Bounds of Cardinality on Subspace Network Codes

Network coding is a new direction in the information and communication theory. In this area algebraic coding for wire channels is based on Grassmann metric which is also called subspace metric. In the theory the main problem is to construct codes with great cardinality and create fast decoding algorithms. Here, we deliver the low bound of subspace network codes. We calculate cardinality of some concrete codes and describe decoding algorithms. We show the interest cases where the cardinality approaches the upper bound.