GB BT04 E1 0 GSM Advanced Technology-32

7/21/2019 GB BT04 E1 0 GSM Advanced Technology-32

1/27

GB_BT04_E1_0 GSM Advanced Technology

Course Objectves!

Understand HR services and implementation methods

Understand principles of ZTE ultra-distance coverage

technology

Understand concepts, features and specifications of

EDGE technology

Grasp satellite Ais transmission configurations


2/27

Contents

1 "# Servces$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$1

!"! #asic $oncepts""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!

!"% HR &rame 'tructure""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!

!"( HR 'ervice )mplementation"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""(

!"* HR 'ervice Upgrade"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""*

!"+ HR $hannel Allocation 'trategies""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""+

!" HR 'ervice Applications"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

% &ltra'(stance Coverage Technology$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$)

%"! Technological #acground""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""".

%"% /rotocol Restrictions""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""".

%"%"! Radio )nterface Restrictions"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""".

%"( #reathrough 0ethods"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!%

%"("! #reathrough 0ethod !"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!%

%"("% #reathrough 0ethod %"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!(

* E(GE Technology$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$1+

("! Definitions""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!1

("% &eatures"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!1

("( 'pecifications""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!2

("* 3ey Technologies""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!.

("*"! EDGE 0odulation 0odes"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""!.

("*"% EDGE Radio #loc 'tructure""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""%4

("*"( $hannel $oding"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""%4

4 Satellte Abs Technology$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$%*


3/27

*"! 5vervie6"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""%(

*"% 'atellite Transmission &eatures and 'olutions"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""%(

*"( Z7G!4-#'' 'atellite Ais /rinciples""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""%*

*"* Z7G!4-#'' 'atellite Ais /hysical $onfigurations and Re8uirements"""""""""""""""""""""""""""""""""""""%*

*"+ Z7G!4-#'' 'atellite Ais $onfigurations""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""%+

*"+"! Timeslot $onfigurations during $ommissioning 9D)/ '6itch 'etting:"""""""""""""""""""""""""""""%+

*"+"% /recautions of Radio /arameter 'ettings""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""%1


4/27

1 HR Services

1.1 Basic Concepts

As defined in G'0 specifications, the G'0 physical layer is comination of &D0A

and TD0A" G'0 fre8uency ands are divided into many %44-H; channels according

to fre8uency division principles" )n G'0 specifications, each channel has an Asolute

Radio &re8uency $hannel


5/27

is enhanced and the net6or congestion rate is reduced" Ho6ever, it also rings aout

the negative effect that the channel coding rate decreases and voice 8uality degrades"

&igure !"% -! sho6s the relationship et6een the &R channel=s frame structure and the

HR channel=s frame structure"

&igure !"%-! Relationship et6een &R-coded Data &rame and HR-coded Data &rame

ZTE e8uipments support oth static HR service and dynamic HR service"

'tatic HR service

'tatic HR service means that the system HR channels are decided in net6or

planning, and the static configuration is made on the system 50$R e8uipments"

During the system running, the HR channel occupies fi?ed carrier and timeslots,and each timeslot on the carrier maintains its status as HR or &R that is set 6hen

eing allocated, and the status can not e changed" &ine ad@ustment can e made

to the static configuration in later net6or optimi;ation"

Dynamic HR service

Dynamic HR service means that only &R service is provided during the system=s

initial running, and the ratio of commissioned HR channels depends on the traffic

change during system running"

hen the traffic increases, the reserved dynamic HR au?iliary timeslots of

Ais interface are used to start the conversion from idle &R channels to HR

channels" )n this 6ay, HR channels are used to increase the system traffic

capacity and reduce the congestion rate"

hen the traffic decreases, the conversion from idle HR channels to &R

channels is started, to guarantee the system voice 8uality 6ith &R channels"

ith dynamic HR service, the advantages of HR service can e fully utili;ed in

handling traffic urst and net6or capacity e?pansion"

2


6/27

* 'atellite Ais Technology

1.3 HR Service Implementation

All Z7G-#'' e8uipments, including #'$ and #T', are designed 6ith good modular

structures" )t maes the system upgrade and e?pansion very easy, and provides

convenience for deploying ne6 functions and ne6 services"

)n ZTE #'' e8uipments, the HR service implementation is different from that of the

traditional &R-ased system in the follo6ing three aspectsB

Transcoder unit 9T$:

Ais interface unit et6een #'$ and #T'

#T' channel coding>decoding unit

&igure !"( -% illustrates the structure of Z7G!4-#'' system that reali;es HR service"

The HR frame structure of each node is descried in the figure"

Uplink: conversion from 8 kbps to 16 kbps

Downlink: conversion from 16 kbps to 8 kbps

BB

TT

SS

BB

SS

CC

TT

CC

UU

BB

SS

CC

RR

MM

MM

LA

BB

SS

CC

SS

CC

MM

MS supporting

HR-service

BB

TT

SS

BB

SS

CC

TT

CC

UU

BB

SS

CC

TT

CC

UU

BB

SS

CC

RR

MM

MM

BB

SS

CC

RR

MM

MM

OM-R Server OM-R lient

LA

BB

SS

CC

SS

CC

MM

BB

SS

CC

SS

CC

MM

!rocessing HR fr"me

#-interf"ce 6$

kbps voice c%"nnel

onfiguring HR&

perform"nce me"surement&

"n' service flow processing

16 kbps

HR c%"nnel

16 kbps

HR c%"nnel#bis interf"ce 8

kbps HR c%"nnel

Uplink: 'eco'e HR fr"me to 6$ kbps voice

c%"nnel

Downlink: enco'e 6$ kbps voice c%"nnel into

16 kbps HR c%"nnel

onfiguring HR&

perform"nce me"surement&

"n' relev"nt O(M

processing

&igure !"(-% 'chematic Diagram of Z7G!4-#'' 'ystem 9'upporting HR 'ervice:

)n Z7G!4-#'' system, as sho6n in &igure !"( -%, the HR service implementation

process in uplin direction is as follo6sB

The HR frame is processed y #T' first and then sent to R00 through Ais interface"

3


7/27

G#C#T4*CE!C4 G'0 Advanced Technology

#)// performs the internal conversion from 2 ps channel to ! ps channel and

then sends the frame to #it-5riented '6itching


8/27


(" Add the T$ unit 9actually, the EDRT oard: that supports HR service" The EDRT

oard can automatically recogni;e the uplin voice coding format at Ais

interface" The do6nlin coding automatically adopts the same code as that in

uplin coding" )f the system has een configured 6ith the EDRT oard that

supports HR service, then such EDRT oards can support HR service only

through soft6are upgrade" )f the system has een configured 6ith oards that do

not support HR service through soft6are upgrade, then add the EDRT oard that

supports HR service, and the original oards can still e used to allocate &R

channels"

*" $ommissioning the HR service means e?panding the system capacity" Thus A-

interface capacity should e e?panded according to ne6 capacity planning"

0oreover, capacity e?pansion should e performed for the


9/27


system 6ill automatically allocate another resource instead"

The T$ that supports HR service also supports &R and E&R" After T$s related to&R and E&R are occupied, the system 6ill allocate T$s that support HR service to

satisfy &R and E&R re8uirements" After T$s that support HR service are

occupied, the system stops allocating HR radio resource, and allocates the &R

channel and E&R channel until the T$ resource that supports HR service is

availale"

1.& HR Service Applications

ith the HR service, rapid capacity e?pansion can e reali;ed on the current net6or

to relieve the pressure of radio net6or fre8uency ands and capacity, and solve the

traffic congestion" )n different situations, such as common capacity e?pansion or

handling emergency urst traffic, different strategies should e adopted"

!" HR applications in area 6ith urst traffic

The HR service is most effective in handling urst traffic in areas such as the

stadium, campus, or rende;vous" These areas all have the common feature that

the heavy traffic occurs periodically or suddenly" &or e?ample, the traffic

increases suddenly during a match in a stadium, and the traffic on campus

increases suddenly after class" The dynamic HR service is most appropriate to

apply in such situations" )n normal cases, the traffic is lo6, and the channel is in

&R status" hen the traffic increases suddenly, the channel automatically

converts to HR status, relieving the traffic congestion and avoiding the 6aste

that is usually caused y the common capacity e?pansion"

%" HR applications in area 6ith dense traffic

The traffic is dense in areas such as the dense uran area, airport, rail6aystation, and pla;a" ith the rapid development of net6or suscriers, the

re8uirement of capacity e?pansion in such areas also increases greatly"

)n order to avoid fre8uent net6or ad@ustment, the HR service can e adopted to

temporarily relieve the pressure of capacity e?pansion" #efore the ne?t capacity

e?pansion is performed, commissioning the dynamic HR or static HR can

handle the emergent capacity increase" The HR service, comined 6ith a long-

term planning and capacity e?pansion, provides a fle?ile choice for operators in

capacity e?pansion" 0oreover, the HR service is also a solution for net6or

6


10/27


capacity e?pansion for dense uran area 6here the fre8uency resource is limited

and the site e?pansion is infeasile"

(" HR applications in area 6ith lo6-end users

)n some areas 6ith lo6-end users such as the remote rural area, operators also

provide the coverage to enhance their competition po6er" Ho6ever, such areas

have sparse users and the Average Revenue /er User 9AR/U: is lo6, the ratio of

investigation to output of the operator is very lo6"

These lo6-end users do not have high re8uirement for the voice 8uality" Thus

the HR service 9static HR or dynamic HR: can e adopted together 6ith some

6ide-coverage technologies to reali;e a lo6-cost coverage"

5n the other hand, the urst traffic might occur in such lo6-end traffic areas,

such as capacity changes due to users= migration" The HR service can e used as

a practical solution for such prolems"

7


11/27

2 Ultra'(istance Covera"e Tec%nolo")

2.1 Tec%nolo"ical Bac*"roun#

)t is specified in G'0 protocols that the ma?imum access radius of G'0 .44 0H;

system is (+ m, and the corresponding Time Advance 9TA: is (" 5n 'A$$H, TAs of

the ! header and the protocol message of each layer are all set in its"

'uch restrictions in G'0 protocols are mainly due to that the coverage larger than (+

m is difficult to reali;e in the G'0 .44 0H; environment, and can e reali;ed only

in some special propagation environments"

ith the evolution of G'0 protocols, there are more fre8uency ands" #ecause the

propagation loss of G'0 *44 0H; system is less that that of G'0 .44 0H; system, it

is specified that the coverage radius of the former can e larger than (+ m, the

ma?imum access radius of the former can e !%4 m, and the corresponding TA is up

to %!." &or the time eing, e?cept for G'0 *44 0H; system, other G'0 systems do

not support TA that is larger than ("

2.2 +rotocol Restrictions

This section introduces restrictions of the coverage distance in G'0 protocols"

2.2.1 Ra#io Inter,ace Restrictions

)n G'0 system, each carrier adopts the TD0A mode, that is, eight timeslots constitute

a frame, and the eight timeslots correspond to eight physical channels respectively, as

sho6n in&igure %"% -("

)S1 )S* )S+ )S$ )S, )S6 )S- )S.)S.)S- )S1

&rame

Time A?is

&igure %"%-( G'0 'ystem &rame Definition

During the call process, one user occupies one timeslot 9time 6indo6:, and at the ase

9


12/27

station, each timeslot corresponds to a user" Thus the 0'-sent data that is received y

the ase station can only fall into the user=s time 6indo6, other6ise, the ne?t channel

6ill e influenced"

)f 0' is in the idle status, it does not no6 the distance from it to #T'" Therefore,

6hen sending the first access re8uest, 0' taes its o6n time 6indo6 as reference"

#ecause delay e?ists in space transmission, the time 6indo6 has a certain offset 6hen

the 0' signal actually reaches #T', that is, delay e?ists, as sho6n in &igure %"% -*"

)ot"l 'el"/

0"se st"tion

MS

Uplink 'el"/ Downlink 'el"/)ime

Sen' Receive

&igure %"%-* Access /ulse Delay

#T' has strict re8uirement for the time 6indo6" )n order to mae the 0' signal fall

into the receiving time 6indo6 of #T' efore it reaches #T', 0' must send the signal

ahead of time" #T' specifies the TA and sends it to 0'" The TA is in it unit"

The length of a TA is one yte" As specified in G'0 protocols, oth G'0 .44 0H;

system and G'0 !244 0H; system uses si? its to send the TA and the other t6o its

are reserved" Thus the ma?imum TA value is (, i"e" ( its, of 6hich each it e8uals

(". ms"

The space transmission delay includes uplin delay and do6nlin delay 9the uplin

distance e8uals the do6nlin distance:" The signal is transmitted at the velocity of

light" The ma?imum coverage radius is calculated as follo6sB

9( F (". F !4-: F ( F !42> %(+ m

Thus for G'0 .44 0H; system and G'0 !244 0H; system, the ma?imum coverage

radius is specified as (+ m in G'0 protocols" The follo6ing lists the restrictionsB

!" Restrictions of Access #urst 9A#:

&or the A# of 0', 0' sends it according to its o6n time reference TA 4"

0


13/27


14/27


PREMEASUREMENT REPORT

CHANNEL REQUIRED

HANDOVER DETECT

TALKER INDICATION

LISTENER INDICATION

HANDOVER COMMAND 9if the pre-synchroni;ation mode is adopted:

IMMIDIATE ASSIGNMENT

ASSIGNMENT COMMAND

PHISICAL INFORMATION

VGCS UPLINK GRANTED

PDCH ASSIGNMENT COMMAND

The aove messages are restricted y the condition TA I (, thus if TA J (, the

normal signaling processing 6ill e influenced"

2.3 Brea*t%rou"% Met%o#sThere are t6o methods to rea the restriction of coverage distance specified in G'0

protocols 9i"e" the ma?imum TA is (, or the ma?imum coverage radius of G'0 .44

0H; system and G'0 !244 0H; system is (+ m:"

#reathrough method !

Adopts G'0 *44 0H; system, or reali;es the method specified in G'0 *44 0H;

system in G'0 .44 0H; system"

#reathrough method %

#T' adopts the special radio channel mapping technology and improved #T'

receiving technology at radio interface, to guarantee there is no mutual interference

et6een #T's"

2.3.1 Brea*t%rou"% Met%o# 1

According to G'0 protocols, only the G'0 *44 0H; system can have TA that is

larger than ( and the ma?imum TA value is %!."

2


15/27


&or G'0 *44 0H; system, t6o fre8uency ands are defined in G'0 protocolsB G'0

*+4 0H; and G'0 *24 0H;" As to date, the G'0 *44 0H; system has not een

commerciali;ed"

The follo6ing lists the advantage and disadvantage of reathrough method !B

Advantage

'ince the specification in G'0 protocol is roen through, there is no capacity

limit 6hen reali;ing a coverage distance larger than (+ m"

Disadvantage

#ecause the G'0 .44 0H; 0' does not adapt to G'0 *44 0H; system,appropriate 0' is re8uired, ut it is difficult to reali;e in actual applications"

2.3.2 Brea*t%rou"% Met%o# 2

)f the coverage radius e?ceeds (+ m, then 0' must support TA J (" Ho6ever, the

ma?imum TA recogni;ed y G'0 .44 0H; 0' is ( its" )t is impossile to upgrade

all 0's, thus the restriction that the ma?imum coverage radius is (+ m can e roen

through y applying special radio channel mapping technology and improved #T'

receiving technology at the radio interface" )n other 6ords, #'' should e upgraded"

The follo6ing lists the advantage and disadvantage of reathrough method %B

Advantage

)t is easy to e applied ecause no change should e made in 0' and the cost is

lo6"

Disadvantage

A certain system capacity is sacrificed" )n normal cases, one carrier provides eight

channels" )f the coverage area is very large, there might not e eight channels" The

numer of channels depends on specific net6oring solutions"

The follo6ing introduces a simple and practical solutionB

)f the coverage radius of G'0 .44 0H; system is larger than (+ m, then t6o

timeslots are used to function as one channel to satisfy the re8uirement of a 4 m !%4

m coverage area" )n other 6ords, 6hen 0' sends a channel re8uest, the access urst

pulse received at #T' spans t6o timeslots, thus the control channel adopts t6o

physical channels, i"e" t6o consecutive timeslots"

3


16/27


The ma?imum TA value of 0' at the radio interface is (" )f the space delay is larger

than (, the time during 6hich the signal arrives #T' spans t6o timeslots, as sho6n in

&igure %"( -+" The dedicated control channel and the traffic channel also use t6o

ad@acent physical channels"

. . 11

Total space delayB ,(

. 6 -1 *

* + $ , 6 -

+ $ , .-6,

'ent y

#T'

'ent y

0'

'end 6ith a TA of ,( its

&igure %"(-+ Delay Relationships

$onsidering that #T' adopts t6o timeslots to process a user=s data, the second timeslot

is called e?tended channel, as sho6n in&igure %"( -"

% ( * + , 1 %

. . 11

&rame

E?tended channel

&igure %"(- E?tended $hannel

&igure %"( -1 sho6s the carriers after channel e?pansion" 5riginally, a TR7 can

provide eight physical channelsK after the channel e?pansion, a TR7 has four physical

channels, the carrier capacity is halved"

.

.

+*1

1 * + $ , 6 -Origin"l )R

23ten'e'c%"nnel )R

&igure %"(-1 Actual


17/27


can not reach !%4 m due to large propagation loss of G'0 .44 0H; system and

uplin>do6nlin alance prolems"

To restrict the upper-layer signaling, perform the follo6ing operationsB

Upgrade #'$ soft6are, and e?pand the TA field definition in the original messageK

Adopt the actual TA value at #T'K

&or a TA to e sent to 0', if TA I (, then send the actual TA value to 0'K if TA J

(, then al6ays send ( to 0'"

5


18/27

3 -(- Tec%nolo")

3.1 (e,initions

Enhanced Data for G'0 Evolution 9EDGE: includes Enhanced General /acet Radio

'ervice 9EG/R': and Enhanced $ircuit '6itched Data 9E$'D:" EDGE is a method

used to improve the data transmission rate during G'0 radio connection"

Essentially, EDGE is only a ne6 modulating and channel encoding technology, 6hich

can e used to transmit /acet s6itching 9/': and $ircuit '6itching 9$': data>voice"

As an evolved G/R'-to-U0T' solution, EDGE enales the net6or operator to use

current radio net6or e8uipments to the ma?imum e?tent" )t also provides /$

multimedia communication services ahead of time efore the third generation moile

net6or ecome commerciali;ed"

3.2 Features

The system architecture of EDGE net6or is similar to that of G'0 net6or" Thefollo6ing lists features of the EDGE technology in the access service and net6or

estalishmentB

!" Access service

The and6idth is increased greatly" The pea transmission rate of moile data

service is up to (2* ps"

)t provides more precise net6or-layer positioning service"

%"


19/27

communication control layer, and communication connection layer" The

interface et6een layers is standard" The hierarchical architecture maes the call

control and communication connection mutually independent" )t also fully uses

advantages of the pacet s6itching net6or, maing the and6idth allocation

closely related to the traffic" )t especially suits the o)/ service"

0edia Gate6ay 90G: is adopted in EDGE" 0G has the same functions as

'ignaling Transfer /oint 9'T/:, and can reali;e the signaling net6or

estalishment in )/ net6or" 0oreover, 0G is not only the interface et6een

G'0 circuit s6itching service and /'T< ut also the interface et6een Radio

Access


20/27


/hase %B provides real-time services not included in phase ! and adopts the ne6

modulating technology"

The EDGE standardi;ation, 6hich 6as initiated y ET')>'0G%, has started from the

feasiility research y Ericsson and


21/27


&igure ("*-2 2-/'3 0odulation 0ode

$ompared 6ith G0'3, 2-/'3 has the same symol rate, ut the it rate triples"

'ymol rateB %14"2(( sym>s

Timeslot it rateB 4 %%"2 ps 9G0'3:K 4 ." ps 92-/'3:

3.!.2 -(- Ra#io Bloc* Structure

&igure ("* -.sho6s the structure of EDGE radio loc"

&igure ("*-. EDGE Radio #loc 'tructure

3.!.3 C%annel Co#in"

The nine 0$'s of EDGE are categori;ed into three groups according to their

characteristicsB

&amily A 90$'-(, 0$'-, 0$'- 2, 0$'-.:

&amily # 90$'-%, 0$'-+, 0$'-1:

&amily $ 90$'-!, 0$'-*:

&or coding scheme structures in the same group, either one structure includes another

or eing included y another, 6hich maes it easy to reali;e conversion et6een

coding rates"

)n practical applications, alance should e ept et6een the transmission rate of valid

20


22/27


information and the valid transmission 8uality" The lo6-rate channel coding scheme,

6hich contains many redundancy error correction codes ut 6ithout transmitting much

valid information, is suitale for an environment 6ith poor transmission 8uality" &or

e?ample, on the edge of a cell, the lo6-rate G0'3 modulation method 0$'! * is

more suitale for compensating poor lin 8ualityK in the central area of a cell 6here

propagation conditions are good, the high-rate 0$' is often adopted"

As sho6n in&igure ("* -!4, EDGE has distinctive advantages over G/R'"

%%"*

%.",

**"2

+*"*

+."%

G0'3

2-/'3

overhead O protectionpayload of user

0$'-!

0$'-%

0$'-(

0$'-*

0$'-+

0$'-,

0$'-1

0$'-2

0$'-.

2"2

!!"%

!*"2

!1",

G0'3

$'-!

$'-%

$'-(

$'-*

2 2"2

!% !%"2

!*"* !+"%

%4 %4"2

G/R'

EDGE

&igure ("*-!4 EDGE vs" G/R'

2


23/27

! Satellite A0is Tec%nolo")

!.1 vervie

)t is inconvenient to reali;e transmission in remote areas or islands" Usually, the

transmission et6een #T' and #'$ is reali;ed y the leased satellite lin"

!.2 Satellite Transmission Features an# Solutions

The follo6ing prolems 6ill e encountered 6hen the satellite lin is used to reali;e

transmission et6een #T' and #'$"

The delay of Ais lin is long" The information sent from the satellite ground

station is transferred through the satellite and then received y another ground

station" The end-to-end delay is not less than %4 ms, 6hich does not have much

to do 6ith the ground station=s position"

#ER

The satellite lin=s #ER is much larger than that of the ground lin" #ecause of

this factor and the influence of fading, the #ER change is very large" 5n the

other hand, the large delay and #ER on the transmission lin 6ill cause the

message throughput to drop"

$loc

The precision of the satellite Ais cloc is not very good"

The aove prolems do not occur 6hen the ground lin is used to reali;e transmission

et6een #T' and #'$, thus they should e resolved first"

'olutionB

#T' cloc

#ecause the precision of the cloc e?tracted from Ais interface is much less

than the cloc precision specified in G'0 protocols, such a cloc is not used to

synchroni;e #T' any more" )nstead, 6hen using the satellite lin to connect

Ais interface, the high-precision cloc source inside #T' is often used as #T'=

cloc source" )n other 6ords, the inner cloc of #T' is used for synchroni;ation"

23


24/27

/rotocol timer

Ad@ust the interval of timers in some #T'>#'$ protocols to mae theseprotocols to adapt to large delay" The A/D timer of Ais is influenced most"

!.3 415'BSS Satellite A0is +rinciples

Z7G!4-#T' reali;es the satellite Ais y setting transmission modes through setting

D)/ s6itches at #T'" According to the D)/ s6itch setting, #T' sets corresponding

inner processing modes" #'$ automatically identifies the #T' processing mode and

performs relevant processing"

)n order to save the cost of satellite transmission, the satellite Ais often adopts Ais

multiple?ing mode to reduce the numer of timeslots at Ais interface"

!.! 415'BSS Satellite A0is +%)sical Con,i"urations an#Re6uirements

)nterface et6een #T' and satellite transmissionB E!" PG14(, 1+ Q

5nly some timeslots are used in this E!" The timeslots are allocated as follo6sB

&or a #T', the transmission capacity isB

$E))


25/27


!.$ 415'BSS Satellite A0is Con,i"urations

!.$.1 Timeslot Con,i"urations #urin" Commissionin" 7(I+ Sitc% Settin"8

The satellite Ais is identified y the !-it D)/ s6itch on the acplane of the

common shelf at #T'"


26/27


Tale *"+ -* sho6s the D)/ s6itching settings of #T' 9%: rac""

Tale *"+-* D)/ '6itch 'ettings of #T' 9%: Rac

!+ !* !( !% !! !4 . 2 1 + * ( % ! 4

)


27/27


'AE%C/5RTB the E! port of master cainet that connects 6ith slave cainet %

44B master cainet=s $ port

4!B master cainet=s D port

!4B master cainet=s E port

!!B master cainet=s & port

A#)'C/5RTB 50 port numer

44B port A

4!B port #

!4B port $

!!B port D

A#)'C05DEB transmission mode at Ais interface

4B common Ais transmission mode

!B satellite Ais transmission mode

A#)'CT'B 50 A/D timeslot on Ais interface

444B T'!

44!B T'(!

4!4B T'(4

4!!B T'%.

!44B T'%2

!4!B T'%1

!!4B T'%

!!!B T'%+

!.$.2 +recautions o, Ra#io +arameter Settin"s

After the satellite Ais technology is adopted, the delay at Ais interface increases,

6hich causes the duration of channel allocation to increase" To mae 0' successfully

access the net6or, 6hen setting MRA$H $ontrol /arameterN, set T,_-ntegeras (%

and Ma,_#etrans9the ma?imum times of retransmission: as *"

27

GB BT04 E1 0 GSM Advanced Technology-32

Documents

Transcript of GB BT04 E1 0 GSM Advanced Technology-32