中英文資料外文翻譯文獻(xiàn)場域網(wǎng)絡(luò)的標(biāo)準(zhǔn)化和靈活的IPv6架構(gòu)最后一英里的智能電網(wǎng)構(gòu)架本文旨在為智能電網(wǎng)的最后一英里的基于開放標(biāo)準(zhǔn)IPv6的基礎(chǔ)設(shè)施提供一個(gè)綜合和全面的視角，用于支持一系列先進(jìn)的應(yīng)用程序（如讀表，需求響應(yīng)，遙測，遙信和電網(wǎng)監(jiān)控和自動化）同時(shí)作為多服務(wù)平臺也從中受益。在本文中，我們將展示IPv6網(wǎng)絡(luò)基礎(chǔ)設(shè)施的各種模塊如何提供一個(gè)高效，靈活，安全和多業(yè)務(wù)的基于開放標(biāo)準(zhǔn)的網(wǎng)絡(luò)。為了討論電業(yè)在轉(zhuǎn)型過程中需要處理的一些問題例如遺留的老設(shè)備，網(wǎng)絡(luò)和應(yīng)用程序集成，在過渡期推出的混合網(wǎng)絡(luò)結(jié)構(gòu)的操作，隨后的文件會有更進(jìn)一步的闡述。1.介紹在過去幾年，由于在智能電網(wǎng)基礎(chǔ)設(shè)施的突出作用，最后一英里網(wǎng)絡(luò)已經(jīng)獲得了相當(dāng)大的發(fā)展勢頭。這些網(wǎng)絡(luò)在本文件稱為鄰區(qū)網(wǎng)絡(luò)（NAN），他們支持一系列應(yīng)用不僅包括用電計(jì)量和管理，而且包括需求響應(yīng)（DR）和配電自動化（DA）應(yīng)用高級應(yīng)用；需求響應(yīng)應(yīng)用為用戶提供機(jī)會可以基于實(shí)時(shí)電價(jià)信息而優(yōu)化其能源使用；配電自動化（DA）應(yīng)用它允許分布的監(jiān)測和控制，自動故障檢測，隔離和管理，并作為未來的虛擬電廠，其中包括分布式發(fā)電，住宅能源存儲（例如，電動汽車EV）充電），以及小規(guī)模的社區(qū)電力交易。場區(qū)網(wǎng)絡(luò)（FAN）（（NAN和具有回程廣域網(wǎng)接口的通訊設(shè)備的組合）已經(jīng)成為一個(gè)智能電網(wǎng)的網(wǎng)絡(luò)基礎(chǔ)設(shè)施的核心組成部分。事實(shí)上，他們作為回程網(wǎng)絡(luò)可以為各種其他電網(wǎng)控制設(shè)備提供服務(wù)；例如多租戶服務(wù)（煤氣表和水表），家庭局域網(wǎng)（HAN）設(shè)備的數(shù)據(jù)交換服務(wù)，這些都通過各種無線連接或有線線路連接的技術(shù)。這就形成了對部署的IP協(xié)議套件的需求，并使的公開標(biāo)準(zhǔn)的使用提供了可靠性，可擴(kuò)展性，安全性，跨網(wǎng)絡(luò)和靈活性，從而能為應(yīng)付數(shù)量快速增長的電網(wǎng)配電網(wǎng)絡(luò)的關(guān)鍵應(yīng)用提供支持。IP也使得領(lǐng)區(qū)網(wǎng)絡(luò)（NAN）容易整合到到端到端的網(wǎng)絡(luò)架構(gòu)。通過場區(qū)網(wǎng)絡(luò)正在運(yùn)行的應(yīng)用程序之一是抄表，每個(gè)電表定期把使用數(shù)據(jù)發(fā)向一個(gè)事業(yè)單位端點(diǎn)的應(yīng)用服務(wù)器。因此，在一個(gè)多點(diǎn)到單點(diǎn)（MP2P）模式中，大部分電表的流量是從電表網(wǎng)絡(luò)到事業(yè)單位網(wǎng)絡(luò)的。隨著需求響應(yīng)，分布式能源資源整合和電動汽車充電等應(yīng)用程序的出現(xiàn)和擴(kuò)散，預(yù)計(jì)整個(gè)場區(qū)網(wǎng)絡(luò)的數(shù)據(jù)流量將大幅增加，交通模式和雙向通信的需求會變得復(fù)雜得多。特別是場區(qū)網(wǎng)絡(luò)將支持一些利用網(wǎng)絡(luò)服務(wù)來支持一些使用：單個(gè)儀表通訊：按需抄表，實(shí)時(shí)警報(bào)報(bào)告，把某個(gè)位置的電表關(guān)閉都需要NMS/前端點(diǎn)的點(diǎn)對點(diǎn)（P2P）的通信電表，反之亦然。DA設(shè)備之間的通信。DA設(shè)備的子集需要彼此溝通，以管理和控制在某一特定地區(qū)的電網(wǎng)運(yùn)行，包括在某些情況下點(diǎn)到點(diǎn)之間的相互溝通需要靈活運(yùn)用。HAN應(yīng)用：HAN應(yīng)用程序需要同過單個(gè)電表作為應(yīng)用程序的服務(wù)器來實(shí)現(xiàn)家電和公用事業(yè)頭端的溝通。例如，用戶可以激活直接負(fù)荷控制（DLC），授權(quán)公用事業(yè)公司在電力高峰和/或電價(jià)高時(shí)遠(yuǎn)程關(guān)閉某些家電（例如，A/C，洗衣機(jī)/干衣機(jī)）。電動車充電：用戶不在家時(shí)，需要能夠進(jìn)入各自的車輛充電帳戶信息查看。這是為了當(dāng)他們在路上或走親訪友時(shí)能夠給車充電。驗(yàn)證用戶帳戶信息將需要通過電表到公用事業(yè)頭端服務(wù)器來實(shí)現(xiàn)通訊，以實(shí)現(xiàn)在動態(tài)位置時(shí)同時(shí)對大量的移動車輛充電。多租戶服務(wù)：把在客戶端的信息合并，并在另一端區(qū)分幾個(gè)服務(wù)信息以形成一個(gè)復(fù)雜的多點(diǎn)對多點(diǎn)網(wǎng)絡(luò)（MP2MP）。例如，這可能是一個(gè)連接多個(gè)公用事業(yè)設(shè)備融合的網(wǎng)絡(luò)，比如開放的表計(jì)系統(tǒng)里所提到的英國國家電信運(yùn)營商DCC或德國通信盒。安全性：強(qiáng)大的身份驗(yàn)證機(jī)制用于驗(yàn)證設(shè)備連接到先進(jìn)計(jì)量基礎(chǔ)設(shè)施AMI）網(wǎng)絡(luò)以及加密數(shù)據(jù)對隱私和網(wǎng)絡(luò)保護(hù)。網(wǎng)絡(luò)管理：由于FAN網(wǎng)絡(luò)承載越來越多的流量，并有嚴(yán)格的服務(wù)等級目標(biāo)（SLO），所以監(jiān)控和維護(hù)網(wǎng)絡(luò)的健康和性能，管理網(wǎng)絡(luò)相關(guān)的數(shù)據(jù)就變得至關(guān)重要。這將要求電網(wǎng)狀態(tài)和通訊統(tǒng)計(jì)的通訊，從儀表到通信表計(jì)網(wǎng)絡(luò)管理系統(tǒng)（NMS）/首末端都是MP2P方式。組播服務(wù)：一組儀表可能需要同時(shí)使用多播，如由一個(gè)網(wǎng)絡(luò)管理系統(tǒng)NMS）使用多播請求使軟件或參數(shù)升級，或?qū)λ械膬x表和各種子集儀表發(fā)送多播請求。網(wǎng)絡(luò)協(xié)議的關(guān)鍵優(yōu)勢一個(gè)端到端的IP智能電網(wǎng)架構(gòu)可以影響30年互聯(lián)網(wǎng)協(xié)議技術(shù)的發(fā)展而保證開放標(biāo)準(zhǔn)和互操作性是通過互聯(lián)網(wǎng)的日常使用和其20億最終用戶證明。注意：使用互聯(lián)網(wǎng)協(xié)議套件并不意味著運(yùn)行IP的基礎(chǔ)設(shè)施是已被公開或公開訪問的網(wǎng)絡(luò)，的確許多現(xiàn)有的關(guān)鍵的私營和高度安全的網(wǎng)絡(luò)，如銀行內(nèi)部網(wǎng)絡(luò)IP架構(gòu)，軍事和防御網(wǎng)絡(luò)，公共安全和應(yīng)急反應(yīng)網(wǎng)絡(luò)利用IP架構(gòu)，這里僅舉幾例。信息和通信技術(shù)（ICT）和較傳統(tǒng)的電力行業(yè)之間的差異之一是技術(shù)的生命周期。通過不修改整個(gè)工業(yè)流程而能順利進(jìn)化步驟，證明了AMI的基礎(chǔ)設(shè)施選擇IP分層協(xié)議棧是未來的發(fā)展方向。分銷系統(tǒng)運(yùn)營商（DSO）的知識產(chǎn)權(quán)的主要好處是：開放和基于標(biāo)準(zhǔn)的：網(wǎng)絡(luò)，運(yùn)輸和應(yīng)用層的核心組件都被互聯(lián)網(wǎng)工程任務(wù)組IETF）標(biāo)準(zhǔn)化了，而關(guān)鍵的物理層，數(shù)據(jù)鏈路，和應(yīng)用化協(xié)議來自于一般的工業(yè)組織，如IEC，ANSI，DLMS/COSEM，SAE，IEEE，ITU等。輕量級：AMI，如智能電表，傳感器和執(zhí)行器網(wǎng)絡(luò)最后一公里安裝的設(shè)備不同于PC和服務(wù)器。他們在電源，CPU，內(nèi)存和存儲資源上都是有限的。因此，嵌入式網(wǎng)絡(luò)協(xié)議棧必須在幾個(gè)千字節(jié)的RAM和幾十千字節(jié)的閃存上工作。這種IP協(xié)議棧在過去幾年已被證明可在這種受限的環(huán)境下執(zhí)行。多功能：在智能電網(wǎng)中的最后一英里基礎(chǔ)設(shè)施要面對兩個(gè)主要挑戰(zhàn)。首先，一個(gè)給定的技術(shù)（無線或有線）可能不適合所有領(lǐng)域部署的標(biāo)準(zhǔn)。二，通信技術(shù)發(fā)展的步伐的速度要快于預(yù)期的智能電表的15至20年的壽命。分層IP架構(gòu)是裝備精良，以應(yīng)付任何類型的物理和數(shù)據(jù)鏈路層，使得各種媒體的未來證明可用于部署，并隨著時(shí)間的推移，不改變整體架構(gòu)的解決方案和數(shù)據(jù)流。無處不在：所有最近的不管是通用計(jì)算機(jī)，服務(wù)器，還是輕量級嵌入式系統(tǒng)（TinyOS的，Contiki等）都有一個(gè)集成的雙IP協(xié)議棧（IPv4和IPv6），會隨著時(shí)間的推移增強(qiáng)。這使的新的網(wǎng)絡(luò)特性設(shè)置隨著時(shí)間的推移更容易去適應(yīng)?？蓴U(kuò)展性：所謂互聯(lián)網(wǎng)的普通協(xié)議，IP已經(jīng)大規(guī)模部署而且其擴(kuò)展性也被測試過。數(shù)以百萬計(jì)的私人或公共IP基礎(chǔ)設(shè)施管理的節(jié)點(diǎn)在一個(gè)單一的實(shí)體（類似FAN部署）下已運(yùn)行多年，為不熟悉IP網(wǎng)絡(luò)管理的新來者提供了堅(jiān)實(shí)的基礎(chǔ)。管理和安全：通信基礎(chǔ)設(shè)施的正確操作需要適當(dāng)?shù)墓芾砗桶踩δ堋?0年來運(yùn)行IP網(wǎng)絡(luò)的好處之一是它有很好理解的網(wǎng)絡(luò)管理和安全協(xié)議，機(jī)制和工具集，這些都被廣泛使用。采用^網(wǎng)絡(luò)管理也有利于公用事業(yè)運(yùn)營業(yè)務(wù)的應(yīng)用，利用網(wǎng)絡(luò)管理工具，以改善他們的服務(wù)，例如通過網(wǎng)絡(luò)管理系統(tǒng)（NMS）的幫助確定停電范圍。穩(wěn)定和彈性：超過30年的存在，它不再是一個(gè)問題，IP是一個(gè)可行的的解決方案，考慮到它的大，以及建立知識庫。場區(qū)的網(wǎng)絡(luò)，更重要的是如何，我們可以利用的關(guān)鍵基礎(chǔ)設(shè)施，如金融和防御網(wǎng)絡(luò)以及關(guān)鍵服務(wù)，如語音和視頻已經(jīng)轉(zhuǎn)換積累經(jīng)驗(yàn)的年從封閉的環(huán)境中，以開放的IP標(biāo)準(zhǔn)。這也有利于從專業(yè)的IT生態(tài)系統(tǒng)，可以幫助設(shè)計(jì)，部署和運(yùn)營系統(tǒng)解決方案。端到端的：通過采用IP為網(wǎng)絡(luò)中的任何設(shè)備提供了端到端的和雙向的通信能力。根據(jù)業(yè)務(wù)的要求實(shí)施集中式或分布式數(shù)據(jù)處理架構(gòu)。去除中間協(xié)議轉(zhuǎn)換網(wǎng)關(guān)有利于引進(jìn)新的服務(wù)。IPv6分布式網(wǎng)絡(luò)構(gòu)架附近的區(qū)域網(wǎng)絡(luò)的聯(lián)網(wǎng)需求已被廣泛記載：成本效益，可擴(kuò)展性（網(wǎng)絡(luò)中有數(shù)以百萬的節(jié)點(diǎn)是常見的），安全性，可靠性和靈活性，這些是絕對要求的，而基于開放標(biāo)準(zhǔn)的技術(shù)和適應(yīng)未來的15至20年的壽命是公用事業(yè)的最低期望值。這就解釋了為什么IPv6的套件是最初的選擇，盡管新的IPv6協(xié)議的目的是為了解決這種網(wǎng)絡(luò)的獨(dú)特需求，這些將在下一章討論。采用IPv6有利于在最后一英里成功轉(zhuǎn)型為能源網(wǎng)絡(luò)。然而在描述更多IPv6網(wǎng)絡(luò)組件的細(xì)節(jié)之

前，如IP地址，安全性，服務(wù)質(zhì)量（QoS）,路由和網(wǎng)絡(luò)管理等，首先要問一下我們?yōu)槭裁匆褂枚说蕉说腎Pv6。畢竟，IPv6像任何其他技術(shù)一樣需要適當(dāng)?shù)呐嘤?xùn)勞動力，從技術(shù)人員到評估供應(yīng)商，分包商和承包商的管理人員。贊成在智能電網(wǎng)最后一英里使用端到端IP的主要步驟是要證明IP是輕量級的可以在有限的資源，能源，內(nèi)存和處理能力受限的設(shè)備上使用。因此，F(xiàn)AN視為單一的應(yīng)用程序，存根網(wǎng)絡(luò)終端節(jié)點(diǎn)（例如智能電表）可以通過網(wǎng)關(guān)翻譯IP協(xié)議達(dá)到IP點(diǎn)，每一個(gè)網(wǎng)關(guān)被捆綁到一個(gè)專門的服務(wù)和/或解決方案的供應(yīng)商上。過去的二十年，隨著SNA（通過DLSw的），Appletalk的，DECNET，IPX，X25等協(xié)議的過渡，向我們表明這種網(wǎng)關(guān)的方案只在較小的，單一應(yīng)用的，網(wǎng)絡(luò)下的過渡。但私有協(xié)議和翻譯網(wǎng)關(guān)具有從眾所周知的嚴(yán)重問題，如高資本支出和高運(yùn)行成本，還有重大的技術(shù)限制，包括缺乏端到端的QoS，快速恢復(fù)的一致性，單點(diǎn)故障（除非執(zhí)行復(fù)雜的狀態(tài)故障切換機(jī)制）的條款，限制創(chuàng)新，缺乏可擴(kuò)展性，容易受到安全攻擊等。因此，在許多方面，使用IPv6端到端（IP運(yùn)行網(wǎng)絡(luò)中的每個(gè)設(shè)備）將在服務(wù)領(lǐng)域的區(qū)域網(wǎng)絡(luò)是非常優(yōu)越的。如在圖1所示。802154sub-GHzSubscriberDistributedGenerationDistributionProtectionandControlNetworkResidentialMeteringHAN&SmartEnergyProfile2.0802154sub-GHzSubscriberDistributedGenerationDistributionProtectionandControlNetworkResidentialMeteringHAN&SmartEnergyProfile2.0TransformerDistributionEVChargingLargeC&lPublicWorkForceMonitoringAutomationInfrastructureMetersLightingAutomationSWUpgradeNetworkMonitoringAddressAcquisitionControl&ReconfigurationConfigDownload—EventNotificationTimeDistribution-ConnectedGridManagementPublicorPrivateIPInfrastructure

le:2G/3G/LTE.EthemeVFiber,WiMax,B-PLC,...PLCMesh

IEEEP1901.2

IPv6/6LoWPAN/RPLEthernetIPv6Protectionand

ControlNetwork受限制網(wǎng)絡(luò)的獨(dú)特的網(wǎng)絡(luò)要求NAN網(wǎng)絡(luò)部署下的設(shè)備往往在資源方面受制約，通常命名為IP智能對象?？紤]其獨(dú)特的特點(diǎn)和要求，智能對象的網(wǎng)絡(luò)也被稱為低功耗和有損網(wǎng)絡(luò)（LLN）0典型的IP網(wǎng)絡(luò)有強(qiáng)大的路由器相互聯(lián)系以保持高度穩(wěn)定和快速鏈接，與之相比LLNs通常是低功耗，低帶寬鏈路（無線和有線）鏈接的，之間幾kbps和幾個(gè)數(shù)百kbps的傳輸?shù)男纬闪艘粋€(gè)網(wǎng)狀網(wǎng)絡(luò)以保證正確的操作經(jīng)營。除了提供有限的帶寬，看到這樣的鏈接分組交付率（PDR）在60%和90%之間搖擺不定是不尋常的，同時(shí)有大量不可預(yù)知的錯誤，甚至在時(shí)間間隔之間丟失數(shù)據(jù)。這些現(xiàn)象可以在無線（如IEEE802.15.4g）和電力線載波通信（PLC）的（如IEEEP1901.2）的鏈接上看到，數(shù)據(jù)包傳輸可能在一天中就會發(fā)生變化！IP智能對象的另一個(gè)特點(diǎn)是各種類型的節(jié)點(diǎn)可以在通信基礎(chǔ)設(shè)施中混合。這意味著路由協(xié)議需要有能力管理基于節(jié)點(diǎn)能力的流量，例如：有源供電的電表可以轉(zhuǎn)發(fā)流量并和現(xiàn)有的電池供電的水表共存，或電池供電故障電路指標(biāo)，作為在LLN路由域的一個(gè)支葉。節(jié)點(diǎn)故障也可能大大超過傳統(tǒng)的IP網(wǎng)絡(luò)節(jié)點(diǎn)，傳統(tǒng)IP網(wǎng)絡(luò)都有電源供電并且高度冗余（多處理器，支持不間斷轉(zhuǎn)發(fā)（NSF）的，服務(wù)軟件升級（ISSU）等）。另一個(gè)LLNs必要特點(diǎn)是可伸縮性。有些LLNs是由幾十個(gè)節(jié)點(diǎn)構(gòu)成的；其他是由數(shù)以百萬計(jì)的節(jié)點(diǎn)構(gòu)成的，就像在AMI的網(wǎng)絡(luò)的情況下，他們通常由子網(wǎng)（或更小的網(wǎng)絡(luò)）幾千個(gè)節(jié)點(diǎn)所構(gòu)成的。這就解釋了為什么指定協(xié)議為大規(guī)模，限制性，不穩(wěn)定的環(huán)境帶來了自身的挑戰(zhàn)。例如，在LLN的金科玉律之一，是“under-reacttofailure”與OSPF或ISIS的路由協(xié)議相比，網(wǎng)絡(luò)需要在數(shù)十毫秒內(nèi)重新收斂。面對這一挑戰(zhàn)需要一個(gè)真正的模式的轉(zhuǎn)變，因?yàn)檫^度反應(yīng)會導(dǎo)致非常迅速的網(wǎng)絡(luò)崩潰。此外，控制平面開銷應(yīng)最小化，同時(shí)支持動態(tài)鏈路/節(jié)點(diǎn)指標(biāo)，多拓?fù)渎酚桑ǖ罔F），等等。這也解釋了導(dǎo)致在本文后面討論的各種協(xié)議為什么經(jīng)過重新設(shè)計(jì)，特別是網(wǎng)狀路由RPL）的傳統(tǒng)的IP網(wǎng)絡(luò)開發(fā)的幾種技術(shù)。此外，工作組IETF的輕重量實(shí)施指南［LWIG］正在為受約束的設(shè)備的開發(fā)實(shí)施準(zhǔn)則。最后但并非最不重要的是對使用多年的IP協(xié)議和算法來部署高度安全的網(wǎng)絡(luò)的強(qiáng)烈要求，在本文后面討論。IPv6智能電網(wǎng)最后一英里基礎(chǔ)構(gòu)架的技術(shù)構(gòu)件今天，互聯(lián)網(wǎng)主要是運(yùn)行在IPv4上的，也有些例外，如IPv6是越來越多地被部署在學(xué)術(shù)和研究網(wǎng)絡(luò)，領(lǐng)先的互聯(lián)網(wǎng)服務(wù)供應(yīng)商或企業(yè)，以及政府的網(wǎng)絡(luò)中。IPv4與IPv6的比較參見圖3。但是，由于自2011年2月由IANA管理的地址池耗盡互聯(lián)網(wǎng)面臨的一個(gè)重大轉(zhuǎn)變［經(jīng)合組織］。除了小規(guī)模的AMI和配電自動化領(lǐng)域用IPv4網(wǎng)絡(luò)，其余的有機(jī)會從一開始就用純的IPv6版本開始部署。業(yè)界一直在IPv6領(lǐng)域努力了近15年了，為了使得采用IPv6能得到和IPv4相同的IP服務(wù)（見圖5）全面提出了許多建議，和最新的3G蜂窩演變稱為LTE（長期演進(jìn)）（這些建議來自于美國行政管理和預(yù)算局USOMB，武裝部隊(duì)FAR，歐盟委員會IPv6的建議，區(qū)域互聯(lián)網(wǎng)注冊管理機(jī)構(gòu)的建議，以及IPv4地址枯竭倒數(shù)）。此外，正如上面所討論的所有與新的發(fā)展有關(guān)的IP智能對象和LLNs，都利用或正在建立IPv6技術(shù)。因此，關(guān)于使用IPv6的智能電網(wǎng)FAN幾個(gè)特點(diǎn)來部署的好書在接下來的章節(jié)將廣泛的回顧一下：一個(gè)巨大的地址空間可以容納任何預(yù)期數(shù)百萬的電表的部署（AMI），成千上萬的傳感器（DA）部署于成百上千的二次變電站，以及一些獨(dú)立的電表。這包括額外的地址配備的靈活性，在需要安裝的小型設(shè)備時(shí)有助于適應(yīng)部署的規(guī)模以及降低現(xiàn)場工作人員的任務(wù)。IPv6地址的結(jié)構(gòu)也具有足夠的靈活性來管理大量的子網(wǎng)絡(luò)，這些字網(wǎng)絡(luò)可以創(chuàng)建一些服務(wù)，例如電動汽車充電站或分布式可再生能源。IPv6是在開放的射頻無線網(wǎng)（IEEE802.15.4g，使用數(shù)字無繩超低能源）和電力線的通信基礎(chǔ)設(shè)施（IEEEP1901.2）真正通訊的IP版本，PLC只定義了其協(xié)議版本IPv6的6LoWPAN的適應(yīng)層。IPv6的是事實(shí)上的低功耗和有損網(wǎng)絡(luò)（RPL）的IETF工作組ROLL-RPL的標(biāo)準(zhǔn)化的IETF路由協(xié)議的IP版本，是一個(gè)純IPv6協(xié)議。所有著名的的IP功能，使部署設(shè)計(jì)上的高度可用和安全的通信基礎(chǔ)設(shè)施與網(wǎng)絡(luò)操作中心，公共和/或私營廣域網(wǎng)（WAN）和所有的鄰居區(qū)域網(wǎng)絡(luò)（NAN）綁定。如圖2所示RPLdomainMeshedBSn=BaseStationnERn=EdgeRouterRPLdomainMeshedBSn=BaseStationnERn=EdgeRouternM-SmartMeterCentralSystemER2NeighborhoodAreaNetwork(NAN)CoreNetworkWideAreaNetwork(WAN)圖2所示的一個(gè)基本的FAN前端系統(tǒng)收集儀表讀數(shù)，維護(hù)儀表的配置并監(jiān)控網(wǎng)絡(luò)的運(yùn)行。這是一個(gè)端到端的鏈接，包括通過廣泛提供區(qū)域網(wǎng)絡(luò)（WAN）鏈接的儀表的節(jié)點(diǎn)和附近的區(qū)域網(wǎng)絡(luò)（NAN的）。所以，雖然儀表節(jié)點(diǎn)的物理連接從WAN變到NAN技術(shù)，邏輯上IPv6端到端的鏈接還在維護(hù)。這是通過引入一個(gè)或多個(gè)NAN邊緣的路由器，也被稱為連接到廣域網(wǎng)的IP邊緣路由器，使廣域網(wǎng)和NAN之間實(shí)現(xiàn)雙向數(shù)據(jù)流。在多服務(wù)的基礎(chǔ)設(shè)施情況下，可以預(yù)料IP邊緣路由器必須配置為雙棧--IPv6和IPv4并有IPv4向IPv6的過渡隧道，以及相反的過渡。當(dāng)通過傳統(tǒng)的串口或以太網(wǎng)接口配電自動化設(shè)備，而鏈接只支持IPv4，或提供的遠(yuǎn)程工作人員連接到一個(gè)IPv4以太網(wǎng)或使用僅支持IPv4的廣域網(wǎng)基礎(chǔ)設(shè)施時(shí)（即：GPRS），這種設(shè)置是需要的。IP邊緣路由器將根據(jù)情況進(jìn)行適當(dāng)?shù)呐渲茫缤ㄟ^廣域網(wǎng)或隧道技術(shù)同時(shí)運(yùn)行IPv6和IPv4，互聯(lián)網(wǎng)行業(yè)測試機(jī)制本身已經(jīng)做過很好的測試。配電系統(tǒng)運(yùn)營商（DSO）需要把冗余作為一種方法來提高LLNs通信的可靠性，以及衡量由于通訊和計(jì)量技術(shù)生命周期不兼容對廠商鎖定和技術(shù)鎖定。在廣域網(wǎng)和NAN通過網(wǎng)狀功能或同時(shí)使用多種技術(shù)，可以在幾個(gè)層次實(shí)現(xiàn)冗余。路由可以是從端到端透明的和獨(dú)立的技術(shù)。例如，IP邊緣路由器的廣域網(wǎng)連接可以由私有的可靠的光纖連接，或通過公共靈活的蜂窩通信技術(shù)鏈接，如GPRS/3G/LTE。一個(gè)IP邊緣路由器可以與計(jì)量節(jié)點(diǎn)共存一處，或在變電站以分開的實(shí)體存在，而大多數(shù)的計(jì)量節(jié)點(diǎn)是利用RF或PLC技術(shù)或同時(shí)利用兩種技術(shù)，通過6LoWPAN/IPv6/RPL鏈接建立網(wǎng)狀NAN。由動態(tài)IP路由協(xié)議啟動的多IP邊緣路由器的可能性對防止單點(diǎn)故障來說是重要的，特別是像

由現(xiàn)在的集中器導(dǎo)入的私有PLC和RF網(wǎng)。NAN節(jié)點(diǎn)允許動態(tài)路由運(yùn)輸，如電動汽車，場域工具或傳呼機(jī)。IP邊緣路由器能夠在不同NAN技術(shù)下路由流量，并與其他IP邊緣路由器合作，在全球連接骨干網(wǎng)，這是防止廠商鎖定和技術(shù)鎖定的關(guān)鍵要素，因?yàn)樘娲缘膹V域網(wǎng)和NAN通信技術(shù)可以很容易地適應(yīng)。與之對比，IP（非IP）網(wǎng)關(guān)通過NAN與其他網(wǎng)絡(luò)鏈接，該網(wǎng)絡(luò)的一個(gè)設(shè)備處理狀態(tài)和協(xié)議轉(zhuǎn)換的失敗將不可避免地導(dǎo)致通信故障。這也允許DSO在時(shí)間和地點(diǎn)上能優(yōu)化資本投資（CAPEX）和運(yùn)營成本（OPEX）。以在一些國家的情況的GSM/GPRS為例。雖然這種成熟的技術(shù)是準(zhǔn)備好展示并且成本低，但它可能已經(jīng)是在其生命周期結(jié)束時(shí)，所以有部署的風(fēng)險(xiǎn)。然而，用它做廣域網(wǎng)接入，不僅能輕易的減輕這種風(fēng)險(xiǎn)，把更先進(jìn)的3G/LTE調(diào)制解調(diào)器（部分）從一開始就安裝在IP邊緣路由器上，或當(dāng)覆蓋范圍和價(jià)格合適時(shí)逐漸的把他們替換掉。優(yōu)化成本的DSO關(guān)注的另一個(gè)問題是分散部署。NAN技術(shù)（RF或PLC的網(wǎng)）通常需要足夠密集的節(jié)點(diǎn)分組來實(shí)現(xiàn)網(wǎng)狀功能（要看到它的鄰居）。當(dāng)開始在一個(gè)位置推出時(shí)，必須先安裝一個(gè)IP邊緣路由器，并足夠接近第一個(gè)儀表必須，以確保WAN通信。隨后它作為一個(gè)基礎(chǔ)，隨著更多的鄰居節(jié)點(diǎn)部署將成為一個(gè)較大的NAN網(wǎng)絡(luò)。WebServices/EXIHTTPS/CoAPSNMP,IPfbcDNS,WebServices/EXIHTTPS/CoAPSNMP,IPfbcDNS,NTP,IEC61850IEC6D870DNPIEEE1888MODBUSIEC6196SCIMANSIC12.19/C1222DLMS8SEMTCPJUA-EUO一ounu.A=wuouU3ILL君彖NQMJAHd」<&§考藝芝-EEO0Routing-RPL-EUO一ounu.A=wuouU3ILL君彖NQMJAHd」<&§考藝芝-EEO0Routing-RPLIPv6i'IPv4Addressing,Multicast,QoS,Security&02.1X/EAF'TLS打煎女ACCESSCODlfOlSolution6L0WPAN(RFC6282)802.15.4eMACIEEEa02ll5.4MAC(indudingFHSS1IEEEP1S01_2M^CIEEEBd215.4g(FSK,DSSSOFDM)IEEEP1S01.2PHYIEEE8C2.15.4MACIEEE80GHzDS6SIETFRFC2464IETFRFC5072IETFRFC5121IIEEE802.11W-FiIEEE802.3Etiiarnet2G/3G/LTECellularIEEE802.16WilMax?Standardizationatalllevelstoensureinteroperabilityand*Enablescommonapplicationlayerservicesovervariousreducetechnologyriskforutilitieswiredandwirelesscommunicationtechnologies圖3：智能電網(wǎng)場域網(wǎng)IPv6網(wǎng)絡(luò)協(xié)議棧圖3總結(jié)了被提議的場區(qū)網(wǎng)絡(luò)的整體的端到端IPv6架構(gòu)，并清楚地顯示分層架構(gòu)所提供的力量和靈活性。第一層是相互獨(dú)立，這使得應(yīng)用程序編程接口（API）層與層之間有允許跨層優(yōu)化的可能。例如，可以添加新的鏈接類型，而無需重新審視網(wǎng)絡(luò)尋址方案，或新應(yīng)用程序可以被支持而不影響其余協(xié)議棧。另一個(gè)例子，路由功能在第3層，這使新添加的數(shù)據(jù)鏈路層不影響路由架構(gòu)。在本章的其余部分，我們會詳細(xì)描述FAN網(wǎng)絡(luò)協(xié)議棧的相關(guān)技術(shù)方面，目前知道已經(jīng)現(xiàn)在已有過多的IP協(xié)議而無需任何改變就可以重新使用。外文文獻(xiàn)原文AStandardizedandFlexibleIPv6ArchitectureforFieldAreaNetworksSmartGridLastMileInfrastructureThispaperisintendedtoprovideasyntheticandholisticviewofopenstandardsInternetProtocolversion6(IPv6)basedarchitectureforSmartGridLastMileInfrastructuresinsupportofanumberofadvancedSmartGridapplications(meterreadout,demand-response,telemetry,andgridmonitoringandautomation)anditsbenefitasatrueMulti-Servicesplatform.Inthispaper,weshowhowthevariousbuildingblocksofIPv6networkinginfrastructurecanprovideanefficient,flexible,secure,andmulti-servicenetworkbasedonopenstandards.Inordertodiscusstransitionpathsforelectricutilitiesthatdealwithsuchissuesaslegacydevice,networkandapplicationintegration,andtheoperationofhybridnetworkstructuresduringtransitionalrollouts,afollow-uppaperwillneedtobedeveloped.1、Introduction：LastmilenetworkshavegainedconsiderablemomentumoverthepastfewyearsduetotheirprominentroleintheSmartGridinfrastructure.Thesenetworks—referredasNeighborhoodAreaNetworks(NAN)inthisdocument—supportavarietyofapplicationsincludingnotonlyelectricityusagemeasurementandmanagement,butalsoadvancedapplicationssuchasDemand-Response(DR),whichgivesuserstheopportunitytooptimizetheirenergyusagebasedonreal-timeelectricitypricinginformation,DistributionAutomation(DA),whichallowsdistributionmonitoringandcontrol,andautomaticfaultdetection,isolationandmanagement,andservesasafoundationforfutureVirtualPowerPlants,whichcomprisedistributedpowergeneration,residentialenergystorage(e.g.,incombinationwithElectricVehicle(EV)charging),andsmallscaletradingcommunities.FieldAreaNetworks(FAN)—thecombinationofNANandcommunicationdeviceofferingthebackhaulWANinterface(s)—haveemergedasacentralcomponentoftheSmartGridnetworkinfrastructure.Infact,theycanserveasbackhaulnetworksforavarietyofotherelectricgridcontroldevices;multi-tenantservices(gasandwatermeters),anddataexchangestoHomeAreaNetwork(HAN)devices,allconnectedthroughavarietyofwirelessorwiredlinetechnologies.ThishascreatedtheneedfordeployingtheIP(InternetProtocol)suiteofprotocols,enablingtheuseofopen-standardsthatprovidethereliability,scalability,security,inter-networkingandflexibilityrequiredtocopewiththefast-growingnumberofcriticalapplicationsfortheelectricgridthatdistributionpowernetworksneedtosupport.IPalsofacilitatesintegrationoftheNeighborhoodAreaNetworks(NAN)intoend-to-endnetworkarchitecture.OneapplicationbeingrunoverFieldAreaNetworksismeterreading,whereeachmeterperiodicallyreportsusagedatatoautilityhead-endapplicationserver.ThemajorityofmetertrafficwasthusdirectedfromthemeternetworktotheutilitynetworkinaMultipoint-to-Point(MP2P)fashion.WiththeemergenceandproliferationofapplicationssuchasDemandResponse,distributedenergyresourceintegrationandElectricalVehiclecharging,itisexpectedthatthetrafficvolumeacrosstheFieldAreaNetworkswouldincreasesubstantiallyandtrafficpatternsandbi-directionalcommunicationrequirementswouldbecomesignificantlymorecomplex.Inparticular,FieldAreaNetworksareexpectedtosupportanumberofusecasesleveragingnetworkservices:Communicationwithanindividualmeter.On-demandmeterreading,real-timealertreporting,andshutdownofpowertoasinglelocationrequirePoint-to-Point(P2P)communicationbetweentheNMS/Head-endandtheelectricmeterandviceversa.CommunicationamongDAdevices.SubsetsofDAdevicesneedtocommunicatewitheachotherinordertomanageandcontroltheoperationoftheelectricgridinagivenarea,requiringtheuseofflexiblecommunicationwitheachother,includingPeer-to-Peerinsomecases.HANapplications.HANapplicationstypicallyrequirecommunicationbetweenhomeappliancesandtheutilityhead-endserverthroughindividualmetersactingasapplication’sgateways.Forexample,ausermayactivateDirectLoadControl(DLC)capabilities,empoweringtheutilitycompanytoturnoffordowncertainhomeappliancesremotely(e.g.A/C,washer/dryer),whendemandand/orthecostofelectricityishigh.ElectricVehicleCharging.Usersneedtohaveaccesstotheirindividualvehiclechargingaccountinformationwhileawayfromhomeinordertobeabletochargetheirvehicleswhileontheroadorwhilevisitingfriends.Verifyinguserandaccountinformationwouldrequirecommunicationthroughthemetertotheutilityhead-endserversfrompotentiallyalargesetofnomadicvehiclesbeingchargedsimultaneouslyfromdynamiclocations.Multi-TenantServices.CombininginformationatthecustomersideanddifferentiatinginformationintoseveralservicesattheothersidedevisesforacomplexMultipoint-to-Multipointnetwork(MP2MP).Forexample,thiscouldbeaconvergednetworkconnectingdevicesfrommultipleutilitiesassuggestedbytheUKnationalmulti-utilitytelecomoperatorDCCorGermanymulti-utilitycommunicationboxasspecifiedinOpenMeterSystems.Security.StrongauthenticationmechanismsforvalidatingdevicesthatconnecttotheAdvancedMeteringInfrastructure(AMI)networkaswellasncryptionfordataprivacyandnetworkprotection.NetworkManagement.AstheFANcarriesincreasinglymoretrafficandissubjecttostringentServiceLevelObjectives(SLOs),managingnetwork-relateddatabecomescriticaltomonitoringandmaintainingnetworkhealthandperformance.ThiswouldrequirethecommunicationofgridstatusandcommunicationsstatisticsfromthemeterstotheNetworkManagementSystem(NMS)/Head-endinaMP2Pfashion.?MulticastServices.Groupsofmetersmayneedtobeaddressedsimultaneouslyusingmulticast,e.g.,toenablesoftwareupgradeorparametersupdatessentbyanetworkmanagementsystem(NMS)toallmetersusingmulticastrequests,andmulticastqueriesformeterreadingsofvarioussubsetsofthemeters.TheKeyAdvantagesofInternetProtocolAnend-to-endIPSmart-Gridarchitecturecanleverage30yearsofInternetProtocoltechnologydevelopment[RFC6272]guaranteeingopenstandardsandinteroperabilityaslargelydemonstratedthroughthedailyuseoftheInternetanditstwobillionend-users[Stats].Note~UsingtheInternetprotocolsuitedoesnotmeanthataninfrastructurerunningIPhastobeanopenorpubliclyaccessiblenetworndeed,manyexistingmission-criticalbutprivateandhighlysecurenetworksleveragetheIParchitecture,suchasinter-bankingnetworks,militaryanddefensenetworks,andpublic-safetyandemergency-responswetworks,tonameafew.OneofthedifferencesbetweenInformationandCommunicationsTechnology(ICT)andthemoretraditionalpowerindustryisthelifetimeoftechnologies.SelectingtheIPlayeredstackforAMIinfrastructurebringsfutureproofingthroughsmoothevolutionarystepsthatdonotmodifytheentireindustrialworkflow.KeybenefitsofIPforadistributionsystemoperator(DSO)are:OpenandStandards-based:Corecomponentsofthenetwork,transportandapplicationslayersstandardizedbytheInternetEngineeringTaskForce(IETF)whilekeyphysical,datalink,andapplicationsprotocolscomefromusualindustrialorganizations,suchas,IEC,ANSI,DLMS/COSEM,SAE,IEEE,ITU,etc.Lightweight:DevicesinstalledinthelastmileofanAMInetworksuchassmartmeters,sensors,andactuatorsarenotlikePCandservers.Theyhavelimitedresourcesintermsofpower,CPU,memory,andstorage.Therefore,anembeddednetworkingstackmustworkonfewkilobitsofRAMandafewdozenkilobitsofFlashmemory.IthasbeendemonstratedoverthepastyearsthatproductionIPstacksperformwellinsuchconstrainedenvironments.(See[IP-light])Versatile:LastmileinfrastructureinSmartGridhastodealwithtwokeychallenges.First,onegiventechnology(wirelessorwired)maynotfitallfielddeployment’scriteria.Second,communicationtechnologiesevolveatapacefasterthantheexpected15to20yearslifetimeofasmartmeter.ThelayeredIParchitectureiswellequippedtocopewithanytypeofphysicalanddatalinklayers,makingitfutureproofasvariousmedicanbeusedinadeploymentand,overtime,withoutchangingthewholesolutionarchitectureanddataflow.Ubiquitous:Allrecentoperatingsystemsreleasesfromgeneral-purposecomputersandserverstolightweightembeddedsystems(TinyOS,Contiki,etc.)haveanintegrateddual(IPv4andIPv6)IPstackthatgetsenhancedovertime.Thismakesanewnetworkingfeatureseteasiertoadaptovertime.Scalable:AsthecommonprotocoloftheInternet,IPhasbeenmassivelydeployedandtestedforrobustscalability.MillionsofprivateorpublicIPinfrastructurenodes,managedunderasingleentity(similarlytowhatisexpectedforFANdeployments)havebeenoperationalforyears,offeringstrongfoundationsfornewcomersnotfamiliarwithIPnetworkmanagement.ManageableandSecure:Communicationinfrastructurerequiresappropriatemanagementandsecuritycapabilitiesforproperoperations.Oneofthebenefitsof30yearsofoperationalIPnetworksisitssetofwell-understoodnetworkmanagementandsecurityprotocols,mechanisms,andtoolsetsthatarewidelyavailable.AdoptingIPnetworkmanagementalsohelpsutilityoperationalbusinessapplicationbyleveragingnetwork-managementtoolstoimprovetheirservices,forexamplewhenidentifyingpoweroutagecoveragethroughthehelpoftheNetworkManagementSystem(NMS).Stableandresilient:Withmorethan30yearsofexistence,itisnolongeraquestionthatIPisaworkablesolutionconsideringitslargeandwell-establishedknowledgebase.MoreimportantforFieldAreaNetworksishowwecanleveragetheyearsofexperienceaccumulatedbycriticalinfrastructures,suchasfinancialanddefensenetworksaswellascriticalservicessuchasVoiceandVideothathavealreadytransitionedfromclosedenvironmentstoopenIPstandards.ItalsobenefitsfromalargeecosystemofITprofessionalsthatcanhelpdesigning,deployingandoperatingthesystemsolution.End-to-end:TheadoptionofIPprovidesend-to-endandbi-directionalcommunicationcapabilitiesbetweenanydevicesinthenetwork.Centralizedordistributedarchitecturefordatamanipulationsareimplementedaccordingtobusinessrequirements.Theremovalofintermediateprotocoltranslationgatewaysfacilitatestheintroductionofnewservices.AnIPv6DistributionNetworkArchitectureThenetworkingrequirementsforNeighborhoodAreaNetworkshavebeenextensivelydocumented:costefficiency,scalability(millionsofnodesinanetworkiscommon),security,reliabilityandflexibilityareabsolutemusts,andtechnologiesbasedonopenstandardsandthefutureproofingof15to20yearslifetimeareminimumexpectationsfromutilities.ThisexplainswhytheIPv6suitewastheinitialprotocolofchoice,althoughnewIPv6protocolshavebeendesignedtoaddresstheuniquerequirementsofsuchnetworks,asdiscussedinthenextchapter.TheadoptionofIPv6facilitatesasuccessfultransformationtoconnectedenergynetworkinthelastmile.However,beforedescribingigreaterdetailIPv6networkingcomponentssuchasIPaddressing,security,QualityofService(QoS),androutingandnetworkmanagement,itisworthaskingwhyshouldweuseend-to-endIPv6?Afterall,IPv6asanyothertechnologiesrequiresappropriateeducationtothewholeworkforce,fromtechnicianstotheexecutivesevaluatingvendors,subcontractorsandcontractors.OneofthemajorstepsinfavorofbuildingthemomentumaroundusingIPend-to-endirthelastmileofSmartGridnetworkswastodemonstratethatIPcouldbelightenoughtobeusedonconstraineddeviceswithlimitedresourcesintermsofenergy,memory,andprocessingpower.ThusFANswereseenassingleapplication,stubnetworkswithendnodessuchasmetersnotrunningIPthatcouldbereachedthroughIPthroughprotocol-translationgateways,witheachgatewaybeingtiedtoadedicatdserviceand/orsolution’svendor.Thepasttwodecades,withthetransitionofprotocolssuchasSNA(throughDLSw),Appletalk,DECnet,IPX,andX25,showedusthatsuchgatewayswereviableoptionsonlyduringtransitionperiodswithsmaller,singleapplication,networks.Butproprietaryprotocolandtranslationgatewayssufferfromwell-knownsevereissues,suchashighCapExandOpExl,alongwithsignificanttechnicallimitations2,includinglackofend-to-endcapabilitiesintermsofQoS,fastrecoveryconsistency,singlepointoffailures(unlessimplementingcomplexstatefulfailovermechanisms),limitingfactorsintermsofinnovation(forcingtoleastcommondenominator),lackofscalability,vulnerabilitytosecurityattacks,andmore.Therefore,usingIPv6end-to-end(IPrunningoneachandeverydeviceinthenetwork)willbe,inmanyways,amuchsuperiorapproachformulti-servicesFieldAreaNetworksasshownonFigurel.

Figure1.Multi-ServicesFigure1.Multi-ServicesInfrastructureforLastMileSmartGridTransformationSOurce:Cisco)TheUniqueNetworkRequirementsofConstrainedNetworksDevicesdeployedinthecontextofNANsareoftenconstrainedintermsofresourcesandoftennamedIPSmartObject.Smart-ObjectnetworksarealsoreferredtoasLowpowerandLossyNetworks(LLN)consideringtheiruniquecharacteristicsandrequirements.BycontrastwithtypicalIPnetworks,inwhichpowerfulroutersareinterconnectedbyhighlystableandfastlinks,LLNsareusuallyinterconnectedbylow-power,low-bandwidthlinks(wirelessandwired)operatingbetweenafewkbpsandafew-hundredskbpsandformingameshednetworkforguaranteeingproperoperations.Inadditiontoprovidinglimitedbandwidth,itisnotunusualtoseeonsuchlinksthePacketDeliveryRate(PDR)oscillatingbetween60percentand90percent,withlargeburstsofunpredictableerrorsandevenlossofconnectivityatintervals.Thosebehaviorscanbeobservedonbothwireless(suchasIEEE802.15.4g)andPowerLineCommunication(PLC)(suchasIEEEP1901.2)links,wherepacketdeliveryvariationmayhappenduringthecourseofoneday!AnothercharacteristicofIPsmartobjectsisthatvarioustypesofnodescouldgetmixedinthecommunication’sinfrastructure.Itimpliesthattheroutingprotocolneedstohavethecapabilitymanagingtrafficpathsbasedonnode’scapabilities—ie:poweredelectricmetersabletoforwardtrafficandco-existingwithbatterypoweredwatermeters,orbatterypoweredfaultedcircuitindicators,actingasleavesinaLLNroutingdomain.NodefailuresmayalsobesignificantlymorefrequentthanintraditionalIPnetworkswherenodeshaveasmuchaspowertheyrequireandarehighlyredundant(multiprocessors,supportingnon-stopforwarding(NSF),In-ServiceSoftwareUpgrade(ISSU),etc).AnothernecessarycharacteristicforLLNsisscalability.SomeLLNsaremadeupofdozensofnodes;otherscomprisemillionsofnodes,asisthecaseofAMInetworks,howevertheyareusuallymadeupofsubnets(orsmallernetworks)ofafewthousandnodes.Thisexplainswhyspecifyingprotocolsforverylarge-scale,constrained,andunstableenvironmentsbringsitsownchallenges.Forexample,oneofthegoldenrulesinanLLNisto“under-reacttofailure,”bycontrasttoroutingprotocolssuchasOSPForISIS,wherethenetworkneedstore-convergewithinafewdozensofmilliseconds.Meetingthischallengerequiredarealparadigmshift,sinceover-reactionwouldlead,veryrapidly,tonetworkcollapse.Furthermore,control-planeoverheadshouldbeminimized,whilesupportingdynamiclink/nodemetrics,Multi-TopologyRouting(MTR),andsoforth.ThatexplainswhyseveraltechniquesthatweredevelopedfortraditionalIPnetworkshadbeenredesignedresultinginvariousprotocolsespeciallyforMeshrouting(RPL)asdiscussedlaterinthispaper.Inaddition,theIETFLight-WeightImplementationGuidanceWG[LWIG]isdevelopingimplementationguidelinesforconstraintdevices.Lastbutnotleastisthestrongrequirementfordeployinghighlysecurenetworks,usingyearsofIPprotocolsandalgorithms,asdiscussedlaterinthispaper.TheTechnicalComponentsofIPv6SmartGridLastMileInfrastructureToday,theInternetrunsmostlyoverIPversion4(IPv4),withexceptionsinacademicandresearchnetworks,leadingInternetServiceProvidersorEnterprises,andgovernmentnetworks(whereIPv6isincreasinglybeingdeployed).SeeFigure3foranIPv4-IPv6comparison.However,theInternetfacesamajortransition[OECD]duetotheexhaustionofaddresspoolmanagedbyIANAsinceFebruary2011.WithlittleexistingIPv4networkinglegacyintheareasofAMIandDistributionAutomation,thereisanopportunitytostartdeployingIPv6asthedefactoIPversionfromDayOne.TheindustryhasbeenworkingonIPv6fornearly15years,andtheadoptionofIPv6~whichprovidesthesameIPservicesasIPv4(seefigure5)—wouldbefullyalignedwithnumerousrecommendations(U.S.OMBandFAR,EuropeanCommissionIPv6recommendations,RegionalInternetRegistryrecommendations,andIPv4addressdepletioncountdown)andlatest3GcellularevolutionknownasLTE(LongTermEvolution).Moreover,allnewdevelopmentsinrelationtoIPforSmartObjectsandLLNsasdiscussedabove,makeuseoforarebuiltonIPv6technology.Therefore,theuseofIPv6forSmartGridFANsdeploymentbenefitsfromseveralfeatures,somebeingextensivelyreviewedinthenextsections:Ahugeaddressspaceaccommodatinganyexpectedmulti-millionsmeter’sdeployment(AMI),thousandsofsensors(DA)overthehundredthousandsofsecondarysubstationsandadditionallyallstandalonemeters.Itincludesadditionalflexibilityofaddressconfigurationthathelpsadaptingwiththesizeofdeploymentsaswellastheneedtolowerfieldworkerstaskswheninstallingsmalldevices.ThestructureoftheIPv6addressisalsoflexibleenoughtomanagealargenumberofsub-networksthatmaybecreatedbyfuturesservicessuchase-vehiclechargingstationsordistributedrenewableenergy.IPv6isthedefactoIPversionformetercommunicationoveropenRFMeshwireless(IEEE802.15.4g,DECTUltraLowEnergy)andPowerLineCommunicationsinfrastructures(IEEEP1901.2)usingthe6LoWPANadaptationlayerthatonlydefinesIPv6asitsprotocolversion.IPv6isthedefactoIPversionforthestandardizedIETFRoutingProtocolforLowPowerandLossyNetworks(RPL)—IETFRoLLWG—RPLisanIPv6-onlyprotocol.Thisgoeswithoutforgettingallwell-knownIPfeaturessetthatenablesdesignvariationsforthedeploymentofhighlyavailableandsecuredcommunicationsinfrastructuretyingaNetworkOperationsCenter(s)andallNeighborhoodAreaNetworks(NAN)throughpublicand/orprivateWideAreaNetworks(WAN)linkssuchasshownonFigure2.CentralSystemNeighborhoodAreaNetwork(NAN)BSn=BaseStationCentralSystemNeighborhoodAreaNetwork(NAN)BSn=BaseStationnERn=EdgeRoulernM=SmartMeterFigure2.ExampleofbasicLastMileSmartGridInfrastructurewithseverallevelsofredundancy(Source:Alliander)TheHead-endSystemofabasicFANasshowninFigure2collectsthemeterreadings,maintainsmeterconfigurationsandmonitorsnetworkoperation.Ithasend-to-endconnectionstothemeternodes,providedbywideareaietworks(WANs)andneighborhoodareanetworks(NANs).So,whilethephysicalconnectionstothemeternodeschangefromWANtoNANtechnologies,theprincipleoflogicalend-to-endIPv6connectionsismaintained.ThisisachievedbyintroducingoneormoreroutersatthebordersoftheNAN,alsocalledIPEdgeRoutersthatconnecttotheWAN,enablingbi-directionaldatastreamsbetweenWANandNAN.Incaseofmulti-servicesinfrastructures,itmaybeexpectedthatIPEdgeRoutershavetobeconfiguredasdual-stack—IPv6andIPv4andwillbecapableoftunnelingIPv6overIPv4orvice-versa.ThismayberequiredwhenconnectingoveritsserialorEthernetinterfaceslegacyDistributionAutomationdevicesthatonlyrunIPv4orprovidingremoteworkforceconnectivitytoanIPv4IntranetorwhenusingWANinfrastructurethatareIPv4-only(ie:GPRS).TheIPEdgeRouterwillhavetobeproperlyconfiguredtoaccommodatescenariosuchasrunningbothIPv6andIPv4overtheWANortunnelingoneprotocolversionovertheother,mechanismsthathavebeenwelldefinedandtestedbytheInternetindustry.DistributionSystemOperators(DSOs)requireredundancyasameanstoimprovecommunicationreliabilityintheLLNs,aswellasmeasureagainstvendorlock-inandtechnologylock-induetoincompatibilityinlifetimebetweencommunicationandmeteringtechnologies.RedundancycanbeachievedatseverallevelsthroughmeshcapabilitiesintheWANandNANorbyusingmultipletechnologiessimultaneously.Routingshallbetransparentfromendtoendandindependentfromthetechnology.Forexample,theWANconnectionoftheIPEdgeRouterisestablishedbyaprivatereliablefiberconnectionorbypublicfle