Computers and Electrical Engineering 38 (2012) 1480–1489

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Computers and Electrical Engineering

journal homepage: www.elsevier .com/ locate /compeleceng

Dynamic hierarchical bandwidth allocation using Russian Doll Model inEPON q

S.K. Sadon a,⇑, N.M. Din a, M.H. Al-Mansoori b, N.A. Radzi a, I.S. Mustafa a, M. Yaacob a,M.S.A. Majid a

a Center for Communications Service Convergence Technologies, College of Engineering, Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43000 Kajang, Selangor,Malaysiab Faculy of Engineering, Sohar University, PO Box 44, PCI 311 Sohar, Oman

a r t i c l e i n f o a b s t r a c t

Article history:Received 16 August 2011Received in revised form 2 May 2012Accepted 2 May 2012Available online 19 July 2012

0045-7906/$ - see front matter � 2012 Elsevier Ltdhttp://dx.doi.org/10.1016/j.compeleceng.2012.05.00

q Reviews processed and approved for publication⇑ Corresponding author.

E-mail address: saja.almola@yahoo.com (S.K. Sad

This paper demonstrates a new hierarchical Dynamic Bandwidth Allocation algorithmusing the Russian Doll Model (RDM) to allocate bandwidth for intra-Optical Network Unit(ONU) in an Ethernet Passive Optical Network (EPON). The allocation of bandwidth is basedon the classification and prioritization of service. The algorithm addresses the requests ofONUs and provides differentiated services by balancing priority and fairness. The simula-tion results show that the proposed algorithm performs well in supporting the triple-playservices, i.e. video, voice, and data, as well as making effective adjustment in balancingbandwidth sharing between the ONUs compared with two other existing Dynamic Band-width Allocation (DBA) algorithm. The proposed algorithms shows significant performanceimprovements in terms of bandwidth utilization, packet delay and the fairness.

� 2012 Elsevier Ltd. All rights reserved.

1. Introduction

The world is experiencing rapid changes in communication technology with the introduction of new generation services[1]. The development of communications infrastructure is fast moving with focus on addressing the bottlenecks at the accessnetworks. One of the promising solutions is the Ethernet Passive Optical Network (EPON) [2]. EPON is highly recommendedfor implementing broadband access optical fiber-to-the-home (FTTH) because its components are low cost, it is capable todeliver bundled services to subscribers, it is scalable and compatible with other types of networks [3,4].

An EPON system consists of Optical Line Terminals (OLTs), Optical Network Units (ONUs), and passive optical splitters(POSs). The OLT is placed in the central equipment room such as the local exchange where it acts as a point of access tothe Wide Area Network (WAN) or Metropolitan Access Network (MAN) while the ONU is placed near or integrated intothe client equipment. The OLTs and ONUs are connected by POSs by distributing the downlink data and aggregating the up-link data that carries 802.3 Ethernet frames [5]. The exchange of control information in EPON involves two Multi-Point Con-trol Protocol (MPCP) messages, i.e. REPORT and GATE. A REPORT message is used to periodically inform OLT about the lengthof the queues from ONU. Meanwhile, the GATE message is issued by the OLT to notify each ONU about their assigned trans-mission times. All active ONUs have their own allocated time to transmit data. The allocated time is known as the grantedcycle [6]. Data transmission from network to users is called downstream transmission while upstream transmission is thereverse of that. All available bandwidth is used to broadcast packets to every ONU through the splitter during thedownstream transmission. However, for the upstream direction, available bandwidth is shared among all ONUs at the optical

. All rights reserved.2

by Editor-in-Chief Dr. Manu Malek.

on).

S.K. Sadon et al. / Computers and Electrical Engineering 38 (2012) 1480–1489 1481

splitter. Each of the ONUs will be assigned with their own non-overlapping time-slot by the OLT to avoid collisions betweenframes from different ONUs [7].

Several Dynamic Bandwidth Allocation (DBA) Dynamic Bandwidth Allocation schemes have been developed over theyears to cope with the challenges of high bandwidth utilization and Quality of Service (QoS) provisioning. However, mostof the algorithms focused on allocating the bandwidth within the OLT capacity to multiple ONUs. A further improvementof the intra-ONU bandwidth allocation is important in order to make appropriate scheduling and to use the resources fairly.One technique of differentiated services bandwidth allocation is the Russian Doll Model (RDM) which has been used widelywith Multi Protocol Label Switching (MPLS) [8].

In this paper, we will introduce a new policy for bandwidth allocation based on RDM for intra-ONU. The new intra-ONUwith RDM allocation policy is used in managing the upstream bandwidth allocation. For the inter-ONU allocation, an OLTalgorithm is used to distribute the bandwidth based on a set of weights, as can be seen in other works [9]. This inter-ONU scheduler deals with the aggregated traffic. But in contrast, intra-ONU algorithm dynamically allocates the bandwidthto the users using the RDM allocator based on the class of service where a class with high priority (voice) will be served first,followed by the medium priority (video) and low priority (data). The fairness in bandwidth allocation to different users isinstilled based on the RDM technique [10].

2. Critical review of DBAs

The bandwidth allocation algorithm is a key component in an EPON’s architecture and is responsible for all decisions re-lated to assignment of transmission windows to ONUs. The DBA plays a very important role in upstream EPON for bandwidthoptimization. From the above point of view therefore, finding an algorithm that is able to cope with classes of traffic requir-ing different QoS became necessary.

The DBA schemes can be divided into two categories: single-level and hierarchical. Most of the researches focused on acentralized architecture that uses a single algorithm inside the OLT. The bandwidth allocation decision for the ONU ismade by the OLT. In the centralized approach, the ONU reports have to travel to the distant OLT to inform the OLT abouttheir bandwidth needs in order for the ONU to be granted with upstream bandwidth. Any software failure in the OLT willhalt the ONU upstream transmission [11]. The scheduler location is centralized and the system has only a single-levelalgorithm, which means that a scheduler located in the OLT would receive information from the ONUs and individuallyschedule each queue located in multiple ONUs. Since the information about each individual queue is collected in oneplace, the centralized scheduler can easily ensure that the required service guarantees are preserved and that the excessbandwidth, if any, is fairly divided among backlogged queues. This will concentrate all the intelligence in the OLT and theONU in this case becomes very simple. Single-level algorithm includes interleaved polling with adaptive cycle time (IPACT)scheme by Kramer et al. [12] which was the first algorithm produced in this area. In this algorithm, the OLT polls theONUs individually in a round-robin fashion to dynamically allocate the bandwidth in accordance with the requested band-width of each ONU.

The single level technique is not considered as a multi-service needs for subscribers because it has many disadvan-tages such as; the limited ability to support different QoS access within an ONU because it deals with each ONU as onepiece. The use of a hierarchical scheme can provide expansibility and efficient usage of resource and solve the scalabilityissues by eliminating the need for a separate GATE and REPORT messages to be sent to each queue over an EPON system[13]. In the hierarchical scheme, the packet scheduler is separated from the queue system; therefore, using this schemealso manages the switch overhead issues of the system. Some examples of hierarchical DBA algorithms are described in[2,14].

Assi et al. [9] improved the limited IPACT algorithm by introducing equations that make full usage of the excessive band-width. The excess bandwidth is exploited by fairly distributing it amongst the highly loaded ONUs. However, this DBA maycause wasted bandwidth since the highly loaded ONUs can receive more bandwidth than requested. Thus, Bai et al. [7] pro-pose a weight-based DBA scheme that is called weighted-DBA. The excessive bandwidth from classes that needed less thantheir thresholds in lightly loaded ONUs is distributed among the classes that needed more than their thresholds in highlyloaded ONUs. The excessive bandwidth distribution was performed according to the weights of the buffer that are assignedto each class. This scheduling mechanism can apparently improve bandwidth utilization, but it may not be able to make suf-ficient use of the idle period in many cases besides causing light load punishment due to the priority of categories in thealgorithm which are according to the arrival of packets. Meaning that, packets that arrived before the time of sending theREPORT were given high priority for transmission which is unfair for the light loaded in the real time traffic.

Although DBA’s algorithms have been proposed in previous years [15–19], these algorithms have difficulties in estimatingthe proper allocation of the bandwidth to each ONU for the discontinuous data traffic such as IP traffic [15]. In addition, thequality of service and the subscriber’s satisfaction are still open issues. In our proposed algorithm, we have combined theRDM with DBA in order to address the efficiency and fairness challenges. The proposed RDDBA scheme separated and re-solved fairness and allowed all ONUs to fairly share the uplink bandwidth according to their bandwidth demands for differ-ent traffic priority classes, such as delay-sensitive and best effort streams. The Diffrentiated Services (DiffServ) functionalitieswere realized and also the performance of the system is analyzed to check on the fairness and bandwidth utilization underdifferent traffic patterns.

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3. Russian doll scheme

In past years, the number and variety of multimedia applications running on IP networks have increasingly grown andnetwork providers have started offering a wide range of services, such as voice-over-IP (VoIP), IPTV, and video on demand(VoD) [20,21]. The bandwidth constraints (BC) model is one of the most important aspects of the Diffserv Aware Traffic Engi-neering (DS-TE) architecture [21], which establishes how the bandwidth can be allocated to different traffic classes. The RDMis found to allow greater sharing of bandwidth among different classes where the lower priority class can use higher priorityclass bandwidth up to the summation of their bandwidth constraints values. The higher priority traffic can preempt lowerpriority traffic to get their full allocated bandwidth [22].

RDM can be used to ensure bandwidth efficiency and QoS of many types of services [10]. RDM can be used in conjunctionwith preemption to simultaneously achieve isolation across the three types of classes, so that each class type is guaranteedits share of bandwidth no matter the level of contention by other classes. RDM promotes bandwidth efficiency and provideprotection against QoS degradation of all traffic types.

In the example of RDM as shown in Fig. 1, Cvoice is the traffic class with the strictest QoS requirements; Cvideo is the med-ium priority, while Cdata is the best effort traffic class. The RDM bandwidth constraints shown in Fig. 1 may be expressed asfollows:

� Cvoice(I) is aggregated bandwidth for voice.� Cvideo(I) is aggregated bandwidth for video.� Cdata(I) is aggregated bandwidth for data.� The video and data requested bandwidth are allowed to use their maximum reserved bandwidth as well as share the

extra available bandwidth which is not used by other classes.� The requested voice cannot use more than BC2, which represented the maximum reserved bandwidth for voice.� The requested voice or video cannot use more than BC1, which also represented the maximum reserved shared band-

width for (video and voice).� Requested voice or video or data cannot use more than BC0. Again, represented the maximum reserved shared band-

width for (data, video and voice).

4. Proposed RDDBA algorithm

To address the fairness problem and enhance the bandwidth utilization, we propose a new hierarchical DBA algorithm,employing a Russian Doll approach. The algorithm is called RDDBA, and the main focus of the algorithm is to divide band-width fairly between different ONUs. To demonstrate and distinguish the advantages of using RDM, we will compare ournew algorithm with the existing hierarchical algorithms for upstream transmission developed by Min et al. [23] and whichis given the acronym of MDBA, and that by Assi et al. [9] called ADBA. The reason for comparing RDDBA with MDBA andADBA is that both algorithms are hierarchical and have inter- and intra-ONU allocations. In addition, both can supportthe triple play service and satisfy the Service Level Agreement (SLA). For comparison study, we have used three types ofpriorities and the same requested bandwidth for all three types of traffic in RDDBA, MDBA and ADBA algorithms. All otherparameters were also the same in all the cases.

The RDDBA algorithm utilized two algorithms for inter and intra scheduling for the OLT and ONU, respectively. Theseschemes have been used to optimize the usage of bandwidth for the upstream bandwidth allocation on EPON. ONU is

Fig. 1. Russian doll schematic diagram.

S.K. Sadon et al. / Computers and Electrical Engineering 38 (2012) 1480–1489 1483

allowed to request bandwidth for all its available traffic requests. The OLT will allocate the bandwidth to the ONUs depend-ing on the weight associated with the excess bandwidth available as shown in Fig. 2.

The following steps describe the algorithm in the OLT for inter-ONU bandwidth allocation where Ri is the total requestedbandwidth, Bdemand is the total demanded bandwidth for heavy load, l, k represent the light and heavy load respectively, G isallocated bandwidth, Bexcess is total extra bandwidth saved from the light load, Bi

excess is ratio for extra bandwidth to each ONUand Bmin is the minimum bandwidth that can be allocated to each ONU:

Step 1: The total requested bandwidth for each ONU is calculated by the formula below.

Ri ¼ Rdatai þ Rvideo

i þ Rvoicei ð1Þ

If the requested bandwidth is less than the allowed bandwidth then the bandwidth given is the requested bandwidth.Step 2: The total demanded bandwidth and the excessive bandwidth will be obtained as in equations below in the samemanner as the algorithm in [9].

Bdemandtotal ¼

XN

i¼1

Rki �

XN

i¼1

Bmini;k ð2Þ

Bexcesstotal ¼

XN

i¼1

Bmini;l �

XN

i¼1

Rli ð3Þ

Then the extra bandwidth will be distributed between the ONUs using Eq. (4) below [9], where Rki represents ONUs with

heavy load, while Rli represents ONUs with light load.

data video voiceR R R Ri i i i= + +

Fig. 2. Inter-ONU bandwidth allocation.

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Biexcess ¼

RiPK2iR

ki

� Bexcesstotal ð4Þ

Step 3: The allocation of the bandwidth for each ONU [9] is calculated using the following equation,(

G ¼

Ri if Ri � Bmini orBdemand

total 6 Bexcesstotal

Bmini þ Bexcess

i otherwiseð5Þ

The steps above are depicted in the flow chart of Fig. 2.For the intra-ONU bandwidth allocation, the amounts of bandwidth allocated follow the limits that are based on the RDM

definition [10],

Bc2 ¼ CvoiceðIÞBc1 ¼ CvoiceðIÞ þ CvideoðIÞBc0 ¼ CvideoðIÞ þ CdataðIÞ þ CvoiceðIÞ

ð6Þ

where Bc2 represents the maximum bandwidth that can be allocated to voice, Bc1 is the highest allowed bandwidth for videovoice, and Bc0 is the maximum acceptable bandwidth that can be given to data, video and voice. Cvoice(I) is the aggregatedbandwidth for the traffic class voice with the strictest QoS requirements from OLT which is 20% of total bandwidth andCvideo(I) is the aggregated bandwidth for video from OLT, i.e.50% of total bandwidth, and Cdata(I) is the aggregated bandwidthfor best effort traffic class (data) from OLT, i.e. 30% of total bandwidth.

The flow chart of Fig. 3 depicts the ONU allocation as described above. Sivideo and Sidata are defined as the limit for videoand data bandwidth based on an agreed SLA. If no sufficient bandwidth is available after checking with the RDM limits thenthe SLA ratios as shown in the equations below are used [23]:

Bvideoi ¼ Bavail Svideo

i

h i= Svideo

i þ Sdatai

� �ð7Þ

Bdatai ¼ Bavail Sdata

i

h i= Sv ideo

i þ Sdatai

� �ð8Þ

5. Results and discussion

A simulation study was performed with the traffic profiles as shown in Table 1. In this work, we study the fairness index,bandwidth utilization, and packet delay to prove that the RDDBA algorithm can give better QoS. This has been done by com-paring the RDDBA with existing hierarchical algorithms, i.e. MDBA [23] and ADBA [9]. The reason for comparing with MDBAand ADBA is that the both algorithms are hierarchical and have inter and intra ONU allocation, In addition, both can be testedusing the same simulation environments and support the triple play traffic.

5.1. Fairness index

The fairness index is a measurement tool that shows how far a fair allocation for the bandwidth between the users withrespect to the ideal fairness value can be made. This helps to ascertain whether users or applicators are receiving a fair shareof system resources amongst many ONUs over EPON.

According to [24], the fairness index f, 0 6 f 6 1 is defined as:

f ¼PN

i¼1Bi

� �NPN

i¼1B2i

� �2

ð9Þ

where Ni is the number of ONUs, Bi is the total bandwidth granted to each ONU.The result presented in Fig. 4 shows that the bandwidth is more evenly shared by RDDBA since the fairness index is near

to one. This means that the entire ONUs is getting almost the same amount of the bandwidth granted by the OLT. However,the value is between 0.75 and 0.85 for the MDBA and ADBA algorithms. The idle queues in MDBA and ADBA are taking up thebandwidth and this is addressed in RDDBA which makes a redistribution of the idle queue bandwidth among heavy loadusers through the RDM technique.

5.2. Bandwidth utilization

A prime factor for a carrier to determine a solution’s benefit is to analyze the overall bandwidth that can be sold as ser-vices over the system and successfully allocated to the users in a time period. An efficient DBA algorithm strives to achieve ashigh bandwidth utilization as possible. The bandwidth utilization is calculated as follows.

Fig. 3. Intra-ONU bandwidth allocation.

Table 1Simulation parameters.

Symbol Description 1G EPON

ONUs Total numbers of Optical Network Units 16G Total bandwidth 1GbpsD OLT – ONU distance 20 kmT Cycle time 2 msTg Guard time 1 lsBmin Minimum bandwidth can be allocated to each ONU 62.5 Mbps

Svoicei

Limited bandwidth for voice 64 kbps

Svideoi

Limited bandwidth for video 4 Mbps

Sdatai

Limited bandwidth for data 2 Mbps

S.K. Sadon et al. / Computers and Electrical Engineering 38 (2012) 1480–1489 1485

Fig. 4. Fairness index versus the offered load at high requested bandwidth for voice, video and data for RDDBA, ADBA and MDBA algorithms.

Fig

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B:U ¼ Bactualused

Bofferedtotal

� 100% ð10Þ

The starting point for our comparative study is to look at how the offered load affects the bandwidth utilization of theexisting and the new algorithms. The simulation was conducted for various traffic conditions using MATLAB. The improve-ment of the bandwidth utilization in Russian Doll algorithm was compared to that of MDBA and ADBA algorithms as shownin Fig. 5. When the offered load was in lightly loaded condition, and less than 35%, the bandwidth utilization value for bothMDBA, ADBA and RDDBA became the same which was around 20% because the bandwidth requested is low and both of thealgorithms will be able to grant the bandwidth requested by the ONUs.

However, when the offered load is greater than 35%, we can see that the bandwidth utilization is better for RDDBA com-pared to MDBA because the RDM presence gave more flexibility in sharing the bandwidth. Through RDM, bandwidth is usedefficiently between the types of traffics where we can get up to 90% of bandwidth utilization. Since the bandwidth utilizationfor the new algorithm is higher, the ONUs can be served better by having the ability to optimize bandwidth usage.

5.3. Packet delay

Packet delay, also called latency, can be defined as the time interval between the beginning of the transmission of the firstbyte and the end of reception of the last byte. We have evaluated the packet delay with its components as mentioned in [12],

d ¼ dpoll þ dgrant þ dqueue ð11Þ

where dpoll is the time between packet arrival and next request sent by specific ONU, while dgrant is the time interval fromONU’s request for a transmission window until the granted bandwidth from OLT is received and lastly, dqueue is the queuingdelay after the allocated grant from the OLT arrives to the ONU. On average, the time between packet arrival and next Re-quest sent by that ONU is given by [12],

dpoll ¼T2

ð12Þ

dgrant, is calculated as,

. 5. Bandwidth utilization versus offered load at high requested bandwidth for voice, video and data for RDDBA, ADBA and MDBA algorithms.

Fig. 6a. Delay versus offered load at high requested bandwidth for voice for RDDBA, ADBA and MDBA algorithms.

Fig. 6b. Delay versus offered load at high requested bandwidth for video for RDDBA, ADBA and MDBA algorithms.

Fig. 6c. Delay versus offered load at high requested bandwidth for data for RDDBA, ADBA and MDBA algorithms.

S.K. Sadon et al. / Computers and Electrical Engineering 38 (2012) 1480–1489 1487

dgrant ¼ Tq�Wi;p

Wmax

� �ð13Þ

where q is the queue size at the moment of a new packet arrival and the pending grant size request before the new packetarrived and Wi,p is the pending grant size. On the other hand, dqueue is found to be insignificant compared with the previoustwo delay types [12]:

dqueue ¼q

RT q 6 0ðq�Wi;pÞmod Wmax

RT q > 0

(ð14Þ

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Figs. 6a–c compares the packet delay versus traffic load for the three types of traffic; voice, video, and data. The simulationresults show that the new RDDBA performs better than the MDBA and ADBA algorithms, especially when the traffic load ishigh.

As it was shown from the comparison of RDDBA and MDBA, ADBA algorithms, for the high voice traffic scenario (Fig. 6a),when the offered load is less than 30% the three algorithms show almost the same amount of delay, but when the load ismore than 30%, RDDBA shows lower delay than the ADBA and MDBA algorithm. This is due to the use of the RDM whichallocated the bandwidth as soon as the requested arrived to the intra-ONU. We can also observe that as the offered load in-creased the improvement of delay on the RDDBA algorithm kept increasing more than ADBA and MDBA.

For the high video traffic scenario (Fig. 6b), the delay of the RDDBA, ADBA and MDBA algorithms was very convergentwhen the offered load is less than 20%. Since the video traffic is assigned medium priority in the RDM system, the delaywas higher than the voice, but the delay is lesser for RDDBA compared to ADBA and MDBA, due to the sharing concept ofthe Russian Doll, which allow the video to borrow the extra bandwidth from the higher priority class. The same scenariocan be observed for data (Fig. 6c). Increasing the offered load results in lesser delay for RDDBA compared to ADBA and MDBA.

6. Conclusion

In this paper, we proposed an intra-ONU allocation algorithm based on RDM to support DBA for DiffServ classes and im-prove bandwidth efficiency by allowing the triple play services to share the bandwidth. We called the DBA algorithms asRDDBA and we compared it with ADBA and MDBA. The proposed scheme separates and resolves fairness and allows all ONUsto fairly share the uplink bandwidth according to their bandwidth demands for different traffic priority classes. The DiffServfunctionalities were realized and also the performance of the system is analyzed to prove that the fairness and bandwidthutilization were improved.

By examining the bandwidth utilization, packet delay and fairness performance, we have verified the new RDDBA algo-rithm. The results show that the RDDBA improves upon the ADBA and MDBA as high as 18% in terms of fairness, 40% in termsof bandwidth utilization, 30% in terms of voice delay, 60% in terms of video delay and 40% in terms of data delay respectively.The fairness of RDDBA is supported by allowing all ONUs to fairly share the uplink bandwidth according to the priority of thedifferent traffic classes. At the same time the bandwidth had improved because of the sharing capability in RDM which cansupport well the borrowing and preempting of the triple play traffic.

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Sajaa Kh. Sadon received the B.Sc. in Electronic and Communications Engineering from University of Al-Mosul, Al-Mosul, Iraq, in 2007, and the M.Sc degreefrom Universiti Tenaga Nasional (UNITEN), Malaysia, in 2010. She is currently doing her PhD. in UNITEN. Her research interests include fiber wireless (fi-wi),artificial intelligence and Ethernet passive optical networks.

S.K. Sadon et al. / Computers and Electrical Engineering 38 (2012) 1480–1489 1489

Norashidah Md Din is currently working as an Associate Professor and Deputy Dean at College of Engineering, Universiti Tenaga Nasional, Malaysia. Shehas a degree in Electrical Engineering from Memphis State University, USA and a Master and PhD degrees in Electrical Engineering from Universiti TeknologiMalaysia. She has authored over 100 technical papers. She is a Senior Member of IEEE, a CEng with IET and PEng with Board of Engineers Malaysia. Herresearch interests include communications network and Ethernet passive optical networks.

Mohammed Hayder Al-Mansoori received the B.Sc. degree in Electronic and Communications Engineering from University of Al-Mosul, Al-Mosul, Iraq, in1998, and the M.Sc. and Ph.D degrees from the University Putra Malaysia, Serdang, Malaysia, in 2004 and 2008, respectively. He was with the Department ofElectronics and Communication Engineering, Universiti Tenaga Nasional. He is currently an Associate Professor in the Faculty of Engineering, SoharUniversity, Oman. He has authored and coauthored more than 130 research papers in journals and conference proceedings. Al-Mansoori is a member of theOptical Society of America and IEEE. His research interests include optical fiber communications, optical fiber lasers, and Ethernet passive optical networks.

N.A.M. Radzi received her MEE and BEEE (Hons.) from Universiti Tenaga Nasional in the year 2010 and 2008, respectively. In 2009, she joined theDepartment of Electronics and Communication Engineering, Universiti Tenaga Nasional as a tutor. She is currently working as a lecturer in the sameDepartment. Her research interests include, EPON and IP Optical. She has contributed 20 technical papers in various journals and conference. She is amember of IEEE. Since 2008, she has completed 2 sponsored projects.

Intan Shafinaz Mustafa received the B.Sc. in Electrical and Electronics Engineering from the University of Coventry, UK, in 1996 and M.Sc. degree inCommunications and Network Engineering from Universiti Putra Malaysia, in 2006. She is currently a Lecturer in the Department of Electronics andCommunication Engineering, College of Engineering, Universiti Tenaga Nasional, Malaysia. Her research interests include EPONs, Wireless communicationtechnology, geographic information system and image processing.

Mashkuri Yaacob obtained his M.Sc and PhD degrees respectively in Computer Engineering from the University of Manchester and a Bachelor degree inElectrical Engineering from UNSW, Australia. He was appointed the third Vice-Chancellor of Universiti Tenaga Nasional (UNITEN) in 2007. He has publishedover 250 technical papers in local and international journals and conferences. As Vice Chancellor of UNITEN, he has played a major role in the expansion ofthe leading private University in Malaysia particularly in rebranding the University as a quality private University in Malaysia. UNITEN won the covetedPrime Minister’s Industry Quality Excellence Award in 2009.

Mohd Shahmi Abdul Majid completed his B. Eng. Degree in Electrical & Electronics Engineering from Universiti Tenaga Nasional, Malaysia, in 2009.Currently, he is pursuing his study in Master of Electrical, majoring in communication field at Universiti Tenaga Nasional. His research interestincluded Optical Communication and IP QoS.