Cellular Communication has become an important part of our daily life. Besides using cell phones for voice communication, we are now able to access the Internet, conduct monetary transactions, send text messages etc. using our cell phones, and new services continue to be added. Therefore, it is important to provide users with a secure channel for communication. This paper will give a brief introduction to the various generations of cellular networks. For those not familiar with the cellular network architecture, a brief description of the new 3G cellular network architecture will be provided. Limitations of cellular networks, their security issues and the different types of attacks will be discussed. Then the steps taken in the new 3G networks to combat the different security threats will be provided. Also, the security features of the Wireless Application Protocol (WAP) used to access the Internet will be discussed.