LTE, LTE-Advanced and WiMAX: Towards IMT-Advanced Networks

Comparing Network Architectures

Conceptually, LTE and WiMAX have similar network architectures. Both have an all-IP flat architecture. Their network architectures can be divided into three logical parts: Mobile Station (MS)/User Equipment (UE), Access Service Network (ASN)/Core Network (CN) and Connectivity Service Network (CSN)/Protocol Data Network (PDN). Figure 15.4 and Figure 15.5 show the architectures of WiMAX and LTE respectively. The two networks differ in the functionalities performed by the first part, but not its architectural aspect. Hence, in the sequel, we shall highlight the differences between the two technologies in the last two parts.

ASN/AN (E-UTRAN) and the MME and the S-GW

The ASN in WiMAX consists of an ASN Gateway (ASN-GW) and a BS. The AN (EUTRAN) consists of a network of eNBs connected to each other. The BS is functionally similar to an eNB. The main task of the two is handling traffic to and from the MS. This involves packet transmission, HARQ, link adaptation, and QoS enforcement at the user plane. At the control plane, it involves radio resource management, connection management, handover triggering and DHCP proxy at the control plane.

Figure 15.4 WiMAX Network Architecture.

Figure 15.5 LTE Network Architecture.

The gateway function played by the ASN-GW ...