Lower Bounds for Total Storage of Multiset Combinatorial Batch Codes using Linear Programming

The class of multiset combinatorial batch codes (MCBCs) was introduced by Zhang et al. (2018) as a generalization of combinatorial batch codes (CBCs). MCBCs allow multiple users to retrieve items in parallel in a distributed storage system and a fundamental objective in this study is to determine the minimum total storage given certain requirements.We formulate an integer linear programming problem so that its optimal solution provides a lower bound of the total storage of MCBCs. Borrowing techniques from linear programming, we improve known lower bounds in some cases and also, determine the exact values for some parameters.