height differences cannot be masked.