In this chapter we shall see how different generations have evolved and also have a look at how LTE as a whole has evolved.
Comparison of various different wireless technology:
what are the benefits of LTE?
1. It provides high data rates.
2. It will reduce latency for the applications
3. It will improve throughputs for applications.
4. It is having flexible radio frequency. It can be deployed in multiple bandwidth configurations like 1.4, 3, 5, 10, 15, 20 MHz.
5. MIMO – Multiple Input Multiple Output
Evolution in LTE
Date: Q2 2002
IMS and HSDPA
Date: Q1 2005
Integrated operation with wireless LAN and adds HSUPA, MBMS, enhancements to IMS
Date: Q4 2007
Decreasing latency, improving QOS, and real-time application performance, HSPA+.
Date: Q4 2008 [LTE]
First LTE release, all-IP network(EPC). New OFDMA and MIMO based radio interface, not backward compatible with UMTS, dual-cell HSDPA
Date: Q1 2009 [LTE]
dual-cell HSDPA with MIMO
Date: Q1 2011 [LTE Advanced]
LTE Advanced for IMT-Advanced,
enhanced downlink MIMO,
backward compatible with LTE Rel-8
Date: Q1 2013 [LTE Advanced]
Enhanced carrier aggregation,
further enchanced ICIC,
coordinated multi-point transmission/reception,
Date: Q3 2014 [LTE Advanced]
Downlink MIMO enhancements/3D MIMO,
low cost MTC,
new carrier type,
small cell enhancements,
LTE device-to-device communication
LTE Advanced PRO:
3GPP Release 13,14
Before we dive into the LTE architecture, let us understand basic of RAN.
For any architecture, there will be 3 parts:
- UE : User equipment
- RAN: Radio Access Network
- Core Network.
Here UE will communicate with RAN. Then RAN to Core Network,
RAN stands for Radio Access Network.
It is used to connect individual devices to other parts of the network.
It will reside between user equipment and provides connection to core network.
When a UE is wirelessly connected to core network, RAN transmits signal to vvarious wireless endpoints.
Evolution of RAN
1. For 2G and 2.5G the type of RAN is GERAN – GPRS Edge Radio Access Network. Here mobile is called as Mobile Station.
2. For 3G, mobile is called as UE. Type of RAN used is UTRAN – Universal Terrestrial Radio Access Network.
3. For 4G, mobile is called as UE. Type of RAN used is EUTRAN – Evolved UTRAN or eNB.
4. For 5G, mobile is called as UE. Type of RAN used is NR [New Radio].
Types of RAN
GRAN: Generic Radio Access Network: It is used to manage radio links for Circuit and packet switched core networks.
GERAN: GSM Edge Radio Access Network: It is used to support real time packet data.
UTRAN: UMTS Terrestrial Radio Access Network: It supports both circuit switched and packet switched.
E-UTRAN: Evolved Universal Terrestrial Radio Access Network: It supports only packet switched services. It provides high data rate and low latency.
It is the interface between Mobile and RAN. Sometimes Air Interface is also call as radio interface.
AIR interface is also called as Radio Interface.
It involves both physical and data link layer of OSI model
It is used to provide point to point communication between base station and mobile station.
Some of the AIR interfaces are:
1. FDMA: Frequency Division Multiple Access
2. TDMA: Time Division Multiple Access
3. CDMA: Code Division Multiple Access
4. OFDMA: Orthogonal Frequency Division Multiple Access
Signalling in LTE means, the messages like RRCConnectionRequest etc.
User Data means the data packets like YouTube etc.