Some underlying networks such as Low-Power Wide-Area Networks (LPWAN) have limited communication bandwidth and strict requirements on maximum message size. These requirements may pose a challenge for data or resource exchange between two service layer (SL) entities, for example, because resource representations to be exchanged may have too large a size to be supported by the underlying networks. In some cases, traditional data compression algorithms can be used to alleviate this problem to some degree, but it is recognized herein that there are associated computation costs due to compression and decompression that may not be affordable for constrained IoT devices. Various embodiments described herein address this problem, among others by defining a Resource Representation Common Part (RRCP) and storing it at the service layer. In some cases, the RRCP is not transmitted between SL entities, thereby reducing SL message sizes to cater to the constraints of underlying networks.