Since heterogeneous communicating agents can choose not to communicate, and in some cases can also choose to be homogeneous or at least to minimize their heterogeneity, most of the issues discussed in the previous two scenarios apply in this one as well. But the ability to communicate raises another whole set of issues for which techniques exist. Two of the most studied issues are communication protocols and theories of commitment. The issue of benevolence vs. competitiveness, already discussed in the previous MAS scenario, becomes more complicated in this context. These issues and others along with some of the existing techniques to deal with them and further learning opportunities are described below and summarized in Table 7.
Table 7: The issues, techniques, and learning opportunities for communicating multiagent systems as reflected in the literature.