Transcript 39279920-ppt-on-Edgex

Seminar on
Enhanced Data Rates for GSM
Evolution(EDGE)
High Speed Wireless Terms




1G- It uses analog transmission (AMPS).
2G - Uses digital transmission for voice signals.
- Improved the battery life for wireless phones.
-Added many features like Caller ID, text
messaging
and intelligent roaming.
-Data is usually transported over voice channels
at speeds ranging from 9.6 kbps to 14.4 kbps.
2.5G- No change in the way voice is transported,
-Introduced packet data services, allowing for
speeds of 20 to 40 kbps about the same speed
as a dial-up service.
3G- Increases the speed of packet data transport
through the network to avg. speeds above 100 kbps.
WHAT IS EDGE?



It stands for Enhanced Data rates for GSM Evolution.
EDGE is extended version of GPRS i.e. EGPRS.
First launched in the United States in 2003 by
Cingular, which is now AT&T.
 EDGE is a new set of GSM-bearer
services that provides packet mode
transmission within the GSM
network & interconnects with
external packet data networks.
 Designed to deliver multimedia
applications such as streaming
television, audio and video to mobile
phones at speeds up to 384 Kbps,
theoretically up to 473.8 kbps.
Salient Features of EDGE







Compliment to 3G.
Standardized by ETSI.
EDGE is deployed over GPRS network.
Provides Data Packet delivery service.
Support for leading internet communication
protocols.
Billing based on volume of data transferred.
Utilizes existing GSM/GPRS authentication
and privacy procedures.
Evolution of EDGE/EGPRS
GPRS v/s EDGE
EDGE only introduces a new modulation technique and new
channel coding that can be used to transmit both packetswitched and circuit-switched voice and data services.
 EDGE is an add-on to GPRS and cannot work alone. And is
therefore much easier to introduce than GPRS. GPRS has a
greater impact on the GSM system than EDGE has.
 EDGE offers significantly higher throughput and capacity.
 EDGE can transmit three times as many bits as GPRS during
the same period of time.
 GPRS can transfer data at rates of 115 kbps theoretically
and up to 60 kbps on physical layer,
whereas EDGE/EGRPS can transfer up to 473.6 kbps and
384 kbps respectively.

GPRS v/s EDGE (cont…)
•
•
With EDGE, the same time slot can support more users.
GPRS and EDGE have different protocols and different
behaviour on the base station system side.
•On the core network
side, GPRS and EDGE
share the same packethandling protocols and,
therefore, behave in the
same way.
•GPRS and EDGE share
the same symbol rate, but
the modulation bit rate
differs.
EDGE Network Architecture
A-bis
Base Station
and Tower
PCU
SGSN – Serving GPRS Support Node- takes care of routing, handover and IP
address assignment and Performs security functions and access control.
GGSN – Gateway GPRS Support Node- gateway/anchor to external networks.
HLR – Home Location Register- database that contains subscriber information.
VLR – Visitor Location Register- mobile station’s profiles are preserved in it.
PSTN – Public Switched Telephone Network
BSC – Base Station Controller
GMSC – Gateway Mobile Switching Centre
PCU – Packet Control Unit- Distinguishes data and voice
SGSN – Serving GPRS Support
Node
• Delivers data packets to mobile stations &
vice-versa.
• Detects and Registers new GPRS/EDGE
MS in its serving area.
• Packet Routing, Transfer & Mobility
Management.
• Authenticates and Maintains user profiles.
• Its location register stores location info. &
user profiles.
GGSN – Gateway GPRS Support
Node
• Interfaces GPRS backbone network with
external packet data networks.
• Converts the EDGE packets from SGSN to
the PDP (Packet Data Protocol) format.
• Converts PDP addresses change to GSM
addresses of the destination user.
• Stores the current SGSN address and profile
of the user in its location register.
Impact of EDGE on existing
GSM/GPRS network




Hardware upgrade to BSS (new transceivers in each cell).
Software upgrade to BS and BSC.
No change in the core network.( independent of user bits)
New terminals
 Terminal which provides 8PSK in the uplink and downlink
 Terminal which provides GMSK in the uplink and 8PSK in the
downlink.
EDGE channel coding & frame structure
Burst N
464 bits
1 data block
Convolution
Coding
Rate = 1/3
Length = 7
Puncture
1392 bits
Interleave
Burst N+1
1392 bits
Burst N+2
8PSK
Modulate
156.25 symbols/slot
Burst
Format
468.75 bits
Burst N+3
348 bits
20 m-sec frame with 4 time-slots for each of 8 bearers
8 Time Slots
0
1
2
3
4
5
6
7
1 Time Slot = 576.92 µs
Tail
symbols
3
Data
symbols
58
Training
symbols
26
Modulation: 8PSK, 3 bits/symbol
Symbol rate: 270.833 ksps
Payload/burst: 348 bits
Gross bit rate/time slot: 69.6 kbps - overhead = 59.2 kbps user data
Data
symbols
58
Tail
symbols
3
Guard
symbols
8.25
348 bits/
burst
Example of EDGE Time Slot
Structure
•BCCH: Broadcast Control Channel- carries synchronization, paging and other
signalling information
•TCH: Traffic channel- carries voice traffic data
•PDTCH: Packet data traffic channel- carries packet data traffic for EDGE
•PBCCH: Packet broadcast control channel- additional signalling for EDGE; used
only if needed
8PSK Modulation in EDGE
•New modulation technique 8-PSK.
•High-level linear modulation in 200 kHz TDMA
method that carries three times more
information through an extended
signal constellation.
•Constellation diagram is simply phasor
diagram representing phases as angles
around a circle.
•EDGE produces a 3-bit word for
every change in carrier phase.
•The symbol rate is 271 kb/s.
•Gross bit rates per time slot
is 69.2 kb/s.
EDGE Modulation, Channel Coding
Scheme & Bit Rates
Scheme
Modulation
Maximum
rate [kb/s]
Code
Rate
MCS-9
8PSK
59.2
1.0
MCS-8
8PSK
54.4
0.92
MCS-7
8PSK
44.8
0.76
MCS-6
8PSK
29.6
0.49
MCS-5
8PSK
22.4
0.37
MCS-4
GMSK 17.6
1.0
MCS-3
GMSK 14.8
0.80
MCS-2
GMSK 11.2
0.66
MCS-1
GMSK 8.8
0.53
Types of EDGE
• EDGE Classic
•
•
•
•
Based on the EDGE standard developed by ETSI.
4/12 reuse.
continuous downlinks on first 12 carriers.
2.4 MHz x2 minimum spectrum.
• EDGE Compact
•
•
•
•
•
•
•
1/3 reuse in space.
Can be deployed in less than 1 MHz of spectrum .
frame synchronized base stations.
reuse of 4 in time for control channels.
partial loading for traffic channels.
discontinuous downlinks.
600 KHz x2 minimum spectrum.
EDGE Classic Multi-slot Gain
Average User Throughput (kb/s)
300
250
single-slot
200
150
Multi-slot
100
50
0
9
18
27
36
45
Ave. # of users per sector
Application of EDGE
30% - 50% of business to business use of internet carried
out on mobile devices.
 IBM wireless group working on application to track
employees.
 File transfer and document sharing for collaborative
work.
 Corporate e-mailing.
 Vehicle positioning through GPS.
 E-banking, Online reservation, E-shoping.
 Pictures, Post cards, Greetings, Presentations.
 Video messages and video conferencing.
 News headlines, flight information, traffic reports, weather
reports, maps etc.

EDGE Advantages
 Time to market
 Designed for existing spectrum: 800/900/1800/1900
MHz
 Low risk technology evolution from GSM/GPRS

GSM global scale & scope
 Chipsets, handsets, infrastructure and applications
 Lower capital investment, better vendor selection
 Global roaming

Short-term benefits: Capacity and performance
 Easy implementation on a GSM/GPRS network
 Cost effective
 Increase the capacity and triples the data rate of GPRS
 Enabling new multimedia services
THANK YOU !