Chapter 8

Photonic Networks

Contents

• Basic Networks• SONET/SDH Standards• Broadcast & Select WDM Networks• Wavelength-Routed Networks

Basic Networks• Stations or Data Equipment Terminal (DAT)

• Networks

- Local Area Networks (LAN)

- Metropolitan Area Network (MAN)

- Wide Area Network (WAN)

• Node

• Topology

- Linear Bus

- Ring

- Star

• Switching

• Routing

• Protocol

• Router

3 Network Topologies

Bus Topology

Ring Topology

Star Topology

Passive Linear Bus Topology

Simplex linear bus with uniformly spaced stations

Liner bus versus star coupler

SONET/SDH

STS-1 SONET framewith 51.84 Mb/s

STS-N SONET framewith 51.84N Mb/sN=1,3,12,24,48,192

(90 bytes/row)(9 rows/frame)(8 bits/byte)(125 microsecond/frame)=51.84 Mb/s

SONET/SDH

SONET level Electrical level Line rate (Mb/s) SDH equivalent

OC-1 STS-1 51.84 -

OC-3 STS-3 155.52 STM-1

OC-12 STS-12 622.08 STM-4

OC-24 STS-24 1244.16 STM-8

OC-48 STS-48 2488.32 STM-16

OC-96 STS-96 4976.64 STM-32

OC-12 STS-192 9953.28 STM-64

Technical Information

• For more information about SONET/SDH standards and their range, receiver sensitivity, optical wavelength for various data rate, look at:

• http://www.itu.int (International Communication Union)• ITU-T Recommendations G.652, G.653, G.655, G.957, G.691,

G.692• Tables 12-3, 12-4, 12-5 in the text book give you an idea about ITU

recommendations for different photonic network configurations, standards, and interfaces.

SONET/SDH Ring 2-Fiber UPSR (Unidirectional Path Switched Ring)

Generic two-fiber unidirectional network with counter-rotating protection path.

Flow of primary and protection trafficfrom node 1 to node 3.

SONET/SDH Networks

Add/Drop Multiplexer

WDM Network

Dense WDM deployment of n wavelengths in an OC-192 trunk ring

Broadcast & Select Networks

StarBus

Two physical architectures for a WDM LAN

Wavelength-Routed Networks(Wavelength reuse, wavelength conversion & optical switching)

Optical Cross-Connects (OXC)