MCDP-LAN: an efficient Multimedia Content Distribution Protocol over LAN UPCT. Polytechnic...

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MCDP-LAN: an efficient Multimedia Content Distribution Protocol over LAN

UPCT. Polytechnic University of Cartagena

MCDP-LAN: an efficient Multimedia Content Distribution Protocol

over LAN

By

Francesc Burrull Francisco Miguel Monzo-Sanchez

Fernando CerdanJoan Garcia-Haro

Josemaria Malgosa Sanahuja

Information and Communication Technologies DepartmentUPCT-Spain

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Outline

1. Scenario1. Motivation and equipment

2. Problems1. Weakness of the Client-Server model2. Intense Multimedia contents demand

3. Proposed solution: MCDP-LAN1. Main features2. Typical MCDP-LAN situation3. MCDP-LAN core

4. Summary, Conclusions and Future Work

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Scenario

Motivation

1. Low cost system built with mass deployed technology

2. Need to guarantee robustness in a commercial environment

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Scenario

Equipment

1. Collection of POS (Point of Sales terminals) interconnected with an Ethernet hub

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Scenario

Equipment

1. POS options:

1. Bar-code reader

2. Touch sensitive screen

3. Photo printer

4. Bill reader

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Problems

Weakness of the Client-Server model

1. If a server malfunction occurs the whole system goes down

POS POSPOSPOSPOS

Server

1 2 i N-1 N

Multimedia content

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Problems

Intense Multimedia content demand

POS POSPOSPOSPOS

Server

1 2 i N-1 N

Multimedia content

1. If an intense demand occurs (typical) server collapses

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Proposed solution: MCDP-LAN

Main features

1. Broadcast communications

2. Traffic in the LAN independent of the product demand

3. Traffic independent of the number of POS

4. Traffic only depends on content appearance in the LAN

POS POSPOSPOSPOS1 2 i N-1 N

Multimedia content

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Typical MCDP-LAN situation (I)

1. All of the POS operating normally

POS POSPOSPOSPOS1 2 i N-1 NA

content α

1. New content arrival starts content broadcast

POS POSPOSPOSPOS

α

2 i N-1 NB

αα αα

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Typical MCDP-LAN situation (II)

1. Malfunction of the POS i

POS POSPOSPOSPOS1 2 i N-1 NC

content β

1. After content broadcast:

POS POSPOSPOSPOS2 i N-1 ND

α, βα α, βα, β

α αα αα

α, β

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Typical MCDP-LAN situation (III)

1. (re)appearance of the POS i

POS POSPOSPOSPOS1 2 i N-1 NE

content γ

1. After content broadcast:

POS POSPOSPOSPOS2 i N-1 NF

α, β, γα, γ α, β, γα, β, γα, β, γ

α, βα α, βα, βα, β

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Typical MCDP-LAN situation (IV)

1. Worst case: user in POS i demands content β

1. A broadcast of the content β has to be repeated from any of the POS that has this content: Performance degradation

POS POSPOSPOSPOS2 i N-1 NG

α, β, γα, γ α, β, γα, β, γα, β, γ

β

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MCDP-LAN core

1. Broadcast -normal operation-

1. POS i starts a broadcast -packet 1-

2. POS i receives x acknowledges (1<=x<=N), adds them to a list and timeout of packet 1 expires

3. POS i continues packet 2 broadcast, waiting for all the acknowledgements in the list to broadcast packet 3, and so on.

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MCDP-LAN core

1. Broadcast -special cases-

1. If an expected acknowledgement is missed, then when timeout expires the responsible POS is eliminated from the list

2. If a new unexpected acknowledgement appears the responsible POS is added to the list

3. If a negative acknowledge occurs the list is cleared and the broadcast algorithm restarts from the requested packet.

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MCDP-LAN core

1. Reception

1. Normal operation consists of sending an acknowledgement for every received packet

2. If an unexpected packet is received, it is discarded and a negative acknowledgement is sent

3. If negative acknowledgements are sent often the POS stops the reception of the content (favouring the rest)

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Summary

Conclusions and Future Work

1. The response time using MCDP-LAN model is shorter than using the traditional Client-Server model

2. The required robustness of the system using MCDP-LAN is not compromised by Client-Server networking issues

3. Future work: Adapting the system to a mobile environment

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MCDP-LAN: an efficient Multimedia Content Distribution Protocol

over LAN

By

Francesc Burrull Francisco Miguel Monzo-Sanchez

Fernando CerdanJoan Garcia-Haro

Josemaria Malgosa Sanahuja

Information and Communication Technologies DepartmentUPCT-Spain

MCDP-LAN: an efficient Multimedia Content Distribution Protocol over LAN UPCT. Polytechnic...

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