It's a common misconception that wireless is quicker than wired connections. Wireless works using radio waves where as a wired connection is pretty much instant.
Wireless Internet access tends to be slower than the actual speeds you receive since there are things that can interfere with the connection getting to you such as distance, other devices, and wireless connection speeds. A wired connection will be more secure and in most cases faster.
Wireless referring to wireless high speed using broadband is fast. This is simply a broadband connection broadcasting wirelessly. Dial up typically runs at a much slower speed, broadcasting the signal wirelessly will lessen the speed even more.
Wireless dial-up is slow because wireless is actually slower than by wires, this is because the piece that sends out the wireless signal has to send the signal out in all directions, where-as when it's wired it only has to send the data in one direction.
The keyword is dial-up. Dial-up internet service is the slowest you can get. Wireless just means that you wont be limited to how long cables/cords are to your modem.
Wireless simply means without wires. If you're using a dial-up connection, you will still get the same speeds as you got previously with wires. Your wireless router is capable of hitting higher speeds, but would need a faster connection to begin with.
Wireless, in general, is a fairly fast technology when two computers are speaking to each other using it. However, "wireless dial-up" sounds like you are still connecting to the internet using a modem-based connection, which is inherently slow. Your wireless is likely plenty fast, but it's the dial-up part of things that is slow. For faster internet, consider broadband.
The data transmission rate is rather too low. With a rate of 56 Kbps or less, you will have a tough time in downloading large files such as video clips,software,sharing photos with your friends and families, or playing online computer games. It consume lots of power and the life of the battery becomes low.