Device-to-device (D2D) communication that enables direct communication between nearby mobiles is an exciting and innovative feature of next-generation cellular networks. It will facilitate the interoperability between critical public safety networks and ubiquitous commercial networks based on e.g. LTE. How should we analyze and design such hybrid networks consisting of both cellular and ad hoc links? WNCG Profs. Jeffrey Andrews and Constantine Caramanis, in collaboration with lead researchers and WNCG students Xingqin Lin and Qiaoyang Ye are working to develop novel models for such hybrid cellular systems and to use them for network performance uation and design. This research involved close collaboration with and significant technical inputs the Head of NSN North America Radio Systems, Amitava Ghosh, and Principal Engineer Mazin Al-Shalash WNCG Industrial Affiliate Huawei. Their work has impacted 3GPP standards contributions NSN and Huawei on specific D2D technologies in LTE Release 12.-Device-to-device (D2D) communication that enables direct communication between nearby mobiles is an exciting and innovative feature of next-generation cellular networks. It will facilitate the interoperability between critical public safety networks and ubiquitous commercial networks based on e.g. LTE. How should we analyze and design such hybrid networks consisting of both cellular and ad hoc links? WNCG Profs. Jeffrey Andrews and Constantine Caramanis, in collaboration with lead researchers and WNCG students Xingqin Lin and　Qiaoyang Ye are working to develop novel models for such hybrid cellular systems and to use them for network performance　uation and design.　This research involved close collaboration with and significant technical inputs　the Head of NSN North America Radio Systems, Amitava Ghosh, and Principal Engineer Mazin Al-Shalash　WNCG Industrial Affiliate Huawei. Their work has impacted 3GPP standards contributions　NSN and Huawei on specific D2D technologies in LTE Release 12.