Age-Delay Tradeoffs in Queueing Systems

Wednesday, March 20, 2019 - 3:00pm to 3:30pm

Event Calendar Category

LIDS & Stats Tea

Speaker Name

Rajat Talak

Affiliation

LIDS

Building and Room Number

LIDS Lounge

Information freshness and low latency communication is important to many emerging applications. Age of Information (AoI) serves as a metric of information freshness, and packet delay is a traditional metric of communication latency. We prove that there is a natural tradeoff between the AoI and packet delay. We consider a single server system, in which at most one update packet can be serviced at a time. The system designer controls the order in which the packets get serviced and the service time distribution, with a given service rate. We analyze two tradeoff problems that minimize packet delay and the variance in packet delay, respectively, subject to an average age constraint. We prove a strong age-delay and age-delay variance tradeoff, wherein, as the average age approaches its minimum, the delay and its variance approach infinity. We show that the service time distribution that mininizes average age, must necessarily have an unbounded-second moment.

Rajat Talak is a PhD student at LIDS, MIT, co-advised by Prof. Eytan Modiano and Prof. Sertac Karaman. His current research involves investigation into the new latency metric of Age-of-Information (AoI) and problems of distributed perception. He is also the recipient of Mobihoc 2018 best paper award.