ieee journal on selected areas in communications, february 2009

Broadband Mobile Wireless Network Lab

Convergence of Ethernet PON and IEEE 802.16 Broadband Access Networks and its QoS-Aware Dynamic Bandwidth

Allocation Scheme

+Kun Yang, Shumao Ou,Ken Guild,and +Hsiao-Hwa Chen

+Senior Member, IEEE, Member, IEEE

Presenter ： Pao-Wei Hwang

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, FEBRUARY 2009

112/04/20112/04/20 22/17/17

Abstract

IEEE 802.16 and Ethernet Passive Optical Network (EPON) are two promising broadband access technologies for high-capacity wireless access networks and wired access networks,respectively.

To combine the bandwidth advantage of optical networks with the mobility feature of wireless communications, we propose a convergence of EPON and 802.16 networks in this paper

BMW Lab

112/04/20112/04/20 33/17/17

Outline

INTRODUCTION1

CONVERGED NETWORK MODELS2

DYNAMIC BANDWIDTH ALLOCATION SCHEME: WE-DBA3

EVALUATION DESIGN AND RESULTS4

BMW Lab

CONCLUSION5

112/04/20112/04/20 44/17/17

INTRODUCTION

IEEE 802.16 networks point-to-multipoint (PMP) We consider in this paper only PMP mode where BSs need

to be connected to the Internet. Then, how to backhaul these BSs to the Internet? • This is where EPON comes into place.

An EPON is a point-to-multipoint optical access network Its deployment topology can take different shapes such as

bus, ring, and tree. The most popular EPON topology is tree-based architecture

where transmission occurs between an optical line terminal (OLT) and multiple optical network units (ONUs).

BMW Lab

112/04/20112/04/20 55/17/17

INTRODUCTION

EPON supports a total of one Gbps bandwidth in both downstream and upstream which is shared by a group of (typically 16) remote ONUs.

On the average, each ONU possesses about 1/16 Gbps = 65 Mbps bandwidth.

This value matches the total capacity offered by an 802.16 BS which is about 70 Mbps over a 20 MHz channel [6].

BMW Lab

112/04/20112/04/20 66/17/17

INTRODUCTION

G. Shen, R. S. Tucker, C. Chae, ”Fixed Mobile Convergence Architectures for Broadband Access: Integration of EPON and WiMAX”, IEEE Commun. Mag., August 2007.

BMW Lab

112/04/20112/04/20 77/17/17

CONVERGED NETWORK MODELS

A. Virtual ONU-BS (VOB) We introduce a software module called WE-Bridge (short

for WiMAX-EPON Bridge) which is located between an 802.16 BS and an ONU to coordinate joint resource allocation.

112/04/20112/04/20 88/17/17

CONVERGED NETWORK MODELS

B. QoS Support and Mapping we classify the EPON services into three priorities:

• expedited forwarding (EF)• assured forwarding (AF) • best effort (BE)

IEEE 802.16 standard also defines five types• Unsolicited Grant Service (UGS) • real-time Polling Service(rtPS) • extended real-time Polling Service (ertPS) • non-realtime Polling Service (nrtPS) • BE

BMW Lab

112/04/20112/04/20 99/17/17

DYNAMIC BANDWIDTH ALLOCATION SCHEME: WE-DBA

A. Overall Architecture of Proposed WE-DBA Scheme

BMW Lab

112/04/20112/04/20 1010/17/17


B. DBA at OLT We consider an EPON access network with n VOBs. The transmission rate of the network is R Mbps for both

uplink and downlink. The granting cycle is denoted as ,which is the period

of time during which all VOBs are visited by the DBA. Denote the guard time between two timeslots allocated to

VOBs as . Here we assume that VOBs all have the same weight in

terms of getting bandwidth from the OLT.

TEPON

cycle

T g

BMW Lab

OLT VOB SS

112/04/20112/04/20 1111/17/17


Denote as the average guaranteed bandwidth (in bytes) for each VOB under heavy load operation.

traffic originated from 802.16 SSs, after arriving at VOB i, is converted into three service classes of different QoS requirements: EF, AF and BE.

Denote the priority queues of these three classes as P1, P2 and P3.

be the overall requested bandwidth from VOB i.Breq

i

BMW Lab

Bavg

VOB

3

1, 2

j

reqji

req

i)( BB

)( n

RT nT gEPON

cycleavg

VOBB 18

)(

OLT VOB SS

112/04/20112/04/20 1212/17/17


there is a total of excess bandwidth being wasted

[13], the amount of excess bandwidth is evenly shared among h VOBs ,and each VOB gets a share of

Finally, the granted bandwidth to each VOB i, denoted as , can be calculated as:

BMW Lab

hBBexcess

i

excess

i/

Bg

i

Bexcess

)(

3)(|)(1

reqi

avgVOB

reqi

avgVOB

n

i

reqi

avgVOB

excess

BBif

)( BB BBB

)( BBBmin reqi

excessi

avgVOB

g

iB 4),( OLT VOB SS

112/04/20112/04/20 1313/17/17


C. DBA at VOB The task of VOB-DBA is to assign bandwidth to each SS

based on their prioritized bandwidth requests bandwidth requests

• Bandwidth requests of priority P1 are considered first, and then P2 which is followed by P3.

Note that the bandwidth request for each aggregates the BW needs from all SSs

set

)3,2,1( jP j

BMW Lab

OLT VOB SS

112/04/20112/04/20 1414/17/17

EVALUATION DESIGN AND RESULTS

we created two other DBA schemes, DBA1 and DBA2, for comparison. In DBA1, both the OLT and VOBs statically allocate

bandwidth to its client stations.

DBA2 goes between DBA1 and WE-DBA• DBA2 version is a combination of a fixed 802.16 and a

dynamic EPON.

BMW Lab

112/04/20112/04/20 1515/17/17


Each SS serves m clients and each client has following different types of services generated on different connections

OPNET

BMW Lab

112/04/20112/04/20 1616/17/17


BMW Lab

112/04/20112/04/20 1717/17/17

CONCLUSION

The WEN network combines the bandwidth advantage of optical networks with the mobility feature of wireless communications

Our work in this paper only presents some preliminary study in this area with a particular focus on bandwidth allocation.

Many other topics such as scheduling and admission control are to be investigated

BMW Lab

ieee journal on selected areas in communications, february 2009

Documents