presentation on edge
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PRESENTATION ON EDGE. BY- MAYANK SINGH POOJA YADAV TULIKA SAHU RAKESHWARI LAHRE AAKANKSHA SONI. EDGE. What is EDGE EDGE Modulation and coding schemes Link Adaptation EDGE Management ARQ Window sizing. What is EDGE. E nhanced D ata Rate for G PRS E volution - PowerPoint PPT PresentationTRANSCRIPT
PRESENTATION ON
EDGE
BY- MAYANK SINGH POOJA YADAV TULIKA SAHU RAKESHWARI LAHRE AAKANKSHA SONI
EDGE What is EDGE EDGE
Modulation and coding schemes Link Adaptation
EDGE Management ARQ Window sizing
What is EDGE Enhanced Data Rate for GPRS Evolution
In GSM standards also known as EGPRS (Enhanced GPRS)
Wireless packet data access to Internet Same as GPRS only faster and more robust
Supports asymmetric traffic on the radio link
Difference between EDGE and GPRS is only on air interface
EDGE Bandwidth Requirements EDGE introduces:
8PSK modulation. Increases raw throughput by a factor of
three (over GMSK) More efficient use of Spectrum Increases the
New coding schemes MCS1 to MCS9
EDGE impacts: Air interface Backhaul requirements
GPRS Vs. EDGE
New EDGE Modulation & Coding Schemes
GSM/GPRS uses GMSK modulation (Gaussian Modulated Shift Keying) and 4 Coding Schemes are defined in GPRS : CS1 to CS4.
EDGE introduces a new modulation : 8PSK (8 Phase Shift Keying).
8PSK defines 8 states of the radio signal instead of 2 for GMSK.
3 bits can be coded with 8PSK instead of 1 for GMSK.
GMSK vs 8PSK Modulation
Link Adaptation
• The modulation and coding scheme is selected based on the radio channel condition— For high interference conditions, coding with lower data rates and
better error correcting capability is used— For low interference conditions, coding with higher data rates and
less error correcting capability is used
• Link adaptation improves the through put for the network
• Base station determines coding and modulation schemes to be used for the uplink and the downlink
Link Adaptation mechanism
• Measurement• MS measures the signal quality of
each received block.
• Report• MS reports the signal
measurement to PCU.
• Adaptation• PCU selects the accurate MCS
based on MS measurements.
EDGE Performance More users with more throughput.
Peak Throughput of 473kbps - Average Throughput 120 kbps
2.5 x GPRS Throughput, or 6.5 x GPRS traffic
Up to 2.5x data throughput for equal trafficGPRS
EDGE
GPRSEDGE
Up to 6.5x traffic for same bandwidth (15 kbps/slot)
DataThroughput
Users
Equal Traffic Model
Equal QoS Model(Data Equivalent to Erlang’s Law)
Or
EDGE Significantly improves GPRS Performance
EDGE Management ~ARQ Windows
ARQ Window determines how many MAC blocks can be transmitted before the first block in the window gets acknowledged
If the ARQ window limit is reached before the first block in the windows gets acknowledged, a stalling condition is reached
No new blocks are transmitted Only retransmission of the first unacknowledged block Result in loss of throughputs
Summary EDGE is EGPRS or Enhanced GPRS
Brings speed and robustness New modulation and coding schemes Link adaptation Incremental redundancy
Uses the GSM/GPRS Radio Access equipment
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