Long Term Evolution (LTE)
Long term Evolution commonly known as LTE, is a standard for wireless communication of high speed data. Usually a mobile phone or USB data terminal is used as an access device. This technology is commonly marketed as 4G LTE. This technology is an evolution of the GSM/UMTS standards developed by 3 rd Generation Partnership Project (3GPP). LTE is an update to the UMTS technology rather than replacement that will enable it to provide significantly faster data rates for both uploading and downloading.
1. FDD LTE
2. TDD LTE
Difference between FDD and TDD LTE:
1. physical layer only
2. In FDD, every downlink sub-frame can associated with an uplink sub-frame, but in TDD, the no. of downlink and uplink subframes are different and such association is not possible.
3. Uplink coverage in TDD is generally worse than that of FDD-LTE due to the fact that the uplink transmission is not continuous. However, percentage of coverage for control and data channels is very similar to that of FDD-LTE.
4. The lower performance of TDD-LTE is due to the guard periods otherwise similar for non-delay sensitive traffic.
1.4, 3, 5, 10, 15, 20 MHz
6, 15, 25, 50, 75, 100 no. of resources
Why LTE ?
1. Smartphones exceed PCs
2. 91% of internet traffic is video
3. new business opportunities and increase market demands.
1. Quality over other wireless broadband technologies
2. High data rate, 299.6 Mbps for download and 75.4 Mbps for upload 4×4 MIMO and 20MHz spectrum.
3. Improved support for mobility with high speed data up to 350 km/h or even 500 km/h.
4. Lower latency for data transfer 5 ms for small IP packets and good technology for delay sensitive services like online gaming, voice and video traffic.
5. Lower handover and connection setup time.
6. Simple network architecture and easy to maintenance. It is composed of eNode-Bs in the network side.
7. Uses flexible spectrum bandwidth and scalable.
8. Inter operable with legacy standards GSM/CDMA.
9. It can support cell size from tens of meters (femto and pico cels) up to 100 Km radius macro cells.
1. CAPEX is high
2. Subscriber handset must be backward compatible.
1. OPEX can be lowered
2. Average revenue per user can be increased
3. Congestion can be lowered of 3G
4. Highest spending users can be captured
1. Market acceptance rate is very slow.
2. Device complexity is high.
3. Customer devices are not readily available.
1. GSM – 900/1800 MHz – FDD – Voice/Data (GPRS, EDGE)
2. WCDMA – 2100 MHz – FDD – Voice/Data(HSDPA/HSUPA, HSPA+)
3. CDMA- 800 MHz – FDD – Voice/data(1X, EVDO-rev0, fax)
4. WiMAX – 2300 MHz – TDD – data – (upgradable to LTE)
MOIC has drafted 700MHz and 2600MHz for LTE.
10M GSM project there is a pilot project of LTE in 700 MHz band. LTE can also be launched by upgrading the existing WiMAX BTS and addition of core equipment.