Mobile data traffic has been growing exponentially over the past few years. A report from Cisco shows that the mobile data traffic in 2014 grew 69 percent and was nearly 30 times the size of the entire global Internet in 2000 [item 1) in the Appendix]. One of the primary contributors to the explosive mobile traffic growth is the rapid proliferation of mobile social applications running on multimedia mobile devices (particularly smartphones). These sharp increases in mobile traffic (particularly from mobile social applications) are projected to continue in the foreseeable future. As mobile networks by and large are designed and deployed to meet people's social needs, people's behaviors and interactions in the social domain will shape their ways to access mobile services. Therefore, there is an urgent need to integrate social effects into the design of mobile networks.