LTE is sometimes called a 4G standard, which is actually not correct as it merely satisfies the 3GPP requirements for a 3G standard. In reality, international standardization bodies, such as 3GPP and ITU, have already set high-level requirements for 4G technologies, and those will be met by LTE-Advanced.
The goal for LTE-Advanced is to provide "peak data rates equal to or greater than those of wired networks, e.g., FTTH or VDSL2. It will also maintain an equivalent quality of service compared to wired networks and compatibility with current 3GPP systems, but with a reduced total cost of ownership."
The target peak rates for downlink and uplink speeds are 1 Gbps and 500 Mbps, respectively. These are obviously significant and challenging. However, peak rates are deceiving in real networks as it is rare that individual users can enjoy those speeds, and the reality is often one-tenth of the peak. That is why for operators and end-users the more important figures for performance are rates at the cell edge, average user throughput and spectrum efficiency.
In that regard, the following performance targets have been set in comparing LTE-Advanced to LTE:
- Cell edge user throughput two times higher than that in LTE
- Average user throughput three times higher than that in LTE
- Capacity (spectrum efficiency) three times higher than that in LTE.
Should these be met, then it will ensure that not only users near the antenna benefit from the technology, but also the average user, located at different distances from the base station.
To meet these goals, the industry must develop many new innovative technologies and successfully integrate those to form cost-competitive solutions. As the LTE-Advanced standardization is still in its early stages, candidate technologies remain to be selected, but include relay nodes, UE dual TX antenna solutions for SU-MIMO and diversity MIMO, scalable system bandwidth exceeding 20 MHz, up to 100MHz, flexible spectrum usage, cognitive radio, interference management and suppression, asymmetric bandwidth assignment for FDD, hybrid OFDMA and SC-FDMA in uplink, and uplink/downlink inter eNode-B coordinated MIMO.