Bilal et al. (Maximum distance separable codes over Z4 and Z2 × Z4 Des. Codes Cryptogr. 61 (2011) 31–40) obtained two upper bounds on minimum distance of codes over rings to the case of Z2Z4-additive codes and through these bounds, they introduced two kinds of maximum distance separable codes (MDSS and MDSR), the minimum distance of which meets any of those bounds. Also, they completely determined these two types of codes. In this paper, we generalize these facts on Z2Z2s -additive codes and determine all possible parameters of the MDSS and MDSR codes over Z2 × Z2s .
