Long Term Evolution (LTE) Overview
LTE (Long Term Evolution) is a form of broadband wireless access standardized by the 3GPP, which is a global collaboration of telecommunication associations that work on broadband wireless internet standards under the authority of the ITU. Like WiMAX, which is a competitive technology defined by the IEEE, LTE can serve both fixed and mobile (moving) subscribers. When they serve mobile subscribers, LTE and WiMAX are considered 4G wireless data technologies.
LTE is defined in Release 8 of the 3GPP standards (finalized January 2009), and work on the LTE standard began in 2004. LTE-Advanced is a higher speed version of LTE and will be part of 3GPP’s Release 10. These new WiMAX and LTE technologies will provide pressure on Telcos and MSOs to deploy ever higher DSL, DOCSIS, and FTTH data rates in the markets served by these high bandwidth wireless data technologies.
Since data traffic dominates voice traffic today (on both wireless and wireline networks), all traffic on LTE is transported as data packets. A primary goal for LTE is delivery of high data throughput, and aggregate data rates well over 100 Mbps are possible with LTE systems (1 Gbps with LTE-Advanced). Coupled with LTE’s high data throughput is its low latency, which is generally less than 10 ms.
The high bandwidth and low latency of LTE networks make it well suited to modern Internet applications requiring high throughput and interactivity (for example video over Skype). Initially, LTE will be all about broadband data, and the first expected subscriber products are USB dongles (an early version is shown in the video at the end of this article). Ultimately, LTE USB adaptors should look like this Motorola one shown below, and eventually LTE will be integrated into NetBooks and Laptops.
Highly flexible, LTE can serve both fixed and mobile subscribers. When it serves fixed subscribers, LTE competes with DSL, HFC DOCSIS, and FTTH, though it is never likely to be able to deliver the same levels of dedicated bandwidth owing to its shared architecture. When it serves mobile subscribers, LTE displaces the various 3G technologies like EDGE, UMTS, and CDMA2000. LTE systems may support one of two different modes for mobility: optimized, which supports users to about 10 miles/hr (walking and jogging I suppose), and high-performance, which supports users moving up to about 75 miles/hour (surfing the web between toll booths on the Garden State Parkway, as a passenger of course).
LTE provides scalable spectrum options with 1.4, 3, 5, 10, 15, and 20 Mhz assignments possible. Maximum peak data rates are achieved with the highest spectrum allocations, of course. With 20 Mhz of spectrum, the maximum downstream peak data rate is 326 Mbps using 4×4 MIMO (4 transmit and 4 receive antennas, Multiple Input Multiple Output). 86 Mbps is the maximum uplink peak data rate using 64 QAM on 20 Mhz.
ABI Research is predicting that wireless carriers will spend $8.6B on LTE by 2013, and over 32 million subscribers will be using the services. Some of the world’s largest wireless carriers, including AT&T, China Mobile, Verizon Wireless, and Vodaphone, are all planning to deploy LTE networks. However, AT&T is not in any rush as they believe HSPA release 7 will take them to 20 Mbps sometime in 2009.
The video below shows some demonstrations of Long Term Evolution technology at Mobile World Congress 2009 in Barcelona, Spain.
