This is the author’s version of a work that was submitted/accepted for pub-lication in the following source:

Ingram, David M.E., Schaub, Pascal, & Campbell, Duncan A. (2011) Mul-ticast traffic filtering for sampled value process bus networks. In Fang,John & Cao, Zhenwei (Eds.) Proceedings of the 37th Annual Conferenceof the IEEE Industrial Electronics Society (IECON 2011), IEEE (Instituteof Electrical and Electronics Engineers, Inc.), Crown Conference Centre,Melbourne, VIC, pp. 1-6.

This file was downloaded from: http://eprints.qut.edu.au/43878/

c© Copyright 2011 IEEE

Personal use of this material is permitted. However, permission toreprint/republish this material for advertising or promotional purposes orfor creating new collective works for resale or redistribution to servers orlists, or to reuse any copyrighted component of this work in other worksmust be obtained from the IEEE.

Notice: Changes introduced as a result of publishing processes such ascopy-editing and formatting may not be reflected in this document. For adefinitive version of this work, please refer to the published source:

http://dx.doi.org/10.1109/IECON.2011.6120087

Multicast Traffic Filtering for Sampled ValueProcess Bus Networks

David M. E. IngramSchool of Engineering Systems

Queensland University of TechnologyBrisbane, QLD 4000, Australiaemail: david.ingram@ieee.org

Pascal SchaubPowerlink QueenslandVirginia, QLD 4014

Australia

Duncan A. CampbellSchool of Engineering Systems

Queensland University of TechnologyBrisbane, QLD 4000, Australia

Abstract—Ethernet is a key component of the standardsused for digital process buses in transmission substations,namely IEC 61850 and IEEE Std 1588-2008 (PTPv2).These standards use multicast Ethernet frames that canbe processed by more than one device. This presents somesignificant engineering challenges when implementing asampled value process bus due to the large amount ofnetwork traffic.

A system of network traffic segregation using a com-bination of Virtual LAN (VLAN) and multicast addressfiltering using managed Ethernet switches is presented.This includes VLAN prioritisation of traffic classes suchas the IEC 61850 protocols GOOSE, MMS and sampledvalues (SV), and other protocols like PTPv2. Multicastaddress filtering is used to limit SV/GOOSE traffic todefined subsets of subscribers.

A method to map substation plant reference designationsto multicast address ranges is proposed that enables engi-neers to determine the type of traffic and location of thesource by inspecting the destination address. This methodand the proposed filtering strategy simplifies future changesto the prioritisation of network traffic, and is applicable toboth process bus and station bus applications.

Index Terms—Ethernet networks, IEC 61850,IEEE 1588, multicast filtering, power transmission,protective relaying, smart grids, VLAN

I. INTRODUCTION

The ‘smart grid’ has been defined as an umbrella termfor technologies that are an alternative to the traditionalpractices in power systems, with the following bene-fits: reliability, flexibility, efficiency and environmentallyfriendly operation [1]. Much of the smart grid focushas been in the distribution arena, where distributedautomation provides many benefits. There is also anopportunity to introduce smart technologies into trans-mission networks to improve observability and controlof the high voltage power system, and to achieve greaterinteroperability between substation control equipment.Sampled value (SV) process buses are a means of achiev-ing this [2], and the benefits of a digital process bus havebeen well documented in the literature [3]–[5]. Full scaleprocess bus based substations have been commissionedin China, and more are under construction [6].

A. Standardisation

The IEC Smart grid vision standardisation ‘roadmap’identifies the IEC 61850 series of standards to be keycomponents of substation automation and protectionfor the transmission smart grid [7]. The objective ofIEC 61850 substation automation standardisation is toprovide a communication standard that meets existingneeds, while supporting future developments as technol-ogy improves. IEC 61850 communication profiles arebased, where possible, on existing international stan-dards. An example of the adoption of existing standardsis the use of IEEE Std 802.3 Ethernet for message pass-ing. IEC 61850-9-2 details how instantaneous high speedsampled value (SV) measurements shall be transmittedover an Ethernet network [8]. IEC 61850-8-1 defineshow transduced analogue values and digital statuses canbe transmitted over an Ethernet network using GenericObject Oriented Substation Events (GOOSE) [9]. Man-ufacturing Messaging Specification (MMS, ISO 9506) isspecified in [9] for configuration and control functions.

The same smart grid strategy that proposes IEC 61850for substation automation and control also recommendsthe use of version 2 of the Precision Time Proto-col (PTPv2), IEEE Std 1588-2008, for high accu-racy time synchronisation in substations. Annex F ofIEEE Std 1588-2008 defines a mapping for PTPv2 overEthernet, and is required by the IEEE Std C37.238 powersystem profile (that specifies how PTPv2 will be usedfor power system applications). The same data networkinfrastructure can therefore be used for SV, GOOSE,MMS and for time synchronisation.

B. Substation Terminology

The primary plant in a substation is the high voltageequipment and includes bus bars, circuit breakers, isola-tors, power transformers, current transformers (CTs) andvoltage transformers (VTs). The control equipment thatis the ‘intelligence’ in a substation is termed the Substa-tion Automation System (SAS), and includes protection,control and automation devices (generically referred to

PrimaryPlant

SubstationAutomation

System

Circuit Breaker

Isolator

Current Transformer

CapacitiveVoltage Transformer

ProcessConnection

Feeder toRemote

Substation

To StationBus

Main 1Protection

Main 2Protection

BayController

RevenueMeter

Trip

Trip

Trip

Clo

se

CT

CT

VT

CT VT

CT

Fig. 1. Substation equipment definitions.

as ‘Intelligent Electronic Devices’, or IEDs). The linkbetween the primary plant and SAS are called ‘processconnections’, and are typically copper connections withanalogue voltages and currents (typically 110 VAC and1 AAC respectively in Australia), or digital signals basedon switching battery voltage (typically 125 VDC in Aus-tralia). Fig. 1 shows this diagrammatically for a 132 kVsubstation double-bus feeder bay.

A digital process bus carries information from theprimary plant to the SAS, and from the SAS to theprimary plant over a digital network — it is not justsampled CT and VT data. All likely protocols need tobe considered (GOOSE, MMS, SV, PTPv2) in a sharednetwork process bus design, especially the way in whichthey may interact. A digital process bus uses a MergingUnit (MU) to collect (from digital systems) or sample(from analogue systems) the output of three or fourCTs and VTs (neutral measurement is often omitted)and transmit this information in a standardised form.IEC 61850-9-2 defines the ‘packaging’ and encodingof this transmission, but the actual content can be de-fined by other standards or be vendor specific. Point-point process bus connections have relatively low trafficvolumes, and so the rest of this paper only deals withshared process bus implementations.

A ‘bay’ is the collective name for a circuit breaker andits associated isolators, earth switches and instrumenttransformers [10]. Some substation arrangements, par-ticularly the ‘breaker-and-a-half’ and ‘double-breaker’configurations, group bays common to feeders or trans-formers together into ‘diameters’. This arrangement iscommonly used at 220 kV and above in Australia.Fig. 2 shows two diameter based arrangements (breaker-and-a-half and double-breaker) and two single bay ar-rangements (bus selectable and fixed bus). More detailon switchgear configuration, including less commonarrangements, can be found in Chapter 11 of [11]. Thelargest substations in Queensland have over twenty-five 110 kV bays and seven 275 kV breaker-and-a-halfdiameters. Over 45 three-phase sets of CTs would beused in a substation of this size.

G G

Breakerand a HalfDiameters(1½ Breaker)

DoubleBreaker

Diameters(2 Breaker)

BusSelectable

Bays(Double Busbar)

FixedBus Bays

(Single Busbar)

Circuit Breaker

Bus Isolator

Transformer

G Generator

Fig. 2. Illustration of ‘bays’ and ‘diameters’ as sub-parts of substa-tions. Alternative names for arrangements are shown in brackets.

C. Ethernet Messaging

There are three types of Ethernet message. The mostcommon are unicast messages (received by a singledevice) and broadcast messages (received by all deviceson the same LAN segment). Multicast messages arereceived by multiple devices that each share a commonneed for the message.

GOOSE and SV implement a Publisher/Subscribermodel and the multicast transmission of frames is keyto this. Each subscriber (an IED in this application)receives a copy of messages that it is interested in, andthe publishers do not distinguish between the varioussubscribers [12]. MUs publish SV messages and IEDs(various types) publish GOOSE messages containingdigital or transduced analogue information. IEDs are thesubscribers of SV and GOOSE messages. This modelis connectionless and therefore the publisher transmitsmulticast messages without expecting any acknowledg-ment. This is efficient and enables high levels of real-time traffic to be transmitted by Ethernet.

Large volumes of multicast traffic can affect theperformance of protection IEDs and PTPv2 clocks, andtherefore a means of reducing the amount of multicasttraffic sent to these devices is required.

II. BACKGROUND

A. Ethernet Prioritisation

GOOSE, SV and PTPv2 all specify the use ofVirtual LAN (VLAN) frame tagging according toIEEE Std 802.1Q-2005 [13]. 802.1Q tags provide ad-ditional information to network switches about which

VLAN a frame belongs to (the VLAN ID) and theswitching priority that VLAN aware switches shouldgive to the frame. Eight priority levels are defined, rang-ing (low to high) from 1 (Background) to 7 (NetworkControl). The eighth priority is 0 (Best Effort), which isthe default and ranks higher than Background. Prioritytagging is used to enhance the real time performance ofEthernet, and is a well established technique, as is the useof multicast domains to group receivers that subscribe toparticular data streams [14]–[16].

B. Sampled Value Implementations

In an attempt to reduce the complexity and variabilityof implementing an interoperable process bus basedon IEC 61850-9-2, an implementation guideline wasdeveloped by a group of substation automation expertsthat is commonly referred to as ‘9-2 Light Edition’or ‘9-2LE’ [17]. This guideline specifies the data setsthat are transmitted, sampling rates, time synchronisationrequirements and the physical interfaces to be used. Atypical 9-2LE SV frame is 126 octets long, includingthe Ethernet and 802.1Q headers. Twelve extra octetsof Ethernet framing are transmitted with each message,giving the equivalent of 1104 bits to be transmitted foreach SV frame. The standard 9-2LE sampling rate forprotection applications is 80 samples per nominal powersystem cycle, and this is based on the nominal systemfrequency (no frequency tracking is employed). A MUin a 50 Hz power system will transmit 4000 frames persecond, resulting in a traffic rate of 4.4 Mbit/s, whilea MU in a 60 Hz system would generate traffic of5.3 Mbit/s due to the higher sampling rate of 4800 Hz.Fast Ethernet (100 Mb/s) can accommodate a maximumof eighteen 60 Hz merging units or twenty-two 50 Hzmerging units, providing there is no other network traffic.GOOSE, MMS and PTPv2 traffic need to share thesame network and so the maximum number of MUs isdependent on the rate and size of the other traffic.

A large substation with a process bus may have inexcess of 50 MUs, and so Gigabit Ethernet would berequired if data from all MUs was required in oneplace — this would be the case for whole of substationdisturbance monitoring, power quality measurement orlow impedance bus zone protection.

C. Multicast Addressing and Filtering

GOOSE and SV are multicast protocols, andPTPv2 has a multicast option that is mandated by theIEEE Std C37.238 PTPv2 profile for power systemapplication. The destination multicast address is basedon the Organisation Unique Identifier (OUI) of theorganisation that sponsors the protocol, but withthe group bit set. Informative annexes of [8] and[9] recommend the range 01:0C:CD:01:00:00

to 01:0C:CD:01:01:FF for GOOSE and01:0C:CD:04:00:00 to 01:0C:CD:04:01:FF for SV,but this is not mandatory. The PTP multicast destinationaddress is 01:1B:19:00:00:00 for all messagesexcept peer delay, which uses 01:80:C2:00:00:0E tocircumvent port blocking protocols such as spanningtree and rapid spanning tree.

VLANs are intended to segregate traffic of differentclasses, while using common bearers [18]. The behaviourof multicast and broadcast frames is restricted by VLANsegregation to being distributed only within that VLAN.The combination of reduced broadcast scope and prior-itisation goes a long way towards solving the potentialinteractions between SV and PTPv2.

Multicast address filters limit the distribution of multi-cast addressed frames to the subscriber ports that requirethe data, rather than simply transmitting the frame to allports. This can either be static filtering, defined throughthe switch’s management interface (basic filtering ser-vices), or dynamic filtering control (extended filteringservices) through the use of GARP Multicast Registra-tion Protocol (GMRP) or its replacement, Multiple MACRegistration Protocol (MMRP) [19].

D. Imperfect Multicast Filtering

The microprocessors used in devices such as PTPv2clocks and protection IEDs often have basic support formulticast filtering to reduce CPU load, although moresophisticated devices include internal Ethernet switches.A common basic filtering technique is ‘imperfect hash-ing’, where a multicast destination address is hashed to areduced number of addresses (typically between 64 and256) [20]. Each entry in the hash table represents many(up to 240) multicast addresses, and so address collisionsare likely.

Ideally multicast destination addresses would be se-lected to avoid collisions between GOOSE, SV andPTPv2, but the variety of imperfect hashing implementa-tions and the requirement to use particular OUIs meansthis is not possible, and was identified as a concern inIEC 61850-9-2.

III. FILTERING FOR SUBSTATION AUTOMATION

Two levels of traffic segregation are recommended.The first is through the use of VLAN filtering (802.1Q)to prioritise the protocols and their application, andthe second level is to use multicast address filtering(802.1D) to limit the flow of information within theparticular VLAN. Some VLANs may not require anymulticast filtering, in which case multicast frames will behandled as if they were broadcast frames, but restrictedto that VLAN. This approach is consistent with the draftNetwork Engineering Guidelines that will be publishedas IEC TR 61850-90-4.

The priority assigned to a protection trip GOOSEmessage intended to clear a faulted transmission line willbe higher than for a GOOSE message containing thetemperature of power transformer windings. Prioritisa-tion solely by protocol is not sufficient — the applicationof the protocol needs to be considered. VLAN segrega-tion prevents low cost devices with imperfect multicastfiltering from failing under the onslaught of traffic thatis irrelevant to that device. Separate VLANs should alsobe created for PTPv2 and SV traffic, as well as for MMSif this protocol is used in the process bus.

Multicast address filtering, the second layer, is usedwhere the levels of relevant traffic either exceeds the net-work capacity or the capacity of the subscriber to processmessages. The first situation would arise with a 50 Hzpower system where more than 22 SV sources shareda Fast Ethernet LAN. The backplane of an Ethernetswitch will operate at faster speeds and so can managethe traffic, but the rate of any given link (incoming oroutgoing) cannot exceed 100 Mb/s. Multicast addressfiltering can be applied to subscriber ports to ensure thatonly the relevant messages are put onto the wire. Thisapplication is intended for process bus, but is equallyapplicable to station bus if IEDs cannot deal with aflood of GOOSE messages. Multicast address filteringcan limit the traffic to levels where IED performance isnot degraded.

Most protection IEDs have Fast Ethernet interfaces,and therefore Ethernet switches need to ensure the trafficpassed to the IED does not exceed 100 Mb/s, and ideallywould limit the flow of information to the IED to justwhat is required. An increase in bit rate requires aproportional increase in transmitter power for the biterror rate (BER) to remain the same, and non-linearityin glass fibre optic cable mean there is a limit to theoptical power that can be applied [21]. As a result FastEthernet has advantages over Gigabit Ethernet for longcable runs in substation switchyards.

Fig. 3 shows the application of VLAN and multi-cast address filtering for a medium sized transmissionsubstation with three diameters of breaker-and-a-halfswitchgear and seven bays of folded-bus switchgear. AVLAN is allocated for PTPv2 traffic, but no multicastaddress filtering is used as the addresses are fixed bythe standard. Two GOOSE VLANS are assigned: onefor high priority type 1A trip messages and one forlower priority type 1B and type 2 messages (messagetypes are defined in section 13.7 of IEC 61850-5 [22]).Multicast address filtering is not shown here as it isunlikely that the number of messages would exceed theprocessing capability of an IED. If this were to happenthe multicast address filters could be used. The finalVLAN is used for all SV messages and multicast addressfiltering is used to separate bays and diameters. Each

MU in a diameter is placed into the same multicastgroup, as the associated feeder or transformer protectionIEDs require samples from multiple sets of CTs. Feedersand transformers connected by single circuit breakersin a bay arrangement each have a multicast group. Itis common practice in Australia to give bays that arein line with each other (similar to a diameter, but notconnected) the same locational code. Sharing a multicastgroup simplifies the allocation of addresses.

Fig. 3. Illustration of VLAN and multicast address filtering operatingin multiple dimensions. VLANs are represented by layers and multicastgroups by subdivision of each layer.

Actual VLAN IDs will be an implementation specificdesign decision, however consistency across an organ-isation is recommended. Adoption of multicast filteringmeans that the allocation of VLAN IDs will be based onthe protocol and application, and this is independent ofsubstation topology. The alternative is to have multipleVLANs for the same class of traffic, which complicateschanges to prioritisation in data networks and may in-crease the risk of errors being introduced if configurationis performed by hand.

IV. MULTICAST ADDRESS ALLOCATION

A system is proposed here where the referencedesignators used to identify plant are used to derivedestination multicast addresses. This system is basedupon IEC 61346/IEC 81346, but other systems that usebay/diameter numbering may be able to be adapted usingthe concepts described here.

TABLE IVOLTAGE RELATED OBJECT CLASSES FROM IEC 61346-2.

Code Voltage Range Code Voltage Range

B > 420 kV H 30 kV .. < 45 kV

C 380 kV .. ≤420 kV J 20 kV .. < 30 kV

D 220 kV .. < 380 kV K 10 kV .. < 20 kV

E 110 kV .. < 220 kV L 6 kV .. < 10 kV

F 60 kV .. < 110 kV M 1 kV .. < 6 kV

G 45 kV .. < 60 kV N < 1 kV

A. Reference Designators

The IEC 61346 series of standards (now superseded bythe IEC 81346 series) describes structured principles fornaming objects and is recommended by IEC 61850-6.The structures used can be function oriented, productoriented or location oriented and these determine theinitial character of the designator. These structures can becombined, often in the Function-Equipment form [23].An example of this is a circuit breaker (-QA1: equip-ment) in a substation bay (=D1: function), such as =D1-QA. Substation equipment in Queensland is named basedon a locally modified version of these conventions (ortheir predecessors).

IEC 61346-2 defines classes of infrastructure objectsbased upon letter codes, with the first letter defining theclass of infrastructure objects. The letter codes betweenB and N represent voltage levels and are listed in Table I.

Bay numbering applied to a simplified single linediagram of a 275/132 kV transmission substation isshown in Fig. 4. 275 kV bays are numbed in the D seriesand 132 kV bays are numbered in the E series, as perIEC 61346-2. The operating voltages of classes B-E aretypically considered transmission, F-H sub-transmissionand J-N distribution. The range B-E fits well into ahexadecimal numbering scheme and this forms the basisof the proposed multicast addressing system.

B. Multicast Address Allocation

The authors’ addressing proposal is for the voltageclass code to be the high nibble (half-octet) and thebay number to be the low nibble of the least significantoctet. If more than sixteen bays are present at a particularvoltage level then the next significant octet can representthe group of sixteen, increasing the multicast addressesfor each voltage level. Fig. 5 illustrates how this mappingoperates generically and for specific examples of baydesignations.

If differential protection was used to protect =T1in Fig. 4 then the relay would require SV data from=D1 and =E3 bays. Multicast filters would be createdto enable data addressed to 01:0C:CD:04:00:D1 and

275 kV

132 kV

=D1 =D2 =D3

=E1

=E2

=E3 =E4

=E5 =E6

=E7

-QA1

-QA3

-QA2

-QA1

-QA3

-QA2

-QA1

-QA3

-QA2

-QA1

-QA2

-QA1

-QA1-QA1

-QA1 -QA1

-QA1

=T1 =T2

Fig. 4. Bay numbering for medium sized 275/132 kV substation.

Fig. 5. Mapping of bay level functional designators to multicastaddresses for IEC 61850.

01:0C:CD:04:00:E3 to be delivered to the protectionIED.

It is acknowledged that the multicast ranges recom-mended by the IEC standards are limited to 00:00 to01:FF, but increasing this to 02:FF or 03:FF does notcontradict the normative sections of the standards. Somevendors may limit GOOSE and SV addressing to 01:FFand so interoperability checks will be required if thereare in excess of 31 bays of a particular voltage level(which would be an extremely large substation).

C. Subscriber Configuration

In the example shown by Figs. 3 and 4 the trans-former protection IED for =T1 would subscribe tomulticast SV messages with the destination address01:0C:CD:04:00:D1 and 01:0C:CD:04:00:E3. Thiswould give it access to SV data for CTs adjacentto =D10-QA2, =D1-QA3 and =E3-QA1, all of whichare required for the differential current through thetransformer to be measured. SV data from diameters

=D2/=D3 and bays =E1/=E2/=E4/=E5/=E6/=E7 are notrelevant and will not be sent out of the switch port thatthe IED is connected to. Capacitor bank protection for=E7 will only need subscribe to SV messages with thedestination address 01:0C:CD:04:00:E7.

The complexity of the data network configurationfor a large substation makes automated management ofnetwork switches an attractive option. The SubstationConfiguration Description (SCD) is an XML file thatcontains the system description, and in this the IEDnetwork interfaces are defined. Automated tools couldbe developed to extract this information to streamline theVLAN and multicast address filter configuration of Eth-ernet switches from multiple vendors. Such tools are notrequired if IEDs implement GMRP or MMRP as theseprotocols enable IEDs to configure Ethernet switchesautomatically [6], however there are concerns by someover the effect of connection errors on the data network.It should be noted that at the current time few Ethernetswitches manufacturers have implemented GMRP, andsupport for MMRP is almost non-existent [18].

V. CONCLUSIONS

The need for traffic segregation in a transmissionsubstation process bus is generally accepted, but specificmechanisms for achieving this have not been proposeduntil now. This proposal uses both VLAN and multicastfiltering to separate traffic by application and by groupsof interest. A two stage approach simplifies the engi-neering of a complex substation system and providesconsistency between substations by allowing a commonVLAN structure to be used across a utility. Multicastfilter definitions are site specific, with the addressingused matching the topology of the substation in a clearand straightforward manner.

Whether VLAN-only or VLAN/multicast filtering isused will have little impact on the performance of store-and-forward Ethernet switches. Knowledge about theperformance of sampled value process buses is limitedand it is expected that changes to network parameterswill occur as experience is gained.

A system that is clearly and consistently implementedwill simplify commissioning and ongoing maintenance,and will assist the utility staff that are not data network-ing specialists but are required to work with this nextgeneration of substation automation systems.

REFERENCES

[1] V. Hamidi, K. S. Smith, and R. C. Wilson, “Smart grid tech-nology review within the transmission and distribution sector,”in Proc. Innov. Smart Grid Tech. Conf. Europe 2010 (ISGTE),Gothenburg, Sweden, 11–13 Oct. 2010.

[2] Fangxing Li, Wei Qiao, Hongbin Sun, Hui Wan, Jianhui Wang,Yan Xia, Zhao Xu, and Pei Zhang, “Smart transmission grid:Vision and framework,” IEEE Trans. Smart Grid, vol. 1, no. 2,pp. 168–177, 2010.

[3] A. P. Apostolov, “IEC 61850 based bus protection – principlesand benefits,” in IEEE PES Gen. Mtg 2009, Calgary, Canada,26–30 Jun. 2009.

[4] D. Chatrefou, “Digital substation; application of process bus,”in Proc. Int. Prot. Test. Symp. 2010 (IPTS), Salzburg, Austria,14–15 Oct. 2010.

[5] M. Zadeh, T. Sidhu, and A. Klimek, “Suitability analysis ofpractical directional algorithms for use in directional comparisonbus protection based on IEC61850 process bus,” IET Gen. Trans.Dist., vol. 5, no. 2, pp. 199–208, Feb. 2011.

[6] R. Moore, R. Midence, and M. Goraj, “Practical experiencewith IEEE 1588 high precision time synchronization in electricalsubstation based on IEC 61850 process bus,” in IEEE PES Gen.Mtg 2010, Minneapolis, MN, USA, 25–29 Jul. 2010.

[7] SMB Smart Grid Strategic Group. (2010, Jun.) Smart gridstandardization roadmap. IEC. [Online]. Available: http://www.iec.ch/smartgrid/downloads/sg3_roadmap.pdf

[8] Communication networks and systems in substations – Part 9-2: Specific communication service mapping (SCSM) – Sampledvalues over ISO/IEC 8802-3, IEC 61 850-9-2:2004(E), Apr. 2004.

[9] Communication networks and systems in substations – Part 8-1:Specific communication service mapping (SCSM) – Mappings toMMS (ISO 9506-1 and ISO 9506-2) and to ISO/IEC 8802-3,IEC 61 850-8-1:2004(E), May 2004.

[10] Communication Networks and Systems in Substations – Part1: Introduction and Overview, IEC TR 61 850-1:2003(E), Apr.2003.

[11] H. Gremmel, Switchgear Manual, 11th ed. Berlin, Germany:ABB / Cornelsen Verlag Scriptor GmbH & Co. KG, 2006.[Online]. Available: http://www.t9afcfkv2hnztp4wg.de/index_abb_en_start.html

[12] P. T. Eugster, P. A. Felber, R. Guerraoui, and A.-M. Kermarrec,“The many faces of publish/subscribe,” ACM Comput. Surv.,vol. 35, pp. 114–131, Jun. 2003.

[13] IEEE Standard for Local and Metropolitan Area Networks –Virtual Bridged Local Area Networks, IEEE Std. 802.1Q-2005,19 May 2006.

[14] Q. I. Ali and B. S. Mahmood, “Enhancement of industrialEthernet performance using multicasting/VLAN techniques,” inICTTA 2008, Damascus, Syria, 7–11 Apr. 2008.

[15] M. S. Thomas and I. Ali, “Reliable, fast, and deterministic sub-station communication network architecture and its performancesimulation,” IEEE Trans. Power Del., vol. 25, no. 4, pp. 2364–2370, 2010.

[16] L. Thrybom and G. Prytz, “Multicast filtering in industrialEthernet networks,” in WFCS 2010, Nancy, France, 18–21 May2010, pp. 185–188.

[17] UCA International Users Group. (2004) Implementationguideline for digital interface to instrument trans-formers using IEC 61850-9-2. Raleigh, NC, USA.[Online]. Available: http://tc57wg10.info/downloads/digifspec92ler21040707cb.pdf

[18] L. Thrybom and G. Prytz, “QoS in switched industrial Ethernet,”in ETFA 2009, Palma de Mallorca, Spain, 22–25 Sep. 2009, pp.185–188.

[19] IEEE Standard for Local and Metropolitan Area Networks –Virtual Bridged Local Area Networks – Amendment 7: MultipleRegistration Protocol, IEEE Std. 802.1ak-2007, 22 Jun. 2007.

[20] S. Torres, “MC9S12NE64 Integrated Ethernet Controller,”Freescale Semiconductor, Inc., Application Note AN2692, Sep.2004. [Online]. Available: http://cache.freescale.com/files/microcontrollers/doc/app_note/AN2692.pdf

[21] A. W. Moore, L. B. James, M. Glick, A. Wonfor, R. G. Plumb,I. H. White, D. McAuley, and R. V. Penty, “Optical networkpacket error rate due to physical layer coding,” J. Lightw.Technol., vol. 23, no. 10, pp. 3056–3065, 2005.

[22] Communication Networks and Systems in Substations – Part 5:Communication Requirements for Functions and Device Models,IEC 61 850-5:2003(E), Jul. 2003.

[23] R. García García and E. Gelle, “Applying and adapting theIEC 61346 standard to industrial automation applications,” IEEETrans. Ind. Informat., vol. 2, no. 3, pp. 185–191, Aug. 2006.