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On the Age of Information in a Two-User Multiple Access Setup
Mehrdad Salimnejad1, Nikolaos Pappas1
1Department of Science and Technology, Linköping University, SE-60174 Norrköping, Sweden.
Entropy (Basel, Switzerland)
|April 23, 2022
Summary
This study optimizes Age of Information (AoI) for two users in a multiple access channel. It develops methods to minimize one user's AoI while ensuring the other's AoI stays within limits.
Area of Science:
- Wireless communication networks
- Information theory
- Queueing theory
Background:
- Analyzing Age of Information (AoI) is crucial for real-time systems.
- Understanding traffic characteristics and queueing policies impacts AoI performance.
- Multiple antenna systems with fading channels present unique challenges.
Purpose of the Study:
- To minimize the average AoI for a user with external traffic.
- To ensure the average AoI for a sensor-monitoring user remains below a threshold.
- To develop an optimization framework for a two-user multiple access channel.
Main Methods:
- Analysis of discrete-time queueing models (FCFS, LCFS, packet replacement).
- Derivation of AoI distribution and average AoI for threshold policies.
- Formulation and convex analysis of an optimization problem with queue discipline constraints.
Main Results:
- Derived average AoI for different queueing policies for user 1.
- Derived AoI distribution and average AoI for user 2 under a threshold policy.
- Developed a suboptimal technique to solve non-convex optimization problems for FCFS queueing.
Conclusions:
- The proposed optimization framework effectively manages AoI for diverse traffic types.
- The analytical results provide a foundation for extending AoI optimization to larger systems.
- Numerical results validate the performance of the optimization algorithm.
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