How does wireless PA System works?

Wireless PA System compose of, or using a Wireless Microphone, Power Audio Amplifier and a Speaker System.

1. Wireless microphone systems work using four components: the microphone, a battery, the transmitter and a receiver. The transmitter sends an audio signal over a designated frequency, and the receiver picks up the signal and directs it to a sound system.

http://www.ehow.com/facts_7300419_wireless-microph...

http://en.wikipedia.org/wiki/Wireless_microphone

2. Power Amplifier drive the loudspeakers used in PA systems to make the human voice louder when speaking in a microphone or play recorded music.

http://en.wikipedia.org/wiki/Power_amplifier

3. A loudspeaker (or "speaker") is an electroacoustic transducer that produces sound in response to an electrical audio signal input.

http://en.wikipedia.org/wiki/Speaker_system

When these three component are used together you have a Wireless PA system. "Router" is not included/ needed in the PA (Public Address) system. It is only for networking use in Ethernet sending internet signal to other computer set. If you are using a Wireless microphone, it could be said that your PA system is Wireless. Because the sound from the "human speaker/ announcer/ host/ singer" of a concert program that is using a microphone is send wirelessly or without a cable going to amplifier and then to speaker system so that it will become louder for the audience to be heard. That is why (and the only point) it is called a "wireless PA system".

How this work is simple, a singer is singing in a wireless mic that is connected (without cable) to a power amplifier. The amplifier raise the audio sound to a higher level and send it to a "speaker baffle or box". The speaker that is placed around the school premises in front of an audience heard all the music sung by the singer from it even if they are far away from the stage. The singer, because she is using a wireless mic, can move and dance freely around the stage without the wire cable distracting her performance.

I guess you have already seen a concert, a music video and on parade that an announcer is talking on a microphone (only) without a cable hampering around his body or in stage floor?. That is, they are using a Wireless PA system.

Guide to Selecting Wireless Public Address Systems

http://www.work.com/selecting-wireless-public-addr...

What type of speakers are needed with a wireless microphone system?

all of it sounds truly technical. And prompt isn't 100% guard. If a bomb must be brought on by utilising a cellular telephone, who's favourite with what some sensible evil hacker ought to do to employ a prompt PA gadget.