Project Report on

WDM/TDM-PON

Presenter: Wen GuInstructor: Dr. Samuel Cheng

Outline

z Introduction

z TDM-PON

zWDM-PON

zWDM/TDM-PON

z References

IntroductionLong haul network

z Since the invention of WDM/DWDM, large amount of fiber have deployed all over the backbone network

z Bandwidth grows significantly

z Greatly surpassed the demand of global user.

Access network

z Stay in the phase of copper wires

z xDSL and cable modem provid much higher transmission speed compared to dial up

z There is a trade-off between bandwidth and loop length

z As the convergence of data, voice, and video traffic, the bandwidth of copper wires restrict the higher data rate

z It is unavoidable that fiber will replace traditional copper wires in access network

Figure 1. xDSL Configuration

TDM-PON

z TDM-PON(Passive Optical Network) has emerged as a promising technology to replace conventional access network.

z Point to multipoint (P2MP) topology without any active components from CO to the user.

Figure 2. PON Architecture

PON EvolutionITU-T G.983

ATM-PON (APON)

z The first Passive optical network standard

z Established in the early 90s last century

z Based on ATM

z Mainly developed in Germany

z Typical data rate: 54 Mbps to 155 Mbps

Broadband PON (BPON)

z Support 622 Mbps

IEEE 802.3ah

Ethernet PON (EPON)

Completed in2004 as part of the first mile project

Based on Ethernet protocol

Data rate: 1.25 Gbps in both downstream and upstream direction

ITU-T G.984

Gigabit PON (GPON)

2.5 Gbps in downstream direction and 1.25 Gbps in upsteam direction

10-GEPON

In early 2006, EPON also began to work on 10 Gigabit/second EPONstandard

Figure 3. History of PON development

EPON Architecture

Figure 4. Ethernet Frame format in EPON

Figure 5. EPON Architecture

Evaluation of TDM-PON

Security issues

z Broadcast nature Bandwidth sharing

z each user could get is also diminished.

Short transmission distance

z Due to the fact that many users share an optical splitter

Complicated bandwidth allocation protocol

z The protocol needed to implement TDM and dynamically allocate bandwidth is very complicated and not easy to realize.

WDM-PON

Dedicated wavelength from OLT (CO) to ONU

Point-to-point topology

Remote Node (RN) replace splitterMultiplexer / demultiplexer

Each user is equipped with a transmitter and receiver

WDM-PON Architecture

Figure 6. WDM-PON Architecture

Evaluation

Pros:

Huge bandwidth and guaranteed Quality of Service (QoS)

Safe and good security

Longer transmission distance

Reduce the complexity

Easier to implement compared to TDM-PON.

Cons:

Only but pretty huge issue: cost

z Gbps rates of WDM-PON is too large for a single user

z Big portion of the bandwidth of one wavelength is wasted

z Large number of wavelengths needed

z more fibers

z more transceivers

z build such architecture as well as the maintenance fee

Thus, unless

z Drop of cost of components

z Component installation fee large

z Increase of bandwidth demand

z Actually impractical to implement WDM-PON in at least a few years

So, what can we do?

WDM/TDM-PON

z Compromise between WDM-PON and TDM-PON

z Combine the advantages of Both technologies

z First WDM, then TDM

z One wavelength per ONU

z Several NTs (Network Terminal) connected to one OUN

z Each NT serves one or more users

z Traffic from/to NT are time multiplexed

Figure 7. WDM/TDM PON Architecture (Downstream)

Figure 7. WDM/TDM PON Architecture supporting two topology

Conclusionz Unlike EPON which has already been applied and deployed

z WDM/TDM-PON now is just a proposal and active research area

z Not specified as any standard yet

But we believe

z WDM/TDM-PON combines the advantages of TDM-PON and WDM-PON

z Further research of the protocol and architecture

z WDM/TDM-PON has enormous potential market.

References[1] Stamatios V. Kartalopoulos, Next generation hierarchical CWDM/TDM-PON network

with scalable bandwidth deliverability to the premises, Optical Switching and Networking, Volume 2, Issue 3, November 2005, Pages 163-175.

[2] Glen Kramer and Gerry Pesavento, Ethernet Passive Optical Network (EPON): Buildinga Next-Generation Optical Access Network, IEEE Communication Magazine, Feb. 2002, pp. 66-73.

[3] Lee, C.-H.; Sorin, W. V.; Kim, B. Y., Fiber to the Home Using a PON Infrastructure, Lightwave Technology, Journal of Volume 24, Issue 12, Dec. 2006 Page(s):4568 4583.

[4] Sierra, A.; Kartalopoulos, S.V., Evaluation of Two Prevalent EPON Networks Using Simulation Methods, Telecommunications, 2006. AICT-ICIW '06. International Conference on Internet and Web Applications and Services/Advanced InternationalConference on 19-25 Feb. 2006 Page(s):48 48.

Q ?