LONG TERM EVOLUTION (LTE) ECE 525E-MOBILE COMMUNICATION Thursday, - - PowerPoint PPT Presentation

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LONG TERM EVOLUTION (LTE) ECE 525E-MOBILE COMMUNICATION Thursday, - - PowerPoint PPT Presentation

Apr 19, 2023 580 likes •824 views

LONG TERM EVOLUTION (LTE) ECE 525E-MOBILE COMMUNICATION Thursday, 25 April 2019 1 WHAT IS IS LTE? 1. LTE stands for Long Term Evolution and it was 4 th Generation started as a project in 2004 by the Third Generation LTE Partnership Project

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LONG TERM EVOLUTION (LTE)

ECE 525E-MOBILE COMMUNICATION Thursday, 25 April 2019

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WHAT IS IS LTE?

  • 1. LTE stands for Long Term Evolution and it was

started as a project in 2004 by the Third Generation Partnership Project (3GPP).

  • 2. LTE evolved from an earlier 3GPP system known as

the Universal Mobile Telecommunication System (UMTS),

  • 3. UMTS, on the other hand, had evolved from the

Global System for Mobile Communications (GSM).

  • 4. LTE is an all IP based network, supporting both IPv4

and IPv6

1st Generation AMPS, ETACS 2nd Generation GSM, DAMPS 3rd Generation CDMA2000, WCDMA, UMTS 4th Generation LTE

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MOTIVATION FOR LTE

  • 1. By 2004, there was a rapid increase of mobile data

usage and emergence of new applications such as MMOG (Multimedia Online Gaming), mobile TV, Web streaming contents, etc which required high speeds. 2. Long-Term Evolution (LTE) was proposed as a set of standards to support movement from 3rd to 4th generation mobile communication.

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GOALS OF LTE

The Goals of LTE were to provide:

  • 1. Higher data rates (300Mbps peak downlink and 75 Mbps peak

uplink)

  • 2. Low latency (Time required to connect to the network or enter

power saving states). This is necessary to support gaming and interactive data transfer

  • 3. Packet optimized radio access technology
  • 4. Seamless mobility; and
  • 5. Higher Quality of Service (QoS).

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MIL ILESTONES IN IN THE DEVELOPMENT OF LTE

2000 - UMTS/WCDMA 2002 - High Speed Downlink Packet Access (HSDPA) 2005 - High Speed Uplink Packet Access (HSUPA) 2007 - MIMO, IP Multimedia Subsystem(IMS) 2004 - Work started on LTE specification 2008 – Specifications finalized and approved with UMTS Release 8 2010 - First deployment

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LTE SPECIFICATIONS

PARAMETER DETAILS Data type All packet switched data (voice and data). No circuit switched elements Peak downlink speed 100 (SISO), 172 (2x2 MIMO), 326 (4x4 MIMO) Peak uplink speeds (Mbps) 50 (QPSK), 57 (16QAM), 86 (64QAM) Channel bandwidths (MHz) 1.4, 3, 5, 10, 15, 20 Duplex schemes FDD and TDD Mobility 0 - 15 km/h (optimised), 15 - 120 km/h (high performance) Latency Idle to active less than 100ms Small packets ~10 ms Spectral efficiency Downlink: 3 - 4 times Rel 6 High Speed Downlink Packet Access (HSDPA) Uplink: 2 -3 x Rel 6 High Speed Uplink Packet Access(HSUPA ) Access schemes Orthogonal Frequency Division Multiple Access (OFDMA) -Downlink Frequency Division Multiple Access (SC-FDMA) - Uplink Modulation types supported QPSK, 16QAM, 64QAM (Uplink and downlink)

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COMPARISON OF PERFORMANCE 3RD

RD & 4TH TH GENERATION

WCDMA (UMTS) HSPA HSDPA / HSUPA HSPA+ LTE Max downlink speed 384 kbps 14 Mbps 28 Mbps 100Mbps Max uplink speed 128 kbps 5.7 Mbps 11 Mbps 50 Mbps Latency round trip time approx 150 ms 100 ms 50ms (max) ~10 ms 3GPP releases Rel 99/4 Rel 5 / 6 Rel 7 Rel 8 Approx years of initial roll out 2003 / 4 2005 / 6 HSDPA 2007 / 8 HSUPA 2008 / 9 2009 / 10 Access methodology CDMA CDMA CDMA OFDMA / SC- FDMA

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LTE HIG IGH LEVEL ARCHITECTURE

The high-level network architecture of LTE is comprised of following three main components:

  • 1. The User Equipment (UE)
  • 2. The Evolved UMTS Terrestrial Radio Access Network (E-UTRAN)
  • 3. The Evolved Packet Core (EPC)

Packet Switched Packet Switched

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E-UTRAN OPERATING FREQUENCY BANDS

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USER EQUIPMENT

  • 1. The

internal architecture

  • f

the user equipment for LTE is the same as the one used by UMTS and GSM.

  • 2. The mobile equipment comprised of the

following modules:

a) Mobile Termination (MT) : This handles all the communication functions. b) Terminal Equipment (TE) : This terminates the data streams. c) Universal Subscriber Identity Module (USIM): Stores user-specific data including user's phone number, home network identity and security keys etc. Similar to 2G and 3G.

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ARCHITECTURE OF E-UTRAN

The Evolved UTRAN (E-UTRAN) handles the radio communications between the User Equipment (UE) and the Evolved Packet Core (EPC).

Evolved Node B Evolved Packet Core

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EVOLVED BASE STATION (eNodeB)

  • 1. The Evolved base stations (eNodeB or eNB) controls the mobiles in one or more cells.
  • 2. The base station that is communicating with a mobile is known as its serving eNB.

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Serving eNB

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HOME eNB

1. Home eNB (HeNB) is a base station that has been purchased by a user to provide femtocell coverage within the home or enterprise. 2. A home eNB belongs to a closed subscriber group (CSG) and can only be accessed by mobiles with a USIM that also belongs to the closed subscriber group. 3. The coverage area of a HeNB is called a Femto cell. 4. Home eNB therefore resembles a CENTREX in the fixed/wired telephone networks.

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LTE FEMTO CELLS

  • 1. LTE Femto cells are low power cellular

base stations that employ licenced spectrum.

  • 2. They are deployed in residential,

enterprise, metropolitan hot spots.

  • 3. They provide excellent user experience

through enhanced coverage, performance and location-based services.

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EVOLVED PACKET CORE (E (EPC)

The Evolved Packet Core (EPC) consists of the following:

  • 1. Mobility Management Entity (MME)
  • 2. Home Subscriber Server (HSS)
  • 3. Packet Data Network Gateway (P-

GW):

  • 4. Serving Gateway (S-GW): Acts as a

router by forwards data between the base station and the P-GW.

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Public Data Networks

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FUNCTIONS OF MOBILIT ITY MANAGEMENT ENTITY (M (MME)

  • Mobility Management Entity

(MME) Controls the high-level

  • peration of the mobile by

interpreting signalling messages by using information from the Home Subscriber Server (HSS).

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HOME SUBSCRIBER SERVER (H (HSS)

  • 1. Home Subscriber Server (HSS) is a

central database that contains information about all the network

  • perator's subscribers.
  • 2. It is an evolved version of the Home

Location Register (HLR) in GSM and UMTS networks.

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PACKET DATA NETWORK GATEWAY (P (P-GW)

  • 1. Packet Data Network Gateway (P-

GW) communicates with the

  • utside world using SGi interface.
  • 2. Each packet data network is

identified by an Access Point Name (APN). 3. P-GW has the same role as the GPRS support node (GGSN) in UMTS and GSM.

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SERVING GATEWAY (S (S-GW)

Serving Gateway (S-GW): Acts as a router by forwards data between the base station and the P-GW.

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LTE NETWORK ARCHIT ITECTURE - SUMMARY

Policy and Charging Rules Function (PCRF)

  • Network-wide control of flows: detection,

gating, QoS and flow-based charging

  • authorizes network-wide use of QoS

resources.

Mobility Management Element (MME)

  • Authentication
  • Tracking area list management
  • Idle mode UE reachability
  • S-GW/PDN-GW selection
  • Inter core network node signaling for mobility

between 2G/3G and LTE

  • Bearer management functions .

eNodeB:

  • Manages all radio access functions
  • Radio admission control
  • Scheduling of UL and DL data
  • Scheduling and transmission of paging and

system broadcast

  • IP header compression (PDCP)
  • Outer-ARQ (RLC)

Serving Gateway (S-GW)

  • Serving a large number of eNodeBs,
  • focus on scalability and security

Packet Data Network (PDN) Gateway

  • IP anchor point for bearers
  • UE IP address allocation
  • Per-user based packet filtering
  • Connectivity to packet data network
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SUMMARY OF FUNCT CTIONS OF E-UTRAN & EPC

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Radio Resource Management (RRM) strategies and algorithms for controlling parameters such as transmit power, user allocation, beamforming, data rates, handover criteria, modulation scheme, error coding scheme, etc

RB Control Resource Block (RB) allocation (e.g. Universal Frequency Reuse technique). Non-Access Stratum (NAS) A set of protocols used to convey non-radio signalling between the User Equipment (UE) and the Mobility Management Entity (MME)

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LTE NETWORK AREA

An LTE network area is divided into three different types of geographical areas, i.e

  • 1. MME Pool Area: Area where a UE can move without a

change of serving MME.

  • 2. S-GW Service Area: An area served a serving gateway

(S-GW). The UE can move in this area without a change

  • f S-GW.
  • 3. Tracking Area: Smaller areas used to track the

locations of mobiles that are on standby mode. Same as a Location Area(LA) in GSM.

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LTE RADIO IO PROTOCOL ARCHITECTURE

The radio protocol architecture for LTE is made of two main parts, i.e 1. control plane; and 2. user plane.

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CONTROL PLANE The radio resource control (RRC) protocol writes the signalling messages that are exchanged between the base station (eNodeBs) and the UE. USER PLANE The application creates data packets that are processed by protocols such as TCP, UDP and IP