Internet Engineering Task Force (IETF) T. Watteyne, Ed.
Request for Comments: 7554 Linear Technology
Category: Informational M. Palattella
ISSN: 2070-1721 University of Luxembourg
L. Grieco
Politecnico di Bari
May 2015
Internet Engineering Task Force (IETF) T. Watteyne, Ed.
Request for Comments: 7554 Linear Technology
Category: Informational M. Palattella
ISSN: 2070-1721 University of Luxembourg
L. Grieco
Politecnico di Bari
May 2015
Using IEEE 802.15.4e Time-Slotted Channel Hopping (TSCH) in the Internet of Things (IoT): Problem Statement
在物联网（IoT）中使用IEEE 802.15.4e时隙信道跳频（TSCH）：问题陈述
Abstract
摘要
This document describes the environment, problem statement, and goals for using the Time-Slotted Channel Hopping (TSCH) Medium Access Control (MAC) protocol of IEEE 802.14.4e in the context of Low-Power and Lossy Networks (LLNs). The set of goals enumerated in this document form an initial set only.
本文档描述了在低功率和有损网络（LLN）环境下使用IEEE 802.14.4e的时隙信道跳频（TSCH）媒体访问控制（MAC）协议的环境、问题陈述和目标。本文件中列举的目标集仅构成初始目标集。
Status of This Memo
关于下段备忘
This document is not an Internet Standards Track specification; it is published for informational purposes.
本文件不是互联网标准跟踪规范；它是为了提供信息而发布的。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。并非IESG批准的所有文件都适用于任何级别的互联网标准；见RFC 5741第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7554.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问http://www.rfc-editor.org/info/rfc7554.
Copyright Notice
版权公告
Copyright (c) 2015 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2015 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(http://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. TSCH in the LLN Context . . . . . . . . . . . . . . . . . . . 5
3. Problems and Goals . . . . . . . . . . . . . . . . . . . . . 7
3.1. Network Formation . . . . . . . . . . . . . . . . . . . . 8
3.2. Network Maintenance . . . . . . . . . . . . . . . . . . . 8
3.3. Multi-Hop Topology . . . . . . . . . . . . . . . . . . . 8
3.4. Routing and Timing Parents . . . . . . . . . . . . . . . 8
3.5. Resource Management . . . . . . . . . . . . . . . . . . . 9
3.6. Dataflow Control . . . . . . . . . . . . . . . . . . . . 9
3.7. Deterministic Behavior . . . . . . . . . . . . . . . . . 9
3.8. Scheduling Mechanisms . . . . . . . . . . . . . . . . . . 10
3.9. Secure Communication . . . . . . . . . . . . . . . . . . 10
4. Security Considerations . . . . . . . . . . . . . . . . . . . 11
5. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1. Normative References . . . . . . . . . . . . . . . . . . 11
5.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. TSCH Protocol Highlights . . . . . . . . . . . . . . 15
A.1. Time Slots . . . . . . . . . . . . . . . . . . . . . . . 15
A.2. Slotframes . . . . . . . . . . . . . . . . . . . . . . . 15
A.3. Node TSCH Schedule . . . . . . . . . . . . . . . . . . . 15
A.4. Cells and Bundles . . . . . . . . . . . . . . . . . . . . 16
A.5. Dedicated vs. Shared Cells . . . . . . . . . . . . . . . 17
A.6. Absolute Slot Number . . . . . . . . . . . . . . . . . . 17
A.7. Channel Hopping . . . . . . . . . . . . . . . . . . . . . 17
A.8. Time Synchronization . . . . . . . . . . . . . . . . . . 18
A.9. Power Consumption . . . . . . . . . . . . . . . . . . . . 19
A.10. Network TSCH Schedule . . . . . . . . . . . . . . . . . . 19
A.11. Join Process . . . . . . . . . . . . . . . . . . . . . . 19
A.12. Information Elements . . . . . . . . . . . . . . . . . . 20
A.13. Extensibility . . . . . . . . . . . . . . . . . . . . . . 20
Appendix B. TSCH Features . . . . . . . . . . . . . . . . . . . 21
B.1. Collision-Free Communication . . . . . . . . . . . . . . 21
B.2. Multi-Channel vs. Channel Hopping . . . . . . . . . . . . 21
B.3. Cost of (Continuous) Synchronization . . . . . . . . . . 21
B.4. Topology Stability . . . . . . . . . . . . . . . . . . . 21
B.5. Multiple Concurrent Slotframes . . . . . . . . . . . . . 22
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. TSCH in the LLN Context . . . . . . . . . . . . . . . . . . . 5
3. Problems and Goals . . . . . . . . . . . . . . . . . . . . . 7
3.1. Network Formation . . . . . . . . . . . . . . . . . . . . 8
3.2. Network Maintenance . . . . . . . . . . . . . . . . . . . 8
3.3. Multi-Hop Topology . . . . . . . . . . . . . . . . . . . 8
3.4. Routing and Timing Parents . . . . . . . . . . . . . . . 8
3.5. Resource Management . . . . . . . . . . . . . . . . . . . 9
3.6. Dataflow Control . . . . . . . . . . . . . . . . . . . . 9
3.7. Deterministic Behavior . . . . . . . . . . . . . . . . . 9
3.8. Scheduling Mechanisms . . . . . . . . . . . . . . . . . . 10
3.9. Secure Communication . . . . . . . . . . . . . . . . . . 10
4. Security Considerations . . . . . . . . . . . . . . . . . . . 11
5. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.1. Normative References . . . . . . . . . . . . . . . . . . 11
5.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. TSCH Protocol Highlights . . . . . . . . . . . . . . 15
A.1. Time Slots . . . . . . . . . . . . . . . . . . . . . . . 15
A.2. Slotframes . . . . . . . . . . . . . . . . . . . . . . . 15
A.3. Node TSCH Schedule . . . . . . . . . . . . . . . . . . . 15
A.4. Cells and Bundles . . . . . . . . . . . . . . . . . . . . 16
A.5. Dedicated vs. Shared Cells . . . . . . . . . . . . . . . 17
A.6. Absolute Slot Number . . . . . . . . . . . . . . . . . . 17
A.7. Channel Hopping . . . . . . . . . . . . . . . . . . . . . 17
A.8. Time Synchronization . . . . . . . . . . . . . . . . . . 18
A.9. Power Consumption . . . . . . . . . . . . . . . . . . . . 19
A.10. Network TSCH Schedule . . . . . . . . . . . . . . . . . . 19
A.11. Join Process . . . . . . . . . . . . . . . . . . . . . . 19
A.12. Information Elements . . . . . . . . . . . . . . . . . . 20
A.13. Extensibility . . . . . . . . . . . . . . . . . . . . . . 20
Appendix B. TSCH Features . . . . . . . . . . . . . . . . . . . 21
B.1. Collision-Free Communication . . . . . . . . . . . . . . 21
B.2. Multi-Channel vs. Channel Hopping . . . . . . . . . . . . 21
B.3. Cost of (Continuous) Synchronization . . . . . . . . . . 21
B.4. Topology Stability . . . . . . . . . . . . . . . . . . . 21
B.5. Multiple Concurrent Slotframes . . . . . . . . . . . . . 22
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 23
IEEE 802.15.4e [IEEE.802.15.4e] was published in 2012 as an amendment to the Medium Access Control (MAC) protocol defined by the IEEE 802.15.4 standard (of 2011) [IEEE.802.15.4]. IEEE 802.15.4e will be rolled into the next revision of IEEE 802.15.4, scheduled to be published in 2015. The Time-Slotted Channel Hopping (TSCH) mode of IEEE 802.15.4e is the object of this document. The term "TSCH" refers to TSCH as used in [IEEE.802.15.4e].
IEEE 802.15.4e[IEEE.802.15.4e]于2012年发布，作为对IEEE 802.15.4标准（2011年版）[IEEE.802.15.4]定义的媒体访问控制（MAC）协议的修订。IEEE 802.15.4e将被纳入IEEE 802.15.4的下一版本，该版本计划于2015年发布。IEEE 802.15.4e的时隙信道跳频（TSCH）模式是本文档的目标。术语“TSCH”指[IEEE.802.15.4e]中使用的TSCH。
This document describes the main issues arising from the adoption of the TSCH in the LLN context, following the terminology defined in [TERMS-6TISCH]. Appendix A further gives an overview of the key features of the TSCH amendment to IEEE 802.15.4e. Appendix B details features of TSCH, which might be interesting for the work of the 6TiSCH WG.
本文件根据[TERMS-6TISCH]中定义的术语，描述了在LLN环境下采用TSCH所产生的主要问题。附录A进一步概述了IEEE 802.15.4e TSCH修正案的主要特点。附录B详细介绍了TSCH的特点，这可能会引起第六届科技工作组的兴趣。
TSCH was designed to allow IEEE 802.15.4 devices to support a wide range of applications including, but not limited to, industrial ones [IEEE.802.15.4e]. At its core is a medium access technique that uses time synchronization to achieve low-power operation and channel hopping to enable high reliability. Synchronization accuracy impacts power consumption and can vary from microseconds to milliseconds depending on the solution. This is very different from the "legacy" IEEE 802.15.4 MAC protocol and is therefore better described as a "redesign". TSCH does not amend the physical layer, i.e., it can operate on any hardware that is compliant with IEEE 802.15.4.
TSCH旨在允许IEEE 802.15.4设备支持广泛的应用，包括但不限于工业应用[IEEE.802.15.4e]。其核心是一种媒体接入技术，它使用时间同步实现低功耗操作，并使用信道跳频实现高可靠性。同步精度会影响功耗，根据解决方案的不同，可能会在微秒到毫秒之间变化。这与“传统的”IEEE 802.15.4 MAC协议非常不同，因此最好将其描述为“重新设计”。TSCH不修改物理层，即它可以在符合IEEE 802.15.4的任何硬件上运行。
IEEE 802.15.4e is the latest generation of ultra-lower power and reliable networking solutions for LLNs. [RFC5673] discusses industrial applications and highlights the harsh operating conditions as well as the stringent reliability, availability, and security requirements for an LLN to operate in an industrial environment. In these environments, vast deployment environments with large (metallic) equipment cause multi-path fading and interference to thwart any attempt of a single-channel solution to be reliable; the channel agility of TSCH is the key to its ultra-high reliability. Commercial networking solutions are available today in which nodes consume 10's of microamps on average [CurrentCalculator] with end-to-end packet delivery ratios over 99.999% [Doherty07channel].
IEEE 802.15.4e是针对LLN的最新一代超低功耗和可靠网络解决方案。[RFC5673]讨论了工业应用，并强调了LLN在工业环境中运行的苛刻操作条件以及严格的可靠性、可用性和安全性要求。在这些环境中，具有大型（金属）设备的大型部署环境会导致多径衰落和干扰，从而阻碍单通道解决方案的任何可靠尝试；TSCH的信道灵活性是其超高可靠性的关键。现在可以使用商业网络解决方案，其中节点平均消耗10微安[CurrentCalculator]，端到端数据包交付率超过99.999%[Doherty07channel]。
IEEE 802.15.4e has been designed for low-power constrained devices, often called "motes". Several terms are used in the IETF to refer to those devices, including "LLN nodes" [RFC7102] and "constrained nodes" [RFC7228]. In this document, we use the generic (and shorter) term "node", used as a synonym for "LLN node", "constrained node", or "mote".
IEEE 802.15.4e是为低功耗限制设备设计的，通常被称为“微尘”。IETF中使用了几个术语来指代这些设备，包括“LLN节点”[RFC7102]和“受限节点”[RFC7228]。在本文档中，我们使用通用（和较短）术语“节点”，用作“LLN节点”、“受约束节点”或“mote”的同义词。
Enabling the LLN protocol stack to operate in industrial environments opens up new application domains for these networks. Sensors deployed in smart cities [RFC5548] will be able to be installed for years without needing battery replacement. "Umbrella" networks will interconnect smart elements from different entities in smart buildings [RFC5867]. Peel-and-stick switches will obsolete the need for costly conduits for lighting solutions in smart homes [RFC5826].
使LLN协议栈能够在工业环境中运行，为这些网络开辟了新的应用领域。部署在智能城市的传感器[RFC5548]将能够安装数年而无需更换电池。“伞形”网络将智能建筑中不同实体的智能元件互连[RFC5867]。剥杆式开关将淘汰智能家居照明解决方案中昂贵导管的需求[RFC5826]。
TSCH focuses on the MAC layer only. This clean layering allows for TSCH to fit under an IPv6-enabled protocol stack for LLNs, running an IPv6 over Low-Power Wireless Personal Area Network (6LoWPAN) [RFC6282], the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) [RFC6550], and the Constrained Application Protocol (CoAP) [RFC7252]. What is missing is a functional entity that is in charge of scheduling TSCH time slots for frames to be sent on. In this document, we refer to this entity as the "Logical Link Control" (LLC), bearing in mind that realizations of this entity can be of different types, including a distributed protocol or a centralized server in charge of scheduling.
TSCH只关注MAC层。这种干净的分层允许TSCH适合于支持IPv6的LLN协议栈，运行低功耗无线个人区域网（6LoWPAN）[RFC6282]、低功耗和有损网络的IPv6路由协议（RPL）[RFC6550]和受限应用协议（CoAP）[RFC7252]。缺少的是负责为要发送的帧安排TSCH时隙的功能实体。在本文档中，我们将该实体称为“逻辑链路控制”（LLC），记住该实体的实现可以是不同的类型，包括分布式协议或负责调度的集中式服务器。
While [IEEE.802.15.4e] defines the mechanisms for a TSCH node to communicate, it does not define the policies to build and maintain the communication schedule, match that schedule to the multi-hop paths maintained by RPL, adapt the resources allocated between neighbor nodes to the data traffic flows, enforce a differentiated treatment for data generated at the application layer and signaling messages needed by 6LoWPAN and RPL to discover neighbors, react to topology changes, self-configure IP addresses, or manage keying material.
虽然[IEEE.802.15.4e]定义了TSCH节点的通信机制，但并未定义建立和维护通信调度、将该调度与RPL维护的多跳路径相匹配、使相邻节点之间分配的资源适应数据通信流的策略，对在应用层生成的数据和6LoWPAN和RPL所需的信令消息实施差异化处理，以发现邻居、对拓扑更改作出反应、自行配置IP地址或管理密钥材料。
In other words, TSCH is designed to allow optimizations and strong customizations, simplifying the merging of TSCH with a protocol stack based on IPv6, 6LoWPAN, and RPL.
换句话说，TSCH的设计允许优化和强大的定制，简化了TSCH与基于IPv6、6LoWPAN和RPL的协议栈的合并。
To map the services required by the IP layer to the services provided by the link layer, an adaptation layer is used [Palattella12standardized]. In 2007, the 6LoWPAN WG started working on specifications for transmitting IPv6 packets over IEEE 802.15.4 networks [RFC4919]. A low-power Wireless Personal Area Network (WPAN) is typically composed of a large number of battery-powered devices that are deployed at locations that are unknown a priori. Nodes form a star or a mesh topology and communicate with one another at a low datarate and using short frames. The wireless nature of the links means that they are unreliable in nature. Nodes turn off their radio interface most of the time to conserve energy. Given these
为了将IP层所需的服务映射到链路层提供的服务，使用了一个适配层[Palatella12标准化]。2007年，6LoWPAN工作组开始制定通过IEEE 802.15.4网络传输IPv6数据包的规范[RFC4919]。低功耗无线个人区域网（WPAN）通常由大量部署在未知位置的电池供电设备组成。节点形成星形或网状拓扑，并以低数据速率和短帧相互通信。链路的无线特性意味着它们本质上是不可靠的。节点大部分时间关闭其无线电接口以节省能源。鉴于这些
features, it is clear that the adoption of IPv6 on top of a low-power WPAN is not straightforward but poses strong requirements for the optimization of this adaptation layer.
显然，在低功耗WPAN之上采用IPv6并不简单，但对该适配层的优化提出了强烈的要求。
For instance, due to the IPv6 default minimum MTU size (1280 bytes), an unfragmented IPv6 packet is too large to fit in an IEEE 802.15.4 frame. Moreover, the overhead due to the 40-byte-long IPv6 header wastes the scarce bandwidth available at the PHY layer [RFC4944]. For these reasons, the 6LoWPAN WG has defined an effective adaptation layer [RFC6282]. Further issues encompass the autoconfiguration of IPv6 addresses [RFC2460] [RFC4862], the compliance with the recommendation on supporting link-layer subnet broadcast in shared networks [RFC3819], the reduction of routing and management overhead [RFC6606], the adoption of lightweight application protocols (or novel data encoding techniques), and the support for security mechanisms (confidentiality and integrity protection, device bootstrapping, key establishment, and management).
例如，由于IPv6默认的最小MTU大小（1280字节），未分段的IPv6数据包太大，无法装入IEEE 802.15.4帧。此外，40字节长的IPv6报头造成的开销浪费了物理层可用的稀缺带宽[RFC4944]。由于这些原因，6LoWPAN工作组定义了一个有效的适应层[RFC6282]。进一步的问题包括IPv6地址的自动配置[RFC2460][RFC4862]、遵守关于在共享网络中支持链路层子网广播的建议[RFC3819]、减少路由和管理开销[RFC6606]、采用轻量级应用协议（或新的数据编码技术），以及对安全机制的支持（机密性和完整性保护、设备引导、密钥建立和管理）。
These features can run on top of TSCH. There are, however, important issues to solve, as highlighted in Section 3.
这些功能可以在TSCH上运行。然而，正如第3节所强调的，还有一些重要问题需要解决。
Routing issues are challenging for 6LoWPAN, given the low-power and lossy radio links, the battery-powered nodes, the multi-hop mesh topologies, and the frequent topology changes due to mobility. Successful solutions take into account the specific application requirements, along with IPv6 behavior and 6LoWPAN mechanisms [Palattella12standardized]. The ROLL WG has defined RPL in [RFC6550]. RPL can support a wide variety of link layers, including ones that are constrained, potentially lossy, or typically utilized in conjunction with host or router devices with very limited resources, as in building/home automation [RFC5867] [RFC5826], industrial environments [RFC5673], and urban applications [RFC5548]. RPL is able to quickly build up network routes, distribute routing knowledge among nodes, and adapt to a changing topology. In a typical setting, nodes are connected through multi-hop paths to a small set of root devices, which are usually responsible for data collection and coordination. For each of them, a Destination-Oriented Directed Acyclic Graph (DODAG) is created by accounting for link costs, node attributes/status information, and an Objective Function, which maps the optimization requirements of the target scenario.
考虑到6LoWPAN的低功耗和有损无线链路、电池供电节点、多跳网状拓扑以及由于移动性导致的频繁拓扑变化，路由问题对6LoWPAN来说是一个挑战。成功的解决方案考虑了特定的应用程序需求，以及IPv6行为和6LoWPAN机制[Palatella12标准化]。滚动工作组在[RFC6550]中定义了RPL。RPL可以支持多种链路层，包括受限、可能有损或通常与资源非常有限的主机或路由器设备结合使用的链路层，如在楼宇/家庭自动化[RFC5867][RFC5826]、工业环境[RFC5673]和城市应用[RFC5548]中。RPL能够快速建立网络路由，在节点之间分发路由知识，并适应不断变化的拓扑结构。在典型设置中，节点通过多跳路径连接到一小部分根设备，这些根设备通常负责数据收集和协调。对于每一种情况，通过考虑链路成本、节点属性/状态信息和映射目标场景优化需求的目标函数，创建面向目的地的有向无环图（DODAG）。
The topology is set up based on a Rank metric, which encodes the distance of each node with respect to its reference root, as specified by the Objective Function. Regardless of the way it is computed, the Rank monotonically decreases along the DODAG towards the root, building a gradient. RPL encompass different kinds of traffic and signaling information. Multipoint-to-Point (MP2P) is the
拓扑是基于秩度量建立的，秩度量对每个节点相对于其参考根的距离进行编码，如目标函数所指定。无论计算方式如何，秩都会沿着DODAG向根单调递减，从而形成梯度。RPL包含不同种类的流量和信令信息。多点对点（MP2P）是
dominant traffic in LLN applications. Data is routed towards nodes with some application relevance, such as the LLN gateway to the larger Internet or to the core of private IP networks. In general, these destinations are the DODAG roots and act as data collection points for distributed monitoring applications. Point-to-Multipoint (P2MP) data streams are used for actuation purposes, where messages are sent from DODAG roots to destination nodes. Point-to-Point (P2P) traffic allows communication between two devices belonging to the same LLN, such as a sensor and an actuator. A packet flows from the source to the common ancestor of those two communicating devices, then downward towards the destination. Therefore, RPL has to discover both upward routes (i.e., from nodes to DODAG roots) in order to enable MP2P and P2P flows and downward routes (i.e., from DODAG roots to nodes) to support P2MP and P2P traffic.
LLN应用中的主要流量。数据被路由到与某些应用程序相关的节点，例如到更大的Internet或到专用IP网络核心的LLN网关。通常，这些目的地是DODAG根，充当分布式监控应用程序的数据收集点。点对多点（P2MP）数据流用于驱动目的，其中消息从DODAG根发送到目标节点。点对点（P2P）通信允许属于同一LLN的两个设备之间进行通信，例如传感器和执行器。数据包从源流向这两个通信设备的共同祖先，然后向下流向目的地。因此，RPL必须同时发现上行路由（即从节点到DODAG根）以支持MP2P和P2P流，以及下行路由（即从DODAG根到节点）以支持P2MP和P2P流量。
Section 3 highlights the challenges that need to be addressed to use RPL on top of TSCH.
第3节强调了在TSCH之上使用RPL需要解决的挑战。
Open-source initiatives have emerged around TSCH, with the OpenWSN project [OpenWSN] [OpenWSNETT] being the first open-source implementation of a standards-based protocol stack. This implementation was used as the foundation for an IP for the Smart Objects Alliance (IPSO) [IPSO] interoperability event in 2011. In the absence of a standardized scheduling mechanism for TSCH, a "slotted Aloha" schedule was used.
围绕TSCH已经出现了开源计划，OpenWSN项目[OpenWSN][OpenWSNETT]是第一个基于标准的协议栈的开源实现。此实现被用作IP智能对象联盟（IPSO）[IPSO ]互操作事件的基础（2011）。在缺乏TSCH标准化调度机制的情况下，使用了“时隙Aloha”调度。
As highlighted in Appendix A, TSCH differs from other low-power MAC protocols because of its scheduled nature. TSCH defines the mechanisms to execute a communication schedule; yet, it is the entity that sets up the schedule that controls the topology of the network. This scheduling entity also controls the resources allocated to each link in that topology.
正如附录A中强调的，TSCH由于其调度性质不同于其他低功耗MAC协议。TSCH定义了执行通信计划的机制；然而，正是实体设置了控制网络拓扑的时间表。此调度实体还控制分配给该拓扑中每个链路的资源。
How this entity should operate is out of scope of TSCH. The remainder of this section highlights the problems this entity needs to address. For simplicity, we refer to this entity by the generic name "LLC". Note that the 6top sublayer, currently being defined in [SUBLAYER-6top], can be seen as an embodiment of this generic "LLC".
该实体应如何运营不在TSCH的范围内。本节剩余部分将重点介绍该实体需要解决的问题。为简单起见，我们将该实体称为通用名称“LLC”。请注意，当前在[sublayer-6top]中定义的6top子层可被视为该通用“LLC”的一个实施例。
Some of the issues the LLC needs to target might overlap with the scope of other protocols (e.g., 6LoWPAN, RPL, and RSVP). In this case, the LLC will profit from the services provided by other protocols to pursue these objectives.
LLC需要针对的一些问题可能与其他协议（如6LoWPAN、RPL和RSVP）的范围重叠。在这种情况下，LLC将从其他协议提供的服务中获益，以实现这些目标。
The LLC needs to control the way the network is formed, including how new nodes join and how already joined nodes advertise the presence of the network. The LLC needs to:
LLC需要控制网络的形成方式，包括新节点如何加入以及已经加入的节点如何宣传网络的存在。有限责任公司需要：
1. Define the Information Elements included in the Enhanced Beacons (EBs) [IEEE.802.15.4e] advertising the presence of the network.
1. 定义增强型信标（EBs）[IEEE.802.15.4e]中包含的信息元素，用于宣传网络的存在。
2. (For a new node), define rules to process and filter received EBs.
2. （对于新节点），定义用于处理和筛选接收到的EBs的规则。
3. Define the joining procedure. This might include a mechanism to assign a unique 16-bit address to a node and the management of initial keying material.
3. 定义连接程序。这可能包括为节点分配唯一16位地址的机制以及初始密钥材料的管理。
4. Define a mechanism to secure the joining process and the subsequent optional process of scheduling more communication cells.
4. 定义一种机制，以确保加入过程以及调度更多通信单元的后续可选过程的安全。
Once a network is formed, the LLC needs to maintain the network's health, allowing for nodes to stay synchronized. The LLC needs to:
一旦网络形成，LLC需要保持网络的健康，允许节点保持同步。有限责任公司需要：
1. Manage each node's time source neighbor.
1. 管理每个节点的时间源邻居。
2. Define a mechanism for a node to update the join priority it announces in its EB.
2. 为节点定义一种机制，以更新其在EB中宣布的加入优先级。
3. Schedule transmissions of EBs to advertise the presence of the network.
3. 安排EBs的传输以通告网络的存在。
RPL, given a weighted connectivity graph, determines multi-hop routes. The LLC needs to:
RPL，给定一个加权连通图，确定多跳路由。有限责任公司需要：
1. Define a mechanism to gather topological information, node and link state, which it can then feed to RPL.
1. 定义一种收集拓扑信息、节点和链接状态的机制，然后将其提供给RPL。
2. Ensure that the TSCH schedule contains cells along the multi-hop routes identified by RPL (a cell in a TSCH schedule is an atomic "unit" of resource, see Section 3.5).
2. 确保TSCH计划包含沿RPL标识的多跳路由的单元（TSCH计划中的单元是资源的原子“单位”，请参见第3.5节）。
3. Where applicable, maintain independent sets of cells to transport independent flows of data.
3. 在适用的情况下，维护独立的单元集以传输独立的数据流。
At all times, a TSCH node needs to have a time-source neighbor to which it can synchronize. Therefore, LLC needs to assign a time-source neighbor to allow for correct operation of the TSCH network. A time-source neighbor could, or not, be taken from the RPL routing parent set.
在任何时候，TSCH节点都需要有一个时间源邻居，它可以与之同步。因此，LLC需要分配一个时间源邻居，以允许TSCH网络的正确运行。时间源邻居可以从RPL路由父集合获取，也可以不从RPL路由父集合获取。
A cell in a TSCH schedule is an atomic "unit" of resource. The number of cells to assign between neighbor nodes needs to be appropriate for the size of the traffic flow. The LLC needs to:
TSCH计划中的单元是资源的原子“单位”。在相邻节点之间分配的小区数量需要适合于业务流的大小。有限责任公司需要：
1. Define a mechanism for neighbor nodes to exchange information about their schedule and, if applicable, negotiate the addition/ deletion of cells.
1. 为邻居节点定义一种机制，以交换有关其调度的信息，并在适用的情况下协商单元的添加/删除。
2. Allow for an entity (e.g., a set of devices, a distributed protocol, a Path Computation Element (PCE), etc.) to take control of the schedule.
2. 允许实体（例如，一组设备、分布式协议、路径计算元素（PCE）等）控制调度。
TSCH defines mechanisms for a node to signal when it cannot accept an incoming packet. It does not, however, define the policy that determines when to stop accepting packets. The LLC needs to:
TSCH定义了节点在无法接受传入数据包时发出信号的机制。但是，它没有定义确定何时停止接受数据包的策略。有限责任公司需要：
1. Allow for the implementation and configuration of policy to queue incoming and outgoing packets.
1. 允许实现和配置将传入和传出数据包排队的策略。
2. Manage the buffer space, and indicate to TSCH when to stop accepting incoming packets.
2. 管理缓冲区空间，并向TSCH指示何时停止接收传入数据包。
3. Handle transmissions that have failed. A transmission is declared failed when TSCH has retransmitted the packet multiple times, without receiving an acknowledgment. This covers both dedicated and shared cells.
3. 处理发生故障的传输。当TSCH在未收到确认的情况下多次重新传输数据包时，传输被宣布失败。这包括专用单元和共享单元。
As highlighted in [RFC5673], in some applications, data is generated periodically and has a well-understood data bandwidth requirement, which is deterministic and predictable. The LLC needs to:
正如[RFC5673]中所强调的，在某些应用中，数据是周期性生成的，并且具有众所周知的数据带宽要求，这是确定性和可预测的。有限责任公司需要：
1. Ensure that the data is delivered to its final destination before a deadline possibly determined by the application.
1. 确保在应用程序可能确定的截止日期之前将数据交付到其最终目的地。
2. Provide a mechanism for such deterministic flows to coexist with bursty or infrequent traffic flows of different priorities.
2. 提供一种机制，使此类确定性流与具有不同优先级的突发或不频繁流量共存。
Several scheduling mechanisms can be envisioned and could possibly coexist in the same network. For example, [RPL] describes how the allocation of bandwidth can be optimized by an external PCE [RFC4655]. Another centralized (PCE-based) traffic-aware scheduling algorithm is defined in [TASA-PIMRC]. Alternatively, two neighbor nodes can adapt the number of cells autonomously by monitoring the amount of traffic and negotiating the allocation to extra cell when needed. An example of a decentralized algorithm (i.e., no PCE is needed) is provided in [Tinka10decentralized]. This mechanism can be used to establish multi-hop paths in a fashion similar to RSVP [RFC2205]. The LLC needs to:
可以设想几种调度机制，它们可能共存于同一网络中。例如，[RPL]描述如何通过外部PCE优化带宽分配[RFC4655]。[TASA-PIMRC]中定义了另一种集中式（基于PCE的）流量感知调度算法。或者，两个相邻节点可以通过监视通信量并在需要时协商分配给额外小区来自主调整小区数量。[1]中提供了分散算法的示例（即不需要PCE）。该机制可用于以类似于RSVP[RFC2205]的方式建立多跳路径。有限责任公司需要：
1. Provide a mechanism for two devices to negotiate the allocation and deallocation of cells between them.
1. 为两个设备提供一种机制，以协商它们之间单元的分配和解除分配。
2. Provide a mechanism for the device to monitor and manage the capabilities of a node several hops away.
2. 为设备提供一种机制，以监控和管理几跳之外的节点的功能。
3. Define a mechanism for these different scheduling mechanisms to coexist in the same network.
3. 为这些不同的调度机制定义一种在同一网络中共存的机制。
Given some keying material, TSCH defines mechanisms to encrypt and authenticate MAC frames. It does not define how this keying material is generated. The LLC needs to:
给定一些密钥材料，TSCH定义了加密和验证MAC帧的机制。它不定义如何生成此关键帧材质。有限责任公司需要：
1. Define the keying material and authentication mechanism needed by a new node to join an existing network.
1. 定义新节点加入现有网络所需的密钥材料和身份验证机制。
2. Define a mechanism to allow for the secure transfer of application data between neighbor nodes.
2. 定义允许在相邻节点之间安全传输应用程序数据的机制。
3. Define a mechanism to allow for the secure transfer of signaling data between nodes and the LLC.
3. 定义一种机制，以允许在节点和LLC之间安全传输信令数据。
This memo is an informational overview of existing standards and does not define any new mechanisms or protocols.
本备忘录是对现有标准的信息性概述，未定义任何新机制或协议。
It does describe the need for the 6TiSCH WG to define a secure solution. In particular, Section 3.1 describes security in the join process. Section 3.9 discusses data-frame protection.
它确实描述了6TiSCH工作组定义安全解决方案的需求。特别是，第3.1节描述了连接过程中的安全性。第3.9节讨论数据帧保护。
[IEEE.802.15.4] IEEE, "IEEE Standard for Local and metropolitan area networks -- Part. 15.4: Low-Rate Wireless Personal Area Networks", IEEE Std. 802.15.4-2011, September 2011.
[IEEE.802.15.4]IEEE，“局域网和城域网的IEEE标准——第15.4部分：低速无线个人区域网”，IEEE标准802.15.4-2011，2011年9月。
[IEEE.802.15.4e] IEEE, "IEEE Standard for Local and metropolitan area networks -- Part 15.4: Low-Rate Wireless Personal Area Networks (LR-WPANs) Amendment 1: MAC sublayer", IEEE Std. 802.15.4e-2012, April 2012.
[IEEE.802.15.4e]IEEE，“局域网和城域网的IEEE标准——第15.4部分：低速无线个人区域网（LR WPAN）修改件1:MAC子层”，IEEE标准802.15.4e-2012，2012年4月。
[CurrentCalculator] Linear Technology, "Application Note: Using the Current Calculator to Estimate Mote Power", August 2012, <http://www.linear.com/docs/43189>.
[CurrentCalculator]线性技术，“应用说明：使用当前计算器估算微尘功率”，2012年8月<http://www.linear.com/docs/43189>.
[Doherty07channel] Doherty, L., Lindsay, W., and J. Simon, "Channel-Specific Wireless Sensor Network Path Data", IEEE International Conference on Computer Communications and Networks (ICCCN), pp. 89-94, 2007.
[Doherty07channel]Doherty，L.，Lindsay，W.，和J.Simon，“特定于信道的无线传感器网络路径数据”，IEEE计算机通信和网络国际会议（ICCCN），第89-942007页。
[IPSO] IPSO Alliance, "IP for Smart Objects Alliance Homepage", <http://www.ipso-alliance.org/>.
[IPSO]IPSO联盟，“智能对象联盟主页的IP”<http://www.ipso-alliance.org/>.
[OpenWSN] "Berkeley's OpenWSN Project Homepage", <http://www.openwsn.org/>.
[OpenWSN]“伯克利的OpenWSN项目主页”<http://www.openwsn.org/>.
[OpenWSNETT] Watteyne, T., Vilajosana, X., Kerkez, B., Chraim, F., Weekly, K., Wang, Q., Glaser, S., and K. Pister, "OpenWSN: A Standards-Based Low-Power Wireless Development Environment", Transactions on Emerging Telecommunications Technologies, Volume 23: Issue 5, August 2012.
[OpenWSNETT]Watteyne，T.，Vilajosana，X.，Kerkez，B.，Chraim，F.，Weekly，K.，Wang，Q.，Glaser，S.，和K.Pister，“OpenWSN：基于标准的低功耗无线开发环境”，新兴电信技术交易，第23卷：第5期，2012年8月。
[Palattella12standardized] Palattella, MR., Accettura, N., Vilajosana, X., Watteyne, T., Grieco, LA., Boggia, G., and M. Dohler, "Standardized Protocol Stack For The Internet Of (Important) Things", IEEE Communications Surveys and Tutorials, Volume: 15, Issue 3, December 2012.
[Palatella12标准化]Palatella先生，N.阿克图拉，Vilajosana，X.，Watteyne，T.，Grieco，LA.，Boggia，G.，和M.Dohler，“物联网（重要）的标准协议栈”，IEEE通信调查和教程，第15卷，第3期，2012年12月。
[RFC2205] Braden, R., Ed., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, DOI 10.17487/RFC2205, September 1997, <http://www.rfc-editor.org/info/rfc2205>.
[RFC2205]Braden，R.，Ed.，Zhang，L.，Berson，S.，Herzog，S.，和S.Jamin，“资源保留协议（RSVP）——版本1功能规范”，RFC 2205，DOI 10.17487/RFC2205，1997年9月<http://www.rfc-editor.org/info/rfc2205>.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460, December 1998, <http://www.rfc-editor.org/info/rfc2460>.
[RFC2460]Deering，S.和R.Hinden，“互联网协议，第6版（IPv6）规范”，RFC 2460，DOI 10.17487/RFC2460，1998年12月<http://www.rfc-editor.org/info/rfc2460>.
[RFC3819] Karn, P., Ed., Bormann, C., Fairhurst, G., Grossman, D., Ludwig, R., Mahdavi, J., Montenegro, G., Touch, J., and L. Wood, "Advice for Internet Subnetwork Designers", BCP 89, RFC 3819, DOI 10.17487/RFC3819, July 2004, <http://www.rfc-editor.org/info/rfc3819>.
[RFC3819]Karn，P.，Ed.，Bormann，C.，Fairhurst，G.，Grossman，D.，Ludwig，R.，Mahdavi，J.，黑山，G.，Touch，J.，和L.Wood，“互联网子网络设计师的建议”，BCP 89，RFC 3819，DOI 10.17487/RFC3819，2004年7月<http://www.rfc-editor.org/info/rfc3819>.
[RFC4655] Farrel, A., Vasseur, J., and J. Ash, "A Path Computation Element (PCE)-Based Architecture", RFC 4655, DOI 10.17487/RFC4655, August 2006, <http://www.rfc-editor.org/info/rfc4655>.
[RFC4655]Farrel，A.，Vasseur，J.，和J.Ash，“基于路径计算元素（PCE）的体系结构”，RFC 4655，DOI 10.17487/RFC4655，2006年8月<http://www.rfc-editor.org/info/rfc4655>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, DOI 10.17487/RFC4862, September 2007, <http://www.rfc-editor.org/info/rfc4862>.
[RFC4862]Thomson，S.，Narten，T.和T.Jinmei，“IPv6无状态地址自动配置”，RFC 4862，DOI 10.17487/RFC4862，2007年9月<http://www.rfc-editor.org/info/rfc4862>.
[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs): Overview, Assumptions, Problem Statement, and Goals", RFC 4919, DOI 10.17487/RFC4919, August 2007, <http://www.rfc-editor.org/info/rfc4919>.
[RFC4919]Kushalnagar，N.，黑山，G.和C.Schumacher，“低功率无线个人区域网络（6LoWPANs）上的IPv6：概述，假设，问题陈述和目标”，RFC 4919，DOI 10.17487/RFC4919，2007年8月<http://www.rfc-editor.org/info/rfc4919>.
[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler, "Transmission of IPv6 Packets over IEEE 802.15.4 Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007, <http://www.rfc-editor.org/info/rfc4944>.
[RFC4944]黑山，G.，Kushalnagar，N.，Hui，J.，和D.Culler，“通过IEEE 802.15.4网络传输IPv6数据包”，RFC 4944，DOI 10.17487/RFC4944，2007年9月<http://www.rfc-editor.org/info/rfc4944>.
[RFC5548] Dohler, M., Ed., Watteyne, T., Ed., Winter, T., Ed., and D. Barthel, Ed., "Routing Requirements for Urban Low-Power and Lossy Networks", RFC 5548, DOI 10.17487/RFC5548, May 2009, <http://www.rfc-editor.org/info/rfc5548>.
[RFC5548]Dohler，M.，Ed.，Watteyne，T.，Ed.，Winter，T.，Ed.，和D.Barthel，Ed.，“城市低功率和有损网络的路由要求”，RFC 5548，DOI 10.17487/RFC5548，2009年5月<http://www.rfc-editor.org/info/rfc5548>.
[RFC5673] Pister, K., Ed., Thubert, P., Ed., Dwars, S., and T. Phinney, "Industrial Routing Requirements in Low-Power and Lossy Networks", RFC 5673, DOI 10.17487/RFC5673, October 2009, <http://www.rfc-editor.org/info/rfc5673>.
[RFC5673]Pister，K.，Ed.，Thubert，P.，Ed.，Dwars，S.，和T.Phinney，“低功率和有损网络中的工业路由要求”，RFC 5673，DOI 10.17487/RFC5673，2009年10月<http://www.rfc-editor.org/info/rfc5673>.
[RFC5826] Brandt, A., Buron, J., and G. Porcu, "Home Automation Routing Requirements in Low-Power and Lossy Networks", RFC 5826, DOI 10.17487/RFC5826, April 2010, <http://www.rfc-editor.org/info/rfc5826>.
[RFC5826]Brandt，A.，Buron，J.，和G.Porcu，“低功率和有损网络中的家庭自动化路由要求”，RFC 5826，DOI 10.17487/RFC5826，2010年4月<http://www.rfc-editor.org/info/rfc5826>.
[RFC5867] Martocci, J., Ed., De Mil, P., Riou, N., and W. Vermeylen, "Building Automation Routing Requirements in Low-Power and Lossy Networks", RFC 5867, DOI 10.17487/RFC5867, June 2010, <http://www.rfc-editor.org/info/rfc5867>.
[RFC5867]Martocci，J.，Ed.，De Mil，P.，Riou，N.，和W.Vermeylen，“低功率和有损网络中的楼宇自动化路由要求”，RFC 5867，DOI 10.17487/RFC5867，2010年6月<http://www.rfc-editor.org/info/rfc5867>.
[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6 Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, DOI 10.17487/RFC6282, September 2011, <http://www.rfc-editor.org/info/rfc6282>.
[RFC6282]Hui，J.，Ed.和P.Thubert，“基于IEEE 802.15.4的网络上IPv6数据报的压缩格式”，RFC 6282，DOI 10.17487/RFC6282，2011年9月<http://www.rfc-editor.org/info/rfc6282>.
[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J., Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, JP., and R. Alexander, "RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks", RFC 6550, DOI 10.17487/RFC6550, March 2012, <http://www.rfc-editor.org/info/rfc6550>.
[RFC6550]温特，T.，Ed.，Thubert，P.，Ed.，Brandt，A.，Hui，J.，Kelsey，R.，Levis，P.，Pister，K.，Struik，R.，Vasseur，JP.，和R.Alexander，“RPL:低功耗和有损网络的IPv6路由协议”，RFC 6550，DOI 10.17487/RFC6550，2012年3月<http://www.rfc-editor.org/info/rfc6550>.
[RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem Statement and Requirements for IPv6 over Low-Power Wireless Personal Area Network (6LoWPAN) Routing", RFC 6606, DOI 10.17487/RFC6606, May 2012, <http://www.rfc-editor.org/info/rfc6606>.
[RFC6606]Kim，E.，Kaspar，D.，Gomez，C.，和C.Bormann，“通过低功率无线个人区域网络（6LoWPAN）路由的IPv6问题陈述和要求”，RFC 6606，DOI 10.17487/RFC6606，2012年5月<http://www.rfc-editor.org/info/rfc6606>.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January 2014, <http://www.rfc-editor.org/info/rfc7102>.
[RFC7102]Vasseur，JP.，“低功率和有损网络路由中使用的术语”，RFC 7102，DOI 10.17487/RFC7102，2014年1月<http://www.rfc-editor.org/info/rfc7102>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for Constrained-Node Networks", RFC 7228, DOI 10.17487/RFC7228, May 2014, <http://www.rfc-editor.org/info/rfc7228>.
[RFC7228]Bormann，C.，Ersue，M.和A.Keranen，“受限节点网络的术语”，RFC 7228，DOI 10.17487/RFC7228，2014年5月<http://www.rfc-editor.org/info/rfc7228>.
[RFC7252] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained Application Protocol (CoAP)", RFC 7252, DOI 10.17487/RFC7252, June 2014, <http://www.rfc-editor.org/info/rfc7252>.
[RFC7252]Shelby，Z.，Hartke，K.，和C.Bormann，“受限应用协议（CoAP）”，RFC 7252，DOI 10.17487/RFC7252，2014年6月<http://www.rfc-editor.org/info/rfc7252>.
[RPL] Phinney, T., Thubert, P., and R. Assimiti, "RPL applicability in industrial networks", Work in Progress, draft-ietf-roll-rpl-industrial-applicability-02, October 2013.
[RPL]Phinney，T.，Thubert，P.，和R.Assimiti，“RPL在工业网络中的适用性”，正在进行中的工作，草案-ietf-roll-RPL-industrial-applicability-022013年10月。
[SUBLAYER-6top] Wang, Q., Vilajosana, X., and T. Watteyne, "6TiSCH Operation Sublayer (6top)", Work in Progress, draft-wang-6tisch-6top-sublayer-01, July 2014.
[6top小层]Wang，Q.，Vilajosana，X.，和T.Watteyne，“6top小层操作（6top）”，正在进行的工作，草稿-Wang-6top-6top-01，2014年7月。
[TASA-PIMRC] Palattella, MR., Accettura, N., Dohler, M., Grieco, LA., and G. Boggia, "Traffic Aware Scheduling Algorithm for reliable low-power multi-hop IEEE 802.15.4e networks", IEEE 23rd International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), pp. 327-332, September 2012.
[TASA-PIMRC]Palatella先生，N.Accettura，M.Dohler，M.Grieco，LA.和G.Boggia，“可靠低功率多跳IEEE 802.15.4e网络的流量感知调度算法”，IEEE第23届个人、室内和移动无线电通信国际研讨会（PIMRC），第327-332页，2012年9月。
[TERMS-6TISCH] Palattella, M., Thubert, P., Watteyne, T., and Q. Wang, "Terminology in IPv6 over the TSCH mode of IEEE 802.15.4e", Work in Progress, draft-ietf-6tisch-terminology-04, March 2015.
[TERMS-6TISCH]Palatella，M.，Thubert，P.，Watteyne，T.，和Q.Wang，“IEEE 802.15.4e的TSCH模式下IPv6中的术语”，正在进行的工作，草案-ietf-6TISCH-TERMENCHICS-042015年3月。
[Tinka10decentralized] Tinka, A., Watteyne, T., and K. Pister, "A Decentralized Scheduling Algorithm for Time Synchronized Channel Hopping", Ad Hoc Networks, 2010.
[Tinka，A.，Watteyne，T.，和K.Pister，“时间同步信道跳频的分散调度算法”，Ad Hoc Networks，2010年。
[Watteyne09reliability] Watteyne, T., Mehta, A., and K. Pister, "Reliability Through Frequency Diversity: Why Channel Hopping Makes Sense", Proceedings of the 6th ACM Symposium on Performance Evaluation of Wireless Ad Hoc, Sensor, and Ubiquitous Networks (PE-WASUN), pp. 116-123, October 2009.
[Watteyne09reliability]Watteyne，T.，Mehta，A.，和K.Pister，“通过频率分集实现的可靠性：为什么信道跳频有意义”，第六届ACM无线自组织、传感器和无处不在网络（PE-WASUN）性能评估研讨会论文集，第116-123页，2009年10月。
This appendix gives an overview of the key features of the IEEE 802.15.4e TSCH amendment. It makes no attempt at repeating the standard, rather it focuses on the following:
本附录概述了IEEE 802.15.4e TSCH修正案的主要功能。它没有试图重复该标准，而是着重于以下内容：
o Concepts that are sufficiently different from other IEEE 802.15.4 networking that they may need to be defined and presented precisely.
o 与其他IEEE 802.15.4网络完全不同的概念，可能需要精确定义和呈现。
o Techniques and ideas that are part of IEEE 802.15.4e and that might be useful for the work of the 6TiSCH WG.
o 属于IEEE 802.15.4e的技术和思想，可能对第六届科技工作组的工作有用。
All nodes in a TSCH network are synchronized. Time is sliced up into time slots. A time slot is long enough for a MAC frame of maximum size to be sent from node A to node B, and for node B to reply with an acknowledgment (ACK) frame indicating successful reception.
TSCH网络中的所有节点都是同步的。时间被分割成时间段。时隙的长度足以使最大大小的MAC帧从节点A发送到节点B，并且使节点B用表示成功接收的确认（ACK）帧进行应答。
The duration of a time slot is not defined by the standard. With radios that are compliant with IEEE 802.15.4 operating in the 2.4 GHz frequency band, a maximum-length frame of 127 bytes takes about 4 ms to transmit; a shorter ACK takes about 1 ms. With a 10 ms slot (a typical duration), this leaves 5 ms to radio turnaround, packet processing, and security operations.
标准中未定义时段的持续时间。对于在2.4 GHz频带上运行的符合IEEE 802.15.4的无线电，127字节的最大长度帧需要大约4 ms的传输时间；较短的ACK大约需要1毫秒。使用10毫秒的时隙（典型的持续时间），这将为无线电周转、数据包处理和安全操作留出5毫秒的时间。
Time slots are grouped into one of more slotframes. A slotframe continuously repeats over time. TSCH does not impose a slotframe size. Depending on the application needs, these can range from 10's to 1000's of time slots. The shorter the slotframe, the more often a time slot repeats, resulting in more available bandwidth, but also in a higher power consumption.
时隙被分组到一个或多个时隙帧中。慢帧会随着时间的推移不断重复。TSCH不强制使用slotframe大小。根据应用程序的需要，这些时间段的范围从10到1000。时隙帧越短，时隙重复的频率越高，从而产生更多可用带宽，但也会产生更高的功耗。
A TSCH schedule instructs each node what to do in each time slot: transmit, receive, or sleep. The schedule indicates, for each scheduled (transmit or receive) cell, a channelOffset and the address of the neighbor with which to communicate.
TSCH时间表指示每个节点在每个时隙中做什么：发送、接收或睡眠。对于每个调度（发送或接收）小区，调度指示信道偏移量和与之通信的邻居的地址。
Once a node obtains its schedule, it executes it:
一旦节点获得其计划，它将执行该计划：
o For each transmit cell, the node checks whether there is a packet in the outgoing buffer that matches the neighbor written in the schedule information for that time slot. If there is none, the node keeps its radio off for the duration of the time slot. If there is one, the node can ask for the neighbor to acknowledge it, in which case it has to listen for the acknowledgment after transmitting.
o 对于每个发送小区，节点检查出站缓冲区中是否存在与该时隙的调度信息中写入的邻居相匹配的数据包。如果没有，则节点在时间段内保持其无线电关闭。如果有，节点可以请求邻居确认，在这种情况下，它必须在发送后侦听确认。
o For each receive cell, the node listens for possible incoming packets. If none is received after some listening period, it shuts down its radio. If a packet is received, addressed to the node, and passes security checks, the node can send back an acknowledgment.
o 对于每个接收单元，节点侦听可能的传入数据包。如果在一段收听时间后没有收到任何信号，则会关闭收音机。如果接收到数据包，并将其发送到节点，并且通过安全检查，则节点可以发回确认。
How the schedule is built, updated, and maintained, and by which entity, is outside of the scope of the IEEE 802.15.4e standard.
计划是如何建立、更新和维护的，以及由哪个实体建立、更新和维护的，不属于IEEE 802.15.4e标准的范围。
Assuming the schedule is well built, if node A is scheduled to transmit to node B at slotOffset 5 and channelOffset 11, node B will be scheduled to receive from node A at the same slotOffset and channelOffset.
假设调度构建良好，如果节点A被调度在slotofset 5和channelOffset 11处发送到节点B，则节点B将被调度在相同slotofset和channelOffset处从节点A接收。
A single element of the schedule characterized by a slotOffset and channelOffset, and reserved for node A to transmit to node B (or for node B to receive from node A) within a given slotframe, is called a "scheduled cell".
以时隙设置和信道偏移为特征的调度的单个元素被称为“调度小区”，该元素在给定时隙帧内被保留用于节点A向节点B发送（或用于节点B从节点A接收）。
If there is a lot of data flowing from node A to node B, the schedule might contain multiple cells from A to B, at different times. Multiple cells scheduled to the same neighbor can be equivalent, i.e., the MAC layer sends the packet on whichever of these cells shows up first after the packet was put in the MAC queue. The union of all cells between two neighbors, A and B, is called a "bundle". Since the slotframe repeats over time (and the length of the slotframe is typically constant), each cell gives a "quantum" of bandwidth to a given neighbor. Modifying the number of equivalent cells in a bundle modifies the amount of resources allocated between two neighbors.
如果有大量数据从节点a流向节点B，则调度可能在不同的时间包含从a到B的多个单元格。调度给同一邻居的多个小区可以是等效的，即，MAC层在将数据包放入MAC队列后，在这些小区中的任何一个上发送数据包。两个相邻单元A和B之间的所有单元的结合称为“束”。由于slotframe会随着时间的推移而重复（并且slotframe的长度通常是恒定的），因此每个单元都会向给定的邻居提供带宽的“量子”。修改捆绑包中等效单元的数量会修改在两个相邻单元之间分配的资源量。
By default, each scheduled transmit cell within the TSCH schedule is dedicated, i.e., reserved only for node A to transmit to node B. IEEE 802.15.4e also allows a cell to be marked as shared. In a shared cell, multiple nodes can transmit at the same time, on the same frequency. To avoid contention, TSCH defines a backoff algorithm for shared cells.
默认情况下，TSCH调度中的每个调度发送小区都是专用的，即仅为节点A保留发送到节点B的空间。IEEE 802.15.4e还允许将小区标记为共享。在共享小区中，多个节点可以在同一时间以同一频率进行传输。为了避免争用，TSCH为共享小区定义了退避算法。
A scheduled cell can be marked as both transmitting and receiving. In this case, a node transmits if it has an appropriate packet in its output buffer, or listens otherwise. Marking a cell as [transmit,receive,shared] results in slotted-Aloha behavior.
调度的小区可以同时标记为发送和接收。在这种情况下，如果节点的输出缓冲区中有适当的数据包，则节点进行传输，否则进行侦听。将小区标记为[发送、接收、共享]会导致时隙Aloha行为。
TSCH defines a timeslot counter called Absolute Slot Number (ASN). When a new network is created, the ASN is initialized to 0; from then on, it increments by 1 at each timeslot. In detail:
TSCH定义了一个称为绝对时隙号（ASN）的时隙计数器。创建新网络时，ASN初始化为0；从那时起，它在每个时隙增加1。详细内容：
ASN = (k*S+t)
ASN = (k*S+t)
where k is the slotframe cycle (i.e., the number of slotframe repetitions since the network was started), S the slotframe size, and t the slotOffset. A node learns the current ASN when it joins the network. Since nodes are synchronized, they all know the current value of the ASN, at any time. The ASN is encoded as a 5-byte number: this allows it to increment for hundreds of years (the exact value depends on the duration of a timeslot) without wrapping over. The ASN is used to calculate the frequency to communicate on and can be used for security-related operations.
其中k是slotframe循环（即，自网络启动以来的slotframe重复次数），S是slotframe大小，t是slotofset。节点在加入网络时学习当前ASN。由于节点是同步的，所以它们在任何时候都知道ASN的当前值。ASN编码为一个5字节的数字：这允许它在数百年内递增（确切值取决于一个时隙的持续时间），而无需换行。ASN用于计算通信频率，并可用于安全相关操作。
For each scheduled cell, the schedule specifies a slotOffset and a channelOffset. In a well-built schedule, when node A has a transmit cell to node B on channelOffset 5, node B has a receive cell from node A on the same channelOffset. The channelOffset is translated by both nodes into a frequency using the following function:
对于每个调度单元，调度指定一个Slotofset和一个channelOffset。在构建良好的调度中，当节点a在信道偏移量5上具有到节点B的发射小区时，节点B在相同的信道偏移量上具有来自节点a的接收小区。channelOffset由两个节点使用以下功能转换为频率：
frequency = F {(ASN + channelOffset) mod nFreq}
frequency = F {(ASN + channelOffset) mod nFreq}
The function F consists of a lookup table containing the set of available channels. The value nFreq (the number of available frequencies) is the size of this lookup table. There are as many channelOffset values as there are frequencies available (e.g., 16 when using radios that are compliant with IEEE 802.15.4 at 2.4 GHz, when all channels are used). Since both nodes have the same
函数F由一个包含可用通道集的查找表组成。值nFreq（可用频率的数量）是此查找表的大小。信道偏移值与可用频率一样多（例如，当使用符合IEEE 802.15.4的2.4 GHz无线电时为16，当使用所有信道时为16）。因为两个节点具有相同的
channelOffset written in their schedule for that scheduled cell, and the same ASN counter, they compute the same frequency. At the next iteration (cycle) of the slotframe, however, while the channelOffset is the same, the ASN has changed, resulting in the computation of a different frequency.
channelOffset写在调度单元的调度中，与ASN计数器相同，它们计算相同的频率。然而，在slotframe的下一次迭代（循环）中，当channelOffset相同时，ASN已经改变，导致计算不同的频率。
This results in "channel hopping": even with a static schedule, pairs of neighbors "hop" between the different frequencies when communicating. A way of ensuring communication happens on all available frequencies is to set the number of timeslots in a slotframe to a prime number. Channel hopping is a technique known to efficiently combat multi-path fading and external interference [Watteyne09reliability].
这导致了“信道跳频”：即使在静态调度下，通信时，相邻的成对节点也会在不同频率之间“跳频”。确保在所有可用频率上进行通信的一种方法是将slotframe中的时隙数设置为素数。信道跳频是一种有效对抗多径衰落和外部干扰的技术[Watteyne092]。
Because of the slotted nature of communication in a TSCH network, nodes have to maintain tight synchronization. All nodes are assumed to be equipped with clocks to keep track of time. Yet, because clocks in different nodes drift with respect to one another, neighbor nodes need to periodically resynchronize.
由于TSCH网络中通信的时隙性质，节点必须保持紧密同步。假设所有节点都配备了时钟来跟踪时间。然而，由于不同节点中的时钟相互漂移，相邻节点需要周期性地重新同步。
Each node needs to periodically synchronize its network clock to another node, and it also provides its network time to its neighbors. It is up to the entity that manages the schedule to assign an adequate time source neighbor to each node, i.e., to indicate in the schedule which neighbor is its "time source neighbor". While setting the time source neighbor, it is important to avoid synchronization loops, which could result in the formation of independent clusters of synchronized nodes.
每个节点需要周期性地将其网络时钟同步到另一个节点，并且还向其邻居提供其网络时间。由管理调度的实体为每个节点分配适当的时间源邻居，即在调度中指示哪个邻居是其“时间源邻居”。在设置时间源邻居时，重要的是避免同步循环，这可能导致形成独立的同步节点集群。
TSCH adds timing information in all packets that are exchanged (both data and ACK frames). This means that neighbor nodes can resynchronize to one another whenever they exchange data. In detail, two methods are defined in IEEE 802.15.4e (of 2012) for allowing a device to synchronize in a TSCH network: (i) Acknowledgment-based and (ii) Frame-based synchronization. In both cases, the receiver calculates the difference in time between the expected time of frame arrival and its actual arrival. In Acknowledgment-based synchronization, the receiver provides such information to the sender node in its acknowledgment. In this case, it is the sender node that synchronizes to the clock of the receiver. In Frame-based synchronization, the receiver uses the computed delta for adjusting its own clock. In this case, it is the receiver node that synchronizes to the clock of the sender.
TSCH在交换的所有数据包（数据和ACK帧）中添加定时信息。这意味着邻居节点可以在交换数据时彼此重新同步。具体而言，IEEE 802.15.4e（2012年版）中定义了两种允许设备在TSCH网络中同步的方法：（i）基于确认的同步和（ii）基于帧的同步。在这两种情况下，接收机计算帧到达的预期时间和实际到达时间之间的时间差。在基于确认的同步中，接收方在其确认中向发送方节点提供此类信息。在这种情况下，是发送方节点与接收方的时钟同步。在基于帧的同步中，接收机使用计算出的增量来调整自己的时钟。在这种情况下，是接收方节点与发送方的时钟同步。
Different synchronization policies are possible. Nodes can keep synchronization exclusively by exchanging EBs. Nodes can also keep synchronized by periodically sending valid frames to a time source neighbor and use the acknowledgment to resynchronize. Both methods (or a combination thereof) are valid synchronization policies; which one to use depends on network requirements.
可以使用不同的同步策略。节点可以通过交换EBs以独占方式保持同步。节点还可以通过定期向时间源邻居发送有效帧并使用确认来重新同步来保持同步。两种方法（或其组合）都是有效的同步策略；使用哪一种取决于网络需求。
There are only a handful of activities a node can perform during a timeslot: transmit, receive, or sleep. Each of these operations has some energy cost associated to them; the exact value depends on the hardware used. Given the schedule of a node, it is straightforward to calculate the expected average power consumption of that node.
节点在一个时隙中只能执行少数几个活动：发送、接收或睡眠。这些操作中的每一个都有一些与之相关的能源成本；确切值取决于所使用的硬件。给定一个节点的调度，可以直接计算该节点的预期平均功耗。
The schedule entirely defines the synchronization and communication between nodes. By adding/removing cells between neighbors, one can adapt a schedule to the needs of the application. Intuitive examples are:
时间表完全定义了节点之间的同步和通信。通过在邻居之间添加/删除单元格，可以根据应用程序的需要调整时间表。直观的例子有：
o Make the schedule "sparse" for applications where nodes need to consume as little energy as possible, at the price of reduced bandwidth.
o 对于节点需要消耗尽可能少的能量的应用程序，以降低带宽为代价，使调度变得“稀疏”。
o Make the schedule "dense" for applications where nodes generate a lot of data, at the price of increased power consumption.
o 对于节点生成大量数据的应用程序，以增加功耗为代价，使计划“密集”。
o Add more cells along a multi-hop route over which many packets flow.
o 沿多跳路由添加更多单元格，许多数据包在该路由上流动。
Nodes already part of the network can periodically send EB frames to announce the presence of the network. These contain information about the size of the timeslot used in the network, the current ASN, information about the slotframes and timeslots the beaconing node is listening on, and a 1-byte join priority. The join priority field gives information to make a better decision of which node to join. Even if a node is configured to send all EB frames on the same channelOffset, because of the channel hopping nature of TSCH described in Appendix A.7, this channelOffset translates into a different frequency at different slotframe cycles. As a result, EB frames are sent on all frequencies.
已经是网络一部分的节点可以周期性地发送EB帧来宣布网络的存在。其中包含有关网络中使用的时隙大小、当前ASN、信标节点正在侦听的时隙帧和时隙的信息以及1字节连接优先级的信息。join priority字段提供信息，以便更好地决定要加入哪个节点。即使节点被配置为在同一信道偏移上发送所有EB帧，由于附录a.7中描述的TSCH的信道跳跃性质，该信道偏移在不同的时隙帧周期转换为不同的频率。因此，EB帧在所有频率上发送。
A node wishing to join the network listens for EBs. Since EBs are sent on all frequencies, the joining node can listen on any frequency until it hears an EB. What frequency it listens on is implementation specific. Once it has received one or more EBs, the new node enables the TSCH mode and uses the ASN and the other timing information from the EB to synchronize to the network. Using the slotframe and cell information from the EB, it knows how to contact other nodes in the network.
希望加入网络的节点侦听EBs。由于EB在所有频率上发送，因此加入节点可以在任何频率上监听，直到听到EB为止。它监听的频率取决于具体的实现。一旦接收到一个或多个EB，新节点启用TSCH模式并使用ASN和来自EB的其他定时信息与网络同步。使用来自EB的slotframe和cell信息，它知道如何联系网络中的其他节点。
The IEEE 802.15.4e TSCH standard does not define the steps beyond this network "bootstrap".
IEEE 802.15.4e TSCH标准未定义此网络“引导”之外的步骤。
TSCH introduces the concept of Information Elements (IEs). An IE is a list of Type-Length-Value containers placed at the end of the MAC header. A small number of types are defined for TSCH (e.g., the ASN in the EB is contained in an IE), and an unmanaged range is available for extensions.
TSCH引入了信息元素的概念。IE是放置在MAC头末尾的类型长度值容器列表。为TSCH定义了少量类型（例如，EB中的ASN包含在IE中），非托管范围可用于扩展。
A data bit in the MAC header indicates whether the frame contains IEs. IEs are grouped into Header IEs, consumed by the MAC layer and therefore typically invisible to the next higher layer, and Payload IEs, which are passed untouched to the next higher layer, possibly followed by regular payload. Payload IEs can therefore be used for the next higher layers of two neighbor nodes to exchange information.
MAC报头中的数据位指示帧是否包含IEs。ie被分组为报头ie，由MAC层使用，因此通常对下一更高层不可见，和有效载荷ie，它们被不接触地传递到下一更高层，可能随后是常规有效载荷。因此，有效载荷IEs可用于两个相邻节点的下一个更高层来交换信息。
The TSCH standard is designed to be extensible. It introduces the mechanisms as "building block" (e.g., cells, bundles, slotframes, etc.), but leaves entire freedom to the upper layer to assemble those. The MAC protocol can be extended by defining new Header IEs. An intermediate layer can be defined to manage the MAC layer by defining new Payload IEs.
TSCH标准设计为可扩展的。它将机制作为“构建块”（例如，单元、束、插槽框架等）引入，但将整个自由留给上层来组装它们。MAC协议可以通过定义新的报头IEs来扩展。可以定义中间层，通过定义新的有效负载IEs来管理MAC层。
This section details features of TSCH, which might be interesting for the work of the 6TiSCH WG. It does not define any requirements.
本节详细介绍了TSCH的功能，这可能对第六届ISCH工作组的工作很感兴趣。它没有定义任何要求。
TSCH allows one to design a schedule that yields collision-free communication. This is done by building the schedule with dedicated cells in such a way that at most, one node communicates with a specific neighbor in each slotOffset/channelOffset cell. Multiple pairs of neighbor nodes can exchange data at the same time, but on different frequencies.
TSCH允许设计一个产生无冲突通信的时间表。这是通过使用专用小区构建调度来实现的，这种方式最多允许一个节点与每个Slotofset/channelOffset小区中的特定邻居通信。多对相邻节点可以同时交换数据，但频率不同。
A TSCH schedule looks like a matrix of width "slotframe size", S, and of height "number of frequencies", nFreq. For a scheduling algorithm, cells can be considered atomic "units" to schedule. In particular, because of the channel hopping nature of TSCH, the scheduling algorithm should not worry about the actual frequency communication happens on, since it changes at each slotframe iteration.
TSCH调度看起来像是宽度“slotframe size”S和高度“频率数”nFreq的矩阵。对于调度算法，可以将单元视为要调度的原子“单元”。特别是，由于TSCH的信道跳变特性，调度算法不应担心实际的频率通信发生在，因为它在每个slotframe迭代中都会发生变化。
When there is traffic in the network, nodes that are communicating implicitly resynchronize using the data frames they exchange. In the absence of data traffic, nodes are required to synchronize to their time source neighbor(s) periodically not to drift in time. If they have not been communicating for some time (typically 30 s), nodes can exchange a dummy data frame to resynchronize. The frequency at which such messages need to be transmitted depends on the stability of the clock source and on how "early" each node starts listening for data (the "guard time"). Theoretically, with a 10 ppm clock and a 1 ms guard time, this period can be 100 s. Assuming this exchange causes the node's radio to be on for 5 ms, this yields a radio duty cycle needed to keep synchronized of 5 ms / 100 s = 0.005%. While TSCH does require nodes to resynchronize periodically, the cost of doing so is very low.
当网络中存在流量时，进行隐式通信的节点将使用它们交换的数据帧重新同步。在没有数据流量的情况下，节点需要定期与其时间源邻居同步，以避免时间漂移。如果节点有一段时间（通常为30秒）没有通信，则可以交换虚拟数据帧以重新同步。此类消息需要传输的频率取决于时钟源的稳定性以及每个节点开始侦听数据的“早”程度（“保护时间”）。理论上，使用10 ppm时钟和1 ms保护时间，该周期可以为100 s。假设此交换导致节点的无线电接通5ms，则产生保持同步5ms/100s=0.005%所需的无线电占空比。虽然TSCH确实需要节点定期重新同步，但这样做的成本非常低。
The channel hopping nature of TSCH causes links to be very "stable". Wireless phenomena such as multi-path fading and external interference impact a wireless link between two nodes differently on each frequency. If a transmission from node A to node B fails, retransmitting on a different frequency has a higher likelihood of
TSCH的信道跳变特性导致链路非常“稳定”。多径衰落和外部干扰等无线现象在每个频率上对两个节点之间的无线链路产生不同的影响。如果从节点a到节点B的传输失败，则在不同频率上的重新传输具有更高的失败可能性
succeeding that retransmitting on the same frequency. As a result, even when some frequencies are "behaving bad", channel hopping "smoothens" the contribution of each frequency, resulting in more stable links and therefore a more stable topology.
在同一频率上的重传之后。因此，即使某些频率“表现不好”，信道跳频也会“平滑”每个频率的贡献，从而产生更稳定的链路，从而形成更稳定的拓扑结构。
The TSCH standard allows for multiple slotframes to coexist in a node's schedule. It is possible that, at some timeslot, a node has multiple activities scheduled (e.g., transmit to node B on slotframe 2, receive from node C on slotframe 1). To handle this situation, the TSCH standard defines the following precedence rules:
TSCH标准允许多个时隙帧在节点的调度中共存。在某些时隙，一个节点可能调度了多个活动（例如，在slotframe 2上向节点B发送，在slotframe 1上从节点C接收）。为了处理这种情况，TSCH标准定义了以下优先规则：
1. Transmissions take precedence over receptions;
1. 传输优先于接收；
2. Lower slotframe identifiers take precedence over higher slotframe identifiers.
2. 较低的插槽帧标识符优先于较高的插槽帧标识符。
In the example above, the node would transmit to node B on slotframe 2.
在上面的示例中，节点将在slotframe 2上向节点B发送数据。
Acknowledgments
致谢
Special thanks to Dominique Barthel, Patricia Brett, Guillaume Gaillard, Pat Kinney, Ines Robles, Timothy J. Salo, Jonathan Simon, Rene Struik, and Xavi Vilajosana for reviewing the document and providing valuable feedback. Thanks to the IoT6 European Project (STREP) of the 7th Framework Program (Grant 288445).
特别感谢Dominique Barthel、Patricia Brett、Guillaume Gaillard、Pat Kinney、Ines Robles、Timothy J.Salo、Jonathan Simon、Rene Struik和Xavi Vilajosana审阅了该文件并提供了宝贵的反馈。感谢第七框架计划（288445赠款）的IoT6欧洲项目（STREP）。
Authors' Addresses
作者地址
Thomas Watteyne (editor) Linear Technology 32990 Alvarado-Niles Road, Suite 910 Union City, CA 94587 United States
Thomas Watteyne（编辑）美国加利福尼亚州联合市阿尔瓦拉多·尼尔斯路32990号910室线性技术公司94587
Phone: +1 (510) 400-2978
EMail: twatteyne@linear.com
Phone: +1 (510) 400-2978
EMail: twatteyne@linear.com
Maria Rita Palattella University of Luxembourg Interdisciplinary Centre for Security, Reliability and Trust 4, rue Alphonse Weicker Luxembourg L-2721 Luxembourg
玛丽亚丽塔帕拉特拉大学卢森堡安全、可靠性和信任跨学科中心4，RoueAlpousWikER卢森堡L-1221卢森堡
Phone: +352 46 66 44 5841
EMail: maria-rita.palattella@uni.lu
Phone: +352 46 66 44 5841
EMail: maria-rita.palattella@uni.lu
Luigi Alfredo Grieco Politecnico di Bari Department of Electrical and Information Engineering Via Orabona 4 Bari 70125 Italy
路易吉·阿尔弗雷多·格里科·波利特尼科·迪·巴里电气和信息工程系途经意大利巴里70125奥拉博纳4号
Phone: +39 08 05 96 3911
EMail: a.grieco@poliba.it
Phone: +39 08 05 96 3911
EMail: a.grieco@poliba.it