Basics of LTE (Long Term Evolution)
February 11, 2010
LTE is the new standard of the 3GPP for the next generation of mobile telecommunications; It is the evolution of GSM/WCDMA. The key features of LTE are:
- OFDM in Download link, DFTS-OFDM (“Single-Carrier FDMA”) in Uplink.
- IP flat architecture with the SAE architecture.
- Low latency (10ms for User-plane, 100ms for Control-plane).
- MIMO antennas.
- Building on current investments in the GSM/UMTS.
- Flexible carrier bandwidths: 1.4MHz -20MHz. (1.4, 3, 5, 10, 15 and 20 MHz).
- FDD – TDD.
- LTE can do handover and roaming to existing networks.
- DL-peak: max 326,4 Mbit/s with 4×4 antennas, 172,8 Mbit/s with 2×2 antennas.
- UL-peak: Max 86,4 Mbit/s.
- Up to 200 users at the same time in a 5 MHz cell.
- Average optimum cell distance 5km. Cell of 30km still works good, with a little degradation. Cell of 100km is still acceptable.
- Increased spectrum flexibility, It supports spectrum slices of 1.5 MHz (up to 20 MHz).