Usoro 3-layer ejiri na waya osisi ma ọ bụ eriri oghere, arụpụtara, nwalere na akara dịka ICEA S-121-733 si dị, ọkọlọtọ maka waya osisi na Messenger kwadoro Spacer Cable.Usoro 3-layer a nwere ọta onye ndu (oyi akwa #1), na-esote ihe mkpuchi 2-layer (layers #2 na #3).