LTE (Long Term Evolution) is the step toward the 4G, designed to increase the capacity and speed of mobile telephone networks. LTE is a set of enhancements to the Universal Mobile Telecommunications System. The LTE specification provides downlink peak rates of at least 100 Mbps, an uplink of at least 50 Mbit/s and RAN round-trip times of less than 10 milli sec. LTE supports scalable carrier bandwidths, from 20 MHz down to 1.4 MHz and supports both Frequency Division Duplexing and Time Division Duplexing.
In addition to enabling fixed to mobile migrations of Internet applications such as Voice over IP (VoIP), video streaming, music downloading, mobile TV and many others, LTE networks will also provide the capacity to support an explosion in demand for connectivity from a new generation of consumer devices tailored to those new mobile applications. 3GPP LTE radio technology is optimized to enhance networks by enabling significant new high capacity mobile broadband applications and services, whilst providing cost efficient ubiquitous mobile coverage.
LTE characteristics include:
• Peak LTE throughputs (high spectral efficiency)
• Increased Spectrum efficiency
• Ultra low Latency
- Less than 10 msec for round-trip delay (RTD) from UE to server
- Reduced call setup times (50-100ms)
- wired user experience
• Capacity per cell
- 200 users for 5 MHz, 400 users in larger spectrum allocations
• Flexible spectrum use maximizes flexibility
- 1.4, 3/3.2, 5, 10, 15, 20 MHz
- All frequencies of IMT-2000: 450 MHz to 2.6 GHz
Another key driver behind LTE is the reduction of the cost per byte, which is expected to decrease by a factor of six compared with HSPA today. LTE has multiple inputs and multiple output & collaborative MIMO. Alcatel Lucent, Nokia & Motorola are working to make further enhancements to make LTE successful in industry and to do further enhancements for 4G.
