Why is there no cell service in the restaurant

We like mobile phones, we use them whenever we are free, or when we don’t actually have free time. We use it on the subway, bus, eating, and walking. We use it in many ways, paying bills, playing games, logging on to the Internet, using GPS services, writing messages, watching movies, and making phone calls. But too many mobile phones in public places can also cause problems. Such places include concerts, restaurants, buses, courts, conference rooms, cinemas, museums, gas stations, etc. Can you imagine a person talking loudly to his cell phone while you are watching a movie? Or when you and your girlfriend are enjoying a romantic dinner? In order to protect you from mobile phone noise, we need a mobile cell phone jammer, which is a device that can cut off the mobile phone signal in a certain area. All mobile phones will not display services in this area until you turn off the mobile phone jammer.