Network Working Group H. Jang
Request for Comments: 5270 SAMSUNG
Category: Informational J. Jee
ETRI
Y. Han
KUT
S. Park
SAMSUNG Electronics
J. Cha
ETRI
June 2008
Network Working Group H. Jang
Request for Comments: 5270 SAMSUNG
Category: Informational J. Jee
ETRI
Y. Han
KUT
S. Park
SAMSUNG Electronics
J. Cha
ETRI
June 2008
Mobile IPv6 Fast Handovers over IEEE 802.16e Networks
IEEE 802.16e网络上的移动IPv6快速切换
Status of This Memo
关于下段备忘
This memo provides information for the Internet community. It does not specify an Internet standard of any kind. Distribution of this memo is unlimited.
本备忘录为互联网社区提供信息。它没有规定任何类型的互联网标准。本备忘录的分发不受限制。
Abstract
摘要
This document describes how a Mobile IPv6 Fast Handover can be implemented on link layers conforming to the IEEE 802.16e suite of specifications. The proposed scheme tries to achieve seamless handover by exploiting the link-layer handover indicators and thereby synchronizing the IEEE 802.16e handover procedures with the Mobile IPv6 fast handover procedures efficiently.
本文档描述了如何在符合IEEE 802.16e规范套件的链路层上实现移动IPv6快速切换。该方案试图通过利用链路层切换指示符实现无缝切换，从而使IEEE 802.16e切换过程与移动IPv6快速切换过程高效同步。
Table of Contents
目录
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. IEEE 802.16e Handover Overview . . . . . . . . . . . . . . . . 4
4. Network Topology Acquisition and Network Selection . . . . . . 5
5. Interaction between FMIPv6 and IEEE 802.16e . . . . . . . . . 6
5.1. Access Router Discovery . . . . . . . . . . . . . . . . . 6
5.2. Handover Preparation . . . . . . . . . . . . . . . . . . . 7
5.3. Handover Execution . . . . . . . . . . . . . . . . . . . . 8
5.4. Handover Completion . . . . . . . . . . . . . . . . . . . 9
6. The Examples of Handover Scenario . . . . . . . . . . . . . . 10
6.1. Predictive Mode . . . . . . . . . . . . . . . . . . . . . 10
6.2. Reactive Mode . . . . . . . . . . . . . . . . . . . . . . 12
7. IEEE 802.21 Considerations . . . . . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . . 16
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. IEEE 802.16e Handover Overview . . . . . . . . . . . . . . . . 4
4. Network Topology Acquisition and Network Selection . . . . . . 5
5. Interaction between FMIPv6 and IEEE 802.16e . . . . . . . . . 6
5.1. Access Router Discovery . . . . . . . . . . . . . . . . . 6
5.2. Handover Preparation . . . . . . . . . . . . . . . . . . . 7
5.3. Handover Execution . . . . . . . . . . . . . . . . . . . . 8
5.4. Handover Completion . . . . . . . . . . . . . . . . . . . 9
6. The Examples of Handover Scenario . . . . . . . . . . . . . . 10
6.1. Predictive Mode . . . . . . . . . . . . . . . . . . . . . 10
6.2. Reactive Mode . . . . . . . . . . . . . . . . . . . . . . 12
7. IEEE 802.21 Considerations . . . . . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . . 16
Mobile IPv6 Fast Handover protocol (FMIPv6) [RFC5268] was proposed to complement the Mobile IPv6 (MIPv6) [RFC3775] by reducing the handover latency for the real-time traffic. FMIPv6 assumes the support from the link-layer technology; however, the specific link-layer information available and its available timing differs according to the particular link-layer technology in use, as pointed out in [RFC4260], which provides an FMIPv6 solution for the IEEE 802.11 networks. So, this document is proposed to provide an informational guide to the developers about how to optimize the FMIPv6 handover procedures, specifically in the IEEE 802.16e networks [IEEE802.16][IEEE802.16e].
移动IPv6快速切换协议（FMIPv6）[RFC5268]通过减少实时业务的切换延迟来补充移动IPv6（MIPv6）[RFC3775]。FMIPv6采用链路层技术支持；然而，如[RFC4260]中所指出的，根据使用的特定链路层技术，可用的特定链路层信息及其可用定时不同，该技术为IEEE 802.11网络提供了FMIPv6解决方案。因此，本文件旨在为开发者提供有关如何优化FMIPv6切换程序的信息指南，特别是在IEEE 802.16e网络[IEEE802.16][IEEE802.16e]中。
The proposed scheme achieves seamless handover by exploiting the link-layer handover indicators and designing an efficient interleaving scheme of the 802.16e and the FMIPv6 handover procedures. The scheme targets a hard handover, which is the default handover type of IEEE 802.16e. For the other handover types, i.e., the Macro Diversity Handover (MDHO) and Fast Base Station Switching (FBSS), the base stations in the same diversity set are likely to belong to the same subnet for diversity, and FMIPv6 might not be needed. Regarding the MDHO and the FBSS deployment with FMIPv6, further discussion will be needed and is not in the scope of this document.
该方案利用链路层切换指标，设计了802.16e和FMIPv6切换过程的高效交织方案，实现了无缝切换。该方案以硬切换为目标，硬切换是IEEE 802.16e的默认切换类型。对于其他切换类型，即宏分集切换（MDHO）和快速基站切换（FBSS），相同分集集中的基站可能属于相同的分集子网，并且可能不需要FMIPv6。关于使用FMIPv6的MDHO和FBSS部署，需要进一步讨论，不在本文件范围内。
We begin with a summary of handover procedures of [IEEE802.16e] and then present the optimized complete FMIPv6 handover procedures by using the link-layer handover indicators. The examples of handover scenarios are described for both the predictive mode and reactive mode.
我们首先总结了[IEEE802.16e]的切换过程，然后使用链路层切换指标给出了优化的完整FMIPv6切换过程。针对预测模式和反应模式描述了切换场景的示例。
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document is to be interpreted as described in [RFC2119].
本文件中的关键词“必须”、“不得”、“要求”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。
Most of terms used in this document are defined in MIPv6 [RFC3775] and FMIPv6 [RFC5268].
本文档中使用的大多数术语在MIPv6[RFC3775]和FMIPv6[RFC5268]中定义。
The following terms come from the IEEE 802.16e specification [IEEE802.16e].
以下术语来自IEEE 802.16e规范[IEEE802.16e]。
MOB_NBR-ADV
MOB_NBR-ADV
An IEEE 802.16e neighbor advertisement message sent periodically by a base station.
由基站定期发送的IEEE 802.16e邻居公告消息。
MOB_MSHO-REQ
MOB_MSHO-REQ
An IEEE 802.16e handover request message sent by a mobile node.
由移动节点发送的IEEE 802.16e切换请求消息。
MOB_BSHO-RSP
MOB_BSHO-RSP
An IEEE 802.16e handover response message sent by a base station.
由基站发送的IEEE 802.16e切换响应消息。
MOB_BSHO-REQ
MOB_BSHO-REQ
An IEEE 802.16e handover request message sent by a base station.
由基站发送的IEEE 802.16e切换请求消息。
MOB_HO-IND
暴民
An IEEE 802.16e handover indication message sent by a mobile node.
由移动节点发送的IEEE 802.16e切换指示消息。
BSID
BSID
An IEEE 802.16e base station identifier.
IEEE 802.16e基站标识符。
Compared with the handover in the WLAN (Wireless Local Area Network), the IEEE 802.16e handover mechanism consists of more steps since the 802.16e embraces the functionality for elaborate parameter adjustment and procedural flexibility.
与WLAN（无线局域网）中的切换相比，IEEE 802.16e切换机制由更多步骤组成，因为802.16e包含用于精细参数调整和程序灵活性的功能。
When a mobile node (MN) stays in a link, it listens to the Layer 2 neighbor advertisement messages, named MOB_NBR-ADV, from its serving base station (BS). A BS broadcasts them periodically to identify the network and announce the characteristics of neighbor BSs. Receiving this, the MN decodes this message to find out information about the parameters of neighbor BSs for its future handover. With the provided information in a MOB_NBR-ADV, the MN may minimize the handover latency by obtaining the channel number of neighbors and reducing the scanning time, or may select the better target BS based on the signal strength, Quality-of-Service (QoS) level, service price, etc.
当移动节点（MN）停留在链路中时，它从其服务基站（BS）侦听名为MOB_NBR-ADV的第2层邻居广告消息。基站周期性地广播它们以识别网络并宣布邻居基站的特征。接收到该消息后，MN对该消息进行解码，以查找关于其未来切换的邻居BSs的参数的信息。利用MOB_NBR-ADV中提供的信息，MN可以通过获得邻居的信道数量和减少扫描时间来最小化切换延迟，或者可以基于信号强度、服务质量（QoS）水平、服务价格等选择更好的目标BS。
The handover procedure is conceptually divided into two steps: "handover preparation" and "handover execution" [SH802.16e]. The handover preparation can be initiated by either an MN or a BS.
移交程序在概念上分为两个步骤：“移交准备”和“移交执行”[SH802.16e]。切换准备可以由MN或BS发起。
During this period, neighbors are compared by the metrics such as signal strength or QoS parameters, and a target BS is selected among them. If necessary, the MN may try to associate (initial ranging) with candidate BSs to expedite a future handover. Once the MN decides to handover, it notifies its intent by sending a MOB_MSHO-REQ message to the serving BS (s-BS). The BS then replies with a MOB_BSHO-RSP containing the recommended BSs to the MN after negotiating with candidates. Optionally, it may confirm handover to the target BS (t-BS) over backbone when the target is decided. Alternatively, the BS may trigger handover with a MOB_BSHO-REQ message.
在此期间，通过诸如信号强度或QoS参数之类的度量来比较邻居，并且在其中选择目标BS。如有必要，MN可尝试将（初始测距）与候选bs相关联以加速未来的切换。一旦MN决定切换，它通过向服务BS（s-BS）发送MOB_MSHO-REQ消息来通知其意图。然后，基站在与候选者协商后，向MN回复包含推荐基站的MOB_BSHO-RSP。可选地，当确定目标时，它可以通过主干确认向目标BS（t-BS）的切换。或者，BS可以使用MOB_BSHO-REQ消息触发切换。
After handover preparation, handover execution starts. The MN sends a MOB_HO-IND message to the serving BS as a final indication of its handover. Once it makes a new attachment, it conducts 802.16e ranging through which it can acquire physical parameters from the target BS, tuning its parameters to the target BS. After ranging with the target BS successfully, the MN negotiates basic capabilities such as maximum transmit power and modulator/demodulator type. It then performs authentication and key exchange procedures, and finally registers with the target BS. If the target BS has already learned some contexts such as authentication or capability parameters through backbone, it may omit the corresponding procedures. For the details of the 802.16 handover procedures, refer to Section 6.3.22 of [IEEE802.16e]. After completing registration, the target BS starts
移交准备完成后，移交执行开始。MN向服务BS发送MOB_HO-IND消息作为其切换的最终指示。一旦建立新的连接，它将执行802.16e测距，通过该测距，它可以从目标BS获取物理参数，并将其参数调整到目标BS。在成功地与目标BS测距之后，MN协商诸如最大发射功率和调制器/解调器类型等基本能力。然后，它执行身份验证和密钥交换过程，最后向目标BS注册。如果目标BS已经通过主干学习了一些上下文，例如身份验证或能力参数，那么它可能省略相应的过程。有关802.16移交程序的详细信息，请参阅[IEEE802.16e]第6.3.22节。完成注册后，目标BS开始
to serve the MN and communication via target BS is available. However, in case the MN moves to a different subnet, it should reconfigure a new IP address and reestablish an IP connection. To resume the active session of the previous link, the MN should also perform IP layer handover.
为MN提供服务，并可通过目标BS进行通信。但是，如果MN移动到不同的子网，它应该重新配置新的IP地址并重新建立IP连接。要恢复前一链路的活动会话，MN还应执行IP层切换。
This section describes how discovery of adjacent networks and selection of target network work in the IEEE 802.16e for background information.
本节介绍了在IEEE 802.16e中如何发现相邻网络和选择目标网络，以获取背景信息。
An MN can learn the network topology and acquire the link information in several ways. First of all, it can do that via L2 neighbor advertisements. A BS supporting mobile functionality shall broadcast a MOB_NBR-ADV message periodically that includes the network topology information (its maximum interval is 1 second). This message includes BSIDs and channel information of neighbor BSs, and it is used to facilitate the MN's synchronization with neighbor BSs. An MN can collect the necessary information of the neighbor BSs through this message for its future handover.
MN可以通过多种方式学习网络拓扑和获取链路信息。首先，它可以通过L2邻居广告做到这一点。支持移动功能的基站应定期广播包含网络拓扑信息的MOB_NBR-ADV消息（其最大间隔为1秒）。该消息包括相邻BSs的BSID和信道信息，用于促进MN与相邻BSs的同步。MN可以通过该消息收集邻居BSs的必要信息，以便将来进行切换。
Another method for acquisition of network topology is scanning, which is the process to seek and monitor available BSs in order to find suitable handover targets. While a MOB_NBR-ADV message includes static information about neighbor BSs, scanning provides rather dynamic parameters such as link quality parameters. Since the MOB_NBR-ADV message delivers a list of neighbor BSIDs periodically and scanning provides a way to sort out some adequate BSs, it is recommended that when new BSs are found in the advertisement, the MN identifies them via scanning and resolves their BSIDs to the information of the subnet where the BS is connected. The association, an optional initial ranging procedure occurring during scanning, is one of the helpful methods to facilitate the impending handover. The MN is able to get ranging parameters and service availability information for the purpose of proper selection of the target BS and expediting a potential future handover to it. The detailed explanation of association is described in Section 6.3.22 of [IEEE802.16e].
获取网络拓扑的另一种方法是扫描，这是寻找和监视可用BSs以找到合适的切换目标的过程。虽然MOB_NBR-ADV消息包含关于相邻BSs的静态信息，但扫描提供相当动态的参数，例如链路质量参数。由于MOB_NBR-ADV消息定期发送相邻BSID的列表，并且扫描提供了一种方法来分类一些适当的BSs，因此建议当在广告中发现新的BSs时，MN通过扫描来识别它们，并将它们的BSID解析为BS所连接的子网的信息。关联是扫描期间发生的可选初始测距过程，是促进即将到来的切换的有用方法之一。MN能够获得测距参数和服务可用性信息，以便正确选择目标基站并加快未来向其的潜在切换。有关关联的详细说明，请参见[IEEE802.16e]第6.3.22节。
Besides the methods provided by 802.16e, the MN may rely on other schemes. For instance, the topology information may be provided through the MIIS (Media Independent Information Service) [IEEE802.21], which has been developed by the IEEE 802.21 working group. The MIIS is a framework by which the MN or network can obtain network information to facilitate network selection and handovers.
除了802.16e提供的方法之外，MN还可以依赖于其他方案。例如，拓扑信息可以通过由IEEE 802.21工作组开发的MIIS（媒体独立信息服务）[IEEE802.21]来提供。MIIS是一个框架，通过该框架，MN或网络可以获得网络信息，以促进网络选择和切换。
After learning about neighbors, the MN may compare them to find a BS, which can serve better than the serving BS. The target BS may be determined by considering various criteria such as required QoS, cost, user preference, and policy. How to select the target BS is not in the scope of this document.
在了解邻居之后，MN可以比较它们以找到比服务的BS更好的BS。目标BS可以通过考虑诸如所需QoS、成本、用户偏好和策略等各种标准来确定。如何选择目标基站不在本文档范围内。
In this section, a set of primitives is introduced for an efficient interleaving of the IEEE 802.16e and the FMIPv6 procedures as below. The following sections present the handover procedures in detail by using them.
在本节中，将介绍一组原语，以实现IEEE 802.16e和FMIPv6过程的高效交错，如下所示。以下各节详细介绍了移交程序。
o NEW_LINK_DETECTED (NLD)
o 检测到新链接（NLD）
A trigger from the link layer to the IP layer in the MN to report that a new link has been detected.
从MN中的链路层到IP层的触发器，用于报告已检测到新链路。
o LINK_HANDOVER_IMPEND (LHI)
o 链路移交接收（LHI）
A trigger from the link layer to the IP layer in the MN to report that a link-layer handover decision has been made and its execution is imminent.
在MN中从链路层到IP层的一种触发器，用于报告链路层切换决策已经做出并且即将执行。
o LINK_SWITCH (LSW)
o 链路开关（LSW）
A control command from the IP layer to the link layer in the MN in order to force the MN to switch from an old BS to a new BS.
从IP层到MN中的链路层的一种控制命令，以迫使MN从旧BS切换到新BS。
o LINK_UP (LUP)
o 连接（LUP）
A trigger from the link layer to the IP layer in the MN to report that the MN completes the link-layer connection establishment with a new BS.
在MN中从链路层到IP层的触发器，用于报告MN使用新的BS完成链路层连接建立。
Once a new BS is detected through reception of a MOB_NBR-ADV and scanning, an MN may try to learn the associated access router (AR) information as soon as possible. In order to enable its quick discovery in the IP layer, the link layer (802.16) triggers a NEW_LINK_DETECTED primitive to the IP layer (FMIPv6) on detecting a new BS.
一旦通过接收MOB_NBR-ADV和扫描检测到新BS，MN可以尝试尽快学习相关联的接入路由器（AR）信息。为了能够在IP层中快速发现，链路层（802.16）在检测到新的基站时触发一个新的链路检测原语到IP层（FMIPv6）。
Receiving the NEW_LINK_DETECTED from the link layer, the IP layer tries to learn the associated AR information by exchanging an RtSolPr (Router Solicitation for Proxy Advertisement) and a PrRtAdv (Proxy Router Advertisement) with the PAR (Previous Access Router).
接收到来自链路层的NexOnLink检测，IP层尝试通过交换RTSOPR（代理代理的路由器请求）和PrRTADV（代理路由器广告）与PAR（先前接入路由器）来学习相关的AR信息。
According to [RFC5268], the MN may send an RtSolPr at any convenient time. However, this proposal recommends that, if feasible, the MN send it as soon as possible after receiving the NEW_LINK_DETECTED for quick router discovery because detection of a new BS usually implies MN's movement, which may result in handover.
根据[RFC5268]，MN可以在任何方便的时间发送RtSolPr。然而，该提议建议，如果可行，MN在接收到为快速路由器发现而检测到的新链路后尽快发送它，因为检测到新BS通常意味着MN的移动，这可能导致切换。
Transmission of RtSolPr messages may cause the signaling overhead problem that is mentioned in Section 2 of [RFC4907]. To rate-limit the retransmitted RtSolPr messages, FMIPv6 provides a back-off mechanism. It is also possible that attackers may forge a MOB_NBR-ADV message so that it can contain a bunch of bogus BSIDs or may send a flood of MOB_NBR-ADV messages each of which contains different BSIDs. This problem is mentioned in Section 8.
RtSolPr消息的传输可能会导致[RFC4907]第2节中提到的信令开销问题。为了对重新传输的RtSolPr消息进行速率限制，FMIPv6提供了一种退避机制。攻击者还可能伪造MOB_NBR-ADV消息，使其包含一组伪造的BSID，或发送大量MOB_NBR-ADV消息，每个消息包含不同的BSID。第8节提到了这个问题。
When the MN decides to change links based on its policy such as the degrading signal strength or increasing packet loss rate, it initiates handover by sending a MOB_MSHO-REQ to the BS and will receive a MOB_BSHO-RSP from the BS as a response. Alternatively, the BS may initiate handover by sending a MOB_BSHO-REQ to the MN.
当MN基于其策略（例如信号强度降低或丢包率增加）决定改变链路时，它通过向BS发送MOB_MSHO-REQ来发起切换，并将从BS接收MOB_BSHO-RSP作为响应。或者，BS可以通过向MN发送MOB_BSHO-REQ来发起切换。
On receiving either a MOB_BSHO-RSP or a MOB_BSHO-REQ, the link layer triggers a LINK_HANDOVER_IMPEND in order to signal the IP layer of arrival of MOB_BSHO-REQ/MOB_BSHO-RSP quickly. At this time, the target BS decided in the link layer is delivered to the IP layer as a parameter of the primitive. The primitive is used to report that a link-layer handover decision has been made and its execution is imminent. It can be helpfully used for FMIPv6 as an indication to start the handover preparation procedure, that is to send an FBU (Fast Binding Update) message to the PAR.
在接收到MOB_BSHO-RSP或MOB_BSHO-REQ时，链路层触发链路移交通知，以便向IP层发送MOB_BSHO-REQ/MOB_BSHO-RSP到达的信号。此时，在链路层中确定的目标BS作为原语的参数传递到IP层。原语用于报告链路层切换决策已做出且即将执行。它可以有助于FMIPv6作为启动切换准备过程的指示，即将FBU（快速绑定更新）消息发送到PAR。
To avoid erroneous results due to unreliable and inconsistent characteristics of link, for instance, to move to the unpredicted network or to stay in the current network after sending an FBU, Section 2 of [RFC4907] advises the use of a combination of signal strength data with other techniques rather than relying only on signal strength for handover decision. For example, the LINK_HANDOVER_IMPEND may be sent after validating filtered signal strength measurements with other indications of link loss such as lack of beacon reception.
为了避免由于链路的不可靠和不一致特性而导致的错误结果，例如，在发送FBU后移动到不可预测的网络或留在当前网络，[RFC4907]第2节建议将信号强度数据与其他技术结合使用，而不是仅依赖信号强度进行切换决策。例如，链路移交可以在验证滤波后的信号强度测量以及诸如缺少信标接收之类的链路丢失的其他指示之后发送。
Once the IP layer receives the LINK_HANDOVER_IMPEND, it checks whether or not the specified target network belongs to a different subnet based on the information collected during the Access Router Discovery step. If the target proves to be in the same subnet, the MN can continue to use the current IP address after handover, and there is no need to perform FMIPv6. Otherwise, the IP layer
一旦IP层接收到链路切换通知，它将根据在访问路由器发现步骤中收集的信息检查指定的目标网络是否属于不同的子网。如果证明目标在同一子网中，MN在切换后可以继续使用当前IP地址，不需要执行FMIPv6。否则，IP层
formulates a prospective NCoA (New Care-of Address) with the information provided in the PrRtAdv message and sends an FBU message to the PAR.
用PRRTADV消息中提供的信息制定一个预期的NCOA（新的护理地址），并发送一个FBU消息给PAR。
When the FBU message arrives in the PAR successfully, the PAR and the NAR (New Access Router) process it according to [RFC5268]. The PAR sets up a tunnel between the PCoA (Previous Care-of Address) and NCoA by exchanging HI (Handover Initiate) and HAck (Handover Acknowledge) messages with the NAR, forwarding the packets destined for the MN to the NCoA. The NCoA is confirmed or re-assigned by the NAR in the HAck and, finally delivered to the MN through the FBack (Fast Binding Acknowledgment) in case of predictive mode.
当FBU消息成功到达PAR时，PAR和NAR（新接入路由器）根据[RCF5268]处理它。PAR通过与NAR交换HI（切换启动）和HACK（切换确认）消息，在PCOA（先前的护理地址）和NCoA之间建立隧道，将前往MN的分组转发到NCOA。NCoA由NAR在HAck中确认或重新分配，并在预测模式下通过FBack（快速绑定确认）最终交付给MN。
After the MN sends a MOB_HO-IND to the serving BS, data packet transfer between the MN and the BS is no longer allowed. Note that when a MOB_HO-IND is sent out before an FBack arrives in the MN, it is highly probable that the MN will operate in reactive mode because the serving BS releases all the MN's connections and resources after receiving a MOB_HO-IND. Therefore, if possible, the MN should exchange FBU and FBack messages with the PAR before sending a MOB_HO-IND to the BS so as to operate in predictive mode.
在MN向服务BS发送MOB_HO-IND之后，不再允许MN和BS之间的数据分组传输。注意，当在FBack到达MN之前发送MOB_HO-IND时，MN很可能以反应模式运行，因为服务BS在接收到MOB_HO-IND后释放所有MN的连接和资源。因此，如果可能，在发送MaByHO-Id到BS之前，MN应该与PAR交换FBU和FBACK消息，以便在预测模式下运行。
If the MN receives an FBack message on the previous link, it runs in predictive mode after handover. Otherwise, it should run in reactive mode. In order for the MN to operate in predictive mode as far as possible after handover, implementations may allow use of a LINK_SWITCH primitive. The LINK_SWITCH is a command in order to force the MN to switch from an old BS to a new BS and the similar concept has introduced for the wireless LAN in [RFC5184]. When it is applied, the MN's IP layer issues a LINK_SWITCH primitive to the link layer on receiving the FBack message in the previous link. Until it occurs, the link layer keeps the current (previous) link if feasible and postpones sending a MOB_HO-IND message while waiting for the FBack message.
如果MN在前一链路上接收到FBack消息，则在切换后它以预测模式运行。否则，它应该在反应模式下运行。为了使MN在切换后尽可能在预测模式下操作，实现可以允许使用链路切换原语。LINK_开关是一个命令，用于强制MN从旧BS切换到新BS，并且[RFC5184]中为无线LAN引入了类似的概念。当它被应用时，MN的IP层在接收到前一链路中的FBack消息时向链路层发出链路交换原语。在发生之前，链路层保持当前（先前）链路（如果可行），并在等待FBack消息时推迟发送MOB_HO-IND消息。
After switching links, the MN synchronizes with the target BS and performs the 802.16e network entry procedure. The MN exchanges the RNG-REQ/RSP, SBC-REQ/RSP, PKM-REQ/RSP, and REG-REQ/RSP messages with the target BS. Some of these messages may be omitted if the (previously) serving BS transferred the context to the target BS over the backbone beforehand. When the network entry procedure is completed and the link layer is ready for data transmission, it informs the IP layer of the fact with a LINK_UP primitive.
在切换链路之后，MN与目标BS同步并执行802.16e网络进入过程。MN与目标基站交换RNG-REQ/RSP、SBC-REQ/RSP、PKM-REQ/RSP和REG-REQ/RSP消息。如果（先前）服务BS预先通过主干将上下文传输到目标BS，则可以省略其中一些消息。当网络进入程序完成且链路层准备好进行数据传输时，它会使用链路更新原语通知IP层这一事实。
Section 2 of [RFC4907] recommends that link indications should be designed with built-in damping. The LINK_UP primitive defined in this document is generated by the link layer state machine based on the 802.16e link layer message exchanges, that is, the IEEE 802.16e network entry and the service flow creation procedures. Therefore, the LINK_UP is typically less sensitive to changes in transient link conditions. The link may experience an intermittent loss. Even in such a case, the following FMIPv6 operation is performed only when the MN handovers to the link with a different subnet and there is no signaling overhead as a result of a intermittent loss.
[RFC4907]第2节建议链路指示应采用内置阻尼设计。本文档中定义的LINK_UP原语由链路层状态机根据802.16e链路层消息交换生成，即IEEE 802.16e网络入口和服务流创建过程。因此，链路通常对瞬态链路条件的变化不太敏感。链路可能会间歇性丢失。即使在这种情况下，仅当MN切换到具有不同子网的链路并且没有由于间歇性丢失而导致的信令开销时，才执行以下FMIPv6操作。
When the MN's IP layer receives a LINK_UP primitive from the link layer, it should check whether it has moved into the target network predicted by FMIPv6. In case the target BS is within the same subnet, the MN does not perform the FMIPv6 operation.
当MN的IP层从链路层接收到一个LINK_UP原语时，它应该检查它是否已经移动到FMIPv6预测的目标网络中。如果目标基站位于同一子网内，则MN不执行FMIPv6操作。
* If the MN discovers itself in the predicted target network and receives an FBack message in the previous link, the MN's IP layer sends an UNA (Unsolicited Neighbor Advertisement) to the NAR (predictive mode).
* 如果MN在预测的目标网络中发现自己并在前一链路中接收到FBack消息，则MN的IP层向NAR（预测模式）发送UNA（未经请求的邻居公告）。
* If the MN has moved to the target network without receiving an FBack message in the previous link, the IP layer sends an UNA and also an FBU message immediately after sending the UNA message (reactive mode). The NAR may provide a different IP address by using an RA (Router Advertisement) with a NAACK (Neighbor Advertisement Acknowledge) option other than the formulated NCoA by the MN.
* 如果MN已移动到目标网络而未在前一链路中接收FBack消息，则IP层在发送UNA消息后立即发送UNA以及FBU消息（反应模式）。NAR可以通过使用RA（路由器广告）和NAACK（邻居广告确认）选项而不是MN制定的NCoA来提供不同的IP地址。
* The MN may discover itself in the unpredicted network (erroneous movement). If this is the case, the MN moves to the network that is not the target specified in the LINK_HANDOVER_IMPEND primitive. For the recovery from such an invalid indication, which is mentioned in Section 2 of [RFC4907], the MN should send a new FBU to the PAR according to Section 5.6 of [RFC5268] so that the PAR can update the existing binding entry and redirect the packets to the new confirmed location.
* MN可能发现自己处于不可预测的网络中（错误移动）。如果是这种情况，MN将移动到不是LINK\u HANDOVER\u IMPEND原语中指定的目标的网络。为了从这样的无效指示中恢复，这在[RCF4907]第2节中提到，MN应该根据[RCF5268]的第5.6节发送新的FBU到PAR席，以便PAR可以更新现有绑定条目并将包重定向到新确认的位置。
In both cases of predictive and reactive modes, once the MN has moved into the new link, it uses the NCoA formulated by the MN as a source address of the UNA, irrespective of NCoA availability. It then starts a Duplicate Address Detection (DAD) probe for NCoA according to [RFC4862]. In case the NAR provides the MN with a new NCoA, the MN MUST use the provided NCoA instead of the NCoA formulated by the MN.
在预测模式和反应模式的两种情况下，一旦MN移动到新链路，它将使用MN制定的NCoA作为UNA的源地址，而不管NCoA的可用性如何。然后根据[RFC4862]为NCoA启动重复地址检测（DAD）探测。如果NAR向MN提供新的NCoA，MN必须使用提供的NCoA，而不是MN制定的NCoA。
When the NAR receives an UNA message, it deletes its proxy neighbor cache entry if it exists, and forwards buffered packets to the MN after updating the neighbor cache properly. Detailed UNA processing rules are specified in Section 6.4 of [RFC5268].
当NAR接收到UNA消息时，它删除其代理邻居缓存条目（如果存在），并在正确更新邻居缓存后将缓冲数据包转发给MN。[RFC5268]第6.4节规定了详细的UNA处理规则。
In this section, the recommended handover procedures over 802.16e network are shown for both predictive and reactive modes. It is assumed that the MN handovers to the network that belongs to a different subnet.
在本节中，针对预测模式和反应模式，介绍了802.16e网络上的推荐切换程序。假设MN切换到属于不同子网的网络。
In the following figures, the messages between the MN's Layer 2 (MN L2) and the BS are the IEEE 802.16 messages, while messages between the MN's Layer 3 (MN L3) and the PAR and messages between PAR and NAR are the FMIPv6 messages. The messages between the MN L2 and the MN L3 are primitives introduced in this document.
在下面的图中，MN层2（MN L2）和BS之间的消息是IEEE 802.16消息，而MN层3（MN L3）和PAR之间的消息和PAR和NAR之间的消息是FMIPv6消息。MN L2和MN L3之间的消息是本文档中介绍的原语。
The handover procedures in the predictive mode are briefly described as follows. Figure 3 illustrates these procedures.
下面简要描述预测模式中的切换过程。图3说明了这些过程。
1. A BS broadcasts a MOB_NBR-ADV periodically.
1. BS定期广播MOB_NBR-ADV。
2. If the MN discovers a new neighbor BS in this message, it may perform scanning for the BS.
2. 如果MN在该消息中发现新的邻居BS，则它可以对该BS执行扫描。
3. When a new BS is found through the MOB_NBR-ADV and scanning, the MN's link layer notifies it to the IP layer by a NEW_LINK_DETECTED primitive.
3. 当通过MOB_NBR-ADV和扫描找到新的BS时，MN的链路层通过检测到的新链路原语通知IP层。
4. The MN tries to resolve the new BS's BSID to the associated AR by exchange of RtSolPr and PrRtAdv messages with the PAR.
4. MN尝试通过与PAR交换RTSOPR和PRRTADV消息来将新BS的BSID解析为相关AR。
5. The MN initiates handover by sending a MOB_MSHO-REQ message to the BS and receives a MOB_BSHO-RSP from the BS. Alternatively, the BS may initiate handover by sending a MOB_BSHO-REQ to the MN.
5. MN通过向BS发送MOB_MSHO-REQ消息来发起切换，并从BS接收MOB_BSHO-RSP。或者，BS可以通过向MN发送MOB_BSHO-REQ来发起切换。
6. When the MN receives either a MOB_BSHO-RSP or a MOB_BSHO-REQ from the BS, its link layer triggers a LINK_HANDOVER_IMPEND primitive to the IP layer.
6. 当MN从BS接收到MOB_BSHO-RSP或MOB_BSHO-REQ时，其链路层触发到IP层的链路切换IMPEND原语。
7. On reception of the LINK_HANDOVER_IMPEND, the MN's IP layer identifies that the target delivered along with the LINK_HANDOVER_IMPEND belongs to a different subnet and sends an FBU message to the PAR. On receiving this message, the PAR establishes tunnel between the PCoA and the NCoA by exchange of HI and HAck messages with the NAR, and it forwards packets destined for the MN to the NCoA. During this time, the NAR may confirm NCoA availability in the new link via HAck.
7. 在接收到Link kHoopOrfIfEnter时，MN的IP层识别出与Link kHoopRoad IMPurn一起交付的目标属于不同的子网，并将FBU消息发送到PAR。在接收到该消息时，PAR通过与NAR交换HI和HACK消息来在PCOA和NCOA之间建立隧道，并且它转发前往MN的分组到NCOA。在此期间，NAR可通过HAck确认新链路中NCoA的可用性。
8. The MN receives the FBack message before its handover and sends a MOB_HO-IND message as a final indication of handover. Issue of a MOB_HO-IND may be promoted optionally by using a LINK_SWITCH command from the IP layer. Afterwards it operates in predictive mode in the new link.
8. MN在其切换之前接收FBack消息，并发送MOB_HO-IND消息作为切换的最终指示。MOB_HO-IND的发布可以通过使用来自IP层的LINK_SWITCH命令来选择性地提升。之后，它在新链路中以预测模式运行。
9. The MN conducts handover to the target BS and performs the IEEE 802.16e network entry procedure.
9. MN向目标BS进行切换，并执行IEEE 802.16e网络进入程序。
10. As soon as the network entry procedure is completed, the MN's link layer signals the IP layer with a LINK_UP. On receiving this, the IP layer identifies that it has moved to a predicted target network and received the FBack message in the previous link. It issues an UNA to the NAR by using the NCoA as a source IP address. At the same time, it starts to perform DAD for the NCoA.
10. 一旦网络进入程序完成，MN的链路层就会向IP层发送链路启动信号。在接收到该消息时，IP层识别其已移动到预测的目标网络并在上一链路中接收到FBack消息。它使用NCoA作为源IP地址向NAR发出UNA。同时，它开始为NCoA表演DAD。
11. When the NAR receives the UNA from the MN, it delivers the buffered packets to the MN.
11. 当NAR从MN接收到UNA时，它将缓冲数据包传递给MN。
(MN L3 MN L2) s-BS PAR t-BS NAR
| | | | | |
1-2. | |<---MOB_NBR-ADV --------| | | |
| |<-------Scanning------->| | | |
3. |<-NLD-| | | | |
4. |--------------(RtSolPr)-------------->| | |
|<--------------PrRtAdv----------------| | |
| | | | | |
5. | |------MOB_MSHO-REQ----->| | | |
| |<-----MOB_BSHO-RSP------| | | |
| | or | | | |
| |<-----MOB_BSHO-REQ------| | | |
6. |<-LHI-| | | | |
7. |------------------FBU---------------->| | |
| | | |--------HI-------->|
| | | |<------HACK--------|
|<-----------------FBack---------------|--> | |
| | | Packets==============>|
8. |(LSW)>|-------MOB_HO-IND------>| | | |
disconnect| | | | |
connect | | | | |
9. | |<---------IEEE 802.16 network entry-------->| |
10. |<-LUP-| | | | |
|----------------------------UNA-------------------------->|
11. |<==================================================== Packets
| | | | |
(MN L3 MN L2) s-BS PAR t-BS NAR
| | | | | |
1-2. | |<---MOB_NBR-ADV --------| | | |
| |<-------Scanning------->| | | |
3. |<-NLD-| | | | |
4. |--------------(RtSolPr)-------------->| | |
|<--------------PrRtAdv----------------| | |
| | | | | |
5. | |------MOB_MSHO-REQ----->| | | |
| |<-----MOB_BSHO-RSP------| | | |
| | or | | | |
| |<-----MOB_BSHO-REQ------| | | |
6. |<-LHI-| | | | |
7. |------------------FBU---------------->| | |
| | | |--------HI-------->|
| | | |<------HACK--------|
|<-----------------FBack---------------|--> | |
| | | Packets==============>|
8. |(LSW)>|-------MOB_HO-IND------>| | | |
disconnect| | | | |
connect | | | | |
9. | |<---------IEEE 802.16 network entry-------->| |
10. |<-LUP-| | | | |
|----------------------------UNA-------------------------->|
11. |<==================================================== Packets
| | | | |
Figure 3. Predictive Fast Handover in 802.16e
图3。802.16e中的预测快速切换
The handover procedures in the reactive mode are described as follows. Figure 4 is illustrating these procedures.
反应模式下的切换过程描述如下。图4显示了这些过程。
1. ~ 7. The same as procedures of predictive mode.
1. ~ 7. 与预测模式的程序相同。
8. The MN does not receive the FBack message before handover and sends a MOB_HO-IND message as a final indication of handover. Afterwards, it operates in reactive mode in the new link.
8. MN在切换前不接收FBack消息，并发送MOB_HO-IND消息作为切换的最终指示。之后，它在新链路中以反应模式运行。
9. The MN conducts handover to the target network and performs the 802.16e network entry procedure.
9. MN向目标网络进行切换并执行802.16e网络进入程序。
10. As soon as the network entry procedure is completed, the MN's link layer signals the IP layer with a LINK_UP. On receiving this, the IP layer identifies that it has moved to the predicted target network without receiving the FBack in the previous link. The MN issues an UNA to the NAR by using NCoA as a source IP address and starts to perform DAD for the NCoA. Additionally, it sends an FBU to the PAR in the reactive mode.
10. 一旦网络进入程序完成，MN的链路层就会向IP层发送链路启动信号。在接收到该消息时，IP层识别它已移动到预测的目标网络，而没有在上一链路中接收FBack。MN通过使用NCoA作为源IP地址向NAR发出UNA，并开始为NCoA执行DAD。此外，它在反应模式下将FBU发送到PAR。
11. When the NAR receives the UNA and the FBU from the MN, it forwards the FBack to the PAR. The FBack and Packets are forwarded from the PAR and delivered to the MN (NCoA) through the NAR. The NAR may supply a different IP address than the NCoA by sending an RA with a NAACK option to the MN.
11. 当NAR从MN接收到UNA和FBU时，它将FFACK转发到PAR。FBACK和分组从PAR转发，并通过NAR传递到MN（NCOA）。NAR可以通过向MN发送带有NAACK选项的RA来提供与NCoA不同的IP地址。
(MN L3 MN L2) s-BS PAR t-BS NAR
| | | | | |
1-2. | |<---MOB_NBR-ADV & Scan--| | | |
| |<-------Scanning------->| | | |
3. |<-NLD-| | | | |
4. |--------------(RtSolPr)-------------->| | |
|<--------------PrRtAdv----------------| | |
| | | | | |
5. | |------MOB_MSHO-REQ----->| | | |
| |<-----MOB_BSHO-RSP------| | | |
| | or | | | |
| |<-----MOB_BSHO-REQ------| | | |
6. |<-LHI-| | | | |
7. |--------FBU----X---> | | | |
8. | |-------MOB_HO-IND------>| | | |
disconnect| | | | |
connect | | | | |
9. | |<---------IEEE 802.16 network entry-------->| |
10. |<-LUP-| | | | |
|----------------------------UNA-------------------------->|
|----------------------------FBU--------------------------)|
11. | | | |<-------FBU-------)|
| | | |<-----HI/HAck----->|
| | | | (if necessary) |
| | | Packets & FBack=========>|
|<=========================================================|
| | | | | |
(MN L3 MN L2) s-BS PAR t-BS NAR
| | | | | |
1-2. | |<---MOB_NBR-ADV & Scan--| | | |
| |<-------Scanning------->| | | |
3. |<-NLD-| | | | |
4. |--------------(RtSolPr)-------------->| | |
|<--------------PrRtAdv----------------| | |
| | | | | |
5. | |------MOB_MSHO-REQ----->| | | |
| |<-----MOB_BSHO-RSP------| | | |
| | or | | | |
| |<-----MOB_BSHO-REQ------| | | |
6. |<-LHI-| | | | |
7. |--------FBU----X---> | | | |
8. | |-------MOB_HO-IND------>| | | |
disconnect| | | | |
connect | | | | |
9. | |<---------IEEE 802.16 network entry-------->| |
10. |<-LUP-| | | | |
|----------------------------UNA-------------------------->|
|----------------------------FBU--------------------------)|
11. | | | |<-------FBU-------)|
| | | |<-----HI/HAck----->|
| | | | (if necessary) |
| | | Packets & FBack=========>|
|<=========================================================|
| | | | | |
Figure 4. Reactive Fast Handover in 802.16e
图4。802.16e中的反应式快速切换
It is worth noting that great research has been conducted on defining generic services in the IEEE 802.21 working group that facilitate handovers between heterogeneous access links. The standard works are named as a Media Independent Handover (MIH) Service [IEEE802.21], and propose three kinds of services: Media Independent Event Service (MIES), Media Independent Command Service (MICS), and Media Independent Information Service (MIIS).
值得注意的是，IEEE 802.21工作组在定义通用服务方面进行了大量研究，以促进异构接入链路之间的切换。标准工程被命名为媒体独立移交（MIH）服务[IEEE802.21]，并提出了三种服务：媒体独立事件服务（MIES）、媒体独立指挥服务（MICS）和媒体独立信息服务（MIIS）。
An MIES defines the events triggered from lower layers (physical and link) to higher layers (network and above) in order to report changes of physical and link-layer conditions. On the other hand, an MICS supports the commands sent from higher layers to lower layers, and it provides users with a way of managing the link behavior relevant to handovers and mobility. An MIIS provides a framework by which the MN or network can obtain network information to facilitate network selection and handovers.
MIES定义从较低层（物理层和链路层）到较高层（网络层和更高层）触发的事件，以便报告物理层和链路层条件的变化。另一方面，MICS支持从较高层发送到较低层的命令，它为用户提供了一种管理与切换和移动性相关的链路行为的方法。MIIS提供了一个框架，通过该框架，MN或网络可以获得网络信息，以促进网络选择和切换。
Although the purpose of IEEE 802.21 has been developed to enhance the user experience of MNs roaming between heterogeneous networks, the results may be utilized to optimize the handover performance in a homogeneous network. When the MIH primitives are available for handover in the 802.16e network, the MN can use them instead of the primitives proposed in this document. Table 1 shows examples of the mapping between the proposed primitives and the MIH primitives.
尽管IEEE 802.21的目的是增强异构网络之间MNs漫游的用户体验，但其结果可用于优化同质网络中的切换性能。当MIH原语可用于802.16e网络中的切换时，MN可以使用它们来代替本文中提出的原语。表1显示了建议的原语和MIH原语之间的映射示例。
+-------------------------+-------------------------+
| Proposed primitives | MIH primitives |
+===================================================+
| NEW_LINK_DETECTED | LINK_DETECTED |
+---------------------------------------------------+
| LINK_HANDOVER_IMPEND | LINK_HANDOVER_IMMINENT |
+---------------------------------------------------+
| LINK_SWITCH | HANDOVER_COMMIT |
+---------------------------------------------------+
| LINK_UP | LINK_UP |
+---------------------------------------------------+
+-------------------------+-------------------------+
| Proposed primitives | MIH primitives |
+===================================================+
| NEW_LINK_DETECTED | LINK_DETECTED |
+---------------------------------------------------+
| LINK_HANDOVER_IMPEND | LINK_HANDOVER_IMMINENT |
+---------------------------------------------------+
| LINK_SWITCH | HANDOVER_COMMIT |
+---------------------------------------------------+
| LINK_UP | LINK_UP |
+---------------------------------------------------+
Table 1. The Proposed Primitives and MIH Primitives
表1。提出的基元和MIH基元
The primitives defined in this document are used only for local indication inside of the MN, so no security mechanism is required to protect those primitives. However, FMIPv6 messages and IEEE 802.16e messages, which may trigger the primitives, need to be protected.
本文档中定义的原语仅用于MN内部的本地指示，因此不需要任何安全机制来保护这些原语。但是，可能触发原语的FMIPv6消息和IEEE 802.16e消息需要保护。
Security considerations of the FMIPv6 specification [RFC5268] are applicable to this document. It is also worthwhile to note that the IEEE802.16e has a security sub-layer that provides subscribers with privacy and authentication over the broadband wireless network. This layer has two main component protocols: a privacy key management protocol (PKM) for key management and authentication and an encapsulation protocol for encrypting data. From the perspective of the 802.16e, FMIPv6 messages are considered as data and are delivered securely by using those protocols.
FMIPv6规范[RFC5268]的安全注意事项适用于本文件。还值得注意的是，IEEE802.16e有一个安全子层，通过宽带无线网络为用户提供隐私和身份验证。该层有两个主要组件协议：用于密钥管理和身份验证的隐私密钥管理协议（PKM）和用于加密数据的封装协议。从802.16e的角度来看，FMIPv6消息被视为数据，并通过使用这些协议安全地传递。
However, some of IEEE 802.16e management messages are sent without authentication. For example, there is no protection to secure 802.16e broadcast messages. It may be possible for the attacker to maliciously forge a MOB_NBR-ADV message so that it contains the bogus BSIDs, or send a flood of MOB_NBR-ADV messages having different bogus BSIDs toward the MN. As a result, the MN may trigger a bunch of NEW_LINK_DETECTED primitives and send useless consecutive RtSolPr messages to the PAR, finally resulting in wasting the air resources. Therefore, the MN SHOULD perform scanning when detecting new BSs in the received MOB_NBR-ADV messages in order to assure the included neighbor information.
但是，某些IEEE 802.16e管理消息在发送时未经身份验证。例如，没有保护来保护802.16e广播消息的安全。攻击者可能恶意伪造MOB_NBR-ADV消息，使其包含虚假BSID，或向MN发送大量具有不同虚假BSID的MOB_NBR-ADV消息。因此，MN可能触发一组NexOnLink检测的原语，并将无用的连续RTSOPR消息发送到PAR，最终导致浪费空中资源。因此，当在接收到的MOB_NBR-ADV消息中检测到新的bs时，MN应该执行扫描，以确保包括的邻居信息。
It is also possible that attackers try a DoS (Denial-of-Service) attack by sending a flood of MOB_BSHO-REQ messages and triggering LINK_HANDOVER_IMPEND primitives in the MN. But the IEEE 802.16e provides a message authentication scheme for management messages involved in handover as well as network entry procedures by using a message authentication code (MAC) such as HMAC/CMAC (hashed/cipher MAC). Thus, those management messages are protected from the malicious use by attackers who intend to trigger LINK_HANDOVER_IMPEND or LINK_UP primitives in the MN.
攻击者还可能通过发送大量MOB_BSHO-REQ消息并触发MN中的链路切换IMPEND原语来尝试DoS（拒绝服务）攻击。但是IEEE 802.16e通过使用消息认证码（MAC），例如HMAC/CMAC（散列/密码MAC），为涉及切换和网络进入过程的管理消息提供了消息认证方案。因此，这些管理消息受到保护，免受攻击者的恶意使用，这些攻击者打算触发MN中的链路切换提示或链路启动原语。
Many thanks to the IETF Mobility Working Group members of KWISF (Korea Wireless Internet Standardization Forum) for their efforts on this work. In addition, we would like to thank Alper E. Yegin, Jinhyeock Choi, Rajeev Koodli, Jonne Soininen, Gabriel Montenegro, Singh Ajoy, Yoshihiro Ohba, Behcet Sarikaya, Vijay Devarapalli, and Ved Kafle who have provided technical advice.
非常感谢KWISF（韩国无线互联网标准化论坛）的IETF移动工作组成员在这项工作中所做的努力。此外，我们还要感谢阿尔珀·E·叶金、崔真孝、拉吉耶夫·库德利、乔恩·索尼宁、加布里埃尔·黑山、辛格·阿霍伊、大贺吉弘、贝塞特·萨里卡亚、维杰·德瓦拉帕利和维德·卡夫勒，他们提供了技术建议。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004.
[RFC3775]Johnson，D.，Perkins，C.，和J.Arkko，“IPv6中的移动支持”，RFC 37752004年6月。
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC 4862, September 2007.
[RFC4862]Thomson，S.，Narten，T.，和T.Jinmei，“IPv6无状态地址自动配置”，RFC 48622007年9月。
[RFC5268] Koodli, R., Ed., "Mobile IPv6 Fast Handovers", RFC 5268, June 2008.
[RFC5268]Koodli，R.，Ed.，“移动IPv6快速切换”，RFC 5268，2008年6月。
[IEEE802.16] "IEEE Standard for Local and Metropolitan Area Networks, Part 16: Air Interface for Fixed Broadband Wireless Access Systems", IEEE Std 802.16-2004, October 2004.
[IEEE802.16]“局域网和城域网的IEEE标准，第16部分：固定宽带无线接入系统的空中接口”，IEEE标准802.16-2004，2004年10月。
[IEEE802.16e] "IEEE Standard for Local and Metropolitan Area Networks, Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands and Corrigendum 1", IEEE Std 802.16e-2005 and IEEE Std 802.16-2004/Cor 1-2005, February 2006.
[IEEE802.16e]“局域网和城域网的IEEE标准，修改件2：许可频带内固定和移动组合操作的物理和介质访问控制层和勘误表1”，IEEE标准802.16e-2005和IEEE标准802.16-2004/Cor 1-2005，2006年2月。
[RFC4260] McCann, P., "Mobile IPv6 Fast Handovers for 802.11 Networks", RFC 4260, November 2005.
[RFC4260]McCann，P.，“802.11网络的移动IPv6快速切换”，RFC 4260，2005年11月。
[RFC5184] Teraoka, F., Gogo, K., Mitsuya, K., Shibui, R., and K. Mitani, "Unified Layer 2 (L2) Abstractions for Layer 3 (L3)-Driven Fast Handover", RFC 5184, May 2008.
[RFC5184]Teraoka，F.，Gogo，K.，Mitsuya，K.，Shibui，R.，和K.Mitani，“第3层（L3）驱动的快速切换的统一第2层（L2）抽象”，RFC 5184，2008年5月。
[RFC4907] Aboba, B., "Architectural Implications of Link Indications", RFC 4907, June 2007.
[RFC4907]Aboba，B.“连接指示的建筑影响”，RFC 4907，2007年6月。
[IEEE802.21] "Draft IEEE Standard for Local and Metropolitan Area Networks: Media Independent Handover Services", IEEE Std P802.21 D9.0, February 2008.
[IEEE802.21]“局域网和城域网IEEE标准草案：媒体独立切换服务”，IEEE标准P802.21 D9.0，2008年2月。
[SH802.16e] Kim, K., Kim, C., and T. Kim, "A Seamless Handover Mechanism for IEEE 802.16e Broadband Wireless Access", International Conference on Computational Science vol. 2, pp.527-534, 2005.
[SH802.16e]Kim，K.，Kim，C.，和T.Kim，“IEEE 802.16e宽带无线接入的无缝切换机制”，国际计算科学会议第2卷，第527-534页，2005年。
Authors' Addresses
作者地址
Heejin Jang SAMSUNG Advanced Institute of Technology P.O. Box 111 Suwon 440-600 Korea
Heejin Jang三星高级技术学院邮政信箱111水原440-600韩国
EMail: heejin.jang@gmail.com
EMail: heejin.jang@gmail.com
Junghoon Jee Electronics and Telecommunications Research Institute 161 Gajeong-dong, Yuseong-gu Daejon 305-350 Korea
韩国大阪余城Gajeong dong 161 Junghoon Jee电子和电信研究所305-350
EMail: jhjee@etri.re.kr
EMail: jhjee@etri.re.kr
Youn-Hee Han Korea University of Technology and Education Gajeon-ri, Byeongcheon-myeon Cheonan 330-708 Korea
高丽大学科技教育学院Byeongcheon myeon Cheonan，韩国330708
EMail: yhhan@kut.ac.kr
EMail: yhhan@kut.ac.kr
Soohong Daniel Park SAMSUNG Electronics 416 Maetan-3dong, Yeongtong-gu Suwon 442-742 Korea
Soohong Daniel Park三星电子416 Maetan-3dong，永通谷水原442-742韩国
EMail: soohong.park@samsung.com
EMail: soohong.park@samsung.com
Jaesun Cha Electronics and Telecommunications Research Institute 161 Gajeong-dong, Yuseong-gu Daejon 305-350 Korea
在顺查电子和电信研究所，韩国大田余城Gajeong dong 161 305-350
EMail: jscha@etri.re.kr
EMail: jscha@etri.re.kr
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