Question: what is tnl in lte?
Answer: The E-UTRAN is layered into a Radio Network Layer (RNL) and a Transport Network Layer (TNL). The E-UTRAN architecture, i.e. the E-UTRAN logical nodes and interfaces between them, are defined as part of the RNL. ... The overall LTE architecture and E-UTRAN architecture are described in 3GPP TS 36.401 [2].