Monday, April 2, 2012

Long Term Evolution, LTE


The latest technology in wireless communication is Long Term Evolution or shortly called as LTE. Its a 3GPP project, that is third generation partnership project between the UMTS and other GSM operators. The most important thing about LTE is, it is downward compatible with GSM. So the operators who have already deployed GSM can now easily upgrade their service to LTE with very less cost. LTE is a 4G (4th generation ) technology. Currently in Malaysia, there are 9 company which have LTE licenses. The 9 companies are Maxis, DiGi, Celcom, U Mobile, P1, AMAX, YTL, REDtone  and Puncak Semangat Sdn. Bhd.

Speed Comparison for wireless communication


LTE can reach 100Mbps downlink speed and upto 75Mbps uplink speed. It used OFDMA or Orthogonal Frequency Division Multiple Access for downlink and SC-FDMA or Single Carrier Frequency Division Multiple Access for Uplink. The base station in LTE is called as eNode B and the mobile station is called as UE or User Equipment. Downlink is from the eNode B to UE and Uplink is vice versa. LTE supports multiple bandwidths right from 1.4MHz to 20MHz, it is this flexibility of LTE that is attracting the operators from all over the world. The main reason for this is there is a tight lock in the spectrum now because of so many wireless applications.


Benefit of LTE


LTE can use the same 3G tower, that means using LTE technology we don’t need to waste money upgrading the towers for 4G.
LTE offers much higher data throughput and lower latency than 3G. it offers a reduced latency of 10 to 20 ms, which is a substantial improvement over the latency of 40 to 60 ms offered by 3G. lower latency promises a much better  customer experience with real-time  applications such as online gaming  and video conferencing.
LTE will have two to four times the spectrum efficiency of the current 3G technology. Thus, total cost of ownership for LTE is expected to be a fourth that of 3G on a per MB basis.
LTE have with superior indoor penetration and  likely to deliver a far more consistent user experience than the current 3G technology
LTE and 3G Technology Performance comparison 


LTE as an alternative to 3G and WIMAX


Although LTE offers many benefits, there are several challenges that need to be overcome before LTE can become a credible alternative to 3G and WiMAX. Table below summarize the advantage and challenge of LTE

Application of LTE

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,  the first expected subscriber products are smartphones. However, laptops and netbook can connect to LTE through USB dongles like the one showing below



LTE Equipment

 LTE enodeB equipment


Configuration of eNodeB
The base station in LTE is called as eNode B . An eNodeB is composed of three remote radio heads (RRHs) and one baseband unit (BBU). An RRH transmits and receives wireless signals. It converts the digital baseband signals from BBU into radio frequency (RF) signals and power-amplifies them to transmit to UE. The BBU is responsible for digital baseband signal processing. The digital baseband signals received from the RRH(s) are demodulated and IP packets are transmitted to the core network.

Table below shown the specification of eNodeB