Exploiting Storage for Computing: Computation Reuse in Collaborative Edge Computing
Xingqiu He, Chaoqun You, Tony Q. S. Quek
TL;DR
Addresses duplicate computations and latency in Collaborative Edge Computing (CEC) by enabling cross-BS computation reuse. The authors formulate a weighted response-time minimization problem that jointly optimizes caching decisions $x^a_{nk}$, cache-searching $y^a_n$, workload distribution $\lambda^a_n$, and CPU allocation $f^a_n$, and solve it via alternating minimization with a bisection-based caching scheme and a projected-gradient-descent scheduler. The problem is NP-hard, but the paper provides polynomial-time approximate algorithms with convergence guarantees. Numerical results show substantial reductions in weighted delay across diverse workloads and network scales, validating the practicality of collaborative caching in edge networks.
Abstract
Collaborative Edge Computing (CEC) is a new edge computing paradigm that enables neighboring edge servers to share computational resources with each other. Although CEC can enhance the utilization of computational resources, it still suffers from resource waste. The primary reason is that end-users from the same area are likely to offload similar tasks to edge servers, thereby leading to duplicate computations. To improve system efficiency, the computation results of previously executed tasks can be cached and then reused by subsequent tasks. However, most existing computation reuse algorithms only consider one edge server, which significantly limits the effectiveness of computation reuse. To address this issue, this paper applies computation reuse in CEC networks to exploit the collaboration among edge servers. We formulate an optimization problem that aims to minimize the overall task response time and decompose it into a caching subproblem and a scheduling subproblem. By analyzing the properties of optimal solutions, we show that the optimal caching decisions can be efficiently searched using the bisection method. For the scheduling subproblem, we utilize projected gradient descent and backtracking to find a local minimum. Numerical results show that our algorithm significantly reduces the response time in various situations.
