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

The ITU-R Requirements for IMT-Advanced Networks

The general requirements for IMT-Advanced surpass the performance levels of 3G networks. Enhanced support of basic services (i.e., conversational, interactive, streaming and background) is expected. Figure 1.3 shows the famous “Van diagram” which illustrates the relationship between the IMT-Advanced requirements and previous generations. The figure shows the serving area, with one axis being the sustainable data rate supported, while the other shows the mobility level at which that rate can be supported. For example, high mobility (>120 km/h) could only be supported up to ∼15Mbit/s in Enhanced IMT-2000. The expectation, per the van diagram, is that the technologies will enable the support of data rates that are at least an order of magnitude higher. For stationary to low mobility (<10 km/h) it is foreseen that data rates surpassing 1Gbit/s can be sustained, while >100 Mbit/s are projected for high mobility levels.

Figure 1.3 3GPP's “van diagram”, illustrating the data rates expected to be sustained in systems beyond enhanced IMT-2000 at the different mobility levels.

While the data rates are perhaps a key defining characteristics of IMT-Advanced networks, the requirements in general will enable such networks to exhibit other important features, including the following [6].

A high degree of commonality of functionality worldwide with ...