ISO/IEC TR 29181-4:2013

TECHNICAL ISO/IEC
REPORT TR
29181-4
First edition
2013-10-15
Information technology — Future
Network — Problem statement and
requirements —
Part 4:
Mobility
Technologies de l’information — Réseaux du futur — Énoncé du
problème et exigences —
Partie 4: Mobilité
Reference number
©
ISO/IEC 2013
© ISO/IEC 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO/IEC 2013 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviations. 2
5 General . 3
5.1 Mobile environment in FN . 3
5.2 Related works on mobility in FN . 4
6 Problem statement of current network in mobile environment .5
6.1 Overloaded semantics of IP address . 5
6.2 Single common protocol for heterogeneous networks . 5
6.3 Integration of data delivery and control function. 5
6.4 Centralized mobility control . 5
7 Architectural requirements for mobility support in FN . 6
7.1 Separation of identifier and locator . 6
7.2 Support of heterogeneous access networks . 6
7.3 Separation of mobility control function from user data delivery . 6
7.4 Support of distributed mobility control . 6
8 Functional requirements for mobility support in FN . 6
8.1 Location management . 6
8.2 Route optimization . 7
8.3 Handover control . 7
Annex A (informative) Existing IP-based mobility control protocols . 8
Annex B (informative) High-level architecture of mobility control in FN .14
Annex C (informative) Distributed mobility control in Proxy MIPv6 networks .18
Annex D (informative) Additional considerations for FN mobility
....................................................................................20
Bibliography .21
© ISO/IEC 2013 – All rights reserved iii

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work. In the field of information technology, ISO and IEC have established a joint technical committee,
ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the national bodies
casting a vote.
In exceptional circumstances, when the joint technical committee has collected data of a different kind
from that which is normally published as an International Standard (“state of the art”, for example), it
may decide to publish a Technical Report. A Technical Report is entirely informative in nature and shall
be subject to review every five years in the same manner as an International Standard.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO/IEC TR 29181-4 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 6, Telecommunications and information exchange between systems.
ISO/IEC TR 29181 consists of the following parts, under the general title Information technology —
Future Network — Problem statement and requirements:
— Part 1: Overall aspects
— Part 2: Naming and addressing
— Part 3: Switching and routing
— Part 4: Mobility
— Part 5: Security
— Part 6: Media transport
— Part 7: Service composition
iv © ISO/IEC 2013 – All rights reserved

Introduction
This part of ISO/IEC TR 29181 (Future Network: Problem Statement and Requirements) describes the
problems of the current network and the requirements for Future Network in the mobility perspective.
The general description on the problem statement and requirements for Future Network is given in
ISO/IEC TR 29181-1. In addition, ISO/IEC TR 29181-4 establishes the problem statement and requirements
for Future Network from the viewpoint of architecture and functionality for mobility support.
In general, the mobility issues can be classified into link-layer, network-layer, and transport/application
layer mobility management. It is noted that the link-layer mobility issues have been addressed and well
defined in the relevant SDOs, such as 3GPPs, IEEE 802, etc. The transport/application layer mobility
issues are also associated with the particular transport/application protocols used by mobile nodes.
On the other hand, the network layer mobility control issues are quite dependent on the network
architecture. Accordingly, this part of ISO/IEC TR 29181 will focus on the mobility issues of Future
Network in the network-layer perspective.
This part of ISO/IEC TR 29181 may be applicable to the overall design of Future Network architecture.
© ISO/IEC 2013 – All rights reserved v

TECHNICAL REPORT ISO/IEC TR 29181-4:2013(E)
Information technology — Future Network — Problem
statement and requirements —
Part 4:
Mobility
1 Scope
This part of ISO/IEC TR 29181 describes the problem statements of current network and the requirements
for Future Network in the mobility perspective. This part of ISO/IEC TR 29181 mainly specifies
— problems of the current network in mobile environment, and
— requirements for mobility support in Future Network.
In addition, this part of ISO/IEC TR 29181 gives information on
— existing mobility control schemes in the current network,
— examples of high-level mobility control architecture for Future Network,
— distributed mobility control in the Proxy Mobile IPv6 networks, and
— additional considerations for Future Network mobility.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO/IEC TR 29181 (all parts), Information technology — Future Network — Problem statement and requirements
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
Future Network
FN
network of the future which is made on clean-slate design approach as well as incremental design
approach; it should provide futuristic capabilities and services beyond the limitations of the current
network including the Internet
[SOURCE: ISO/IEC TR 29181-1]
© ISO/IEC 2013 – All rights reserved 1

3.2
Node Identifier
NID
globally unique identifier for a network node or host
[SOURCE: ISO/IEC TR 29181-2]
Note 1 to entry: Identifier (ID) is a generic term that is associated with various types of objects, whereas NID is used
to represent a host in the network. In this part of ISO/IEC TR 29181, the term of ID is used with the meaning of NID.
3.3
Locator
LOC
IP address to connection mapping
[SOURCE: ISO/IEC TR 29181-2]
Note 1 to entry: In this part of ISO/IEC TR 29181, LOC is used to represent the location of a host in the network,
which is also used for delivery of data packets in the network.
3.4
Mobility
ability for user to communicate or access the services, irrespective of changes of its location
[SOURCE: ITU-T Recommendation Q.1706/Y.2801]
4 Abbreviations
ACK Acknowledgement
AR Access Router
CN Correspondent Node
FN Future Network
GILL Global Identifier and Local Locator
GW Gateway
HA Home Agent
HMI Hierarchical MIP
ID Identifier
IP Internet Protocol
ISP Internet Services Provider
LMC Local Mobility Controller
LOC Locator
MIP Mobile IP
MN Mobile Node
NID Node ID
PMIP Proxy Mobile IP
2 © ISO/IEC 2013 – All rights reserved

SCTP Stream Control Transmission Protocol
TCP Transmission Control Protocol
TR Technical Report
UDP User Datagram Protocol
5 General
5.1 Mobile environment in FN
With an explosive growth of the number of subscribers of 3G/4G cellular systems and also other wireless
data systems such as WiFi and WiMAX, the mobile networks now become the key driver toward the
Future Network (FN). The number of people who surf the network on their phones has doubled since
2006. In near future, there will likely be more mobile and wireless users than wired ones. In addition,
a variety of new types of wireless access networks like ad hoc networks and sensor networks are
emerging, and they will be the major access means to FN.
Figure 1 illustrates the network environment, in which the users or things in FN will benefit from a
variety of access ways to the network anytime, anywhere, and through any interfaces. In particular,
it is expected that ‘mobile’ users/things, rather ‘fixed’ ones, will become more dominant in FN. In this
context, a crucial requirement for FN is to provide seamless services for the mobile users/things through
the mobile-oriented FN.
Figure 1 — Network environment in FN
With a recent trend of network convergence, it is expected that the all kinds of networks will be evolved
or revolved toward a unified network, i.e. ‘mobile-oriented convergence network’ as shown in Figure 2,
including computer or telecommunication networks.
© ISO/IEC 2013 – All rights reserved 3

Figure 2 — Convergence of Internet and telecommunication in FN
Historically, the computer networks (i. e., Internet) and the telecommunication networks have been
evolved until now, with quite different design philosophy and business purposes. From the perspective
of the convergence trends, however, FN should be designed to make full use of the pros of both computer
networks and telecommunication networks.
In addition, it is noted that the current cellular system is a very successful model in the wireless/mobile
systems and provides a lot of desirable features to support the mobile environment. Therefore, it is
recommended to readily exploit the useful features of cellular mobile systems in the design of FN
architecture, to the extent possible.
5.2 Related works on mobility in FN
It is noted that the current network, such as Internet, was basically designed for fixed network
environment, rather than for the mobile network environment. This has enforced Internet to add
a lot extensional features to satisfy the requirements for mobile networks, as shown in the example
of Mobile IP (MIP) that has been made in the IETF. The examples of mobility schemes for current
network are described in the Annex A, which include the transport-layer and application-layer mobility
schemes that have been so far proposed in the IETF. However, this patch-on approach seems to be just a
temporal heuristic to the problems in the mobile environment, rather than an optimization approach to
substantially solve the mobile-related issues.
Based on these observations, some activities already started to design the FN for mobile environment
rather than fixed environment. A typical example is eMobility, which is a FP7 project of EU. eMobility
envisions the third generation Internet as the wireless/mobile Internet with the name of ‘Post-IP.’ The
4WARD, another FP7 project for design of FN architecture, is also targeted to effectively support the
mobile environment. The other European projects for mobility include Trilogy.
We also note a lot of Future Internet Design (FIND) projects, which are very closely related with
wireless/mobile environments. Especially, the “Mobility First” project is recently proposed as a
candidate approach for FN. This proposal is with the recognition that the network is changing very
rapidly from fixed hosts to mobile devices, in which it is stated that a FN architecture should support
mobile devices as ‘first-class’ users and also provide a variety of new applications efficiently, securely,
and at a large scale. The Global Environment for Network Innovation (GENI), a representative testbed
project for FN, also agrees that wireless/mobile will be the major access means for FN. We note that
some design documents of GENI already covers the issues including ad hoc and sensor networks.
AKARI is a representative research activity on FN in Japan, which deals with the issues on the separation
of Identifier (ID) and Locator (LOC) and the managed mesh network to support mobile environment.
Especially, the ID-LOC split architecture covers the primary issues in mobile environment such as
mobility and multi-homing, etc. On the other hand, Mobile Oriented Future Internet (MOFI) is a project
of designing the architecture and protocols of FN in Korea.
4 © ISO/IEC 2013 – All rights reserved

In the perspective of standardization activities, the ITU-T has so far identified the mobility management
requirements and frameworks for next-generation networks, which include ITU-T Q.1706, Q.1707,
Q.1708, and Q.1709. It is noted that some preliminary works for Future Networks are also in progress in
the ITU-T SG13.
From these observations, we can see that there is a crucial need to design the architecture of FN to more
effectively support the mobile environment.
6 Problem statement of current network in mobile environment
6.1 Overloaded semantics of IP address
In the current IP-based networks, an IP address has overloaded semantics as Identifier (ID) and Locator
(LOC). In mobile environment, however, the location of mobile host is likely to continue to change by
movement. This means that the static allocation of LOC (IP address) to a host may become problematic
in mobile networks. In the meantime, ID needs to be kept persistently (without change) to maintain an
on-going sessions against movement of a host. Accordingly, ID and LOC should be separated to support
the mobility in Future Network.
Another critical concern is that an IP address, as an ID, is allocated to a network interface of a host, rather
the host itself. Accordingly, if a host has multiple interfaces, multiple IP addresses must be allocated
to a single host. This may give serious inefficiency to a multi-homing host, since the same host has to
use different IDs for communication. Therefore, ID needs to be allocated to a host itself rather than its
network interface.
As for the allocation of IP address, it does not make sense to allocate IP address to a mobile host, since
it may continue to move on. Accordingly, in mobile environments, it is suggested that an address or LOC
should be allocated to a certain fixed node in the network, rather than the host itself.
6.2 Single common protocol for heterogeneous networks
It is expected that future mobile networks will consist of a variety of heterogeneous wireless networks.
Such wireless networks are likely to have quite different characteristics, ranged from managed mobile
networks to light-weight senor networks. On the other hand, the backbone network will be evolved
to optical network with high bandwidth, which is quite different from wireless access networks.
Accordingly, a single common IP protocol and/or addressing scheme of current Internet may not
effectively support the FN with optical backbone and heterogeneous wireless access networks.
6.3 Integration of data delivery and control function
In most of current Internet protocols, data delivery and control function are integrated and implemented
at the same devices, and the data and control traffics are routed along the same path, as shown in the IP
and ICMP protocols. However, the control information for signalling is mission-critical and thus needs
to be delivered more urgently and reliably, compared to usual data traffics. Thus, the control function
needs to be separated from data traffics.
6.4 Centralized mobility control
Most of the current mobility control schemes in IP-based networks are based on a centralized mobility
anchor, such as Home Agent (HA) of Mobile IP. This is because the existing mobile networks were originally
designed as a hierarchical architecture to support circuit-based voice traffics. In the centralized control,
however, the routing path through a centralized anchor tends to be longer, which results in non-optimal
routes and performance degradation. Moreover, the centralized approach is vulnerable to a single point
of failure or attack.
It is noted that an ever-increasing demand of mobile Internet traffics has enforced non-hierarchical or flat
architecture on mobile networks, so as to provide data services more cost-effectively. Accordingly, we
need to consider the distributed mobility control to support a flat architecture of future mobile networks.
© ISO/IEC 2013 – All rights reserved 5

7 Architectural requirements for mobility support in FN
7.1 Separation of identifier and locator
To avoid the overloaded semantics of IP address, ID should be separated from LOC (IP address). ID is
used to identify a host itself in the network, whereas a LOC is used to represent the current location
of a host in the network. ID is not an IP address, but a persistent ID. ID is given statically, not allocated
dynamically. An IP address is used as LOC (e. g., IP address of an access router that the mobile host is
attached to).
7.2 Support of heterogeneous access networks
Future Network should support a variety of heterogeneous access networks. To meet this requirement, the
protocols and/or addressing schemes used for packet delivery may be different between access network
and backbone network, and/or between access networks. In particular, the protocols for access networks
may be designed by considering the heterogeneous wireless link characteristics, whereas the protocols
for backbone networks may be designed to be as simple as possible by considering the optical networks.
7.3 Separation of mobility control function from user data delivery
In Future Network, to deal with mission-critical control information (e.g. for mobility control) effectively,
it is recommended that the mobility control function should be separated from the user data plane.
In particular, the mobility control function will be performed as a network-based scheme to enhance
deployment, resource utilization and protocol performance.
7.4 Support of distributed mobility control
It is expected that the future mobile network will be evolved to a flat architecture, not a hierarchical
structure. Accordingly, the Future Network should be designed to provide a distributed mobility
control for flat network architecture. In the distributed mobility control, the route optimization can be
intrinsically supported, and we can reduce unnecessary traffics flowing into the core network. This can
also mitigate the problem of a single point of failure to a local network.
For information, the high-level architecture of mobility control in FN is discussed in the Annex B, and
the use of Proxy MIP for distributed mobility control is discussed in the Annex C.
8 Functional requirements for mobility support in FN
8.1 Location management
To support the mobility, the Future Network should provide the location management function so as
to keep track of the movement of a host in the network and also to locate the host for data delivery.
The location management function is used for supporting the prospective ‘incoming’ session (or call)
to the mobile user. The location management function includes the following sub-functions: location
registration/update and location query/response (for user data transport) that may be performed with
a service control function for call/session establishment.
The location registration and update functions are used to keep track of the current location of a host.
When a host is attached to the network, it may register its current location with the network, possibly
via an appropriate location database. When the host moves into the other network, the corresponding
LOC will be updated. In the location registration and update function, the mapping information between
IDs and LOCs will be managed and updated all the time.
The location query and response functions are used to locate a host for data delivery. The information
of the current location of a host will be identified through the suitable location query and response
operations. It is noted that the location query and response operations may be performed together with
a relevant service control function.
6 © ISO/IEC 2013 – All rights reserved

8.2 Route optimization
To support the mobility, the Future Network should provide the route optimization function by which
the two communicating hosts can exchange the data packets through a shorter path. This can also give
performance benefits by reducing packet propagation delays, bandwidth consumption and congestions
in the network.
8.3 Handover control
To support the mobility in Future Network, the handover control function should be provided to realize
‘session continuity’ for ‘on-going’ sessions of mobile hosts. To provide the seamless mobility or session
continuity, the handover control functions will be performed to minimize the data loss and handover
latency during handover.
In general, the handover control schemes can be divided by the protocol layer into the handover control
in the link layer, the handover control in the network layer, and the handover control in the transport or
application layer. Each of the handover schemes will be performed using the corresponding signalling
between the entities associated with handover. The handover signalling will be based on the movement
detection (in the link-layer and/or in the network layer). A different handover control protocol or
scheme can be employed, depending on how to use the information on movement detection and/or how
to perform the handover signalling.
It is noted that the link-layer handover issues have been addressed and well defined in the relevant
SDOs, such as 3GPPs, IEEE 802, etc. The transport/application layer handover issues are also associated
with the particular transport/application protocols used by mobile nodes. On the other hand, the
network layer handover control issues are quite dependent on the network architecture. Accordingly,
the mobility issues of FN can be addressed, in particular, in the network-layer perspective.
© ISO/IEC 2013 – All rights reserved 7

Annex A
(informative)
Existing IP-based mobility control protocols
A.1 Network-layer mobility control protocols
A.1.1 Mobile IP
Mobile IP (MIP) is a protocol to support the IP mobility and is specified in the IETF. MIP may be divided
into Mobile IPv4 (MIPv4) and Mobile IPv6 (MIPv6) per the associated IP version. These two protocols
basically provide similar functionality. Details of MIPv4 and MIPv6 are described in IETF RFC 3344 and
RFC 3775, respectively.
MIPv4 operates between the following entities: Mobile Node (MN), Home Agent (HA), Foreign Agent
(FA) and Correspondent Node (CN). When a MN moves into a new subnet, it registers with the HA with
a Care-of Address (CoA). The CoA represents an IP address of FA. The MN must register its CoA with
the HA whenever the MN changes its subnet. If the HA receives packets destined for MN from the CN,
and the MN is roaming in a visited network, the HA intercepts these packets and forwards them to the
CoA through the mobile IP tunnel. The FA decapsulates the received packets from the HA and delivers
the original packets to the MN. MIP does not support fast handover for time-critical and loss-sensitive
applications. To address this problem, the MIP has been extended to Fast Handover for MIP (FMIP) and
Hierarchical MIP (HMIP).
In HMIP, the access networks are organized hierarchically. Gateway Foreign Agents (GFAs) of MIPv4,
or Mobility Anchor Points (MAPs) in MIPv6, are responsible for mobility management of mobile nodes
within the local domain. Therefore, the movement of mobile modes within the local domain will be
hidden from the HA and CN in the other networks, and thus the registration latency and signalling
overhead can be decreased considerably. The HMIP architecture for MIPv4 is also known as ‘regional
registration’.
In FMIP, the MIP registration procedures can start only after the link layer handover is complete. It is
noted that, if appropriate information could be obtained from the lower-layer (before the link layer
handover is completed), the MIP handover latency could be reduced. This is the main concept of the
FMIP approach. In addition, a bidirectional tunnel between access routers can be used to support low
loss and low latency handover.
A.1.2 Proxy Mobile IP
MIPv6 requires client functionality in the IPv6 stack of a MN. Exchange of signalling messages between
MN and HA enables the creation and maintenance of a binding between the MN’s home address and its
care-of address. MIP requires the IP host to send IP mobility management signalling messages to the HA,
which is loca
...