A comparative study of wimax and lte

Seminar Presentation

By

Hanie Salim

B080021ec

B.Tech Electronics and Communication Engineering ,NIT Calicut

A COMPARATIVE STUDY OF

WiMAX AND LTE

Importance

Mobile device and mobile networks are more

popular

More data required

People want to access internet from anywhere

Services like IPTV increase the need for high data

rates

As demand increased, current telecommunication

networks reach their limits

Solution-next generation networks like WiMAX and

LTE

19/09/20112 Hanie Salim (B080021EC),NIT calicut

19/09/20113

An overview of current telecommunication networks

Figure taken from www.dailywireless.orgHanie Salim (B080021EC),NIT calicut

19/09/20114

Worldwide interoperability for microwave access

IEEE 802.16d standard in 2004 – fixed wireless

internet service

Enhanced version IEEE 802.16e in 2006- Mobile

wireless access

Managed by WiMAX forum for interoperability of

different products

Supports transfer rates up to 46 Mbps in DL and

4 Mbps in UL

Hanie Salim (B080021EC),NIT calicut

19/09/20115

Supports scalable system bandwidth using time

division duplex(TDD)

So it can use 3.5,5,7,8.75 and 10 MHz as BW

Supports both TDD and FDD, prefers TDD

Maximum coverage is 50 km for fixed usage and 5km

for mobile usage

Support vehicular speed up to 120 kmph

2 major releases-WiMAX release 1.0 and release 2.0


19/09/20116

Features of WiMAX release 1.0

Access service network(ASN) & Connectivity service

network (CSN) mobility for mobility support

Paging & location management

IPV4 & IPV6 connectivity

Pre provisioned / static QoS

Optional radio resource management(RRM)

Network discovery/selection

Roaming (RADIUS only)

3gpp WLAN compatible internetworking


19/09/20117

WiMAX release 1.5 features:

Over the Air (OTA) activation & provisioning

Location based services (LBS)

Multicast broadcast services (MBS)

IMS(IP multimedia subsystem) integration

Dynamic QoS and policy and charging (PCC) compatible with 3GPP Release 7

Telephony VoIP with emergency call services and lawful interception

Full NAP sharing support

Diameter-based authentication, authorization and accounting (AAA)


19/09/20118

QoS for WiMAX:

Reservation based access

Use frames, each frame -2

sub frames

Duration 2 to 20 ms

Flexible ratio for DL/UL

WiMAX frame

Figure source: www.ecee.colarado.eduHanie Salim (B080021EC),NIT calicut

http://www.ecee.colarado.edu/

19/09/20119

Use OFDMA in DL & UL

OFDMA- multi-user ver. Of OFDM

Advantages of OFDMA –high spectral efficiency,

efficient implementation using FFT & low sensitivity

to time synchronization errors

scalable by flexibly adjusting FFT sizes & channel BW

with fixed symbol duration and subcarrier spacing

Sensitive to frequency sensitive errors


19/09/201110

3 power saving classes- different on-off time

• Class 1 - window increase exponentially from

minimum value to maximum

• Class 2 - fixed sleep window length

• Class 3 – MS know when to expect next packet

Security sub layer present under MAC layer

Extensible Authentication Protocol (EAP)

Privacy and Key Management protocol (PKM)

Encapsulation protocol


19/09/201111

Use MIMO technology to increase transfer rate

2 categories:

• Open loop MIMO- the transmitters do not need

explicit knowledge of the channels

• Closed loop MIMO- transmitter forms antenna

beams adaptively based on the channel side

information (Tx AA)

Logical entities of NRM

• Access service network(ASN)

• Connectivity service network (CSN)


19/09/201112

Network reference model for WiMAX

Figure source: www.eetimes.comHanie Salim (B080021EC),NIT calicut

19/09/201113

Long term evolution-developed by 3GPP in 2008

LTE standard is officially known as “document 3GPP

Release 8” Or 3.9G

Supports peak data rates of 100 Mbps in DL & 50

Mbps in UL, using 20 MHz spectrum

With MIMO it can reach up to 300Mbps

Variable spectrum 1.25, 2.5, 5, 10, 15 and 20 MHz

A cell radius 100 km with slight degradation after 30

km and reach over 200 users per cell (with 5 MHz

spectrum)


19/09/201114

Optimized for low speeds 0 - 15 km/h , supports

speeds up to 350 km/h.

RTT below 10 ms possible.

Use OFDMA in DL & SCFDMA in UL

OFDMA - power inefficient, because of high peak-to-

average-power ratio (PAPR)

Since DL start from BS no problem, But UL start from

MS ,hence SCFDMA (low PAPR)


19/09/201115

Architecture:

Two-node architecture - only two nodes are involved between user equipment & core network.

The base station (eNodeB) & the serving gateway (S-GW) in the user plane and the mobility management entity (MME) in the control plane.

LTE architecture is composed of Core Network (CN) and Access Network (AN), where CN corresponds to the Evolved Packet Core (EPC) and AN refers to E-UTRAN.

The CN and AN together correspond to Evolved Packet System (EPS)


19/09/201116

LTE overall architecture

Figure source: www.wiki.hsc.comHanie Salim (B080021EC),NIT calicut

19/09/201117

EPS connects user to Packet data network(PDN)

Functions of MME- CN node signalling for mobility

between 3GPP access networks, S-GW selection,

roaming, authentication, bearer management functions

and NAS (Non Access Stratum) signalling

S-GW terminates the interface towards E-UTRAN.

For each user in EPS, at given time, a single S-GW is

responsible for transferring user IP packets, lawful

interception & mobility anchor for inter eNodeB

handover and for inter-3GPP mobility.


19/09/201118

Power-saving mechanisms: turn off the transmitter

when idle.

• It uses Discontinued Reception (DRX) & Discontinued

Transmission (DTX).

Security mechanisms : similar to WiMAX

• use security keys between transmitter &receiver to

ensure a secure connection .

• LTE also offers a key derivation protocol, which resets

the connection if corrupt keys are detected.


19/09/201119

QoS:

Reservation based access

Each frame is 10 ms long

The 0th and the 5th sub frames are always reserved for DL

Other frames can be DL, UL or a switch point

This switch point method makes the transmission more dynamic in allocating resources

Figure source: IT pro 2010


19/09/201120

Figure source: IT pro 2010

4 x 4 MIMO configuration


Comparison

19/09/201121

Released in 2005

46 Mbps in DL and up to 4 Mbps in UL

Support BW 3.5 MHz to 10 MHz

Range up to 50 km, optimized for 1.5 to 5 km

Support speed up to 120 km/h

Released in 2009

300 Mbps in Dl and 75 Mbps in the UL

Support bigger range of BW 1.4 MHz to 20 MHz

Bigger range up to 100 km, optimized for 30 km

Support speed up to 350 km/h


Comparison

19/09/201122

Use OFDMA in both DL

and UL

Frame is separated into DL

and UL sub-frame allocate

resources to different users

Duplex mode only TDD is

commercially available

Backward compatibility to

3G/2G not present

Use SCFDMA in UL and

OFDMA in DL

From 10 sub-frames only 2

are reserved for DL, more

dynamic, so they reach

smaller delays.

Both FDD & TDD

Inter radio technology

handover possible


4G Requirements

19/09/201123

Both WiMAX & LTE do not meet all 4G requirements

4G specifications, also known as IMT-Advanced:

Max. data rates up to 100 Mbps for mobile access

Max. data rates up to 1 Gbps for fixed access

Flat all-IP architecture

High mobility up to 500 km/h.

scalable channel bandwidth

Solution : LTE’s successor, LTE-Advanced and

WiMAX’ next release WiMAX 2.0.


19/09/201124

Long term evolution advanced, officially known as

3GPP Release 10

Recognized as IMT A in October 2010

Commercial availability expected from 2014

Peak data rate of 1 Gbps in DL (low mobility) & up to

500Mbps in UL

BW extended up to 100 MHz using channel

aggregation

MIMO to be used in UL also

Support 8x8 MIMO


WiMAX 2.0

19/09/201125

WiMAX release 2.0 recognized as IMT in October

2010

IEEE 802.16m standardized in April 2011

Backward compatibility with all 802.16 standards

DL rate >300 Mbps, 4x4 @ 20MHZ

UL rate >135 Mbps, 2x4 @ 20MHz

Support channel BW of 5,10,20,40 MHz

Mobility up to 350 km/h


19/09/201126

Technical comparison of LTE and WiMAX

Figure source: www.kuncoro.co.ukHanie Salim (B080021EC),NIT calicut

References

19/09/201127

[1] M.Chang, Z. Abichar, and Chau –Yun Hsu, “Wimax vs. lte: Who will lead the broadband mobile internet?,” IT Professional, vol. 12, no. 3, pp. 26 - 32, 2010.

[2] Ozgur Oyman , Jeffrey Foerster ,Yong-jooTcha and Seong-Choon Lee , “Toward Enhanced Mobile Video Services over WiMAX and LTE,” IEEE Communications Magazine ,vol. 48,no.8,pp. 68 – 76,2010

[3] J. Conti, “Lte vs wimax: the battle continues,” Engineering Technology, 2010.

[4] Leo Yi ,Kai Miao ,Adrian Liu,” A comparative study of WiMAX and LTE as the next generation mobile enterprise network,” Advanced Communication Technology(ICACT),pp. 654-658,feb 2011.


A comparative study of wimax and lte

Technology

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