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Kojo, Editor 3 Category: Informational February, 2004 4 Expires: August, 2004 6 Mobility Related Terminology 8 Status of this Memo 10 This document is an Internet-Draft and is in full conformance with 11 all provisions of Section 10 of RFC2026. 13 Internet-Drafts are working documents of the Internet Engineering 14 Task Force (IETF), its areas, and its working groups. Note that 15 other groups may also distribute working documents as Internet- 16 Drafts. 18 Internet-Drafts are draft documents valid for a maximum of six months 19 and may be updated, replaced, or obsoleted by other documents at any 20 time. It is inappropriate to use Internet-Drafts as reference 21 material or to cite them other than as "work in progress." 23 The list of current Internet-Drafts can be accessed at 24 http://www.ietf.org/ietf/1id-abstracts.txt 26 The list of Internet-Draft Shadow Directories can be accessed at 27 http://www.ietf.org/shadow.html. 29 Copyright Notice 31 Copyright (C) The Internet Society (2004). All Rights Reserved. 33 Abstract 35 There is a need for common definitions of terminology in the work to 36 be done around IP mobility. This document defines terms for mobility 37 related terminology. The document originated out of work done in the 38 Seamoby Working Group but has broader applicability for terminology 39 used in IETF-wide discourse on technology for mobility and IP 40 networks. Other working groups dealing with mobility may want to take 41 advantage of this terminology. 43 Table of Contents 45 1 Introduction ................................................. 2 46 2 General Terms ................................................ 3 47 3 Mobile Access Networks and Mobile Networks ................... 9 48 4 Handover Terminology ......................................... 13 49 4.1 Scope of Handover .......................................... 14 50 4.2 Handover Control ........................................... 15 51 4.3 Simultaneous connectivity to Access Routers ................ 17 52 4.4 Performance and Functional Aspects ......................... 17 53 4.5 Micro Diversity, Macro Diversity, and IP Diversity ......... 18 54 4.6 Paging, and Mobile Node States and Modes ................... 19 55 4.7 Context Transfer ........................................... 21 56 4.8 Candidate Access Router Discovery .......................... 21 57 4.9 Types of Mobility .......................................... 22 58 5 Specific Terminology for Mobile Ad-Hoc Networking ............ 23 59 6 Security-related Terminology ................................. 24 60 7 Security Considerations ...................................... 25 61 8 Contributors ................................................. 25 62 9 Acknowledgments .............................................. 25 63 10 Informative References ...................................... 26 64 11 Authors' Addresses .......................................... 27 65 12 Appendix A - Index of Terms ................................. 29 67 1. Introduction 69 This document presents terminology to be used for documents and 70 discussions within the Seamoby Working Group. Other mobility related 71 working groups could take advantage of this terminology, in order to 72 create a common terminology for the area of mobility in IP networks. 73 These groups would include MIP, MANET, ROHC and NEMO. 75 Some terms and their definitions that are not directly related to the 76 IP world are included for the purpose of harmonizing the terminology. 77 For example, 'Access Point' and 'base station' refer to the same 78 component, from the point of view of IP, but 'Access Router' has a 79 very different meaning. The presented terminology may also, it is 80 hoped, be adequate to cover mobile ad-hoc networks. 82 The proposed terminology is not meant to assert any new terminology. 83 Rather the authors would welcome discussion on more exact definitions 84 as well as missing or unnecessary terms. This work is a 85 collaborative enterprise between people from many different 86 engineering backgrounds and so already presents a first step in 87 harmonizing the terminology. 89 The terminology in this draft is divided into several sections. 90 First, there is a list of terms for general use and mobile access 91 networks followed by terms related to handovers, and finally some 92 terms used within the MANET and NEMO working group. 94 2. General Terms 96 Bandwidth 98 The total width of the frequency band available to or used by a 99 communications channel. Usually measured in Hertz (Hz). The 100 bandwidth of a channel limits the available channel capacity. 102 Bandwidth utilization 104 The actual rate of information transfer achieved over a link, 105 expressed as a percentage of the theoretical maximum channel 106 capacity on that link, according to Shannon's Law. 108 Beacon 110 A control message broadcast by a node (especially, a base 111 station) informing all the other nodes in its neighborhood of the 112 continuing presence of the broadcasting node, possibly along with 113 additional status or configuration information. 115 Binding Update (BU) 117 A message indicating a mobile node's current mobility binding, 118 and in particular its care-of address. 120 Care-of-Address (CoA) 122 An IP address associated with a mobile node while visiting a 123 foreign link; the subnet prefix of this IP address is a foreign 124 subnet prefix. A packet addressed to the mobile node which 125 arrives at the mobile node's home network when the mobile node is 126 away from home and has registered a Care-of Address will be 127 forwarded to that address by the Home Agent in the home network. 129 Channel 131 A subdivision of the physical medium allowing possibly shared 132 independent uses of the medium. Channels may be made available 133 by subdividing the medium into distinct time slots, or distinct 134 spectral bands, or decorrelated coding sequences. 136 Channel access protocol 138 A protocol for mediating access to, and possibly allocation of, 139 the various channels available within the physical communications 140 medium. Nodes participating in the channel access protocol agree 141 to communicate only when they have uncontested access to one of 142 the channels, so that there will be no interference. 144 Channel capacity 146 The total capacity of a link to carry information (typically 147 bits) per unit time. With a given bandwidth, the theoretical 148 maximum channel capacity is given by Shannon's Law. The actual 149 channel capacity of a channel is determined by the channel 150 bandwidth, the coding system used, and the signal to noise ratio. 152 Control message 154 Information passed between two or more network nodes for 155 maintaining protocol state, which may be unrelated to any 156 specific application. 158 Distance vector 160 A characteristic of some routing protocols in which, for each 161 desired destination, a node maintains information about the 162 distance to that destination, and a vector (next hop) towards 163 that destination. 165 Fairness 167 A property of channel access protocols whereby a medium is made 168 fairly available to all eligible nodes on the link. Fairness 169 does not strictly imply equality, especially in cases where nodes 170 are given link access according to unequal priority or 171 classification. 173 Flooding 175 The process of delivering data or control messages to every node 176 within the network under consideration. 178 Foreign subnet prefix 180 A bit string that consists of some number of initial bits of an 181 IP address which identifies a node's foreign link within the 182 Internet topology. 184 Forwarding node 186 A node which performs the function of forwarding datagrams from 187 one of its neighbors to another. 189 Home Address (HoA) 191 An IP address assigned to a mobile node, used as the permanent 192 address of the mobile node. This address is within the mobile 193 node's home link. Standard IP routing mechanisms will deliver 194 packets destined for a mobile node's home address to its home 195 link [11]. 197 Home Agent (HA) 199 A router on a mobile node's home link with which the mobile node 200 has registered its current care-of address. While the mobile node 201 is away from home, the home agent intercepts packets on the home 202 link destined to the mobile node's home address, encapsulates 203 them, and tunnels them to the mobile node's registered care-of 204 address. 206 Home subnet prefix 208 A bit string that consists of some number of initial bits of an 209 IP address which identifies a node's home link within the 210 Internet topology (i.e. the IP subnet prefix corresponding to the 211 mobile node's home address, as defined in [11]). 213 Interface 215 A node's point of attachment to a link. 217 IP access address 219 An IP address (often dynamically allocated) which a node uses to 220 designate its current point of attachment to the local network. 221 The IP access address is typically to be distinguished from the 222 mobile node's home address; in fact, while visiting a foreign 223 network the former may be considered unsuitable for use as an 224 end-point address by any but the most short-lived applications. 225 Instead, the IP access address is typically used as the care-of 226 address of the node. 228 Link 230 A communication facility or physical medium that can sustain data 231 communications between multiple network nodes, such as an 232 Ethernet (simple or bridged). A link is the layer immediately 233 below IP. In a layered network stack model, the Link Layer (Layer 234 2) is normally below the Network (IP) Layer (Layer 3), and above 235 the Physical Layer (Layer 1). 237 Asymmetric link 239 A link with transmission characteristics which are different 240 depending upon the relative position or design characteristics of 241 the transmitter and the receiver of data on the link. For 242 instance, the range of one transmitter may be much higher than 243 the range of another transmitter on the same medium. 245 Link establishment 247 The process of establishing a link between the mobile node and 248 the local network. This may involve allocating a channel, or 249 other local wireless resources, possibly including a minimum 250 level of service or bandwidth. 252 Link-layer trigger (L2 Trigger) 254 Information from the link layer that informs the network layer of 255 the detailed events involved in handover sequencing at the link 256 layer. L2 triggers are not specific to any particular link layer, 257 but rather represent generalizations of link layer information 258 available from a wide variety of link layer protocols [4]. 260 Link state 262 A characterization of some routing protocols in which every node 263 within the network is expected to maintain information about 264 every link within the network topology. 266 Link-level acknowledgment 268 A protocol strategy, typically employed over wireless media, 269 requiring neighbors to acknowledge receipt of packets (typically 270 unicast only) from the transmitter. Such strategies aim to avoid 271 packet loss or delay resulting from lack of, or unwanted 272 characteristics of, higher level protocols. Link-layer 273 acknowledgments are often used as part of Automatic Repeat- 274 Request (ARQ) algorithms for increasing link reliability. 276 Local broadcast 278 The delivery of data to every node within range of the 279 transmitter. 281 Loop-free 283 A property of routing protocols whereby the path taken by a data 284 packet from source to destination never transits the same 285 intermediate node twice before arrival at the destination. 287 Medium Access Protocol (MAC) 289 A protocol for mediating access to, and possibly allocation of, 290 the physical communications medium. Nodes participating in the 291 medium access protocol can communicate only when they have 292 uncontested access to the medium, so that there will be no 293 interference. When the physical medium is a radio channel, the 294 MAC is the same as the Channel Access Protocol. 296 Mobile network prefix 298 A bit string that consists of some number of initial bits of an 299 IP address which identifies the entire mobile network within the 300 Internet topology. All nodes in a mobile network necessarily have 301 an address containing this prefix. 303 Mobility factor 305 The relative frequency of node movement, compared to the 306 frequency of application initiation. 308 Multipoint relay (MPR) 310 A node which is selected by its one-hop neighbor to re-transmit 311 all broadcast messages that it receives. The message must be new 312 and the time-to-live field of the message must be greater than 313 one. Multipoint relaying is a technique to reduce the number of 314 redundant re-transmissions while diffusing a broadcast message in 315 the network. 317 Neighbor 319 A "neighbor" is any other node to which data may be propagated 320 directly over the communications medium without relying on the 321 assistance of any other forwarding node. 323 Neighborhood 325 All the nodes which can receive data on the same link from one 326 node whenever it transmits data. 328 Next hop 330 A neighbor which has been selected to forward packets along the 331 way to a particular destination. 333 Payload 335 The actual data within a packet, not including network protocol 336 headers which were not inserted by an application. Note that 337 payloads are different between layers: user data is the payload 338 of TCP, which are the payload of IP, which three are the payload 339 of link layer protocols etc. Thus, it is important to identify 340 the scope when talking about payloads. 342 Prefix 344 A bit string that consists of some number of initial bits of an 345 address. 347 Routing table 349 The table where forwarding nodes keep information (including next 350 hop) for various destinations. 352 Route entry 354 An entry for a specific destination (unicast or multicast) in the 355 routing table. 357 Route establishment 359 The process of determining a route between a source and a 360 destination. 362 Route activation 364 The process of putting a route into use after it has been 365 determined. 367 Routing proxy 369 A node that routes packets by overlays, e.g.. by tunneling, 370 between communicating partners. The Home Agent and Foreign Agent 371 are examples of routing proxies, in that they receive packets 372 destined for the mobile node and tunnel them to the current 373 address of the mobile node. 375 Shannon's Law 377 A statement defining the theoretical maximum rate at which error- 378 free digits can be transmitted over a bandwidth-limited channel 379 in the presence of noise. No practical error correction coding 380 system exists that can closely approach the theoretical 381 performance limit given by Shannon's law. 383 Signal strength 385 The detectable power of the signal carrying the data bits, as 386 seen by the receiver of the signal. 388 Source route 390 A source route from node A to node B is an ordered list of IP 391 addresses, starting with the IP address of node A and ending with 392 the IP address of the node B. Between A and B, the source route 393 includes an ordered list intermediate hops between A and B, as 394 well as the interface index of the interface through which the 395 packet should be transmitted to reach the next hop. The list of 396 intermediate hops might not include all visited nodes, some hops 397 might be omitted for a reason or another. 399 Spatial re-use 401 Simultaneous use of channels with identical or close physical 402 characteristics, but located spatially far enough apart to avoid 403 interference (i.e., co-channel interference) 405 System-wide broadcast 407 Same as flooding, but used in contrast to local broadcast. 409 Subnet 411 A subnet is a logical group of connected network nodes. In IP 412 networks, nodes in a subnet share a common network mask (in IPV4) 413 or a network prefix (in IPv6). 415 Topology (Network Topology) 417 The interconnection structure of a network: which nodes are 418 directly connected to each other, and through which links they 419 are connected. Some simple topologies have been given names, 420 such as for instance 'bus topology', 'mesh topology', 'ring 421 topology', 'star topology' and 'tree topology'. 423 Triggered update 425 A solicited route update transmitted by a router along a path to 426 a destination. 428 3. Mobile Access Networks and Mobile Networks 430 In order to support host mobility a set of nodes towards the network 431 edge may need to have specific functions. Such a set of nodes forms a 432 mobile access network that may or may not be part of the global 433 Internet. Figure 1 presents two examples of such access network 434 topologies. The figure depicts a reference architecture which 435 illustrates an IP network with components defined in this section. 437 We intend to define the concept of the Access Network (AN) which may 438 also support enhanced mobility. It is possible that to support 439 routing and QoS for mobile nodes, existing routing protocols (e.g., 440 Open Shortest Path First (OSPF) [16]) may not be appropriate to 441 maintain forwarding information for these mobile nodes as they change 442 their points of attachment to the Access Network. These new functions 443 are implemented in routers with additional capabilities. We can 444 distinguish three types of Access Network components: Access Routers 445 (AR) which handle the last hop to the mobile, typically over a 446 wireless link; Access Network Gateways (ANG) which form the boundary 447 on the fixed network side and shield the fixed network from the 448 specialized routing protocols; and (optionally) other internal Access 449 Network Routers which may also be needed in some cases to support the 450 protocols. The Access Network consists of the equipment needed to 451 support this specialized routing, i.e. AR or ANG. AR and ANG may be 452 the same physical nodes. 454 In addition, we present a few basic terms on mobile networks, that 455 is, mobile network, mobile router (MR), and mobile network node 456 (MNN). More terminology for discussing mobile networks can be found 457 in [15]. A more thorough discussion of mobile networks can be found 458 in the working group documents of the NEMO Working Group. 460 Note: this reference architecture is not well suited for people 461 dealing with Mobile Ad-hoc Networks (MANET). 463 | 464 | 465 --- ------ ------- | 466 --- | <--> | | -------| AR | -------------------| | | 467 | |--[] --- /------ \ /| ANG |--| 468 --- AP / \ / | | | 469 MH / \ / ------- | 470 (with wireless ___ / ------- | 471 device) | |---- | ANR | | 472 --- ------- | 473 AP / \ | 474 / \ ------- | 475 --- ------ / \| | | 476 | |-------| AR |---------------------| ANG |--| 477 --- ------ | | | 478 AP ------- | 479 | 480 Access Network (AN) 1 | 481 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -| 482 Access Network (AN) 2 | 483 | 484 | 485 --- ------ ------- | 486 --- | <--> | | -------| AR | -------------------| | | 487 | |--[] --- /------ /| ANG |--| 488 --- AP / / | | | 489 MH / / ------- | 490 (with wireless ___ / / | 491 device) | |---- / | 492 --- / | 493 AP / | 494 / | 495 | --- ------ ------- | 496 --- | | <->| |-------| AR |---------| ANR | | 497 | |-| [] --- \ ------ ------- | 498 --- | -----| AP \ / | 499 MNN |--i MR e \ / | 500 | ------ --- \ ------ / | 501 --- | (with | |-------| AR |------- | 502 | |-| wireless --- ------ | 503 --- | device) AP | 504 MNN 'i': MR ingress interface | 505 'e': MR egress interface | 506 | 508 Figure 1: Reference Network Architecture 510 Mobile Node (MN) 512 An IP node capable of changing its point of attachment to the 513 network. A Mobile Node may either be a Mobile Host (no forwarding 514 functionality) or a Mobile Router (forwarding functionality). 516 Mobile Host (MH) 518 A mobile node that is an end host and not a router. A Mobile Host 519 is capable of sending and receiving packets, that is, being a 520 source or destination of traffic, but not a forwarder of it. 522 Fixed Node (FN) 524 A node, either a host or a router, unable to change its point of 525 attachment to the network and its IP address without breaking 526 open sessions. 528 Mobile network 530 An entire network, moving as a unit, which dynamically changes 531 its point of attachment to the Internet and thus its reachability 532 in the topology. The mobile network is composed of one or more 533 IP-subnets and is connected to the global Internet via one or 534 more Mobile Routers (MR). The internal configuration of the 535 mobile network is assumed to be relatively stable with respect to 536 the MR. 538 Mobile Router (MR) 540 A router capable of changing its point of attachment to the 541 network, moving from one link to another link. The MR is capable 542 of forwarding packets between two or more interfaces, and 543 possibly running a dynamic routing protocol modifying the state 544 by which it does packet forwarding. 546 A MR acting as a gateway between an entire mobile network and the 547 rest of the Internet has one or more egress interface(s) and one 548 or more ingress interface(s). Packets forwarded upstream to the 549 rest of the Internet are transmitted through one of the MR's 550 egress interface; packets forwarded downstream to the mobile 551 network are transmitted through one of the MR's ingress 552 interface. 554 Ingress interface 556 The interface of a MR attached to a link inside the mobile 557 network. 559 Egress interface 561 The interface of a MR attached to the home link if the MR is at 562 home, or attached to a foreign link if the MR is in a foreign 563 network. 565 Mobile Network Node (MNN) 567 Any node (host or router) located within a mobile network, either 568 permanently or temporarily. A Mobile Network Node may either be a 569 mobile node or a fixed node. 571 Access Link (AL) 573 A last-hop link between a Mobile Node and an Access Point. That 574 is, a facility or medium over which an Access Point and the 575 Mobile Node can communicate at the link layer, i.e., the layer 576 immediately below IP. 578 Access Point (AP) 580 An Access Point is a layer 2 device which is connected to one or 581 more Access Routers and offers the wireless link connection to 582 the Mobile Node. Access Points are sometimes called base 583 stations or access point transceivers. An Access Point may be a 584 separate entity or co-located with an Access Router. 586 Radio Cell 588 The geographical area within which an Access Point provides radio 589 coverage, i.e. where radio communication between a Mobile Node 590 and the specific Access Point is possible. 592 Access Network Router (ANR) 594 An IP router in the Access Network. An Access Network Router may 595 include Access Network specific functionalities, for example, 596 related to mobility and/or QoS. This is to distinguish between 597 ordinary routers and routers that have Access Network-related 598 special functionality. An ANR is neither an AR nor an ANG. 600 Access Router (AR) 602 An Access Network Router residing on the edge of an Access 603 Network and connected to one or more Access Points. The Access 604 Points may be of different technology. An Access Router offers 605 IP connectivity to Mobile Nodes, acting as a default router to 606 the Mobile Nodes it is currently serving. The Access Router may 607 include intelligence beyond a simple forwarding service offered 608 by ordinary IP routers. 610 Access Network Gateway (ANG) 612 An Access Network Router that separates an Access Network from 613 other IP networks, much in the same way as an ordinary gateway 614 router. The Access Network Gateway looks to the other IP networks 615 like a standard IP router. In a small network, an ANG may also 616 offer the services of an AR, namely offer the IP connectivity to 617 the mobile nodes. 619 Access Network (AN) 621 An IP network which includes one or more Access Network Routers. 623 Administrative Domain (AD) 625 A collection of networks under the same administrative control 626 and grouped together for administrative purposes [5]. 628 Serving Access Router (SAR) 630 The Access Router currently offering the connectivity to the MN. 631 This is usually the point of departure for the MN as it makes its 632 way towards a new Access Router (at which time the Serving Access 633 Router takes the role of the Old Access Router). There may be 634 several Serving Access Routers serving the Mobile Node at the 635 same time. 637 New Access Router (NAR) 639 The Access Router that offers connectivity to the Mobile Node 640 after a handover. 642 Previous Access Router (PAR) 644 An Access Router that offered connectivity to the Mobile Node 645 prior to a handover. This is the Serving Access Router that will 646 cease or has ceased to offer connectivity to the Mobile Node. 648 Candidate Access Router (CAR) 650 An Access Router to which the Mobile Node may do a handoff. 652 4. Handover Terminology 654 These terms refer to different perspectives and approaches to 655 supporting different aspects of mobility. Distinctions can be made 656 according to the scope, range overlap, performance characteristics, 657 diversity characteristics, state transitions, mobility types, and 658 control modes of handover techniques. 660 Roaming 662 An operator-based term involving formal agreements between 663 operators that allows a mobile to get connectivity from a foreign 664 network. Roaming (a particular aspect of user mobility) 665 includes, for example, the functionality by which users can 666 communicate their identity to the local AN so that inter-AN 667 agreements can be activated and service and applications in the 668 MN's home network can be made available to the user locally. 670 Handover (also known as handoff) 672 The process by which an active MN (in the Active State, see 673 section 4.6) changes its point of attachment to the network, or 674 when such a change is attempted. The access network may provide 675 features to minimize the interruption to sessions in progress. 677 There are different types of handover classified according to 678 different aspects involved in the handover. Some of this 679 terminology follows the description in [4]. 681 4.1. Scope of Handover 683 Layer 2 handover 685 A handover where the MN changes APs (or some other aspect of the 686 radio channel) connected to the same AR's interface. This type of 687 handover is transparent to the routing at the IP layer (or it 688 appears simply as a link layer reconfiguration without any 689 mobility implications). 691 Intra-AR handover 693 A handover which changes the AR's network interface to the 694 mobile. That is, the Serving AR remains the same but routing 695 changes internal to the AR take place. 697 Intra-AN handover 699 A handover where the MN changes ARs inside the same AN. Such a 700 handover is not necessarily visible outside the AN. In case the 701 ANG serving the MN changes, this handover is seen outside the AN 702 due to a change in the routing paths. Note that the ANG may 703 change for only some of the MN's data flows. 705 Inter-AN handover 707 A handover where the MN moves to a new AN. This requires some 708 sort of host mobility ANs, which typically is be provided by the 709 external IP core. Note that this would have to involve the 710 assignment of a new IP access address (e.g., a new care-of 711 address [9]) to the MN. 713 Intra-technology handover 715 A handover between equipment of the same technology. 717 Inter-technology handover 719 A handover between equipment of different technologies. 721 Horizontal handover 723 This involves MNs moving between access points of the same type 724 (in terms of coverage, data rate and mobility), such as, UMTS to 725 UMTS, or WLAN to WLAN. 727 Vertical handover 729 This involves MNs moving between access points of different type, 730 such as, UMTS to WLAN. 732 Note that the difference between a horizontal and vertical handover 733 is vague. For example, a handover from an AP with 802.11b WLAN link 734 to an AP with 802.11g WLAN link may be considered as either a 735 vertical or a horizontal handover, depending on an individual's point 736 of view. 738 Note also that the IP layer sees network interfaces and IP addresses, 739 rather than specific technologies used by those interfaces. Thus, 740 horizontal and vertical handovers may or may not be noticed at the IP 741 layer. Usually a handover can be noticed if the IP address assigned 742 to the interface changes, the network interface itself changes (which 743 can also change the IP address), or there is a link outage, for 744 example, when the mobile node moves out of coverage for a while. For 745 example, in a GPRS network a horizontal handover happens usually 746 unnoticed by the IP layer. Similarly, a WLAN horizontal handover may 747 be noticed if the IP address of the interface changes. On the other 748 hand, vertical handovers often change the network interface and are, 749 therefore, noticed on the IP layer. Still, some specific network 750 cards may be able to switch between access technologies (e.g. GPRS to 751 UMTS) without changing the network interface. Moreover, either of the 752 two handovers may or may not result in changing the AR. For example, 753 an AR could control WLAN and Bluetooth access points, and the mobile 754 node could do horizontal and vertical handovers under the same AR 755 without changing its IP address or even the network interface. 757 4.2. Handover Control 759 A handover must be one of the following two types (a): 761 Mobile-initiated handover 763 The MN is the one that makes the initial decision to initiate the 764 handover. 766 Network-initiated handover 768 The network makes the initial decision to initiate the handover. 770 A handover is also one of the following two types (b): 772 Mobile-controlled handover 773 The MN has the primary control over the handover process. 775 Network-controlled handover 777 The network has the primary control over the handover process. 779 A handover decision usually involves some sort of measurements about 780 when and where to handover to. Therefore, a handover is also either 781 of these three types (c): 783 Mobile-assisted handover 785 Information and measurement from the MN are used by the AR to 786 decide on the execution of a handover. 788 Network-assisted handover 790 A handover where the AN collects information that can be used by 791 the MN in a handover decision. 793 Unassisted handover 795 A handover where no assistance is provided by the MN or the AR to 796 each other. 798 Note that it is possible that the MN and the AR both do measurements 799 and decide on the handover. 801 A handover is also one of the following two types (d): 803 Push handover 805 A handover either initiated by the PAR, or where the MN initiates 806 a handover via the PAR. 808 Pull handover 810 A handover either initiated by the NAR, or where the MN initiates 811 a handover via the NAR. 813 The handover is also either proactive or reactive (e): 815 Planned handover 817 A proactive (expected) handover where some signaling can be done 818 in advance of the MN getting connected to the new AR, e.g. 819 building a temporary tunnel from the previous AR to the new AR. 821 Unplanned handover 823 A reactive (unexpected) handover where no signaling is done in 824 advance of the MN's move of the previous AR to the new AR. 826 The five handover types (a-e) are mostly independent, and every 827 handover should be classifiable according to each of these types. 829 4.3. Simultaneous connectivity to Access Routers 831 Make-before-break (MBB) 833 During a MBB handover the MN makes the new connection before the 834 old one is broken. Thus, the MN can communicate simultaneously 835 with the old and new AR during the handover. This should not be 836 confused with "soft handover" which relies on macro diversity, 837 described in Section 4.5. 839 Break-before-make (BBM) 841 During a BBM handover the MN breaks the old connection before the 842 new connection is made. Thus the MN cannot communicate 843 simultaneously with the old and the new AR. 845 4.4. Performance and Functional Aspects 847 Handover latency 849 Handover latency is the difference between the time a MN is last 850 able to send and/or receive an IP packet by way of the PAR, and 851 the time the MN is able to send and/or receive an IP packet 852 through the NAR. Adapted from [4]. 854 Smooth handover 856 A handover that aims primarily to minimize packet loss, with no 857 explicit concern for additional delays in packet forwarding. 859 Fast handover 861 A handover that aims primarily to minimize handover latency, with 862 no explicit interest in packet loss. 864 Seamless handover 866 A handover in which there is no change in service capability, 867 security, or quality. In practice, some degradation in service is 868 to be expected. The definition of a seamless handover in the 869 practical case should be that other protocols, applications, or 870 end users do not detect any change in service capability, 871 security or quality, which would have a bearing on their (normal) 872 operation. As a consequence, what would be a seamless handover 873 for one less demanding application might not be seamless for 874 another more demanding application. See [7] for more discussion 875 on the topic. 877 Throughput 878 The amount of data from a source to a destination processed by 879 the protocol for which throughput is to be measured for instance, 880 IP, TCP, or the MAC protocol. The throughput differs between 881 protocol layers. 883 Goodput 885 The total bandwidth used, less the volume of control messages, 886 protocol overhead from the data packets, and packets dropped due 887 to CRC errors. 889 Pathloss 891 A reduction in signal strength caused by traversing the physical 892 medium constituting the link. 894 Hidden-terminal problem 896 The problem whereby a transmitting node can fail in its attempt 897 to transmit data because of destructive interference which is 898 only detectable at the receiving node, not the transmitting node. 900 Exposed terminal problem 902 The problem whereby a transmitting node A prevents another node B 903 from transmitting, although node B could have safely transmitted 904 to anyone else but the transmitting node A. 906 4.5. Micro Diversity, Macro Diversity, and IP Diversity 908 Certain air interfaces (e.g. the Universal Mobile Telephone System 909 (UMTS) Terrestrial Radio Access Network (UTRAN) running in Frequency 910 Division Duplex (FDD) mode) require or at least support macro 911 diversity combining. Essentially, this refers to the fact that a 912 single MN is able to send and receive over two independent radio 913 channels ('diversity branches') at the same time; the information 914 received over different branches is compared and that from the better 915 branch passed to the upper layers. This can be used both to improve 916 overall performance, and to provide a seamless type of handover at 917 layer 2, since a new branch can be added before the old is deleted. 918 See also [6]. 920 It is necessary to differentiate between combining/diversity that 921 occurs at the physical and radio link layers, where the relevant unit 922 of data is the radio frame, and that which occurs at layer 3, the 923 network layer, where what is considered is the IP packet itself. 925 In the following definitions micro- and macro diversity refer to 926 protocol layers below the network layer, and IP diversity refers to 927 the network layer. 929 Micro diversity 931 for example, two antennas on the same transmitter send the same 932 signal to a receiver over a slightly different path to overcome 933 fading. 935 Macro diversity 937 Duplicating or combining actions taking place over multiple APs, 938 possibly attached to different ARs. This may require support 939 from the network layer to move the radio frames between the base 940 stations and a central combining point. 942 IP diversity 944 Refers to the process of duplicating IP packets and sending them 945 to the receiver through more than one point of attachment. This 946 is semantically allowed by IP because it does not guarantee 947 packet uniqueness, and higher level protocols are assumed to 948 eliminate duplicates whenever that is important for the 949 application. 951 4.6. Paging, and Mobile Node States and Modes 953 Mobile systems may employ the use of MN states in order to operate 954 more efficiently without degrading the performance of the system. The 955 term 'mode' is also common and means the same as 'state'. 957 A MN is always in one of the following three states: 959 Active state 961 When the AN knows the MN's SAR and the MN can send and receive IP 962 packets. The access link may not be active, but the radio layer 963 is able to establish one without assistance from the network 964 layer. The MN has an IP address assigned. 966 Dormant state 968 A state in which the mobile restricts its ability to receive 969 normal IP traffic by reducing its monitoring of radio channels. 970 The AN knows the MN's Paging Area, but the MN has no SAR and so 971 packets cannot be delivered to the MN without the AN initiating 972 paging. Often also called Idle state. 974 Time-slotted dormant mode 976 A dormant mode implementation in which the mobile alternates 977 between periods of not listening for any radio traffic and 978 listening for traffic. Time-slotted dormant mode implementations 979 are typically synchronized with the network so the network can 980 deliver paging messages to the mobile during listening periods. 982 Inactive state 984 the MN is in neither the Active nor Dormant State. The MN is no 985 longer listening for any packets, not even periodically, and not 986 sending packets. The MN may be in a powered off state, it may 987 have shut down all interfaces to drastically conserve power, or 988 it may be out of range of a radio access point. The MN does not 989 necessarily have an IP access address from the AN. 991 Note: in fact, as well as the MN being in one of these three states, 992 the AN also stores which state it believes the MN is in. Normally 993 these are consistent; the definitions above assume so. 995 Here are some additional definitions for paging, taking into account 996 the above state definitions. 998 Paging 1000 A procedure initiated by the Access Network to move a Dormant MN 1001 into the Active State. As a result of paging, the MN establishes 1002 a SAR and the IP routes are set up. 1004 Location updating 1006 A procedure initiated by the MN, by which it informs the AN that 1007 it has moved into a new paging area. 1009 Paging area 1011 A part of the Access Network, typically containing a number of 1012 ARs/APs, which corresponds to some geographical area. The AN 1013 keeps and updates a list of all the Dormant MNs present in the 1014 area. If the MN is within the radio coverage of the area it will 1015 be able to receive paging messages sent within that Paging Area. 1017 Paging area registrations 1019 Signaling from a dormant mode mobile node to the network, by 1020 which it establishes its presence in a new paging area. Paging 1021 Area Registrations thus enable the network to maintain a rough 1022 idea of where the mobile is located. 1024 Paging channel 1026 A radio channel dedicated to signaling dormant mode mobiles for 1027 paging purposes. By current practice, the paging channel carries 1028 only control traffic necessary for the radio link, although some 1029 paging protocols have provision for carrying arbitrary traffic 1030 (and thus could potentially be used to carry IP). 1032 Traffic channel 1034 The radio channel on which IP traffic to an active mobile is 1035 typically sent. This channel is used by a mobile that is 1036 actively sending and receiving IP traffic, and is not 1037 continuously active in a dormant mode mobile. For some radio 1038 link protocols, this may be the only channel available. 1040 4.7. Context Transfer 1042 Context 1044 The information on the current state of a routing-related service 1045 required to re-establish the routing-related service on a new 1046 subnet without having to perform the entire protocol exchange 1047 with the MN from scratch. 1049 Feature context 1051 The collection of information representing the context for a 1052 given feature. The full context associated with a MN is the 1053 collection of one or more feature contexts. 1055 Context transfer 1057 The movement of context from one router or other network entity 1058 to another as a means of re-establishing routing related services 1059 on a new subnet or collection of subnets. 1061 Routing-related service 1063 A modification to the default routing treatment of packets to and 1064 from the MN. Initially establishing routing-related services 1065 usually requires a protocol exchange with the MN. An example of a 1066 routing-related service is header compression. The service may 1067 also be indirectly related to routing, for example, security. 1068 Security may not affect the forwarding decision of all 1069 intermediate routers, but a packet may be dropped if it fails a 1070 security check (can't be encrypted, authentication failed, etc.). 1071 Dropping the packet is basically a routing decision. 1073 4.8. Candidate Access Router Discovery 1075 Capability of an AR 1077 A characteristic of the service offered by an AR that may be of 1078 interest to an MN when the AR is being considered as a handoff 1079 candidate. 1081 Candidate AR (CAR) 1083 An AR to which MN has a choice of performing IP-level handoff. 1084 This means that MN has the right radio interface to connect to an 1085 AP that is served by this AR, as well as the coverage of this AR 1086 overlaps with that of the AR to which MN is currently attached. 1088 Target AR (TAR) 1090 An AR with which the procedures for the MN's IP-level handoff are 1091 initiated. TAR is selected after running a TAR Selection 1092 Algorithm that takes into account the capabilities of CARs, 1093 preferences of MN and any local policies. 1095 4.9. Types of Mobility 1097 We can differentiate between host and network mobility, and various 1098 types of network mobility. Terminology related more to applications 1099 such as the Session Initiation Protocol, such as personal mobility, 1100 is out of scope for this document. 1102 Host mobility support 1104 Refers to the function of allowing a mobile node to change its 1105 point of attachment to the network, without interrupting IP 1106 packet delivery to/from that node. There may be different sub- 1107 functions depending on what the current level of service is being 1108 provided; in particular, support for host mobility usually 1109 implies active and dormant modes of operation, depending on 1110 whether the node has any current sessions or not. Access Network 1111 procedures are required to keep track of the current point of 1112 attachment of all the MNs or establish it at will. Accurate 1113 location and routing procedures are required in order to maintain 1114 the integrity of the communication. Host mobility is often 1115 called 'terminal mobility'. 1117 Network mobility support 1119 Refers to the function of allowing an entire network to change 1120 its point of attachment to the Internet, and, thus, its 1121 reachability in the topology, without interrupting IP packet 1122 delivery to/from that mobile network. 1124 Two subcategories of mobility can be identified within both host 1125 mobility and network mobility: 1127 Global mobility 1129 Same as Macro mobility. 1131 Local mobility 1133 Same as Micro mobility. 1135 Macro mobility 1137 Mobility over a large area. This includes mobility support and 1138 associated address registration procedures that are needed when a 1139 MN moves between IP domains. Inter-AN handovers typically involve 1140 macro-mobility protocols. Mobile-IP can be seen as a means to 1141 provide macro mobility. 1143 Micro mobility 1145 Mobility over a small area. Usually this means mobility within 1146 an IP domain with an emphasis on support for active mode using 1147 handover, although it may include idle mode procedures also. 1148 Micro-mobility protocols exploit the locality of movement by 1149 confining movement related changes and signaling to the access 1150 network. 1152 Local mobility management 1154 Local mobility management (LMM) is a generic term for protocols 1155 dealing with IP mobility management confined within the access 1156 network. LMM messages are not routed outside the access network, 1157 although a handover may trigger Mobile IP messages to be sent to 1158 correspondent nodes and home agents. 1160 5. Specific Terminology for Mobile Ad-Hoc Networking 1162 Cluster 1164 A group of nodes located within close physical proximity, 1165 typically all within range of one another, which can be grouped 1166 together for the purpose of limiting the production and 1167 propagation of routing information. 1169 Cluster head 1171 A cluster head is a node (often elected in the cluster formation 1172 process) that has complete knowledge about group membership and 1173 link state information in the cluster. Each cluster should have 1174 one and only one cluster head. 1176 Cluster member 1178 All nodes within a cluster EXCEPT the cluster head are called 1179 members of that cluster. 1181 Convergence 1183 The process of approaching a state of equilibrium in which all 1184 nodes in the network agree on a consistent collection of state 1185 about the topology of the network, and in which no further 1186 control messages are needed to establish the consistency of the 1187 network topology. 1189 Convergence time 1191 The time which is required for a network to reach convergence 1192 after an event (typically, the movement of a mobile node) which 1193 changes the network topology. 1195 Laydown 1197 The relative physical location of the nodes within the ad hoc 1198 network. 1200 Pathloss matrix 1202 A matrix of coefficients describing the pathloss between any two 1203 nodes in an ad hoc network. When the links are asymmetric, the 1204 matrix is also asymmetric. 1206 Scenario 1208 The tuple 1209 characterizing a class of ad hoc networks. 1211 6. Security-related Terminology 1213 This section includes terminology commonly used around mobile and 1214 wireless networking. Only a mobility-related subset of the entire 1215 security terminology is presented. 1217 Authorization-enabling extension 1219 An authentication which makes a (registration) message acceptable 1220 to the ultimate recipient of the registration message. An 1221 authorization-enabling extension must contain an SPI (see below) 1222 [12]. 1224 Mobility security association 1226 A collection of security contexts, between a pair of nodes, which 1227 may be applied to mobility-related protocol messages exchanged 1228 between them. In Mobile IP, each context indicates an 1229 authentication algorithm and mode, a secret (a shared key, or 1230 appropriate public/private key pair), and a style of replay 1231 protection in use. Mobility security associations may be stored 1232 separately from the node's IPsec Security Policy Database (SPD) 1233 [12]. 1235 Registration key 1237 A key used in the Mobility Security Association between a mobile 1238 node and a foreign agent. A registration key is typically only 1239 used once or a very few times, and only for the purposes of 1240 verifying a small volume of Authentication data [14]. 1242 Security context 1244 A security context between two nodes defines the manner in which 1245 two nodes choose to mutually authenticate each other, and 1246 indicates an authentication algorithm and mode. 1248 Security Parameter Index (SPI) 1250 An index identifying a security context between a pair of routers 1251 among the contexts available in the mobility security 1252 association. 1254 The Mobile IPv6 specification includes more security terminology 1255 related to MIPv6 bindings [11]. Terminology about the MIP 1256 challenge/response mechanism can be found in [13]. 1258 7. Security Considerations 1260 This document presents only terminology. There are no security issues 1261 in this document. 1263 8. Contributors 1265 This draft was initially based on the work of 1267 o Tapio Suihko, VTT Information Technology, Finland 1268 o Phil Eardley and Dave Wisely, BT, UK 1269 o Robert Hancock, Siemens/Roke Manor Research, UK, 1270 o Nikos Georganopoulos, King's College London 1271 o Markku Kojo and Jukka Manner, University of Helsinki, Finland. 1273 Since revision -02 of the document draft-manner-seamoby-terms-02.txt, 1274 Charles Perkins has given as input terminology related to ad-hoc 1275 networks. 1277 Thierry Ernst has provided the terminology for discussing mobile 1278 networks. 1280 Henrik Levkowetz did a final check of the definitions in revision -05 1281 and suggested a number of changes. 1283 9. Acknowledgments 1285 This work has been partially performed in the framework of the IST 1286 project IST-2000-28584 MIND, which is partly funded by the European 1287 Union. Some of the authors would like to acknowledge the help of 1288 their colleagues in preparing this document. 1290 Randy Presuhn did a very thorough and helpful review of the -02 1291 version of the terminology. 1293 Some definitions of terminology have been adapted from [1], [7], [3], 1294 [2], [4], [9], [10], [11] and [12]. 1296 10. Informative References 1298 [1] Blair, D., Tweedly, A., Thomas, M., Trostle, J. and 1299 Ramalho, M., "Realtime Mobile IPv6 Framework", Work in 1300 Progress. 1302 [2] Calhoun, P., Montenegro, G. and Perkins, C., "Mobile IP 1303 Regionalized Tunnel Management", Work in Progress. 1305 [3] Deering, S. and Hinden, R., "Internet Protocol, Version 6 1306 (IPv6) Specification". RFC 2460, December 1998. 1308 [4] Dommety, G. (ed.), "Fast Handovers for Mobile IPv6", Work in 1309 Progress. 1311 [5] Yavatkar, R., Pendarakis, D. and Guerin, R., "A Framework for 1312 Policy-based Admission Control". RFC 2753, January 2000. 1314 [6] Kempf, J., McCann, P. and Roberts, P., "IP Mobility and the 1315 CDMA Radio Access Network: Applicability Statement for Soft 1316 Handoff", Work in Progress. 1318 [7] Kempf, J. (ed.), "Problem Description: Reasons For Doing 1319 Context Transfers Between Nodes in an IP Access Network". 1320 RFC 3374, September 2002. 1322 [8] Pandya, R., "Emerging Mobile and Personal Communication 1323 Systems". IEEE Communications Magazine, 33:44--52, June 1995. 1325 [9] Ramjee, R., La Porta, T., Thuel, S., Varadhan, K. and 1326 Salgarelli, L., "IP micro-mobility support using HAWAII", Work 1327 in Progress. 1329 [10] Trossen, D., Krishnamurthi, G., Chaskar, H. and Kempf, J., 1330 "Issues in candidate access router discovery for seamless 1331 IP-level handoffs", Work in Progress. 1333 [11] Johnson, D., Perkins, D. and Arkko, J., "Mobility 1334 Support in IPv6", Work in Progress. 1336 [12] Perkins, C. (ed.), "IP Mobility Support for IPv4". RFC 3344, 1337 August 2002. 1339 [13] Perkins, C., Calhoun, P. and Bharatia, J., "Mobile 1340 IPv4 Challenge/Response Extensions (revised)", Work in 1341 Progress. 1343 [14] Perkins, C. and Calhoun, P., "AAA Registration Keys for Mobile 1344 IP", Work in Progress. 1346 [15] Ernst, T. and Lach, H., "Network Mobility Support 1347 Terminology", Work in Progress. 1349 [16] Moy, J., OSPF Version 2. RFC 2328, April 1998. 1351 11. Authors' Addresses 1353 Jukka Manner 1354 Department of Computer Science 1355 University of Helsinki 1356 P.O. Box 26 (Teollisuuskatu 23) 1357 FIN-00014 HELSINKI 1358 Finland 1360 Voice: +358-9-191-44210 1361 Fax: +358-9-191-44441 1362 E-Mail: jmanner@cs.helsinki.fi 1364 Markku Kojo 1365 Department of Computer Science 1366 University of Helsinki 1367 P.O. Box 26 (Teollisuuskatu 23) 1368 FIN-00014 HELSINKI 1369 Finland 1371 Voice: +358-9-191-44179 1372 Fax: +358-9-191-44441 1373 E-Mail: kojo@cs.helsinki.fi 1375 Charles E. Perkins 1376 Communications Systems Lab 1377 Nokia Research Center 1378 313 Fairchild Drive 1379 Mountain View, California 94043 1380 USA 1381 Phone: +1-650 625-2986 1382 E-Mail: charliep@iprg.nokia.com 1383 Fax: +1 650 625-2502 1385 Tapio Suihko 1386 VTT Information Technology 1387 P.O. Box 1203 1388 FIN-02044 VTT 1389 Finland 1391 Voice: +358-9-456-6078 1392 Fax: +358-9-456-7028 1393 E-Mail: tapio.suihko@vtt.fi 1394 Phil Eardley 1395 BTexaCT 1396 Adastral Park 1397 Martlesham 1398 Ipswich IP5 3RE 1399 United Kingdom 1401 Voice: +44-1473-645938 1402 Fax: +44-1473-646885 1403 E-Mail: philip.eardley@bt.com 1405 Dave Wisely 1406 BTexaCT 1407 Adastral Park 1408 Martlesham 1409 Ipswich IP5 3RE 1410 United Kingdom 1412 Voice: +44-1473-643848 1413 Fax: +44-1473-646885 1414 E-Mail: dave.wisely@bt.com 1416 Robert Hancock 1417 Roke Manor Research Ltd 1418 Romsey, Hants, SO51 0ZN 1419 United Kingdom 1421 Voice: +44-1794-833601 1422 Fax: +44-1794-833434 1423 E-Mail: robert.hancock@roke.co.uk 1425 Nikos Georganopoulos 1426 King's College London 1427 Strand 1428 London WC2R 2LS 1429 United Kingdom 1431 Voice: +44-20-78482889 1432 Fax: +44-20-78482664 1433 E-Mail: nikolaos.georganopoulos@kcl.ac.uk 1435 12. Appendix A - Index of Terms 1437 AD ............................................................. 13 1438 AL ............................................................. 12 1439 AN ............................................................. 13 1440 ANG ............................................................ 12 1441 ANR ............................................................ 12 1442 AP ............................................................. 12 1443 AR ............................................................. 12 1444 Access Link .................................................... 12 1445 Access Network ................................................. 13 1446 Access Network Gateway ......................................... 12 1447 Access Network Router .......................................... 12 1448 Access Point ................................................... 12 1449 Access Router .................................................. 12 1450 Active state ................................................... 19 1451 Administrative Domain .......................................... 13 1452 Asymmetric link ................................................. 5 1453 Authorization-enabling extension ............................... 24 1454 BBM ............................................................ 17 1455 BU .............................................................. 3 1456 Bandwidth ....................................................... 3 1457 Bandwidth utilization ........................................... 3 1458 Beacon .......................................................... 3 1459 Binding Update .................................................. 3 1460 Break-before-make .............................................. 17 1461 CAR ............................................................ 13 1462 CAR ............................................................ 21 1463 Candidate AR ................................................... 21 1464 Candidate Access Router ........................................ 13 1465 Capability of an AR ............................................ 21 1466 Care-of-Address ................................................. 3 1467 Channel ......................................................... 3 1468 Channel access protocol ......................................... 3 1469 Channel capacity ................................................ 3 1470 Cluster ........................................................ 23 1471 Cluster head ................................................... 23 1472 Cluster member ................................................. 23 1473 CoA ............................................................. 3 1474 Context ........................................................ 21 1475 Context transfer ............................................... 21 1476 Control message ................................................. 4 1477 Convergence .................................................... 23 1478 Convergence time ............................................... 23 1479 Distance vector ................................................. 4 1480 Dormant state .................................................. 19 1481 Egress interface ............................................... 11 1482 Exposed terminal problem ....................................... 18 1483 FN ............................................................. 11 1484 Fairness ........................................................ 4 1485 Fast handover .................................................. 17 1486 Feature context ................................................ 21 1487 Fixed Node ..................................................... 11 1488 Flooding ........................................................ 4 1489 Foreign subnet prefix ........................................... 4 1490 Forwarding node ................................................. 4 1491 Global mobility ................................................ 22 1492 Goodput ........................................................ 18 1493 HA .............................................................. 4 1494 Handoff ........................................................ 14 1495 Handover ....................................................... 14 1496 Handover latency ............................................... 17 1497 Hidden-terminal problem ........................................ 18 1498 HoA ............................................................. 4 1499 Home Address .................................................... 4 1500 Home Agent ...................................................... 4 1501 Home subnet prefix .............................................. 5 1502 Horizontal Handover ............................................ 15 1503 Host mobility support .......................................... 22 1504 IP access address ............................................... 5 1505 IP diversity ................................................... 19 1506 Inactive state ................................................. 19 1507 Ingress interface .............................................. 11 1508 Inter-AN handover .............................................. 14 1509 Inter-technology handover ...................................... 14 1510 Interface ....................................................... 5 1511 Intra-AN handover .............................................. 14 1512 Intra-AR handover .............................................. 14 1513 Intra-technology handover ...................................... 14 1514 L2 Trigger ...................................................... 5 1515 Laydown ........................................................ 24 1516 Layer 2 handover ............................................... 14 1517 Link ............................................................ 5 1518 Link establishment .............................................. 5 1519 Link state ...................................................... 6 1520 Link-layer trigger .............................................. 5 1521 Link-level acknowledgment ....................................... 6 1522 Local broadcast ................................................. 6 1523 Local mobility ................................................. 22 1524 Local mobility management ...................................... 23 1525 Location updating .............................................. 20 1526 Loop-free ....................................................... 6 1527 MAC ............................................................. 6 1528 MBB ............................................................ 17 1529 MH ............................................................. 11 1530 MN ............................................................. 11 1531 MNN ............................................................ 12 1532 MPR ............................................................. 7 1533 MR ............................................................. 11 1534 Macro diversity ................................................ 19 1535 Macro mobility ................................................. 22 1536 Make-before-break .............................................. 17 1537 Medium Access Protocol .......................................... 6 1538 Micro diversity ................................................ 18 1539 Micro mobility ................................................. 23 1540 Mobile Host .................................................... 11 1541 Mobile Network Node ............................................ 12 1542 Mobile Node .................................................... 11 1543 Mobile Router .................................................. 11 1544 Mobile network ................................................. 11 1545 Mobile network prefix ........................................... 6 1546 Mobile-assisted handover ....................................... 16 1547 Mobile-controlled handover ..................................... 15 1548 Mobile-initiated handover ...................................... 15 1549 Mobility factor ................................................. 6 1550 Mobility security association .................................. 24 1551 Multipoint relay ................................................ 7 1552 NAR ............................................................ 13 1553 Neighbor ........................................................ 7 1554 Neighborhood .................................................... 7 1555 Network mobility support ....................................... 22 1556 Network-assisted handover ...................................... 16 1557 Network-controlled handover .................................... 15 1558 Network-initiated handover ..................................... 15 1559 New Access Router .............................................. 13 1560 Next hop ........................................................ 7 1561 PAR ............................................................ 13 1562 Paging ......................................................... 20 1563 Paging area .................................................... 20 1564 Paging area registrations ...................................... 20 1565 Paging channel ................................................. 20 1566 Pathloss ....................................................... 18 1567 Pathloss matrix ................................................ 24 1568 Payload ......................................................... 7 1569 Planned handover ............................................... 16 1570 Prefix .......................................................... 7 1571 Previous Access Router ......................................... 13 1572 Pull handover .................................................. 16 1573 Push handover .................................................. 16 1574 Radio Cell ..................................................... 12 1575 Registration key ............................................... 24 1576 Roaming ........................................................ 13 1577 Route activation ................................................ 8 1578 Route entry ..................................................... 7 1579 Route establishment ............................................. 7 1580 Route table ..................................................... 7 1581 Routing proxy ................................................... 8 1582 Routing-related service ........................................ 21 1583 SAR ............................................................ 13 1584 SPI ............................................................ 25 1585 Scenario ....................................................... 24 1586 Seamless handover .............................................. 17 1587 Security Parameter Index ....................................... 25 1588 Security context ............................................... 24 1589 Serving Access Router .......................................... 13 1590 Shannon's Law ................................................... 8 1591 Signal strength ................................................. 8 1592 Smooth handover ................................................ 17 1593 Source route .................................................... 8 1594 Spatial re-use .................................................. 8 1595 Subnet .......................................................... 8 1596 System-wide broadcast ........................................... 8 1597 TAR ............................................................ 21 1598 Target AR ...................................................... 21 1599 Throughput ..................................................... 17 1600 Time-slotted dormant mode ...................................... 19 1601 Topology ........................................................ 9 1602 Traffic channel ................................................ 20 1603 Triggered update ................................................ 9 1604 Unassisted handover ............................................ 16 1605 Unplanned handover ............................................. 16 1606 Vertical Handover .............................................. 15 1608 Full Copyright Statement 1610 Copyright (C) The Internet Society (2004). 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