222902960-694-cellular-network

8/12/2019 222902960-694-Cellular-Network

1/64

Mobile Handset Cellular

Network


2/64

Cellular Network Basics

There are many types of cellular services; before delvinginto details, focus on basics helps navigate the !acronymsoup"#

Cellular network$telephony is a radio%based technology;radio waves are electromagnetic waves that antennaspropagate

Most signals are in the &'( MH), *(( MH), +&(( MH), and+*(( MH) freuency bands

Cell phones operate in this frequency

range (note the logarithmicscale)


3/64

Cellular Network

Base stations transmit to and receive frommobiles at the assigned spectrum Multiple base stations use the same spectrum spectral

reuse#

The service area of each base station is called acell

-ach mobile terminal is typically served by the.closest/ base stations Hando0 when terminals move


4/64

Cellular Network1enerations

2t is useful to think of cellularNetwork$telephony in terms of generations3

(13 Briefcase%si)e mobile radio telephones

+13 Analogcellular telephony 413 Digitalcellular telephony

513 High-speeddigital cellular telephonyincluding video telephony#

613 27%based !anytime, anywhere" voice, data,and multimedia telephony at fasterdata ratesthan 51to be deployed in 4(+484(+'#


5/64

-volution of CellularNetworks

+1 41 51 6149'1


6/64

The Multiple :ccess 7roblem

The base stations need to servemany mobile terminals at the sametime both downlink and uplink#

:ll mobiles in the cell need totransmit to the base station

2nterference among di0erent sendersand receivers

o we need multiple access scheme


7/64

Multiple :ccess chemes


8/64

cient guard band is reuired to prevent ad?acent channelinterference

@sually, mobile terminals will have one downlink freuencyband and one uplink freuency band

=i0erent cellular network protocols use di0erent freuencies


9/64

Time =ivision Multiple:ccess

Time is divided into slots and only one mobile terminaltransmits during each slot ike during the lecture, only one can talk, but others may take

the oor in turn

-ach user is given a speciDc slot9 No competition in cellularnetwork

@nlike Carrier ensing Multiple :ccess CM:# in Ai


10/64

Code =ivision Multiple:ccess

@se of orthogonal codes to separate di0erenttransmissions

-ach symbol of bit is transmitted as a largernumber of bits using the user speciDc code 8preading Bandwidth occupied by the signal is much larger than

the information transmission rate

But all users use the same freuency band togetherErthogonal amongusers


11/64

411M#


12/64

1M

:bbreviation for 1lobal ystem forMobile Communications

Concurrent development in @: and-urope in the +*&(/s

The -uropean system was called1M and deployed in the early+**(/s


13/64

1M ervices

Foice, 59+ kH) hort Message ervice M#

+*&' 1M standard that allows messages of at most +G(chars9 incl9 spaces# to be sent between handsets and otherstations

Ever 496 billionpeople use it; multi%billion industry 1eneral 7acket Iadio ervice 17I#

1M upgrade that provides 27%based packet datatransmission up to ++6 kbps

@sers can !simultaneously" make calls and send data 17I provides !always on" 2nternet access and the

Multimedia Messaging ervice MM# whereby users cansend rich teJt, audio, video messages to each other

7erformance degrades as number of users increase 17I is an eJample of 49'1 telephony 8 41 service similar

to 51


14/64

1M Channels

7hysical Channel3 -ach timeslot on a carrier is referredto as a physical channel

ogical Channel3 Fariety of information is transmittedbetween the M and BT9 =i0erent types of logicalchannels3

Tra>c channel

Control Channel

Downlink

Uplink

Channels


15/64

1M


16/64

1M :rchitecture


17/64

Mobile tation M#

M is the user/s handset and has twoparts

Mobile -uipment Iadio euipment @ser interface 7rocessing capability and memory reuired

for various tasks Call signalling

-ncryption M

-uipment 2M-2 number

ubscriber 2dentity Module


18/64

ubscriber 2dentity Module

: small smart card

-ncryption codes needed to identify thesubscriber

ubscriber 2M2 number ubscriber/s own information telephone

directory#

Third party applications banking etc9#

Can also be used in other systems besides 1M,e9g9, some A:N access points accept 2M baseduser authentication


19/64

Base tation ubsystem

Base Transceiver ystem BT# Controls several transmitters -ach transmitter has & time slots, some used for

signaling, on a speciDc freuency

Base tation Controller BC# Controls the channel time slot# allocationimplemented by the BTes

Manages the handovers within B area Knows which mobile stations are within the cell and

informs the MC$FI about this

Transcoding Iate and :daptation @nit TI:@# 7erforms coding between the G6kbps 7CM coding

used in the backbone network and the +5 kbpscoding used for the Mobile tation M#


20/64

Network and witchingubsystem

The backbone of a 1M network is a telephonenetwork with additional cellular network capabilities

Mobile witching Center MC# :n typical telephony eJchange 2=N eJchange# which

supports mobile communications

Fisitor ocation Iegister FI# : database, part of the MC Contains the location of the active Mobile tations

1ateway Mobile witching Center 1MC# inks the system to 7TN and other operators

Home ocation Iegister HI# Contain subscriber information, including authenticationinformation in :uthentication Center :uC#

-uipment 2dentity Iegister -2I# 2nternational Mobile tation -uipment 2dentity 2M-2#

codes for e9g9, blacklisting stolen phones


21/64

Home ocation Iegister

Ene database per operator Contains all the permanent subscriber information

M2=N Mobile ubscriber 2=N number# is thetelephone number of the subscriber

2nternational Mobile ubscriber 2dentity 2M2# is a +'digit code used to identify the subscriber

2t incorporates a country code and operator code

2M2 code is used to link the M2=N number to thesubscriber/s 2M ubscriber 2dentity Module#

Charging information

ervices available to the customer :lso the subscriber/s present ocation :rea Code,

which refers to the MC, which can connect to theM9


22/64

Ether ystems

Eperations upport ystem The management network for the whole 1M

network @sually vendor dependent Fery loosely speciDed in the 1M standards

Falue added services Foice mail Call forwarding 1roup calls

hort Message ervice Center tores and forwards the M messages ike an -%mail server Ieuired to operate the M services


23/64

ocation @pdates

The cells overlap and usually a mobilestation can .see/ several transceiversBTes#

The M monitors the identiDer for the BCcontrolling the cells

Ahen the mobile station reaches a newBC/s area, it reuests an location update

The update is forwarded to the MC,entered into the FI, the old BC is notiDedand an acknowledgement is passed back


24/64

Hando0 Handover#

Ahen a call is in process, the changes inlocation need special processing

Aithin a B, the BC, which knows thecurrent radio link conDguration includingfeedbacks from the M#, prepares anavailable channel in the new BT

The M is told to switch over to the newBT

This is called a hard hando0 2n a soft hando0, the M is connected to two

BTes simultaneously


25/64

Ioaming

Ahen a M enters another operatorsnetwork, it can be allowed to use theservices of this operator Eperator to operator agreements and

contracts

Higher billing

The M is identiDed by the information inthe 2M card and the identiDcation reuestis forwarded to the home operatorThe home HI is updated to reect the M/s

current location


26/64

51, 59'1 and 61 T-#


27/64

51 Everview

51 is created by 2T@%T and is called2MT%4(((


28/64

-volution from 41

IS-95 IS-136 & PDCGSM-

EDGE

GPRS

HSCSDIS-95B

Cdma2000-1xRTT

Cdma2000-1xEV,DV,DO

Cdma2000-3xRTT

W-CDMA

EDGE

TD-SCDMA

2G

3G

25G

3GPP3GPP2


29/64

ervice Ioadmap

Improved performance, decreasing cost of delivery

Typicalaverage bitrates(peak rateshigher)

WEB!"#$%'(C#")#"a*+ da*a a+%%S*"+am'( ad#./d+#

V#+ & SMSP"+%+'+.#a*#'

xHTM !"#$%'(A))a*#' d#$'#ad'(

E-ma

MMS )*"+ . /d+#

M**a%'(

3G-specific services takeadvantage of higher bandwidth

and/or real-time o!

3G-specific services takeadvantage of higher bandwidth

and/or real-time o!

" n#mber of mobileservices are bearer

independent in nat#re

" n#mber of mobileservices are bearer

independent in nat#re

$!%&"'-'bps

*+%",

bps

G&.!03kbps

G&.!'0'kbps

G!12

kbps

P%-*#-*a

B"#ad!a'd' $d+ a"+a

Vd+# %a"'(Vd+# *++)#'4R+a-*m+ IPm*m+da a'd (am+%

M*a%*'(

CDMA

2000-

EVDO

CDMA

2000-

EVDV

CDMA

20001x


30/64

1M -volution to 51

&SM*9Gkbps onetimeslot#1M =ata:lso called C=

&SM&'n'()l P)*k'+ R),io S'(-i*'.=ata rates up to L ++' kbpsMaJ3 & timeslots used as any one time7acket switched; resources not tied up all thetime

Contention based9 ->cient, but variabledelays

&PRS

HSCSD

Hi/ Sp'', Ci(*i+ Swi+*', D)+)=edicate up to 6 timeslots for data connectionL '( kbps1ood for real%time applications c9w9 17I2ne>cient % ties up resources, even whennothing sentNot as popular as 17I many skipping HC=#

ED&E

En)n*', D)+) R)+'. 2o( &lo3)lE-ol+ion@ses &7K modulation5J improvement in data rate on shortdistancesCan fall back to 1MK for greaterdistancesCombine with 17I -17I# L 5&6 kbpsCan also be combined with HC=

WCDM


31/64

@MT

@niversal Mobile Telecommunicationsystem @MT#

@MT is an upgrade from 1M via 17I or-=1-

The standardi)ation work for @MT is carriedout by Third 1eneration 7artnership 7ro?ect5177#

=ata rates of @MT are3

+66 kbps for rural 5&6 kbps for urban outdoor 4(6& kbps for indoor and low range outdoor

Firtual Home -nvironment FH-#


32/64

@MT


33/64

@MT :rchitecture

SD

obile !tation

MSC.

VR

4ase !tation

!#bsystem

GMSC

5etwork !#bsystem

ACEIR HR

6ther 5etworks

#*+7 I'*+"8a+% a/+ !++' #m**+d 8#" a"*4 )")#%+%

GGSSGS

BTSBSC

#d+

BRC

RNS

7T."5

SIMME

SIMME

PST

PM

I'*+"'+*


34/64

@MT Network :rchitecture

@MT network architecture consists ofthree domains

Core Network CN#3 7rovide switching, routing

and transit for user tra>c @MT Terrestrial Iadio :ccess Network

@TI:N#3 7rovides the air interface accessmethod for user euipment9

@ser -uipment @-#3 Terminals work as airinterface counterpart for base stations9 Thevarious identities are3 2M2, TM2, 7%TM2, T2,M2=N, 2M-2, 2M-2F


35/64


36/64

59'1 H7:#High peed 7acket :ccess H7:# is an amalgamation oftwo mobile telephony protocols, High peed =ownlink7acket :ccess H=7:# and High peed @plink 7acket:ccess H@7:#, that eJtends and improves theperformance of eJisting AC=M:protocols

59'1 introduces many new features that will enhancethe @MT technology in future9 +J-F%=F alreadysupports most of the features that will be provided in59'19 These include3

% :daptive Modulation and Coding

%


37/64

61 T-#

T- stands for ong Term -volution

NeJt 1eneration mobile broadbandtechnology

7romises data transfer rates of +((Mbps

Based on @MT 51 technology Eptimi)ed for :ll%27 tra>c


38/64

:dvantages of T-


39/64

Comparison of T- peed


40/64

Ma?or T- Iadio Technogies

@ses Erthogonal


41/64

T- :rchitecture


42/64

T- vs @MT


43/64

C).' S+,4Mo3ili+4 Do3l'6E,/', Swo(,

2o( HSP N'+wo(k.Fung Po Tso, City University of Hong Kong

Jin Teng, hio !tate University"ei#ia Jia, City University of Hong Kong

Dong $uan, hio !tate University

ACM Mobihoc10


44/64

ConteJt

-volved hardwaretechnologies

P

2mproved network bandwidthQ

-ntertainment apps onmobile

66MobiHoc R+(


45/64

ConteJt

6'MobiHoc R+(

W'n 4o )(' NO"o3il' 4o .'


46/64

ConteJt

MobiHoc R+( 6G

W'n 4o )(' o3il' 4o.'


47/64

ConteJt

MobiHoc R+( 6O

Million.o2 p)..'n/'(. p'( ,)49


48/64

ConteJt

6&MobiHoc R+(

C)n HSP

p(o-i,' +'.)' l'-'l o2.'(-i*' +oo3il' .'(.

on p3li*+()n.po(+:

pictures/ source3 Aikipedia

HSP No,' #

HSP No,' #


49/64

Eutline

Measurement Methodology

1eneral 2mpact of Mobility

Mobility 2mpact on Bandwidthharing

Mobility 2mpact in Transitional Iegion

Conclusion

MobiHoc R+( 6*


50/64

Measurement Ioutes

"4p' -'()/'

Sp'',

Hi/'.+

Sp'',

C)()*+'(i.+i*.

Trains 6( kmh +(( kmh urface ground

ubways 5( kmh &( kmh @nderground

elf%drivingFehicles S

Buses

'( S 5(kmh

&( kmh urface ground


51/64

Measurement Ioute

'+MobiHoc R+(

O-'( 100k in ;on+.


52/64

Measurement etup

Two ervers3

ab S =ata Center

Three types of

evaluations3 download only;

upload only;simultaneousdownload Supload9

'4MobiHoc R+(


53/64

1eneral 2mpact of Mobility

: large spread of H=7: bit rates andsignal uality

'5MobiHoc R+(


54/64

ConteJt

'6MobiHoc R+(

Co%%on &ie'( )obility is irrelevant, if notdetri%ental, to the fairness in H!PAband'idth sharing a%ong users

Ebservation3 The bandwidth sharingpractice in stationary H7:environments is unfair9 2n contrast,

mobility surprisingly improves fairnessof bandwidth sharing fairer#9

Bandwidth haring among


55/64

Bandwidth haring among@sers

Mobility actually improves thefairness of bandwidth sharing amongusers

''MobiHoc R+(

Bandwidth haring among


56/64

Bandwidth haring among@sers

@- can hardly keep its dominancyunder rapid change of radioenvironment9

Mobile nodes may see better signaluality at new locations

Cell to cell based scheduling

algorithm prevent unfairness frompropagating

'GMobiHoc R+(


57/64

ConteJt

'OMobiHoc R+(

Co%%on &ie'( )obility a*e+ts all o'seually. And TCP o's su*er %ore than UDPones

Ebservation3 TC7 ows uneJpectedlysee much better performance duringmobility than @=7 ows9

Bandwidth haring among Tra>c


58/64

Bandwidth haring among Tra>c


59/64

Bandwidth haring among Tra>cc is much constrained andadaptive to the channel condition,while @=7 tra>c keeps pumping

almost the same amount of dataregardless of the channel condition

'*MobiHoc R+(


60/64

ConteJt

G(MobiHoc R+(

Co%%on &ie'( Hando*s are triggered in thetransitional region bet'een +ells and al'aysresult in a better 'ireless +onne+tion

Ebservation3 Nearly 5( of all hando0s,selection of a base station with poorersignal uality can be witnessed

Mobility 2mpact in Transitional


61/64

Mobility 2mpact in TransitionalIegions

throughput oftendrops sharply,and sometimes,

as high as *(during hando0period9

G+MobiHoc R+(

Mobility 2mpact in Transitional


62/64

Mobility 2mpact in TransitionalIegions

-c$2o of the newbase stations arestatistically betterthan the originalbase stations by+(dBm9

But almost 5(of all the hando0sdo not end upwith a betterbase stations

G4MobiHoc R+(


63/64

Conclusion

Mobility is a double edged sword

=egrades H7: services, e9g9throughput

2mproves fairness in bandwidthallocation among users and tra>c ows

Communication characteristics in

H7: transitional regions are verycomplicated

MobiHoc R+( G5


64/64

:cknowledgement

7art of the slides are adapted fromthe slides of 7osco Tso, HarishFishwanath, -rran i and Uustino

orenco, aro Felra?an and TC 2ndia

222902960-694-cellular-network

Documents