فهرست مقالات Dumtochukwu Oyeka مقاله 1 - Re-CAC: A Re-Engineered Call Admission Control for LTE Downlink Networks Using Stepwise Bandwidth Degradation Concept Vitalis Onyeke Udora Nwawelu Bonaventure Ekengwu Nnaemeka Asiegbu Benjamin Ezurike Dumtochukwu Oyeka Chukwudi Chukwudozie Chimdalu Okide Journal of Information Systems and Telecommunication (JIST) , شماره 2 , سال 14 , زمستان 2026