Optimizing Information Freshness in Wireless Networks Under General Interference Constraints

Abstract

Age of information (AoI) is a recently proposed metric for measuring information freshness. AoI measures the time that elapsed since the last received update was generated. We consider the problem of minimizing average and peak AoI in a wireless networks, consisting of a set of source-destination links, under general interference constraints. When fresh information is always available for transmission, we show that a stationary scheduling policy is peak age optimal. We also prove that this policy achieves average age that is within a factor of two of the optimal average age. In the case where fresh information is not always available, and packet/information generation rate has to be controlled along with scheduling links for transmission, we prove an important separation principle: the optimal scheduling policy can be designed assuming fresh information, and independently, the packet generation rate control can be done by ignoring interference. Peak and average AoI for discrete time G/Ber/1 queue is analyzed for the first time, which may be of independent interest. arXiv:1803.06467v2 [cs.IT] 9 Dec 2019Lemma 1: We have A ave (π) = A p (π) for any stationary policy π ∈ Π st .

Optimizing Information Freshness in Wireless Networks: A Stochastic Geometry Approach

“…where [38] for a detailed proof. From (7), it is obvious that the principle of optimizing information freshness consists in maximizing the link throughput.…”

“…The theorem then follows from taking (38) and (39) into (37) and performing further algebraic manipulation. Using a similar approach as in the proof of Theorem 2, we have that for all 0 < κ < 1, in order to achieve η S (θ XjΦ , θ XjΦ ) > κ, we will need the following condition to hold:…”

Minimizing Age of Information With Power Constraints: Multi-User Opportunistic Scheduling in Multi-State Time-Varying Channels

“…Rajat et. al studied a joint rate control and scheduling problem for age minimization under general interference constraints [19], where joint rate control and scheduling policies are investigated for age optimality, and a separation principle policy is found to be approximately optimal. However, no power constraint is considered in that work.…”

“…Let X n (W ) and A n (W ) denote the average AoI and the average scheduling probability of sensor n, respectively. By computing the optimum resource allocation vector {y * x,q } through solving LP (19), function g n (W ) can be computed as follows:…”

“…Since all the sensors are identical, it can be concluded that the average scheduling probability of each sensor is smaller than 1 N . Hence, we can fix W = 0 and add another constraint on the activation probability to the LP (19),…”