Lead University: Lehigh University
PI: Rick Blum, Department of Electrical and Computer Engineering
Co-PI: Shalinee Kishore, Department of Electrical and Computer Engineering
PA Industry: Avago

Over the last decade, mobile backhaul networks have increasingly become packet-switched in nature, owing to the growing mobile data demands of end-users. In order to support the ubiquitous deployment of 4G cell towers, it is necessary for these backhaul networks to also help provide microsecond-level time synchronization between cell towers. To this end, time synchronization techniques based on the IEEE 1588 Precision Time Protocol (PTP) are being studied in the context of packet-switched mobile backhaul networks. A drawback of packet-switched networks is that they suffer from unpredictable network traversal times, a phenomenon referred to as Packet Delay Variation (PDV). It is very important to combat the effects of PDV since it can severely degrade the accuracy of packet-based synchronization. The proposed research aims to develop such PDV cancellation techniques. Under two previous PITA grants, the statistical nature of PDV was studied under many different network conditions, theoretical performance limits for PDV cancellation were derived, and new PDV cancellation methods were developed. The proposed research will involve the further development and refinement of these PDV cancellation methods. Methods to automatically adapt these methods to changing network conditions will also be studied. New challenges, including synchronization using multiple time sources, and improving the robustness of synchronization against malicious attacks will also be studied.The efficiency of the proposed schemes will be tested via simulations and their implementations will be optimized for ARM processors. The project is a collaboration between the Lehigh team and the System Architecture Group at the Avago Technologies facilities in Allentown, PA.  Avago Technologies is an electronics company that develops network technology.