Shouting “fuwuyuan” when you need the waiter at your table might be rude in other countries but in China is very common. As it is, restaurants are vey noisy, people talking loud, laughing, shouting ‘fuwuyuan’ every 5 minutes, waiters yelling at each other, chairs squeaking every time someone gets up, managers arguing with the kitchen staff in front of customers, etc… I have seen it all in China!
At the beginning I was a little shy to call the waiter, I felt bad to yell at them. So I would raise my hand hoping I caught their attention but then grew tired of leaving it on the air for the longest time. I learned they will not come or even glance over your table unless you yell ‘fuwuyuan.’ After a month or so, I became used to it. At times I even had to yell really loud because the noise inside the restaurant was too much.
Every restaurant is different, not all of them are noisy and have grumpy chinese waiters. Western food restaurants tend to be better, but that goes with the price of your meal. In most chinese-not-so-expensive restaurants the waiters tend to disappear at times, give you attitude, or forget you had ordered rice (who does not eat rice in China!?).