Both radio and core network evolution
all-IP packet-switched architecture
standardised by 3GPP
lower CAPEX ans OPEX involved
Evolved from Universal Mobile Telecommunication System (UMTS), which in turn evolved from the Global
Also aligned with 4G (fourth-generation mobile)
LTE is backward compatible with GSM/EDGE/UMTS/CDMA/WCDMA systems on existing 2G and 3G spectrum , even hand-over and roaming to existing mobile networks.
Motivation for evolution
Wireless/cellular technology standards are constantly evolving for better efficiency and performance.
LTE evolved as a result of rapid increase of mobile data usage. Applications such as voice over IP (VOIP), streaming multimedia, videoconferencing , cellular modemetc.
It provides packet-switched traffic with seamless mobility and higher qos than predecessors.
Also high data rate, throughput, low latency and packet optimized radioaccess technology on flexible bandwidth deployments.
Peak Data Rate
uplink – 75Mbps(20MHz bandwidth)
downlink – 150 Mbps(UE Category 4, 2×2 MIMO, 20MHz bandwidth) , 300 Mbps(UE category 5, 4×4 MIMO, 20MHz bandwidth)
carrier bandwidth can range from 1.4 MHz up to 20 MHz. Ultimately bandwidth used by carrier depends on frequency band and the amount of spectrum available with a network operator
Mobility 350 km/h
Multiple Access Schemes
uplink: SC-FDMA (Single Carrier Frequency Division Multiple Access) 50Mbps+ (20MHz spectrum)
downlink: OFDM (Orthogonal Frequency Division Multiple Access) 100Mbps+ (20MHz spectrum)
Multi-Antenna Technology , Multi-user collaborative MIMO for Uplink and TxAA, spatial multiplexing, CDD ,max 4×4 array for downlink
Coverage 5 – 100km with slight degradation after 30km
LTE architecture supports hard QoS and guaranteed bit rate (GBR) for radio bearers.
All interfaces between network nodes are IP based
Duplexing – Time Division Duplex (TDD) , Frequency Division Duplex (FDD) and half duples FD
(MIMO) Multiple Input Multiple Output transmissions – LTE devices have to support this. Allows the base station to transmit several data streams over the same carrier simultaneously.
Modulation Schemes QPSK, 16QAM, 64QAM(optional)
Primarily composed of
- User Equipment (UE)
- Evolved UMTS Terrestrial Radio Access Network (E-UTRAN).
- Evolved Packet Core (EPC).
LTE devices capable of CAT6 speeds (Category 6 )
Increased peak data rate, downlink 3 Gbps, Uplink 1.5 Gbps ( 1 Gbps = 1000 Mbps)
spectral efficiency from 16bps/Hz in R8 to 30 bps/Hz in R10
Carrier Aggregation (CA)
enhanced use of multi-antenna techniques
support for Relay Nodes (RN)
3GPP on LTE – https://www.3gpp.org/technologies/keywords-acronyms/98-lte
ETSI on LTE; Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception – https://www.etsi.org/deliver/etsi_ts/136100_136199/136101/10.03.00_60/ts_136101v100300p.pdf