Challenges and Prospects of Wireless Network in 4G

8/13/2019 Challenges and Prospects of Wireless Network in 4G

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Challenges and Prospects of Wireless Network in 4GNitin Goel J. P. Dixit

Assistant Professor Assistant Professor I n te g ra l U n iv e rs i ty , L u ck n ow A I MT , L u ck n ow nitingoel435@ gmail.com, jpdixit_2006@ yahoo.co.in

Abstract: T h e s e d a y s , m o b i l i t y i s o n e o f t h e m o s t i m p o r t a n t f e a t u r e s i n c o m m u n i c a t i o n n e t w o r k s . I t h a s s u c h a n e n o r m o u s i m p a c t t h a t

wireless communication has become an inevitable part of our life.The need has fueled rapid innovation in the technology and as a result

w e a c k n o w l e d g e a s i g n i f i c a n t c h a n g e i n t h e w i r e l e s s t e c h n o l o g i e s w h i c h a r e k n o w n a s 1 G , 2 G , 3 G a n d 4 G . H o w e v e r , n o s i n g l e n e t w o r k and no single technology dominate the wireless communication.Therefore, seamless global network connectivityis a significant challenge

f a c in g w i r e l e s s a n d m o bi l e n e t w o rk . I t d e m a n ds f o r r a p i d i n n o va t i on a n d m o re r a p id r o l l o u t o f g l o b al c o n ne c t i vi t y . I n t h i s p a p e r, w e

present technological advancements in different generations in wireless networking with a special focus on some significant changes int h e 3 G a n d 4 G w i r e l e s s t e c h n o lo g y fo r i m p l e me n ta t i on o f d a t a t r a ns f e r a n d v o i c e c o mm u ni c a ti o n.

Index term : wireless technology, mobile network.

I.INTRODUCTION

T h e 3 r d G e ne r a ti o n w i re l es s n e tw o rk , c o mm o nl y k n ow n a s 3 G , i s a f a mi l y o f d i ff e re n t m o b il e t e le c om m un i ca t io n t e ch n iq u e s

d e fi n e d b y t h e I n te r n at i on a l T e le c o mm u ni c at i on U n io n (ITU), w h ic h i n cl ud e G SM , U M TS , W iM AX , a n d C DM A 20 0 0. T hes e r v i c e s w h i c h a r e i n c l u d i n g i n t h i s g e n e r a t i o n s n e t w o r k a r e w i d e - a r e a w i r e l e s s v o i c e t e l e p h o n e , v i d e o c a l l s , a n d w i r e l e s s d a t a , a l li n a m o b i l e e n v i r o n m e n t . C o m p a r e d t o 2 G a n d 2 . 5 G s e r v i c e s , 3 G a l l o w s s i m u l t a n e o u s u s e o f s p e e c h a n d d a t a s e r v i c e s a n d h i g h e r

d a t a r a t e s ( u p t o 1 4 . 0 m b p s o n t h e d o w n l i n k a n d 5 . 8 m b p s o n t h e u p l i n k ) . T h e 3 G n e t w o r k s e n a b l e n e t w o r k o p e r a t o r s t o o f f e r u s e r s a w i d e r r a n g e o f m o r e a d v a n c e d s e r v i c e s a n d f e a t u r e s w h i l e a c h i e v i n g g r e a t e r n e t w o r k c a p a c i t y t h r o u g h i m p r o v e d s p e c t r a lefficiency.

NitinGoel is an Assistant Professor in Integral University, Lucknow, India. Mobile: +919044899 057; Email:[email protected].

J.p.dixit is an Assistant Professor in Ambalika Institute of Management & Technology, luck now, India. Mob- +917376253763 Email: jpdixit_2006yahoo.co.in

F i g- 1 - W i re l es s N e tw o rk S t ru c tu r e

A typical wireless network structure is shown in Fig.1. The satellite covers a large geographical region which usually

c o nt a in s d i ff e re n t m e tr o po l it a n a r ea s . A m e tr o po l it a n a r ea c o ns i s ts o f s e ve r al c a mp u se s w h ic h c o nt a in b u il d in g s,

h ou se s, a nd o th er p la ce s a nd t he n a r ou te r c ov er a p ar ti cu la r o ff ic e o r b ui ld in g. T he 4 G i s t he m os t a dv an ce d

generation of cellular wireless standards. It is a successor of the 3G technology with an aim to provide high data rate

to broadband Internet access to mobile as well as stationary users. The 4G mobile network must have target peak data

r a t e s o f u p t o 1 0 0 M b i t / s f o r h i g h m o b i l i t y s u c h a s m o b i l e a c c e s s a n d u p t o 1 G b i t / s f o r l o w m o b i l i t y s u c h a s l o c a lwireless access. Scalable bandwidth up to at least 40 MHz should be provided. A 4G system is expected to provide a

comprehensive and secure all-IP based solution where facilities such as IP telephony, ultra-broadband internet access,


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o nl in e g am in g s er vi ce s a nd H DT V s t re am ed m ul ti me di a m ay b e p ro vi de d t o u se rs [ 14 ].

II. E v o l u t i o n a n d R e v o l u t i o n o f W i r e l e s s T e c h n o l o g i e s

T he d em an d f o r n et wo rk ed c on su me r s ys te ms a n d d e vi ce s i s l ar g e a n d g ro wi ng r ap id l y w he re t he w ir el es s t ec hn o lo g y a ndtechnological standard are evolving according to the world. W ireless telecommunications has evolved from 2G in the 20th centuryto the current 3G in the 21st century; and current work being done is leading to 4G. The 4G, also known as Fourth-Generation, is a

term used to describe the next complete evolution in wireless communications. A 4G system is a complete replacement for current3 G n e t w o r k s a n d w i l l b e a b l e t o p r o v i d e a c o m p r e h e n s i v e a n d s e c u r e I P s o l u t i o n w h e r e v o i c e , d a t a , a n d s t r e a m e d m u l t i m e d i a c a nbe given to users on an "anytime, anywhere" basis at much higher data rates than previously known generations.India is one of the countries where the market of wireless is growing at a very fast pace. In India, about 490 million users has beena d d i n g a b o u t 1 4 m i l l i o n s u b s c r i b e r s e a c h m o n t h a n d t h e g o v e r n m e n t h a s p e n c i l e d i n r e v e n u e o f 3 5 0 b i l l i o n r u p e e s ( $ 7 . 6 b i l l i o n )f r om t h e a u c ti o n o f 3 G s p e ct r um [ 1 ] .After getting the 3G licenses, China Mobile, the world's top mobile carrier with 500 million subscribers, is already looking for then e x t g e n e r a t i o n , p l a n n i n g t o b u i l d a t r i a l L T E n e t w o r k i n m u l t i p l e c i t i e s n e x t y e a r , C h a i r m a n W a n g J i a n z h o u s a i d i n t h e p r e s sc o n fe r en c e o n N o v e mb e r 2 0 0 9 [ 1 ] .A T & T , o n e o f t h e w o r l d s l a r g e s t t e l e c o m m u n i c a t i o n s p r o v i d e r s , w i l l b e g i n i t s o w n r o l l o u t o f a 4 G N e t w o r k i n 2 0 1 1 , e n a b l i n g i t sv a s t u s e r b a s e t o e x p l o r e n e w d o w n l o a d i n g s p e e d s a n d c a p a b i l i t i e s . T h e u t i l i z a t i o n o f L T E m o b i l e b r o a d b a n d t e c h n o l o g y i s a no p p o r t un i t y f o r t h e c o r p o r a t io n to e x p an d it s h o r i z o ns i n t o 4 G t er r i t o ry , u p s t a g in g c u r r e n t 3 G c ap a b i l i ti e s [ 3 ] .

I n J a pa n t h e s u cc e ss o f t h e I -m od e c o mb i ne d w i th t h e o v er a ll d e ma n d f o r c o nt i nu i ng t e ch n ol o gi c al

enhancements and customer demand for specific services such as mobile broadband access, suggests strongly that 3Gn e tw o rk m u st e v en t ua l ly t a ke o f f e l s e wh e re [ 2] .I n 4 G n e t w o r k t o a c c o m m o d a t e t h e r e q u i r e m e n t s s u c h a s h i g h u s a b i l i t y a n d p e r s o n a l i z a t i o n o f 4 G ( m o b i l e )

n e tw o rk s , c o nv e nt i on a l h a nd h el d s i ng l e n e tw o rk - in t er f ac e m ob i le d e vi c es a r e e vo l vi n g i n to m ul t i hu e d d e vi c es .M or eo ve r, o wi ng t o t he r ec en t a dv an ce s i n t he m ob il e m id dl ew ar e t ec hn ol og ie s, h ar dw ar e t ec hn ol og ie s a nda s s oc i at i on w i th t h e h um a n u s e r , h a nd h el d m o bi l e d e v i ce s a r e e v ol v in g i n to d a ta p r od u ce r s a n d i n t u rn a c ti n g a s

Nomadic Mobile Service (NMS) providers [4].T he s uc ce ss o f w i re l es s a cc es s t ec hn ol og ie s, s uc h a s w ir el es s L AN s, h as f or ce d m ob il e o pe ra to rs a nd

m an uf ac tu re rs t o c on si de r t he ir i nt eg ra ti on i nt o 3 G i nf ra st ru ct ur es . N ow ad ay s, s ev er al r es ea rc h g ro up s a nds ta nd ar di za ti on b od ie s a re w or ki ng t o p ro vi de s uc h i nt eg ra te d a rc hi te ct ur es . O ne o f t he m ai n a im s o f t he sea r ch i te c tu r es i s t o p r ov i de s e am l es s s e rv i ce c o nt i nu i ty t o u s er s t h at m o ve f r om o n e a c ce s s s ys t em t o a n ot h er [ 5 ].

I n t h e v i s i o n o f m o b i l e n e t w o r k s , i n t e g r a t e d a n d p e r s o n a l i z e d s e r v i c e s a r e e n v i s a g e d a t a n y d e s i r e d t i m e a n d

any location. This vision is, partly, to be realized by making use of the mobile, often handheld or otherwise wearabled e v i c e s , c o n n e c t e d t o t h e I n t e r n e t u s i n g o n e o r m o r e o f t h e n e t w o r k i n t e r f a c e s e m b e d d e d i n t h e s e d e v i c e s [ 6 ] . Weinvestigate mathematical programming models for supporting the decisions on where to install new base stations andhow to select their configuration (antenna height and tilt, sector orientations, maximum emission power, pilot signal,e t c. ) s o a s t o f i nd a t r a de - of f b e tw e en m a xi m iz i ng c o ve r ag e a n d m i ni m iz i ng c o st s [ 8 ].

4 G m o b il e c o m mu n i c at i o n s y s t em h a s s t e e p e d t h e r a c e i n i t s i m p le m e n ta t i o n a t t h e e a r l i e s t . 4 G w i r e l es s b e i n ga n u p c o m i n g s t a n d a r d w i t n e s s e s b u r g e o n i n g i n t e r e s t a m o n g s t r e s e a r c h e r s a n d v e n d o r s . I t i s b e i n g d e s i g n e d t o a l l o ws ea ml es s i nt eg ra ti on a nd c om mu ni ca ti on b et we en w ir el es s d ev ic es a cr os s d iv er se w i re le s s s ta nd ar ds a s w el l a s

broadband networks wirelessly [9]. As 3G wireless systems evolve towards 4G, various wireless network technologyo rg an iz at io ns l oo ki ng a t n et wo rk a rc hi te ct ur es f or 4 G a re c on si de ri ng a r ed es ig n o f t he n et wo rk a wa y f ro m t het r ad i ti o na l c e nt r al i z ed , h i er a rc h ic a l d e si g n t o wa r ds a m o re d i s tr i bu t ed o p er a ti o n o f n e tw o rk f u nc t io n s [ 1 0] .

T h e p r a c t i c a l s u c c e s s o f t h e f u t u r e g e n e r a t i o n m o b i l e s y s t e m s s u c h a s 4 G r e l i e s l a r g e l y i n i t s f l e x i b i l i t y i n

providing adaptive and cost-effective services. Service discovery is an essentialmechanism to achieve this goal [11].T he p as t a nd r ec en t r es ea rc h e ff or ts i nv es ti ga te d t he g at he ri ng o f l ow -l ev el i nf or ma ti on , i mp le me nt at io n- a nddomain-driven approaches for context frameworks and conceptual models of context, vertical approaches combiningt he a s pe ct s o f m od el in g b ut t he i mp le me nt at io n i s s t il l m is si ng [ 12 ].T he i nt eg ra ti on o f a m ul ti tu de o f w ir el es sn e t w o r k s i s e x p e c t e d t o l e a d t o t h e e m e r g e n c e o f t h e 4 G w i r e l e s s t e c h n o l o g i e s . U n d e r t h e m o t i v a t i o n o f i n c r e a s i n gt e ch n ol o gy t h e l e ve l s o f u s er s a ti s f ac t io n m a in t ai n in g s e am l es s c o nn e ct i vi t y a n d a s a t is f ac t or y l e ve l o f q u al i ty o f s e r v ic e i s a l s o i n c r ea s i n g [ 1 3 ].


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Fig-2- Different Wireless Technologies

F i g . 2 s h o w s d i f f e r e n c e b e t w e e n a l l e x i s t i n g w i r e l e s s t e c h n o l o g i e s a c c o r d i n g t o t h e r e c o v e r a g e a r e a a n d b a n d w i d t h a v a i l a b i l i t y .T h e e x is t en c e o f 4 G N e tw o rk s i n t o da y s t e ch n o lo g y- d ri v en s o ci e ty i s i m po r ta n t i n d ic a to r o f a d va n c em e nt a n d c h an g e . T h e4Gnetworks are designed to facilitate improved wireless capabilities, network speeds, and visual technologies. It is anticipated thata s t he s e n et wo rk s c on ti nu e t o t hr iv e, t he d em a nd f or a dv a nc ed r el a te d t ec hn o lo gi es w il l a l so g ro w, t he re b y c re at in g n ewa l t e rn a t i v e s f o r sa v v y t e c h n o lo g y u s e r s t o e x ce e d t he i r de s i r e d e x p e c t a ti o n s .

III. CO MP AR IS IO N o f W i r e l e s s T e c h n o l o g i e s

3G Features

Data rates:I T U h a s n o t p r o v i d e d a c l e a r d e f i n i t i o n o f t h e d a t a r a t e u s e r s c a n e x p e c t f r o m 3 G e q u i p m e n t o r p r o v i d e r s . T h u s , u s e r so f 3 G s e r v i c e m a y n o t b e a b l e t o p o i n t t o t h e s t a n d a r d s a n d s a y t h a t t h e s p e c i f i e d r a t e s a r e n o t b e i n g m e t . W h i l e s t a t i n g t h a t " i t i sexpected that IMT-2000 will provide higher transmission rates minimum data rate of 2 Mbit/s for stationary or walking users, and348 kbit/s for moving vehicle, the ITU does not actually clearly specify minimum or average rates or what modes of the interfacesq u a l if y a s 3 G , s o v a r io u s r a t e s a r e s o l d a s 3 G in t e n d e d t o m e et c u s t o me r s e x p e c t at i o n s o f b r o a d b an d d a t a [ 2 ] .

A c c e s s s c h e m e s :I n 1 9 9 9 , I T U a p p r o v e d f i v e r a d i o i n t e r f a c e s f o r I M T - 2 0 0 0 a s a p a r t o f t h e I T U - R M . 1 4 5 7 r e c o m m e n d a t i o n i nw h i c h W i - M a x w a s a d d e d i n 2 0 0 7 . T h e r e a r e e v o l u t i o n a r y s t a n d a r d s t h a t a r e b a c k w a r d c o m p a t i b l e t o p r e - e x i s t i n g 2 G n e t w o r k s a sw e ll a s r e vo l u ti o n ar y s t a nd a r ds t h a t r e q u i re a l l- n ew n e tw o rk s a n d f r eq u en c y a l lo c a ti o n s. T h e l a te r g r ou p i s t h e U M T S f a m i ly ,which consists of standards developed for IMT-2000, as well as the independently developed standards DERT and W iMax, whichw e re i n c lu d e d b e c a u s e t h e y f i t t h e I M T -2 0 0 0 d e f in i ti o n . S o m e o f a c ce s s s c he m es i n 3 G n e tw o rk s a r e T D M A S i n g le - Ca r ri e r ( I M T - SC ) , C D M A M u l t i -C a r r i er ( I M T - M C ) , C D MA D i r e c t S p r e a d( I M T - D S) , F D M A/ T D M A ( I M T - F T) , a n d I P - O F D MA [ 2 ] .

Security: 3G networks offer a greater degree of security than 2G networks. Authentication to the network assures the user that he isc o n n e c t i n g t o t h e i n t e n d e d n e t w o r k . 3 G n e t w o r k s u s e m o r e r o b u s t b l o c k c r y p t o i n s t e a d o f t h e o l d e r s t r e a m c i p h e r . I n a d d i t i o n , i to f fe r s i n fr a st r uc t ur e s e cu r it y , a n d e n d -t o -e n d s e cu r it y w h il e a c ce s si n gt h e a p p li c a ti o n f r am e wo r ks [ 2 ] .

Applications: T h e b a n d w i d t h a n d l o c a t i o n i n f o r m a t i o n a v a i l a b l e t o 3 G d e v i c e s g i v e r i s e t o a p p l i c a t i o n s t h a t w e r e n o t p r e v i o u s l ya v a il a b le t o m ob i le p h o ne u s er s . S o me o f t he a p p li c a ti o ns a r e :

M o b i l e T V a T V c h a nn e l m a y b e p r o v i d e d o n a m o b il e h a n d s e t d i r e c tl y . V i d e o o n d e m a n d a v i d e o m a y b e t r a ns m i t te d t o t h e s u b s c r i be r o r a p r ov i d e r c an s e n d a m o v ie t o t h e s u b s c r i be r . V i d e o c o n f e r en c i n g a s u b s c r i be r c a n se e t h e p e r s o n t o wh o m h e i s ta l k i n g t o . T e l e -m e d i c i ne - a m e d ic a l p r o v i d e r c a n m o ni t o r s a n d p r o vi d e s a dv i c e t o t h e p a ti e n t s .

L o c a t i o n - b a s e d s e r v i c e s - a p r o v i d e r c a n s e n d l o c a l i z e d w e a t h e r o r t r a f f i c c o n d i t i o n s t h r o u g h p h o n e , o r t h e p h o n e a l l o w st h e s u b sc r ib e r t o f in d n e a rb y l o ca t io n s .

4G Features

A c c o r d i n g t o t h e m e m b e r s o f t h e 4 G w o r k i n g g r o u p , t h e i n f r a s t r u c t u r e a n d t h e t e r m i n a l s o f 4 G w i l l h a v e a l m o s t a l l t h e s t a n d a r d sfrom 2G to 3G implemented. Although the infrastructure of 4G is packet-basedthe existing 2G and 3G users may easily adopt to it.S o m e p r o p o s a l s s u g g e s t i t h a s a n o p e n I n t er n e t p l a t f or m . M a j o r te c h n o l o gi e s w h ic h a r e i n c lu d e d i n 4 G a r e Fl a s h - OF D M , 8 0 2 . 16 e -m o b i l e v e r s i on o f W i- M a x , an d H C -S D M A .

Data rates:T h e 4 G d e fi n e s a c l e ar p i c tu r e o f t h e d a t a r a te s . I n 4 G w i re l es s c o mm u ni c at i on s t an d a rd t h e re i s f l ex i bl e c h an n e lbandwidth, between 5 and 20 MHz, optionally up to 40 MHz.The minimum data rate of 100 Mbit/s while the client physicallym o v e s a t h i g h s p e e d s r e l a t i v e t o t h e s t a t i o n , a n d 1 G b i t / s w h i l e c l i e n t a n d s t a t i o n a r e i n r e l a t i v e l y f i x e d p o s i t i o n s a s d e f i n e d b y t h eI T U . T h e d a t a r a t e o f a t le a s t 1 0 0 M b i t / s b et w e e n a n y t w o p o i n t s i n t h e w o rl d a n d p e a k l i n k s p e c t r al e f f i c ie n c y o f 1 5 b i t / s / Hz i n t h ed o w n l i n k , a n d 6 . 7 5 b i t / s / H z i n t h e u p l i n k ( m e a n i n g t h a t 1 0 0 0 M b i t / s i n t h e d o w n l i n k s h o u l d b e p o s s i b l e o v e r l e s s t h a n 6 7 M H z

bandwidth). System spectral efficiency of up to 3 bit/s/Hz/cell in the downlink and 2.25 bit/s/Hz/cell for indoor usage [3].

Access schemes: A s t h e w i r e l e s s s t a n d a r d s e v o l v e d , t h e a c c e s s t e c h n i q u e s u s e d a l s o e x h i b i t e d i n c r e a s e i n e f f i c i e n c y , c a p a c i t y a n d


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s c a l a b i l i t y . T h e f i r s t g e n e r a t i o n w i r e l e s s s t a n d a r d s u s e d T D M A a n d F D M A . I n t h e w i r e l e s s s y s t e m , T D M A i s p r o v e d t o b e l e s se f f i c i e n t i n h a n d l i n g t h e h i g h d a t a r a t e s y s t e m a s i t r e q u i r e s l a r g e g u a r d b a n d t o a v o i d t h e i n t e r c h a n n e l i n t e r f e r e n c e a n d F D M Ac o n s u m e d m o r e b a n d w i d t h f o r g u a r d t o a v o i d i n t e r c a r r i e r i n t e r f e r e n c e . S o , i n s e c o n d g e n e r a t i o n a s e t o f s t a n d a r d w h i c h i s t h ec o m b i n a t i o n o f F D M A a n d T D M A a n d t h e o t h e r s e t i n t r o d u c e d a n a c c e s s s c h e m e c a l l e d C D M A . U s e o f C D M A t e c h n i q u e f o r m u l t i p l e x i n g i n c r e a s e s t h e s y s t e m c a p a c i t y . B u t t h e r e i s a d r a w b a c k o f C D M A s y s t e m . A C D M A n e t w o r k d o e s n o t r e j e c t n e wc l i e n t e v e n i f i t a p p r o a c h e s i t s l i m i t s , r e s u l t i n g i n a d e n i a l o f s e r v i c e t o a l l c l i e n t s w h e n t h e n e t w o r k o v e r l o a d s . H o w e v e r , C D M An e t w o r k p r e v e n t s t h e o v e r l o a d i n g p r o b l e m b y n o t a l l o w i n g t h e s y s t e m t o r e a c h t o i t s c a p a c i t y . M o r e o v e r , i t i s e f f i c i e n t e n o u g h t oh a n d l e t h e m u l t i p a t h c h a n n e l s . I t e n a b l e d t h e t h i r d g e n e r a t i o n s y s t e m s , s u c h a s I S 2 0 0 0 , U M T S , T D - C D M A a n d T D - S C D M A , t ou se C DM A a s t he a cc es s s ch em e. H owe ve r, t he i ss ue wi th C DM A i s t ha t i t s uf fe rs f ro m p oo r s pe ct ra l f le xi bil ity a nd

c o mp u ta t io n a ll y i n te n si v e t i me - do m ai n e q u al i za t io n f o r w i de b a nd c h an n e ls [ 9 ] .Recently, new access schemes like OFDMA, SC-FDMA, interleaved FDMA and MC-CDMA are gaining more importance for then e x t g e n e r a t i o n s y s t e m s . T h e s e a r e b a s e d o n e f f i c i e n t a l g o r i t h m a n d f r e q u e n c y d o m a i n e q u a l i z a t i o n , r e s u l t i n g l o w e r n u m b e r o f m u l t i p l i c a t i o n s p e r s e c o n d . T h e y a l s o m a k e i t p o s s i b l e t o c o n t r o l t h e b a n d w i d t h a n d f o r m t h e s p e c t r u m i n d i f f e r e n t p o s s i b l e w a y .T h ey r e qu i r e a d v a nc e d d y na m ic c h an n e l a l lo c a ti o n a n d t r af f ic s c he d u li n g.W i M A X i s u s i n g O F D M A a s t h e d o w n l i n k a n d u p l i n k a s w e l l . F o r t h e n e x t g e n e r a t i o n w i r e l e s s n e t w o r k O F D M A i s u s e d f o r t h edownlink and IFDMA is being considered for the uplink since OFDMA contributes more issues and results in nonlinear operationo f a m p l i f i e r s . I F D M A i s u s e f u l a s i t p r o v i d e s l e s s p o w e r f l u c t u a t i o n a n d t h u s a v o i d s a m p l i f i e r i s s u e s . T h e s e a c c e s s s c h e m e s o f f e r t h e s a m e e f f i c ie n c i e s w h i c h c a n b e o b t a i n e d b y t h e o l d e r t e c h no l o g i e s l ik e C D M A a n d t h e y c a n a l s o a c h ie v e g r e a t e r s c al a b i li t y a n dh i g h e r d a t a r at e s [ 3 ].

TABLE1:C OMPARITIVE FEATUR ES

Key

Featur es

Access

Pr otocols

Key Features Level of

Evolution

1G FDMA

An a lo g , p rima rilyvo ice , le ssse cu re , su p p o rt fo r lo w b itra te d a ta

Acce ss toa n d ro a min ga cro sssin g le typ e o f a n a lo gwire le ssn e two rks

2Gand2.5G

TDMA,CDMA

Dig ita l, mo rese cu re , vo icea n d d a ta

Acce ss toa n d ro a min ga cro sssin g le typ e o f d ig ita lwire le ss

n e two rks a n da cce ss to 1 G

3Gand3.5G

CDMA2 0 00 ,W-CDMA,HSDPA,TD-SCDM

A

Dig ita l, mu ltime d ia ,g lo b a lro a min g a cro ss asin g le typ e o f wire le ss n e two rk(fo r e xa mp le ,ce llu la r), limite d IPin te ro p e ra b ility,1 4 4 Kb p s to se ve ra lMb p s

Acce ss toa n d ro a min ga cro ssd ig ita lmu ltime d iawire le ssn e two rks a n da cce ss to 2 Ga n d 1 G

4G TBD Glo ba l ro ami ng

a cro ss mu ltip lewire le ss n e two rks,1 0 Mb p s-1 0 0 Mb p s, IPin te ro p e ra b ility fo r se a mle ss mo b ileIn te rn e t

Acce ss toa n d ro a min g

a cro ssd ive rse a n dheterogeneous mo b ilea n d wire le ssbroadbandn e two rksa n d a cce ss to3 G, 2 G, a n d1 G

T ab l e 1 : e x pl ai n t h e c o mp ar at iv e f ea tu re o f 3 G a n d 4 G m o bi le n et wo rk s i n r es p ec t o f a c ce ss p r ot o co l s, k ey f ea tu r es a n d t h ee v o lu t io n . T h e o t h e r i m p o rt a nt a d v an t a ge o f t h e a b o ve m e nt i on e d a c c e ss t e ch n i qu e s a r e t h at t h ey r e q ui r e l e s s c o m p l ex i ty f o r e q u a l i z a t i o n a t t h e r e c e i v e r . T h i s i s t h e a d v a n t a g e o f M I M O e n v i r o n m e n t s i n c e t h e s p a t i a l m u l t i p l e x i n g t r a n s m i s s i o n o f M I M O

s y st e m i n he r en t ly r e q ui r es h i gh c o mp l ex i ty e q u al i za t io n a t t h e r e ce i v er .

IPv6 support: 3G is based on two parallel infrastructures consisting of circuit switched and packet switched networks. 4G is basedo n ly o n p a c k et s w i tc h in g t e ch n iq u e . T h is p r o v i de s l o w l a te n cy i n d a t a t ra n s mi s si o n.T h e p r o b l e m w i t h 4 G i s t h a t b y t h e t i m e o f i t s d e p l o y m e n t t h e I P v 4 a d d r e s s e s w o u l d h a v e b e e n e x h a u s t e d . S o , I P v 6 s u p p o r t i s


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e s s e n ti a l t o s u p po r t a l a r g e n u m b e r o f wi r e l e ss - e n a bl e d d e v i c e s . B y i n c r e as i n g t h e nu m b e r o f I P a d d r e s s , I P v 6 re m o v e s t h e ne e d f o r Network Address Translation (a method of sharing a limited number of addresses among a larger group of devices) which is a

n e c e s si t y t o c o mm u n i c at e e v e n t o d a y b e c a u s e o f d e pl e t i o n o f I Pv 4 a d d re s s e s .

IV. P r i m a r y C h a l l e n g e s

L o w L a t e n c y H a n d o f f : A n i m po r ta n tg o al i s t o a l lo w a u s er t o u s e f u ll y -i n te r ac t iv e c o mm u ni c at i on a c ro s s a l l t h ea v ai l ab l e n e tw o rk s , e v en t h ou g h t h e n e tw o rk s p r ov i de d i ff e re n t le v el s o f se r vi c e [ 9 ].

P o w e r S a v i n g s : P o w e r r e q u i r e m e n t s h o u l d b e m i n i m i z e d a s m a n a g i n g m u l t i p l e w i r e l e s s n e t w o r k s a v a i l a b l e i n t h ea r e a an d k e e p a l l o f t h e m u p da t e d a l l t h e t i m e i s v e r y c o s t l y a f f a ir . A t a l l l e v e l s t h e p o w er c o n s u m p ti o n m a t t e rs a n de f f e ct i v e m a n ag e m en t o f t h e n e t w o r k i n t e r fa c e s i s c r u c i a l [ 9 ] .

B a nd w id t h O v er h ea d :I m p l e m e n t i n g h a n d o f f s i n w i r e l e s s n e t w o r k r e q u i r e s a d d i t i o n a l t r a f f i c i n t h e f o r m o f p a c k e t s a n d h a n d o f f m e s s a g e sthat are necessary to provide service for users in roaming, and we need to minimize these costs and also provide lessd i sr u pt i on p o ss i bl e w h il e u s er m ov es b e tw e en n e tw o rk s .

D i s co v er t h e r i gh t t i m e t o p er f or m h a nd o ff sI t i s d i ff i cu l t t o p r ed i ct w h en t h e m o bi l e w i ll d i sc o nn e ct f r om t h e c u rr e nt n e tw o rk a n d c o n n ec t t o o t he r n e tw o rk

a c c o r d i n g t o i t s c h a r a c t e r i s t i c s . I t i s d i f f i c u l t t o o b t a i n h i g h e r l e v e l n e t w o r k c h a r a c t e r i s t i c s s u c h a s p a c k e t e r r o r r a t e ,s i gn a l s t r en g th a n d q u al i ty .

W o rk w i th a ll c om m er c ia l ly a v ai l ab l e d e vi c e s o v er w hi c h w e d o n o t h a ve d i re c t c o nt r ol .F or h an do ff w e m us t d ep en d o n e xi s ti ng n et wo rk t ec hn ol og ie s t o p ro vi de t he f ul l r an ge o f w i re l es s n et wo rk s.A lt ho ug h w e a ss um e t ha t w e c an c on tr ol c er ta in r oo m- si ze a nd b ui ld in g- si ze n et wo rk , w e a ls o a ss um e t ha t t hew id e- ar ea n et wo rk i s o w ne d a nd a dm in is te re d b y a t hi rd p ar ty a nd t ha t w e c an no t d ir ec tl y c on tr ol .

T a bl e 2 :S W O T a n a l y s e s f o r 3 G a n d 4 G

S tren gth Weaknes s Opp ortun ity Th rea t

3G Provided ata andspeechservicesu nd er h ig hmobilityenvironment w it h h ig hsecurity,w id es t a ll yo f t el eco moperatorsandequipmentsuppliers,maturetechniquesand

equipment.

C omparativelysmall

bandwidth,limitedn u m b e r o f e n duserequipment,largeinvestments,networku pd ating athigh cost

Has a hig hmarketdemand,combinedwith WLANto provide al ar ge r v ar ie tyof services,can becombinedw it h W iM AXto saveinvestmentson fiber networkingan d improveimplementation s p e e d i n t h e

meanwhile

Threatened bytheco-developmentof WLAN+ V o I P ,WiMAX

4G Largecoveragewith highcapacity,unifiedstandards,comparatively lowequipmentcosts, fasta n d f l e x i b l enetworking,licensedfrequency

band

Immaturet e ch n i qu e a n duserequipment,complexwirelessenvironment,unstable

performancein kin ddistancetransmission,s u f f er i n g f r o mlots of interference

on th el i c e n s e d b a n d

Ca n becombinedwi th WLAN,3 G a n d A D S Letc, serve asthe last mileso lu tion for

both fixedaccess an dwirelessaccess.

ADSL,CABLE,fiberMAN,WLANand 3G.


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Table 2: explain the strength and weakness of other technologies. It also show the opportunity and threats for 3G and4 G t e c h no l o g ie s i n t h e c u r r en t e n v ir o n me n t .

V. CONCLUSION

4 G a n d 3 G w i ll c o ex i st . H o we v er , 4 G w i ll b e t h e d om i na t in g t e ch n ol o gy , s i nc e o n o n e h a nd e q ui p me n t s u pp l ie r sa n d T e l e c o m o p e r a t o r s h a v e i n v e s t e d l e s s m o n e y i n 4 G i n c o m p a r i s o n t o 3 G ; o n t h e o t h e r h a n d , 4 G t e c h n o l o g i e s i sv e r y e f f i c i e n t a n d c o n t a i n a l l t h e p r o p e r t y t h a t i s c o n t a i n b y t h e p r e v i o u s t e c h n o l o g i e s . B e i n g t h e c o m p l e m e n t a r y o f

3 G , 4 G w i l l s e r v e s a n i m p o r t a n t w i d e b a n d i n t e r n e t a c c e s s m e t h o d f o r b o t h i n d o o r s c e n a r i o a n d h o t - s p o t a r e a s . 4 G i scontaining a new wireless metropolitan access technique with many favorable features like flexibility, cost-efficiencyand fastnetworking, etc. There are both competition and cooperation among the two techniques. It's advisable that thet w o o f t h em c o op e ra t e a n d c o mp l em e nt w i th e a ch o t he r w h il e d e ve l op i ng t o ge t he r . T h us a b r an d- n ew f u tu r e f o r m o b il e c o m mu n i ca t i o n i s h i g hl y e x p e ct a b l e.

R e f e r e n c e s

[1]. http://computing.in.msn.com/article.aspx?cp-documentid=3453484 ( a c t i ve t i l l m a y , 2 01 0 )[ 2 ]. M ar k J o hn so n, V P b u si ne ss D e v el op me nt V i s ua l R e v e n u e A s s u r a n c e , F r a u d & S e c u r i t y i n 3 G T e l e c o m S e r v i c e s , journal of E conomic

Crime Management , Fall 2002, Volume 1, issue 2.[ 3 ]. B . T ha i a nd A. Se ne vi r at ne , IP MoA : Integrated P ersonal Mobility A rchitecture, Comp. and Commun., 2001.[ 4] . H as sw aA ., N . N as se r a n d H . H as sa ne in , G e n e ri c V e r t i ca l H a n d o ff D e c i s io n F u n c t io n f o r H e t e r og e n e ou s W i r e le s s N e t w o rk s , i n 2 nd

IE E E /IF IP International Conference on Wireless and Optical Communications Networks (WOCN ' 05). March 2005: Dubai, UAE.[ 5 ]. M ur r ay K. , R. M at hu r an d D . Pe sc h, Intelligent A ccess and Mobility Management in Heterogeneous Wireless Networks using P olicy, in

A CM 1st International Workshop on Information and Communication technologies. 2003: Dublin, Ireland. p. 181-186.[ 6 ]. S al am ah M ., F . T an su , an d N. K ha li l, B uffering R equirements for Lossless V ertical Handoffs in Wireless Overlay Networks, i n t h e 5 7 t h

IE E E Semiannual V ehicular Technology Conference, 2003 (V TC 2003-Spring) . April 2003: Jeju Island, Korea. p. 1984-1987.[ 7]. Chen L.-J., et al., U SH A: a s im pl e a nd p ra ct ic al s ea ml es s v er ti ca l h an d of f s o lu ti on , in IE E E Consumer Communications and

Networking Conference (CCNC' 06). 2 0 0 6 : La s V e g a s, U S A[ 8 ] . E d oa r do A ma l di , An t on i o C ap o ne a n d Fe d er i c o Ma l uc e ll i R adio planning and coverage optimization of 3G cellular networks P u b l i s h e d

online: 4 January 2007 in Springer Science+B usiness Media, LLC 2007 .[ 9] . J ive sh Go vil a nd J iv ik aGo vi l 4 G M ob il e C om mu ni ca ti on S ys te ms : T ur ns , T re nd s a n d T ra ns i ti on publis hed in 2 00 7 I EE E D OI

10.1109/ICCIT.2007.305.[ 10 ] . R aj ee v A gr aw al a nd A n a nd Be de ka r A nalysis of P aging in Distributed A rchitectures for 4G Systems p u b l i s h e d i n A ugust 1216, 2007,

Honolulu, Hawaii, USA . 2007 A CM.

[ 11 ]. K un Y an g an d Ch ri s To dd Model-based Service Discovery for F uture Generation Mobile Systems published in IW CMC06, July 36,

2006, Vancouver, British Columbia, Canada 2006 ACM.[ 12 ] . T ho ma s S pr i ng er a nd K ay K ad ne r Middleware Support for Context-A wareness in 4G E nvironments p u bl i s he d i n P roceedings of the 2006International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM' 06) 2006 IE E E .

[13]. A h m ed H a s s w a, N i d al N a s s e r a n d H o s s a m A seamless context-aware architecture for fourth generation wireless networks P u bl i s he donline: 12 A pril 2007 Springer Science+B usiness B .V . 2007

[14]. W . W . Lu, Broadband W ireless Mobile: 3G and Beyond, W elay copy write @ 2002.


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