UTKARSH.V.SHARMAMBA Tech (Telecom) 528

WIRELESS QUALITY OF SERVICES

BUT I SAY IT AS…

Quality of Experience…

Factors affecting QOE… Delay Jitter Drop

DELAY & JITTER

t

t

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Original Signal

Delay

Jitter

DROP

One or more packets of data travelling across a computer network fail to reach their destination

sourceDestinat

ion

Network medium

Packet drop

TYPES OF SERVICES

Data Voice Video

[Presentation flow here on will be analysis of the effects of QOE factors on the services]

DATA SERVICES

Something which is stored is data

Delay Retransmission as timer might expire Drop Retransmission

Thus Data service = BEST EFFORT SERVICE

Sender Receiver

1 2 nn+1...

VOICE- A REAL TIME SERVICE

Effect of Drop on voice: No effect because of Voice

concealment program (VCP) running on receiver side.

Thus Voice is NOT DROP SENSITIVE SERVICE

Drops allowed = 1 in 10000 packets.

RRAAMM or RAAAMM

R AR M MA AR M MA

EFFECT OF DELAY ON VOICE

Thus Voice = DELAY SENSITIVE SERVICE

1sec

1sec 3sec

3Sec

Hhheellloo hello (easily interpretable)

Hhhhhhhheeeeeellllllllllllllloooooooooo Hello (Difficult to understand) Hampers QOE

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VIDEO – A REAL TIME SERVICE

If I-Frame (Max Info about frame) drops: Blank Screen. QOE Reduces

If P-Frame or B-frame (less info) drops: Screen doesn’t go blank but Glitch is noticed.

QOE Reduces.

Thus Video = DROP SENSITIVE SERVICE

I- Frame P-Frame

B - Frame I - Frame

THUS WE NOTICED THAT:

DATA Best effort service VOICE Delay sensitive service VIDEO Drop sensitive service.

QUALITY OF SERVICE

QOS

The ability of a network to:- Classify

Incoming information packets as voice, video or data.

Prioritize The forwarding of the classified packets as per

their sensitivity.

Is what exactly is known as QUALITY OF SERVICE.

• IP Network employees QOS easily.

QOS EXAMPLE. This intelligent network is the IP

Network.

QOS Classified incoming info packets. Prioritize the packets.

1 voice 2video 3Data.

Voice

64Kb

Data 700MB

Video 20MB

2MB

THANK YOU