Experimental Scenarios of ICN Integration in 4G Mobile Networks
draft-irtf-icnrg-icn-lte-4g-09

Document Type Active Internet-Draft (icnrg RG)
Authors Prakash Suthar  , Milan Stolic  , Anil Jangam  , Dirk Trossen 
Last updated 2021-02-22
Replaces draft-suthar-icnrg-icn-lte-4g
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ICN Research Group                                        Prakash Suthar
Internet-Draft                                               Google Inc.
Intended status: Informational                              Milan Stolic
Expires: August 26, 2021                                Anil Jangam, Ed.
                                                      Cisco Systems Inc.
                                                            Dirk Trossen
                                                     Huawei Technologies
                                                       February 22, 2021

    Experimental Scenarios of ICN Integration in 4G Mobile Networks
                     draft-irtf-icnrg-icn-lte-4g-09

Abstract

   4G mobile network uses IP-based transport for the control plane to
   establish the data session at the user plane for the actual data
   delivery.  In the existing architecture, IP-based unicast is used for
   the delivery of multimedia content to a mobile terminal, where each
   user is receiving a separate stream from the server.  From a
   bandwidth and routing perspective, this approach is inefficient.
   Evolved multimedia broadcast and multicast service (eMBMS) provides
   capabilities for delivering contents to multiple users
   simultaneously, but its deployment is very limited or at an
   experimental stage due to numerous challenges.  The focus of this
   draft is to list the options for use of Information centric
   technology (ICN) in 4G mobile networks and elaborate the experimental
   setups for its further evaluation.  The experimental setups discussed
   provide for using ICN either natively or with existing mobility
   protocol stack.  With further investigations based on the listed
   experiments, ICN with its inherent capabilities such as, network-
   layer multicast, anchorless mobility, security, and optimized data
   delivery using local caching at the edge may provide a viable
   alternative to IP transport in 4G mobile networks.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   Internet-Drafts are draft documents valid for a maximum of six months
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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on August 26, 2021.

Copyright Notice

   Copyright (c) 2021 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  3GPP Terminology and Concepts . . . . . . . . . . . . . . . .   3
   3.  4G Mobile Network Architecture  . . . . . . . . . . . . . . .   7
     3.1.  Network Overview  . . . . . . . . . . . . . . . . . . . .   7
     3.2.  Mobile Network Quality of Service . . . . . . . . . . . .   9
     3.3.  Data Transport Using IP . . . . . . . . . . . . . . . . .  10
     3.4.  Virtualized Mobile Networks . . . . . . . . . . . . . . .  10
   4.  Data Transport Using ICN  . . . . . . . . . . . . . . . . . .  11
   5.  Experimental Scenarios for ICN Deployment . . . . . . . . . .  13
     5.1.  General Considerations  . . . . . . . . . . . . . . . . .  13
     5.2.  Scenarios of ICN Integration  . . . . . . . . . . . . . .  14
     5.3.  Integration of ICN in 4G Control Plane  . . . . . . . . .  17
     5.4.  Integration of ICN in 4G User Plane . . . . . . . . . . .  19
       5.4.1.  Dual Transport (IP/ICN) Mode in Mobile Terminal . . .  19
       5.4.2.  Using ICN in Mobile Terminal  . . . . . . . . . . . .  23
       5.4.3.  Using ICN in eNodeB . . . . . . . . . . . . . . . . .  24
       5.4.4.  Using ICN in Packet Core (SGW, PGW) Gateways  . . . .  26
   6.  ICN Deployment Goals  . . . . . . . . . . . . . . . . . . . .  27
     6.1.  An Experimental Test Setup  . . . . . . . . . . . . . . .  28
     6.2.  Open Questions to be Addressed  . . . . . . . . . . . . .  29
   7.  Security and Privacy Considerations . . . . . . . . . . . . .  29
     7.1.  Security Considerations . . . . . . . . . . . . . . . . .  29
     7.2.  Privacy Considerations  . . . . . . . . . . . . . . . . .  30
   8.  Summary . . . . . . . . . . . . . . . . . . . . . . . . . . .  32
   9.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  33
   10. References  . . . . . . . . . . . . . . . . . . . . . . . . .  33

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     10.1.  Normative References . . . . . . . . . . . . . . . . . .  34
     10.2.  Informative References . . . . . . . . . . . . . . . . .  34
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  39

1.  Introduction

   4G mobile technology is built as an all-IP network using routing
   protocols (OSPF, ISIS, BGP, etc.) to establish network routes.
   Stickiness of an IP address to a device is the key to get connected
   to a mobile network.  The same IP address is maintained through the
   session until the device gets detached or moves to another network.

   Key protocols used in 4G networks are GPRS Tunneling protocol (GTP),
   DIAMETER, and other protocols that are built on top of IP.  One of
   the biggest challenges with IP-based routing in 4G is that it is not
   optimized for data transport.  As an alternative to IP routing, this
   draft presents and list the possible options for integration of
   Information Centric Networking (ICN) in 3GPP 4G mobile network,
   offering an opportunity to leverage inherent ICN capabilities such as
   in-network caching, multicast, anchorless mobility management, and
   authentication.  This draft also discuss how those options affect
   mobile providers and end users.

   The goal of the proposed experiments is to present possibilities to
   create simulated environments for evaluation of the benefits of ICN
   protocol deployment in a 4G mobile network in different scenarios
   that have been analyzed in this document.  The consensus of the
   Information-Centric Networking Research Group (ICNRG) is to publish
   this document in order to facilitate experiments to show deployment
   options and qualitative and quantitative benefits of ICN protocol
   deployment in 4G mobile networks.

2.  3GPP Terminology and Concepts

   1.   Access Point Name

        The Access Point Name (APN) is a Fully Qualified Domain Name
        (FQDN) and resolves to a set of gateways in an operator's
        network.  APN identifies the packet data network (PDN) with
        which a mobile data user wants to communicate.  In addition to
        identifying a PDN, an APN may also be used to define the type of
        service, QoS, and other logical entities inside GGSN, PGW.

   2.   Control Plane

        The control plane carries signaling traffic and is responsible
        for routing between eNodeB and MME, MME and HSS, MME and SGW,
        SGW and PGW, etc.  Control plane signaling is required to

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        authenticate and authorize the mobile terminal and establish a
        mobility session with mobile gateways (SGW/PGW).  Control plane
        functions also include system configuration and management.

   3.   Dual Address PDN/PDP Type

        The dual address Packet Data Network/Packet Data Protocol (PDN/
        PDP) Type (IPv4v6) is used in 3GPP context, in many cases as a
        synonym for dual stack; i.e., a connection type capable of
        serving IPv4 and IPv6 simultaneously.

   4.   eNodeB

        The eNodeB is a base station entity that supports the Long-Term
        Evolution (LTE) air interface.

   5.   Evolved Packet Core

        The Evolved Packet Core (EPC) is an evolution of the 3GPP GPRS
        system characterized by a higher-data-rate, lower-latency,
        packet-optimized system.  The EPC comprises some sub components
        of the EPS core such as Mobility Management Entity (MME),
        Serving Gateway (SGW), Packet Data Network Gateway (PDN-GW), and
        Home Subscriber Server (HSS).

   6.   Evolved Packet System

        The Evolved Packet System (EPS) is an evolution of the 3GPP GPRS
        system characterized by a higher-data-rate, lower-latency,
        packet-optimized system that supports multiple Radio Access
        Technologies (RATs).  The EPS comprises the EPC together with
        the Evolved Universal Terrestrial Radio Access (E-UTRA) and the
        Evolved Universal Terrestrial Radio Access Network (E-UTRAN).

   7.   Evolved UTRAN

        The E-UTRAN is a communications network sometimes referred to as
        4G, and consists of eNodeB (4G base stations).  The E-UTRAN
        allows connectivity between the User Equipment and the core
        network.

   8.   GPRS Tunneling Protocol

        The GPRS Tunneling Protocol (GTP) [TS29.060] [TS29.274]
        [TS29.281] is a tunneling protocol defined by 3GPP.  It is a
        network-based mobility protocol, working similar to Proxy Mobile
        IPv6 (PMIPv6).  However, GTP also provides functionality beyond

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        mobility, such as in-band signaling related to QoS and charging,
        among others.

   9.   Gateway GPRS Support Node

        The Gateway GPRS Support Node (GGSN) is a gateway function in
        the GPRS and 3G network that provides connectivity to the
        Internet or other PDNs.  The host attaches to a GGSN identified
        by an APN assigned to it by an operator.  The GGSN also serves
        as the topological anchor for addresses/prefixes assigned to the
        User Equipment.

   10.  General Packet Radio Service

        The General Packet Radio Service (GPRS) is a packet-oriented
        mobile data service available to users of the 2G and 3G cellular
        communication systems--the GSM--specified by 3GPP.

   11.  Home Subscriber Server

        The Home Subscriber Server (HSS) is a database for a given
        subscriber and was introduced in 3GPP Release-5.  It is the
        entity containing subscription-related information to support
        the network entities that handle calls/sessions.

   12.  Mobility Management Entity

        The Mobility Management Entity (MME) is a network element
        responsible for control plane functionalities, including
        authentication, authorization, bearer management, layer-2
        mobility, and so on.  The MME is essentially the control plane
        part of the SGSN in the GPRS.  The user plane traffic bypasses
        the MME.

   13.  Public Land Mobile Network

        The Public Land Mobile Network (PLMN) is a network operated by a
        single administration.  A PLMN (and, therefore, also an
        operator) is identified by the Mobile Country Code (MCC) and the
        Mobile Network Code (MNC).  Each (telecommunications) operator
        providing mobile services has its own PLMN.

   14.  Policy and Charging Control

        The Policy and Charging Control (PCC) framework is used for QoS
        policy and charging control.  It has two main functions: flow-
        based charging (including online credit control), and policy
        control (for example, gating control, QoS control, and QoS

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        signaling).  It is optional to 3GPP EPS but needed if dynamic
        policy and charging control by means of PCC rules based on user
        and services are desired.

   15.  Packet Data Network

        The Packet Data Network (PDN) is a packet-based network that
        either belongs to the operator or is an external network such as
        the Internet or a corporate intranet.  The user eventually
        accesses services in one or more PDNs.  The operator's packet
        core networks are separated from packet data networks either by
        GGSNs or PDN Gateways (PGWs).

   16.  Serving Gateway

        The Serving Gateway (SGW) is a gateway function in the EPS,
        which terminates the interface towards the E-UTRAN.  The SGW is
        the Mobility Anchor point for layer-2 mobility (inter-eNodeB
        handovers).  For each mobile terminal connected with the EPS,
        there is only one SGW at any given point in time.  The SGW is
        essentially the user plane part of the GPRS's SGSN.

   17.  Packet Data Network Gateway

        The Packet Data Network Gateway (PGW) is a gateway function in
        the Evolved Packet System (EPS), which provides connectivity to
        the Internet or other PDNs.  The host attaches to a PGW
        identified by an APN assigned to it by an operator.  The PGW
        also serves as the topological anchor for addresses/prefixes
        assigned to the User Equipment.

   18.  Packet Data Protocol Context

        A Packet Data Protocol (PDP) context is the equivalent of a
        virtual connection between the mobile terminal (MT) and a PDN
        using a specific gateway.

   19.  Packet Data Protocol Type

        A Packet Data Protocol Type (PDP Type) identifies the used/
        allowed protocols within the PDP context.  Examples are IPv4,
        IPv6, and IPv4v6 (dual-stack).

   20.  Serving GPRS Support Node

        The Serving GPRS Support Node (SGSN) is a network element
        located between the radio access network (RAN) and the gateway
        (GGSN).  A per-MT point-to-point (p2p) tunnel between the GGSN

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        and SGSN transports the packets between the mobile terminal and
        the gateway.

   21.  Mobile Terminal/User Equipment

        The terms User Equipment (UE), Mobile Station (MS), Mobile Node
        (MN), and mobile refer to the devices that are hosts with the
        ability to obtain Internet connectivity via a 3GPP network.  An
        MS comprises the Terminal Equipment (TE) and a Mobile Terminal
        (MT).  The terms MT, MS, MN, and mobile are used interchangeably
        within this document.

   22.  User Plane

        The user plane refers to data traffic and the required bearers
        for the data traffic.  In practice, IP is the only data traffic
        protocol used in the user plane.

3.  4G Mobile Network Architecture

   This section provide a high-level overview of typical 4G mobile
   network architecture and their key functions related to a possibility
   of using of ICN technology.

3.1.  Network Overview

   4G mobile networks are designed to use IP transport for communication
   among different elements such as eNodeB, MME, SGW/PGW, HSS, PCRF, etc
   [GRAYSON].  For backward compatibility with 3G, it has support for
   legacy Circuit Switch features such as voice and SMS through
   transitional CS fallback and flexible IMS deployment.  For each
   mobile device attached to the radio (eNodeB), there is a separate
   overlay tunnel (GPRS Tunneling Protocol, GTP) between eNodeB and
   Mobile gateways (i.e., SGW, PGW).

   When any mobile terminal is powered up, it attaches to a mobile
   network based on its configuration and subscription.  After a
   successful attachment procedure, the mobile terminal registers with
   the mobile core network using IPv4 and/or IPv6 address based on
   request and capabilities offered by mobile gateways.

   The GTP tunnel is used to carry user traffic between gateways and
   mobile terminal, therefore using the unicast delivery for any data
   transfer.  It is also important to understand the overhead of GTP and
   IPSec protocols.  All mobile backhaul traffic is encapsulated using a
   GTP tunnel, which has overhead of 8 bytes on top of IP and UDP
   [NGMN].  Additionally, if IPSec is used for security (which is often
   required if the Service Provider is using a shared backhaul), it adds

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   overhead based on the IPSec tunneling model (tunnel or transport) as
   well as the encryption and authentication header algorithm used.  If
   we consider as an example an Advanced Encryption Standard (AES)
   encryption, the overhead can be significant [OLTEANU], particularly
   for smaller payloads.

                                          +-------+  Diameter  +-------+
                                          |  HSS  |------------|  SPR  |
                                          +-------+            +-------+
                                              |                    |
           +------+   +------+      S4        |                +-------+
           |  3G  |---| SGSN |----------------|------+  +------| PCRF  |
        ^  |NodeB |   |      |---------+  +---+      |  |      +-------+
   +-+  |  +------+   +------+   S3    |  |  S6a     |  |Gxc       |
   | |  |                          +-------+         |  |          |Gx
   +-+  |       +------------------|  MME  |------+  |  |          |
   MT   v       |       S1MME      +-------+  S11 |  |  |          |
          +----+-+                              +-------+     +-------+
          |4G/LTE|------------------------------|  SGW  |-----|  PGW  |
          |eNodeB|            S1U               +-------+  +--|       |
          +------+                                         |  +-------+
                                     +---------------------+    |  |
    S1U GTP Tunnel traffic           |          +-------+       |  |
    S2a GRE Tunnel traffic           |S2A       | ePDG  |-------+  |
    S2b GRE Tunnel traffic           |          +-------+  S2B     |SGi
    SGi IP traffic                   |              |              |
                                +---------+   +---------+       +-----+
                                | Trusted |   |Untrusted|       | CDN |
                                |non-3GPP |   |non-3GPP |       +-----+
                                +---------+   +---------+
                                     |             |
                                    +-+           +-+
                                    | |           | |
                                    +-+           +-+
                                    MT            MT

                   Figure 1: 4G Mobile Network Overview

   If we consider the combined impact of GTP, IPSec and unicast traffic,
   the data delivery is not efficient because of overhead.  The IETF has
   developed various header compression algorithms to reduce the
   overhead associated with IP packets.  Some techniques are robust
   header compression (ROHC) and enhanced compression of the real-time
   transport protocol (ECRTP) so that the impact of overhead created by
   GTP, IPsec, etc., is reduced to some extent [BROWER].  For commercial
   mobile networks, 3GPP has adopted different mechanisms for header
   compression to achieve efficiency in data delivery [TS25.323]; those

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   solutions can be adapted to other data protocols, such as ICN, too
   [ICNLOWPAN] [TLVCOMP].

3.2.  Mobile Network Quality of Service

   During the mobile terminal attachment procedure, a default bearer is
   created for each mobile terminal and it is assigned to the default
   Access Point Name (APN), which provides the default transport.  For
   any QoS-aware application, one or more new dedicated bearers are
   established between eNodeB and Mobile Gateway.  Dedicated bearer can
   be requested either by mobile terminal or mobile gateway based on
   direction of first data flow.  There are many bearers (logical paths)
   established between eNodeB and mobile gateway for each mobile
   terminal catering to different data flow simultaneously.

   While all traffic within a certain bearer receives the same
   treatment, QoS parameters supporting these requirements can be very
   granular in different bearers.  These values vary for the control,
   management and user traffic, and can be very different depending on
   application key parameters such as latency, jitter (important for
   voice and other real-time applications), packet loss, and queuing
   mechanism (strict priority, low-latency, fair, and so on).

   Implementation of QoS for mobile networks is done at two stages: at
   content prioritization/marking and transport marking, and congestion
   management.  From the transport perspective, QoS is defined at layer
   2 as class of service (CoS) and at layer 3 as Differentiated Services
   (DS).  The mapping of DSCP to CoS takes place at layer 2/3 switching
   and routing elements. 3GPP has a specified a QoS Class Identifier
   (QCI), which represents different types of content and equivalent
   mappings to the DSCP at transport layer [TS23.401].  However, this
   requires manual configuration at different elements and is therefore
   prone to possible misconfigurations.

   In summary, QoS configuration in mobile networks for user plane
   traffic requires synchronization of parameters among different
   platforms.  Normally, QoS in IP is implemented using DiffServ, which
   uses hop-by-hop QoS configuration at each router.  Any inconsistency
   in IP QoS configuration at routers in the forwarding path can result
   in a poor subscriber experience (e.g., packet classified as high
   priority can go to a lower priority queue).  By deploying ICN, we
   intend to enhance the subscriber experience using policy-based
   configuration, which can be associated with the named contents
   [ICNQoS] at the ICN forwarder.  Further investigation is underway to
   understand how QoS in ICN [I-D.anilj-icnrg-dnc-qos-icn] can be
   implemented with reference to the ICN QoS guidelines
   [I-D.oran-icnrg-qosarch] to meet the QoS requirements [RFC4594].

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3.3.  Data Transport Using IP

   The data delivered to mobile devices is sent in unicast semantic
   inside the GTP tunnel from an eNodeB to a PDN gateway (PGW), as
   described in 3GPP specifications [TS23.401].  While the technology
   exists to address the issue of possible multicast delivery, there are
   many difficulties related to multicast protocol implementations on
   the RAN side of the network.  By using eMBMS [EMBMS], multicast
   routing can be enabled in mobile backhaul between eNodeB and Mobile
   Gateways (SGW) however for radio interface it requires broadcast
   which implies that we need dedicated radio channel.  Implementation
   of eMBMS in RAN is still lagging behind due to complexities related
   to client mobility, handovers, and the fact that the potential gain
   to Service Providers may not justify the investment, which explains
   the prevalence of unicast delivery in mobile networks.  Techniques to
   handle multicast (such as LTE-B or eMBMS) have been designed to
   handle pre-planned content delivery, such as live content, which
   contrasts user behavior today, largely based on content (or video) on
   demand model.

   To ease the burden on the bandwidth of the SGi interface, caching is
   introduced in a similar manner as with many Enterprises.  In mobile
   networks, whenever possible, cached data is delivered.  Caching
   servers are placed at a centralized location, typically in the
   Service Provider's Data Center, or in some cases lightly distributed
   in Packet Core locations with the PGW nodes close to the Internet and
   IP services access (SGi interface).  This is a very inefficient
   concept because traffic must traverse the entire backhaul path for
   the data to be delivered to the end user.  Other issues, such as out-
   of-order delivery, contribute to this complexity and inefficiency,
   which needs to be addressed at the application level.

3.4.  Virtualized Mobile Networks

   The Mobile gateways deployed in a major Service Provider network are
   either based on dedicated hardware or, commercially off the shelf
   (COTS) based x86 technology.  With the adoption of Mobile Virtual
   Network Operators (MVNO), public safety networks, and enterprise
   mobility networks, elastic mobile core architecture are needed.  By
   deploying the mobile packet core on COTS platform, using a
   virtualized infrastructure (NFVI) framework and end-to-end
   orchestration, new deployments can be simplified to provide optimized
   total cost of ownership (TCO).

   While virtualization is growing, and many mobile providers use a
   hybrid architecture that consists of dedicated and virtualized
   infrastructures, the control and data planes are still the same.
   There is also work under way to separate the control and user plane

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   for the network to scale better.  Virtualized mobile networks and
   network slicing with control and user plane separation provide a
   mechanism to evolve the GTP-based architecture towards an Openflow
   SDN-based signaling for 4G and proposed 5G core.  Some early
   architecture work for 5G mobile technologies provides a mechanism for
   control and user plane separation and simplifies the mobility call
   flow by introducing Openflow-based signaling [ICN5G].  This has been
   considered by 3GPP [EPCCUPS] and is also described in [SDN5G].

4.  Data Transport Using ICN

   For mobile devices, the edge connectivity is between mobile terminal
   and a router or mobile edge computing (MEC) [MECSPEC] element.  Edge
   computing has the capability of processing client requests and
   segregating control and user traffic at the edge of radio, rather
   than sending all requests to the mobile gateway.

             +----------+
             | Content  +----------------------------------------+
             | Publisher|                                        |
             +---+---+--+                                        |
                 |   |    +--+             +--+           +--+   |
                 |   +--->|R1|------------>|R2|---------->|R4|   |
                 |        +--+             +--+           +--+   |
                 |                           |   Cached          |
                 |                           v   content         |
                 |                         +--+  at R3           |
                 |                +========|R3|---+              |
                 |                #        +--+   |              |
                 |                #               |              |
                 |                v               v              |
                 |               +-+             +-+             |
                 +---------------| |-------------| |-------------+
                                 +-+             +-+
                              Consumer-1      Consumer-2
                           Mobile Terminal  Mobile Terminal

                         ===> Content flow from cache
                         ---> Content flow from publisher

                        Figure 2: ICN Architecture

   Edge computing transforms radio access network into an intelligent
   service edge capable of delivering services directly from the edge of
   the network, while providing the best possible performance to the
   client.  Edge computing can be an ideal candidate for implementing
   ICN forwarders in addition to its usual function of managing mobile

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   termination.  In addition to edge computing, other transport
   elements, such as routers, can work as ICN forwarders.

   Data transport using ICN is different to IP-based transport by
   introducing uniquely named-data as a core design principle.
   Communication in ICN takes place between the content provider
   (producer) and the end user (consumer), as described in Figure 2.

   Every node in a physical path between a client and a content provider
   is called the ICN forwarder or router.  It can route the request
   intelligently and cache content so it can be delivered locally for
   subsequent requests from any other client.  For mobile networks,
   transport between a client and a content provider consists of radio
   network + mobile backhaul and IP core transport + Mobile Gateways +
   Internet + content data network (CDN).

   To understand the suitability of ICN for mobile networks, we will
   discuss the ICN framework by describing its protocols architecture
   and different types of messages to then consider how we can use this
   in mobile networks for delivering content more efficiently.  ICN uses
   two types of packets called "interest packet" and "data packet" as
   described in Figure 3.

                  +------------------------------------+
         Interest | +------+     +------+     +------+ |        +-----+
    +-+        ---->|  CS  |---->| PIT  |---->| FIB  |--------->| CDN |
    | |           | +------+     +------+     +------+ |        +-----+
    +-+           |     |      Add  |       Drop |     | Forward
    MT         <--------+      Intf v       Nack v     |
            Data  |                                    |
                  +------------------------------------+

                  +------------------------------------+
    +-+           |  Forward                  +------+ |        +-----+
    | | <-------------------------------------| PIT  |<---------| CDN |
    +-+           |                 | Cache   +--+---+ | Data   +-----+
    MT            |              +--v---+        |     |
                  |              |  CS  |        v     |
                  |              +------+      Discard |
                  +------------------------------------+

             Figure 3: ICN Interest, Data Packet and Forwarder

   In an 4G network, when a mobile device wants to receive certain
   content, it will send an Interest message to the closest eNodeB.

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   Interest packets follow the TLV format [RFC8609] and contain
   mandatory fields, such as name of the content and content matching
   restrictions (KeyIdRestr and ContentObjectHashRestr), expressed as a
   tuple [RFC8569].  The content matching tuple uniquely identifies the
   matching data packet for the given Interest packet.  Another
   attribute called HopLimit is used to detect looping Interest
   messages.

   An ICN router will receive an Interest packet and lookup if a request
   for such content has arrived earlier from another client.  If so, it
   may be served from the local cache; otherwise, the request is
   forwarded to the next-hop ICN router.  Each ICN router maintains
   three data structures: Pending Interest Table (PIT), Forwarding
   Information Base (FIB), and Content Store (CS).  The Interest packet
   travels hop-by-hop towards the content provider.  Once the Interest
   packet reaches the content provider, it will return a Data packet
   containing information such as content name, signature, and the
   actual data.

   The data packet travels in reverse direction following the same path
   taken by the Interest packet, maintaining routing symmetry.  Details
   about algorithms used in PIT, FIB, CS, and security trust models are
   described in various resources [CCN]; here, we have explained the
   concept and its applicability to the 4G network.

5.  Experimental Scenarios for ICN Deployment

   In 4G mobile networks, both user and control plane traffic have to be
   transported from the edge to the mobile packet core via IP transport.
   The evolution of the existing mobile packet core using Control and
   User Plane Separation (CUPS) [TS23.714] enables flexible network and
   operations by distributed deployment and the independent scaling of
   control plane and user plane functions - while not affecting the
   functionality of existing nodes subject to this split.

   In this section, we analyze the potential impact of ICN on control
   and user plane traffic for centralized and disaggregated CUPS-based
   mobile network architecture.  We list various experimental options
   and opportunities to study the feasibility of the deployment of ICN
   in 4G networks.  The proposed experiments would help the network and
   OEM designers to understand various issues, optimizations, and
   advantages of deployment of ICN in 4G networks.

5.1.  General Considerations

   In the CUPS architecture, there is an opportunity to shorten the path
   for user plane traffic by deploying offload nodes closer to the edge
   [OFFLOAD].  With this major architecture change, a User Plane

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   Function (UPF) node is placed close to the edge so traffic no longer
   needs to traverse the entire backhaul path to reach the EPC.  In many
   cases, where feasible, the UPF can be collocated with the eNodeB,
   which is also a business decision based on user demand.  Placing a
   Publisher close to the offload site, or at the offload site, provides
   for a significant improvement in user experience, especially with
   latency-sensitive applications.  This capability allows for the
   introduction of ICN and amplifies its advantages.

5.2.  Scenarios of ICN Integration

   The integration of ICN provides an opportunity to further optimize
   the existing data transport in 4G mobile networks.  The various
   opportunities from the coexistence of ICN and IP transport in the
   mobile network are somewhat analogous to the deployment scenarios
   when IPv6 was introduced to interoperate with IPv4 except, with ICN,
   the whole IP stack can be replaced.  We have reviewed [RFC6459] and
   analyzed the impact of ICN on control plane signaling and user plane
   data delivery.  In general, ICN can be used natively by replacing IP
   transport (IPv4 and IPv6) or as an overlay protocol.  Figure 4
   describes a proposal to modify the existing transport protocol stack
   to support ICN in 4G mobile network.

                   +----------------+ +-----------------+
                   | ICN App (new)  | |IP App (existing)|
                   +---------+------+ +-------+---------+
                             |                |
                   +---------+----------------+---------+
                   | Transport Convergence Layer (new)  |
                   +------+---------------------+-------+
                          |                     |
                   +------+------+       +------+-------+
                   |ICN function |       | IP function  |
                   |   (New)     |       | (Existing)   |
                   +------+------+       +------+-------+
                          |                     |
                        (```).                (```).
                      (  ICN  '`.           (  IP   '`.
                      ( Cloud   )           ( Cloud   )
                       ` __..'+'             ` __..'+'

                  Figure 4: IP/ICN Convergence Scenarios

   As shown in Figure 4, for applications - running either in the mobile
   terminal or in the content provider system - to use the ICN transport
   option, we propose a new transport convergence layer (TCL).  The TCL
   helps determine the type of transport (such as ICN or IP), as well as

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   the type of radio interface (LTE or WiFi or both) used to send and
   receive traffic based on preference (e.g., content location, content
   type, content publisher, congestion, cost, QoS).  It helps configure
   and determine the type of connection (native IP or ICN) or the
   overlay mode (ICNoIP or IPoICN) between application and the protocol
   stack (IP or ICN).

   Combined with the existing IP function, the ICN function provides
   support for either native ICN and/or the dual transport (ICN/IP)
   transport functionality.  See Section 5.4.1 for elaborate
   descriptions of these functional layers.

   The TCL can use several mechanisms for transport selection.  It can
   use a per-application configuration through a management interface,
   possibly a user-facing setting realized through a user interface,
   like those used to select cellular over WiFi.  In another option, it
   might use a software API, which an adapted IP application could use
   to specify the type of transport option (such as ICN) to take
   advantage of its benefits.

   Another potential application of TCL is in implementation of network
   slicing, with a slice management capability locally or through an
   interface to an external slice manager via an API [GALIS].  This
   solution can enable network slicing for IP and ICN transport
   selection from the mobile terminal itself.  The TCL could apply slice
   settings to direct certain applications traffic over one slice and
   others over another slice, determined by some form of 'slicing
   policy'.  Slicing policy can be obtained externally from the slice
   manager or configured locally on the mobile terminal.

   From the perspective of applications either on the mobile terminal or
   at a content provider, the following options are possible for
   potential use of ICN natively and/or with IP.

   1.  IP over IP

       In this scenario, the mobile terminal applications are tightly
       integrated with the existing IP transport infrastructure.  The
       TCL has no additional function because packets are forwarded
       directly using an IP protocol stack, which sends packets over the
       IP transport.

   2.  ICN over ICN

       Similar to case 1, ICN applications tightly integrate with the
       ICN transport infrastructure.  The TCL has no additional
       responsibility because packets are forwarded directly using the

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       native ICN protocol stack, which sends packets over the ICN
       transport.

   3.  ICN over IP (ICNoIP)

       In this scenario, the underlying IP transport infrastructure is
       not impacted (that is, ICN is implemented as an IP overlay
       between mobile terminal and content provider).  IP routing is
       used from the Radio Access Network (eNodeB) to the mobile
       backhaul, the IP core, and the Mobile Gateway (SGW/PGW).  The
       mobile terminal attaches to the Mobile Gateway (SGW/PGW) using an
       IP address.  Also, the data transport between Mobile Gateway
       (SGW/PGW) and content publisher uses IP.  The content provider
       can serve content either using IP or ICN, based on the mobile
       terminal request.

       One of the approaches to implement ICN in mobile backhaul
       networks is described in [MBICN].  It implements a GTP-U
       extension header option to encapsulate ICN payload in a GTP
       tunnel.  However, as this design runs ICN as an IP overlay, the
       mobile backhaul can be deployed using native IP.  The proposal
       describes a mechanism where the GTP-U tunnel can be terminated by
       hairpinning the packet before it reaches SGW, if an ICN-enabled
       node is deployed in the mobile backhaul (that is, between eNodeB
       and SGW).  This could be useful when an ICN data packet is stored
       in the ICN node (such as repositories, caches) in the tunnel path
       so that the ICN node can reply without going all the way through
       the mobile core.  While a GTP-U extension header is used to carry
       mobile terminal specific ICN payload, they are not visible to the
       transport, including SGW.  On the other hand, the PGW can use the
       mobile terminal-specific ICN header extension and ICN payload to
       set up an uplink transport towards a content provider in the
       Internet.  In addition, the design assumes a proxy function at
       the edge, to perform ICN data retrieval on behalf of a non-ICN
       end device.

   4.  IP over ICN (IPoICN)

       [IPoICN] provides an architectural framework for running IP as an
       overlay over ICN protocol.  Implementing IP services over ICN
       provides an opportunity to leverage the benefits of ICN in the
       transport infrastructure while there is no impact on end devices
       (MT and access network) as they continue to use IP.  IPoICN
       however, will require an inter-working function (IWF/Border
       Gateway) to translate various transport primitives.  The IWF
       function will provide a mechanism for protocol translation
       between IPoICN and the native IP.  After reviewing [IPoICN], we
       understand and interpret that ICN is implemented in the transport

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       natively; however, IP is implemented in MT, eNodeB, and Mobile
       gateway (SGW/PGW), which is also called as a network attach point
       (NAP).

       For this, said NAP receives an incoming IP or HTTP packet (the
       latter through TCP connection termination) and publishes the
       packet under a suitable ICN name (i.e., the hash over the
       destination IP address for an IP packet or the hash over the FQDN
       of the HTTP request for an HTTP packet) to the ICN network.  In
       the HTTP case, the NAP maintains a pending request mapping table
       to map returning responses to the terminated TCP connection.

   5.  Hybrid ICN (hICN)

       An alternative approach to implement ICN over IP is provided in
       Hybrid ICN [HICN].  It describes a novel approach to integrate
       ICN into IPv6 without creating overlays with a new packet format
       as an encapsulation. hICN addresses the content by encoding a
       location-independent name in an IPv6 address.  It uses two name
       components--name prefix and name suffix--that identify the source
       of data and the data segment within the scope of the name prefix,
       respectively.

       At application layer, hICN maps the name into an IPv6 prefix and,
       thus, uses IP as transport.  As long as the name prefixes, which
       are routable IP prefixes, point towards a mobile GW (PGW or local
       breakout, such as CUPS), there are potentially no updates
       required to any of the mobile core gateways (for example, SGW/
       PGW).  The IPv6 backhaul routes the packets within the mobile
       core. hICN can run in the mobile terminal, in the eNodeB, in the
       mobile backhaul, or in the mobile core.  Finally, as hICN itself
       uses IPv6, it cannot be considered as an alternative transport
       layer.

5.3.  Integration of ICN in 4G Control Plane

   In this section, we analyze signaling messages that are required for
   different procedures, such as attach, handover, tracking area update,
   and so on.  The goal of this analysis is to see if there are any
   benefits to replacing IP-based protocols with ICN for 4G signaling in
   the current architecture.  It is important to understand the concept
   of point of attachment (POA).  When mobile terminal connects to a
   network, it has the following POAs:

   1.  eNodeB managing location or physical POA

   2.  Authentication and Authorization (MME, HSS) managing identity or
       authentication POA

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   3.  Mobile Gateways (SGW, PGW) managing logical or session management
       POA

   In the current architecture, IP transport is used for all messages
   associated with the control plane for mobility and session
   management.  IP is embedded very deeply into these messages utilizing
   TLV syntax for carrying additional attributes such as a layer 3
   transport.  The physical POA in the eNodeB handles both mobility and
   session management for any mobile terminal attached to 4G network.
   The number of mobility management messages between different nodes in
   an 4G network per signaling procedure is shown in Table 1.

   Normally, two types of mobile terminals attach to the 4G network: SIM
   based (need 3GPP mobility protocol for authentication) or non-SIM
   based (which connect to WiFi network).  Both device types require
   authentication.  For non-SIM based devices, AAA is used for
   authentication.  We do not propose to change mobile terminal
   authentication or mobility management messaging for user data
   transport using ICN.  A separate study would be required to analyze
   the impact of ICN on mobility management messages structures and
   flows.  We are merely analyzing the viability of implementing ICN as
   a transport for control plane messages.

   It is important to note that, if MME and HSS do not support ICN
   transport, they still need to support mobile terminal capable of dual
   transport or native ICN.  When mobile terminal initiates an attach
   request using the identity as ICN, MME must be able to parse that
   message and create a session.  MME forwards mobile terminal
   authentication to HSS, so HSS must be able to authenticate an ICN-
   capable mobile terminal and authorize create session [TS23.401].

       +---------------------------+-----+-----+-----+-----+------+
       | 4G Signaling Procedures   | MME | HSS | SGW | PGW | PCRF |
       +---------------------------+-----+-----+-----+-----+------+
       | Attach                    |  10 |   2 |   3 |   2 |    1 |
       | Additional default bearer |   4 |   0 |   3 |   2 |    1 |
       | Dedicated bearer          |   2 |   0 |   2 |   2 |    0 |
       | Idle-to-connect           |   3 |   0 |   1 |   0 |    0 |
       | Connect-to-Idle           |   3 |   0 |   1 |   0 |    0 |
       | X2 handover               |   2 |   0 |   1 |   0 |    0 |
       | S1 handover               |   8 |   0 |   3 |   0 |    0 |
       | Tracking area update      |   2 |   2 |   0 |   0 |    0 |
       | Total                     |  34 |   2 |  14 |   6 |    3 |
       +---------------------------+-----+-----+-----+-----+------+

                Table 1: Signaling Messages in 4G Gateways

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   Anchorless mobility [ALM] provides a fully decentralized, control-
   plane agnostic solution to handle producer mobility in ICN.  Mobility
   management at layer-3 level makes it access agnostic and transparent
   to the end device or the application.  The solution discusses
   handling mobility without having to depend on core network functions
   (e.g.  MME); however, a location update to the core network may still
   be required to support legal compliance requirements such as lawful
   intercept and emergency services.  These aspects are open for further
   study.

   One of the advantages of ICN is in the caching and reusing of the
   content, which does not apply to the transactional signaling
   exchange.  After analyzing 4G signaling call flows [TS23.401] and
   messages inter-dependencies (see Table 1), our recommendation is that
   it is not beneficial to use ICN for control plane and mobility
   management functions.  Among the features of ICN design, Interest
   aggregation and content caching are not applicable to control plane
   signaling messages.  Control plane messages are originated and
   consumed by the applications and they cannot be shared.

5.4.  Integration of ICN in 4G User Plane

   We will consider Figure 1 to discuss different mechanisms to
   integrate ICN in mobile networks.  In Section 5.2, we discussed
   generic experimental setups of ICN integration.  In this section, we
   discuss the specific options of possible use of native ICN in 4G user
   plane.  We consider the following options:

   1.  Dual transport (IP/ICN) mode in Mobile Terminal

   2.  Using ICN in Mobile Terminal

   3.  Using ICN in eNodeB

   4.  Using ICN in mobile gateways (SGW/PGW)

5.4.1.  Dual Transport (IP/ICN) Mode in Mobile Terminal

   The control and user plane communications in 4G mobile networks are
   specified in 3GPP documents [TS23.203] and [TS23.401].  It is
   important to understand that mobile terminal can be either consumer
   (receiving content) or publisher (pushing content for other clients).
   The protocol stack inside the mobile terminal (MT) is complex because
   it must support multiple radio connectivity access to eNodeB(s).

   Figure 5 provides a high-level description of a protocol stack, where
   IP is used at two layers: (1) user plane communication and (2) UDP
   encapsulation.  User plane communication takes place between Packet

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   Data Convergence Protocol (PDCP) and Application layer, whereas UDP
   encapsulation is at GTP protocol stack.

   The protocol interactions and impact of supporting tunneling of ICN
   packet into IP or to support ICN natively are described in Figure 5
   and Figure 6, respectively.

    +--------+                                               +--------+
    |   App  |                                               |  CDN   |
    +--------+                                               +--------+
    |Transp. | |              |               |              |Transp. |
    |Converg.|.|..............|...............|............|.|Converge|
    +--------+ |              |               | +--------+ | +--------+
    |        |.|..............|...............|.|        |.|.|        |
    | ICN/IP | |              |               | | ICN/IP | | |  ICN/IP|
    |        | |              |               | |        | | |        |
    +--------+ | +----+-----+ | +-----+-----+ | +-----+--+ | +--------+
    |        |.|.|    |     |.|.|     |     |.|.|     |  | | |        |
    |  PDCP  | | |PDCP|GTP-U| | |GTP-U|GTP-U| | |GTP-U|  | | |   L2   |
    +--------+ | +----------+ | +-----------+ | +-----+  | | |        |
    |   RLC  |.|.|RLC | UDP |.|.| UDP | UDP |.|.|UDP  |L2|.|.|        |
    +--------+ | +----------+ | +-----------+ | +-----+  | | |        |
    |   MAC  |.|.| MAC|  L2 |.|.| L2  | L2  |.|.|  L2 |  | | |        |
    +--------+ | +----------+ | +-----------+ | +--------+ | +--------+
    |   L1   |.|.| L1 |  L1 |.|.| L1  | L1  |.|.|  L1 |L1|.|.|   L1   |
    +--------+ | +----+-----+ | +-----+-----+ | +-----+--+ | +--------+
        MT     |  BS(eNodeB)  |      SGW      |     PGW    |
              Uu             S1U            S5/S8         SGi

         Figure 5: Dual Transport (IP/ICN) mode in Mobile Terminal

   The protocols and software stack used inside 4G capable mobile
   terminal support both 3G and 4G software interworking and handover.
   3GPP Rel.13 onward specifications describe the use of IP and non-IP
   protocols to establish logical/session connectivity.  We can leverage
   the non-IP protocol-based mechanism to deploy ICN protocol stack in
   the mobile terminal, as well as in eNodeB and mobile gateways (SGW,
   PGW).  The following paragraphs describe per-layer considerations of
   supporting tunneling of ICN packet into IP or to support ICN
   natively.

   1.  An existing application layer can be modified to provide options
       for a new ICN-based application and existing IP-based
       applications.  The mobile terminal can continue to support
       existing IP-based applications or can develop new applications to
       support native ICN, ICNoIP, or IPoICN-based transport.  The
       application layer can be provided with an option of selecting

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       either ICN or IP transport, as well as radio interface, to send
       and receive data traffic.

       Our proposal is to provide an Application Programming Interface
       (API) to the application developers so they can choose either ICN
       or IP transport for exchanging the traffic with the network.  As
       mentioned in Section 5.2, the transport convergence layer (TCL)
       function handles the interaction of applications with multiple
       transport options.

   2.  The transport convergence layer helps determine the type of
       transport (such as ICN, hICN, or IP) and type of radio interface
       (LTE or WiFi, or both) used to send and receive traffic.
       Application layer can make the decision to select a specific
       transport based on preference, such as content location, content
       type, content publisher, congestion, cost, QoS, and so on.  There
       can be an Application Programming Interface (API) to exchange
       parameters required for transport selection.  Southbound
       interactions of Transport Convergence Layer (TCL) will be either
       to IP or ICN at the network layer.

       When selecting the IPoICN mode, the TCL is responsible for
       receiving an incoming IP or HTTP packet and publishing the packet
       to the ICN network under a suitable ICN name (that is, the hash
       over the destination IP address for an IP packet, or the hash
       over the FQDN of the HTTP request for an HTTP packet).

       In the HTTP case, the TCL can maintain a pending request mapping
       table to map returning responses to the originating HTTP request.
       The common API will provide a 'connection' abstraction for this
       HTTP mode of operation, returning the response over said
       connection abstraction, akin to the TCP socket interface, while
       implementing a reliable transport connection semantic over the
       ICN from the mobile terminal to the receiving mobile terminal or
       the PGW.  If the HTTP protocol stack remains unchanged, therefore
       utilizing the TCP protocol for transfer, the TCL operates in
       local TCP termination mode, retrieving the HTTP packet through
       said local termination.

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                  +----------------+ +-----------------+
                  | ICN App (new)  | |IP App (existing)|
                  +---------+------+ +-------+---------+
                            |                |
                  +---------+----------------+---------+
                  | Transport Convergence Layer (new)  |
                  +------+---------------------+-------+
                         |                     |
                  +------+------+       +------+-------+
                  |ICN function |       | IP function  |
                  |   (New)     |       | (Existing)   |
                  +------+------+       +------+-------+
                         |                     |
                  +------+---------------------+-------+
                  | PDCP (updated to support ICN)      |
                  +-----------------+------------------+
                                    |
                  +-----------------+------------------+
                  |          RLC (Existing)            |
                  +-----------------+------------------+
                                    |
                  +-----------------+------------------+
                  |        MAC Layer (Existing)        |
                  +-----------------+------------------+
                                    |
                  +-----------------+------------------+
                  |       Physical L1 (Existing)       |
                  +------------------------------------+

              Figure 6: Dual Stack ICN Protocol Interactions

   3.  The ICN function (forwarder) is proposed to run in parallel to
       the existing IP layer.  The ICN forwarder forwards the ICN
       packets, such as an Interest packet to eNodeB or a response "data
       packet" from eNodeB to the application.

   4.  For the dual-transport scenario, when mobile terminal is not
       supporting ICN as transport, the TCL can use the IP underlay to
       tunnel the ICN packets.  The ICN function can use the IP
       interface to send Interest and Data packets for fetching or
       sending data respectively.  This interface can use the ICN
       overlay over IP.

   5.  To support ICN at network layer in mobile terminal, the PDCP
       layer should be aware of ICN capabilities and parameters.  PDCP
       is located in the Radio Protocol Stack in the LTE Air interface,

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       between IP (Network layer) and Radio Link Control Layer (RLC).
       PDCP performs the following functions [TS36.323]:

       1.  Data transport by listening to upper layer, formatting and
           pushing down to Radio Link Layer (RLC)

       2.  Header compression and decompression using Robust Header
           Compression (ROHC)

       3.  Security protections such as ciphering, deciphering, and
           integrity protection

       4.  Radio layer messages associated with sequencing, packet drop
           detection and re-transmission, and so on.

   6.  No changes are required for lower layer such as RLC, MAC, and
       Physical (L1) as they are not IP aware.

   One key point to understand in this scenario is that ICN is deployed
   as an overlay on top of IP.

5.4.2.  Using ICN in Mobile Terminal

   We can implement ICN natively in mobile terminal by modifying the
   PDCP layer in 3GPP protocols.  Figure 7 provides a high-level
   protocol stack description where ICN can be used at the following
   different layers:

   1.  User plane communication

   2.  Transport layer

   ICN transport would be a substitute of the GTP protocol.  The removal
   of the GTP protocol stack is a significant change in the mobile
   architecture and requires a through study mainly because it is used
   not just for routing but for mobility management functions, such as
   billing, mediation, and policy enforcement.

   The implemention of ICN natively in the mobile terminal leads to a
   changed communication model between mobile terminal and eNodeB.
   Also, we can avoid tunneling the user plane traffic from eNodeB to
   the mobile packet core (SGW, PGW) through a GTP tunnel.

   For native ICN use, an application can be configured to use ICN
   forwarder and it does not need the TCL layer.  Also, to support ICN
   at the network layer, the existing PDCP layer may need to be changed
   to be aware of ICN capabilities and parameters.

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   The native implementation can provide new opportunities to develop
   new use cases leveraging ICN capabilities, such as seamless mobility,
   mobile terminal to mobile terminal content delivery using radio
   network without traversing the mobile gateways, and more.

   +--------+                                                +--------+
   |  App   |                                                |   CDN  |
   +--------+                                                +--------+
   |Transp. | |              |              |              | |Transp. |
   |Converge|.|..............|..............|..............|.|Converge|
   +--------+ |              |              |              | +--------+
   |        |.|..............|..............|..............|.|        |
   | ICN/IP | |              |              |              | |        |
   |        | |              |              |              | |        |
   +--------+ | +----+-----+ | +----------+ | +----------+ | | ICN/IP |
   |        |.|.|    |     | | |          | | |          | | |        |
   |  PDCP  | | |PDCP| ICN |.|.|    ICN   |.|.|    ICN   |.|.|        |
   +--------+ | +----+     | | |          | | |          | | |        |
   |   RLC  |.|.|RLC |     | | |          | | |          | | |        |
   +--------+ | +----------+ | +----------+ | +----------+ | +--------+
   |   MAC  |.|.| MAC|  L2 |.|.|     L2   |.|.|    L2    |.|.|    L2  |
   +--------+ | +----------+ | +----------+ | +----------+ | +--------+
   |   L1   |.|.| L1 |  L1 |.|.|     L1   |.|.|    L1    |.|.|    L1  |
   +--------+ | +----+-----+ | +----------+ | +----------+ | +--------+
       MT     |  BS(eNodeB)  |      SGW     |      PGW     |
              Uu            S1u           S5/S8           SGi

               Figure 7: Using Native ICN in Mobile Terminal

5.4.3.  Using ICN in eNodeB

   The eNodeB is a physical point of attachment for the mobile terminal,
   where radio protocols are converted into IP transport protocol for
   dual transport/overlay and native ICN, respectively (see Figure 6 and
   Figure 7).  When a mobile terminal performs an attach procedure, it
   would be assigned an identity either as IP or dual transport (IP and
   ICN), or ICN endpoint.  Mobile terminal can initiate data traffic
   using any of the following options:

   1.  Native IP (IPv4 or IPv6)

   2.  Native ICN

   3.  Dual transport IP (IPv4/IPv6) and ICN

   The mobile terminal encapsulates a user data transport request into
   PDCP layer and sends the information on the air interface to eNodeB,

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   which in turn receives the information and, using PDCP [TS36.323],
   de-encapsulates the air-interface messages and converts them to
   forward to core mobile gateways (SGW, PGW).  As shown in Figure 8, to
   support ICN natively in eNodeB, it is proposed to provide transport
   convergence layer (TCL) capabilities in eNodeB (similar to as
   provided in MT), which provides the following functions:

   1.  It decides the forwarding strategy for a user data request coming
       from mobile terminal.  The strategy can decide based on
       preference indicated by the application, such as congestion,
       cost, QoS, and so on.

   2.  eNodeB to provide open Application Programming Interface (API) to
       external management systems, to provide capability to eNodeB to
       program the forwarding strategies.

                     +---------------+  |
                     | MT request    |  |    ICN          +---------+
             +---> | content using |--+--- transport -->|         |
             |     |ICN protocol   |  |                 |         |
             |     +---------------+  |                 |         |
             |                        |                 |         |
             |     +---------------+  |                 |         |
         +-+   |     | MT request    |  |    IP           |To mobile|
         | |---+---> | content using |--+--- transport -->|    GW   |
         +-+   |     | IP protocol   |  |                 |(SGW,PGW)|
         MT   |     +---------------+  |                 |         |
             |                        |                 |         |
             |     +---------------+  |                 |         |
             |     | MT request    |  |    Dual stack   |         |
             +---> | content using |--+--- IP+ICN    -->|         |
                     |IP/ICN protocol|  |    transport    +---------+
                     +---------------+  |
                         eNodeB       S1u

               Figure 8: Integration of Native ICN in eNodeB

   3.  eNodeB can be upgraded to support three different types of
       transport: IP, ICN, and dual transport IP+ICN towards mobile
       gateways, as depicted in Figure 8.  It is also proposed to deploy
       IP and/or ICN forwarding capabilities into eNodeB, for efficient
       transfer of data between eNodeB and mobile gateways.  Following
       are choices for forwarding a data request towards mobile
       gateways:

       1.  Assuming eNodeB is IP enabled and the MT requests an IP
           transfer, eNodeB forwards data over IP.

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       2.  Assuming eNodeB is ICN enabled and the MT requests an ICN
           transfer, eNodeB forwards data over ICN.

       3.  Assuming eNodeB is IP enabled and the MT requests an ICN
           transfer, eNodeB overlays ICN on IP and forwards user plane
           traffic over IP.

       4.  Assuming eNodeB is ICN enabled and the MT requests an IP
           transfer, eNodeB overlays IP on ICN and forwards user plane
           traffic over ICN [IPoICN].

5.4.4.  Using ICN in Packet Core (SGW, PGW) Gateways

   Mobile gateways (a.k.a.  Evolved Packet Core (EPC)) include SGW, PGW,
   which perform session management for MT from the initial attach to
   disconnection.  When MT is powered on, it performs NAS signaling and
   attaches to PGW after successful authentication.  PGW is an anchoring
   point for MT and responsible for service creations, authorization,
   maintenance, and so on.  The Entire functionality is managed using IP
   address(es) for MT.

   To implement ICN in EPC, the following functions are proposed:

   1.  Insert ICN attributes in session management layer as additional
       functionality with IP stack.  Session management layer is used
       for performing attach procedures and assigning logical identity
       to user.  After successful authentication by HSS, MME sends a
       create session request (CSR) to SGW and SGW to PGW.

   2.  When MME sends Create Session Request message (Step 12 in
       [TS23.401]) to SGW or PGW, it includes a Protocol Configuration
       Option Information Element (PCO IE) containing MT capabilities.
       We can use PCO IE to carry ICN-related capabilities information
       from MT to PGW.  This information is received from MT during the
       initial attach request in MME.  Details of available TLV, which
       can be used for ICN, are given in subsequent sections.  MT can
       support either native IP, ICN+IP, or native ICN.  IP is referred
       to as both IPv4 and IPv6 protocols.

   3.  For ICN+IP-capable MT, PGW assigns the MT both an IP address and
       ICN identity.  MT selects either of the identities during the
       initial attach procedures and registers with the network for
       session management.  For ICN-capable MT, it will provide only ICN
       attachment.  For native IP-capable MT, there is no change.

   4.  To support ICN-capable attach procedures and use ICN for user
       plane traffic, PGW needs to have full ICN protocol stack
       functionalities.  Typical ICN capabilities include functions such

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       as content store (CS), Pending Interest Table (PIT), Forwarding
       Information Base (FIB) capabilities, and so on.  If MT requests
       ICN in PCO IE, then PGW registers MT with ICN names.  For ICN
       forwarding, PGW caches content locally using CS functionality.

   5.  PCO IE described in [TS24.008] (see Figure 10.5.136 on page 598)
       and [TS24.008] (see Table 10.5.154 on page 599) provide details
       for different fields.

       1.  Octet 3 (configuration protocols define PDN types), which
           contains details about IPv4, IPv6, both or ICN.

       2.  Any combination of Octet 4 to Z can be used to provide
           additional information related to ICN capability.  It is most
           important that PCO IE parameters are matched between MT and
           mobile gateways (SGW, PGW) so they can be interpreted
           properly and the MT can attach successfully.

   6.  The ICN functionalities in SGW and PGW should be matched with MT
       and eNodeB because they will exchange ICN protocols and
       parameters.

   7.  Mobile gateways SGW, PGW will also need ICN forwarding and
       caching capability.  This is especially important if CUPS is
       implemented.  User Plane Function (UPF), comprising the SGW and
       PGW user plane, will be located at the edge of the network and
       close to the end user.  ICN-enabled gateway means that this UPF
       would serve as a forwarder and should be capable of caching, as
       is the case with any other ICN-enabled node.

   8.  The transport between PGW and CDN provider can be either IP or
       ICN.  When MT is attached to PGW with ICN identity and
       communicates with an ICN-enabled CDN provider, it will use ICN
       primitives to fetch the data.  On the other hand, for a MT
       attached with an ICN identity, if PGW must communicate with an IP
       enabled CDN provider, it will have to use an ICN-IP interworking
       gateway to perform conversion between ICN and IP primitives for
       data retrieval.  In the case of CUPS implementation with an
       offload close to the edge, this interworking gateway can be
       collocated with the UPF at the offload site to maximize the path
       optimization.  Further study is required to understand how this
       ICN-to-IP (and vice versa) interworking gateway would function.

6.  ICN Deployment Goals

   This section proposes an experimental lab setup and discusses the
   open issues and questions that use of ICN protocol is intended to
   address.

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6.1.  An Experimental Test Setup

   To further test the modifications proposed in different scenarios, a
   simple lab can be set up, as shown in Figure 9.

     +------------------------------------------+
     | +-----+   +------+   (```).     +------+ |   (````).    +-----+
     | | SUB |-->| EMU  |--(x-haul'.-->| EPC  |--->(  PDN ).-->| CDN |
     | +-----+   +------+   `__..''    +------+ |   `__...'    +-----+
     +------------------------------------------+
                   4G Mobile Network Functions

                 Figure 9: Native ICN Deployment Lab Setup

   The following test scenarios can be set up with VM-based deployment:

   1.  SUB: ICN simulated client (using ndnSIM), a client application on
       workstation requesting content.

   2.  EMU: test unit emulating eNodeB.  This will be a test node
       allowing for UE attachment and routing traffic subsequently from
       the Subscriber to the Publisher.

   3.  EPC: Evolved Packet Core in a single instance (such as 5GOpenCore
       [Open5GCore]).

   4.  CDN: content delivery by a Publisher server.

   For the purpose of this testing, ICN emulating code can be inserted
   in the test code in EMU to emulate ICN-capable eNodeB.  An example of
   the code to be used is NS3 in its LTE model.  Effect of such traffic
   on EPC and CDN can be observed and documented.  In a subsequent
   phase, EPC code supporting ICN can be tested when available.

   Another option is to simulate the UE/eNodeB and EPC functions using
   NS3's LTE [NS3LTE] and EPC [NS3EPC] models respectively.  LTE model
   includes the LTE Radio Protocol stack, which resides entirely within
   the UE and the eNodeB nodes.  This capability provides the simulation
   of UE and eNodeB deployment use cases.  Similarly, EPC model includes
   core network interfaces, protocols and entities, which reside within
   the SGW, PGW and MME nodes, and partially within the eNodeB nodes.

   Even with its current limitations (such as IPv4 only, lack of
   integration with ndnSIM, no support for UE idle state), LTE
   simulation may be a very useful tool.  In any case, both control and
   user plane traffic should be tested independently according to the
   deployment model discussed in Section 5.4.

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6.2.  Open Questions to be Addressed

   There are several open questions with ICN implementation scenarios in
   4G mobile networks that the proposed experiments intend to address.
   Some of these issues are.

   1.  Viability of ICN inclusion in the 3GPP protocol stack.  How
       realistic is it to succeed in modifying the stack, considering
       the scenarios explained in Section 5.4, and complete the user
       session without feature degradation?

   2.  Efficiency gained in terms of the amount of traffic in multicast
       scenarios.

   3.  Efficiency gained in terms of latency for cached content, mainly
       in the CDN use case.

   4.  Confirm how (in)adequate would be ICN implementation in control
       plane (which this draft discourages).

7.  Security and Privacy Considerations

   This section will cover some security and privacy considerations in
   mobile and 4G network because of introduction of ICN.

7.1.  Security Considerations

   To ensure only authenticated mobile terminals are connected to the
   network, 4G mobile network implements various security mechanisms.
   From the perspective of using ICN in the user plane, it needs to take
   care of the following security aspects:

   1.  MT authentication and authorization

   2.  Radio or air interface security

   3.  Denial of service attacks on the mobile gateway, services either
       by the MT or by external entities in the Internet

   4.  Content poisoning either in transport or servers

   5.  Content cache pollution attacks

   6.  Secure naming, routing, and forwarding

   7.  Application security

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   Security over the LTE air interface is provided through cryptographic
   techniques.  When MT is powered up, it performs a key exchange
   between MT's USIM and HSS/Authentication Center using NAS messages,
   including ciphering and integrity protections between MT and MME.
   Details for secure MT authentication, key exchange, ciphering, and
   integrity protections messages are given in the 3GPP call flow
   [TS23.401].  With ICN we are modifying protocol stack for user plane
   and not control plane.  The NAS signaling is exchanged between MT and
   mobile gateways e.g.  MME, using control plane, therefore there is no
   adverse impact of ICN on MT.

   4G uses IP transport in its mobile backhaul (between eNodeB and core
   network).  In case of provider-owned backhaul, service provider may
   require to implement a security mechanism in the backhaul network.
   The native IP transport continues to leverage security mechanism such
   as Internet key exchange (IKE) and the IP security protocol (IPsec).
   More details of mobile backhaul security are provided in 3GPP network
   security specifications [TS33.310] and [TS33.320].  When mobile
   backhaul is upgraded to support dual transport (IP+ICN) or native
   ICN, it is required to implement security techniques that are
   deployed in the mobile backhaul.  When ICN forwarding is enabled on
   mobile transport routers, we need to deploy security practices based
   on [RFC7476] and [RFC7927].

   4G mobile gateways (SGW, PGW) perform some of key functions such as
   content based online/offline billing and accounting, deep packet
   inspection (DPI), and lawful interception (LI).  When ICN is deployed
   in user plane , we need to integrate ICN security for sessions
   between MT and gateway.  If we encrypt user plane payload metadata
   then it might be difficult to perform routing based on contents and
   it may not work because we need decryption keys at every forwarder to
   route the content.  The content itself can be encrypted between
   publisher and consumer to ensure privacy.  Only the user with right
   decryption key shall be able to access the content.  We need further
   research for ICN impact on LI, online/offline charging and
   accounting.

7.2.  Privacy Considerations

   In 4G networks, two main privacy issues are [MUTHANA]

   1.  User Identity Privacy Issues.  The main privacy issue within the
       4G is the exposure of the IMSI.  The IMSI can be intercepted by
       adversaries.  Such attacks are commonly referred to as "IMSI
       catching".

   2.  Location Privacy Issues.  IMSI Catching is closely related to the
       issue of location privacy.  Knowing IMSI of user allows the

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       attacker to track the user's movements and create profile about
       the user and thus breaches the user's location privacy.

   In any network, caching implies a trade-off between network
   efficiency and privacy.  The activity of users is exposed to the
   scrutiny of cache owners with whom they may not have any
   relationship.  By monitoring the cache transactions, an attacker
   could obtain significant information related to the objects accessed,
   topology and timing of the requests [RFC7945].  Privacy concerns are
   amplified by the introduction of new network functions such as
   Information lookup and Network storage, and different forms of
   communication [FOTIOU].  Privacy risks in ICN can be broadly divided
   in the following categories [TOURANI]:

   1.  Timing attack

   2.  Communication monitoring attack

   3.  Censorship and anonymity attack

   4.  Protocol attack

   5.  Naming-signature privacy

   Introduction of TCL effectively enables ICN at the application and/or
   transport layer, depending on the scenario described in section 5.
   Enabling ICN in 4G networks is expected to increase efficiency by
   taking advantage of ICN's inherent characteristics.  This approach
   would potentially leave some of the above-mentioned privacy concerns
   open as a consequence of using ICN transport and ICN inherent privacy
   vulnerabilities.

   1.  IPoIP Section 5.2 would not be affected as TCL has no role in it
       and ICN does not apply

   2.  ICNoICN scenario Section 5.2 has increased risk of a privacy
       attack, and that risk is applicable to ICN protocol in general
       rather than specifically to the 4G implementation.  Since this
       scenario describes communication over ICN transport, every
       forwarder in the path could be a potential risk for privacy
       attack

   3.  ICNoIP scenario Section 5.2 uses IP for transport, so the only
       additional ICN-related potential privacy risk areas are the
       endpoints (consumer and publisher) where, at the application
       layer, content is being served

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   4.  IPoICN scenario Section 5.2 could have potentially increased risk
       due to possible vulnerability of the forwarders in the path of
       ICN transport

   Privacy issues already identified in 4G remain a concern if ICN is
   introduced in any of the scenarios described earlier and compound to
   the new, ICN-related privacy issues.  Many research papers have been
   published proposing solutions to the privacy issues listed above.
   For LTE-specific privacy issues, some of the proposed solutions
   [MUTHANA] are IMSI encryption by a MT, mutual authentication,
   concealing the real IMSI within a random bit stream of certain size
   where only the subscriber and HSS could extract the respective IMSI,
   IMSI replacement with a changing pseudonym that only the HSS server
   can map it the UE's IMSI, and others.  Similarly, some of the
   proposed ICN-specific privacy concerns mitigation methods, applicable
   where ICN transport is introduced as specified earlier in this
   section, include [FOTIOU]:

      Delay for the first, or first k interests on edge routers (timing
      attack)

      Creating a secure tunnel or clients flagging the requests as non-
      cacheable for privacy (communication monitoring attack)

      Encoding interest by mixing content and cover file or using
      hierarchical DNS-based brokering model (censorship and anonymity
      attack)

      Use of rate-limiting requests for a specific namespace (protocol
      attack)

      Cryptographic content hash-based naming or digital identity in an
      overlay network (naming-signature privacy)

   Further research in this area is needed.  Detailed discussion of
   privacy is beyond the scope of this document.

8.  Summary

   In this draft, we have discussed the 4G networks and the experimental
   setups to study the advantages of potential use of ICN for efficient
   delivery of contents to mobile terminals.  We have discussed
   different options to try and test the ICN and dependencies such as
   ICN functionalities and changes required in different 4G network
   elements.  In order to further explore potential use of ICN one can
   devise an experimental set-up consisting of 4G network elements and
   deploy ICN data transport in user plane.  Different options can be
   either overlay, dual transport (IP + ICN), hICN, or natively (by

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   integrating ICN with CDN, eNodeB, SGW, PGW and transport network).
   Note that, for the scenarios discussed above, additional study is
   required for lawful interception, billing/mediation, network slicing,
   and provisioning APIs.

   Edge Computing [CHENG] provides capabilities to deploy
   functionalities such as Content Delivery Network (CDN) caching and
   mobile user plane functions (UPF) [TS23.501].  Recent research for
   delivering real-time video content [MPVCICN] using ICN has also been
   proven to be efficient [NDNRTC] and can be used towards realizing the
   benefits of using ICN in eNodeB, edge computing, mobile gateways
   (SGW, PGW) and CDN.  The key aspect for ICN is in its seamless
   integration in 4G and 5G networks with tangible benefits so we can
   optimize content delivery using a simple and scalable architecture.
   The authors will continue to explore how ICN forwarding in edge
   computing could be used for efficient data delivery from the mobile
   edge.

   Based on our study of control plane signaling, it is not beneficial
   to deploy ICN with existing protocols unless further changes are
   introduced in the control protocol stack itself.

   As a starting step towards use of ICN in user plane, it is proposed
   to incorporate protocol changes in MT, eNodeB, SGW/PGW for data
   transport.  ICN has inherent capabilities for mobility and content
   caching, which can improve the efficiency of data transport for
   unicast and multicast delivery.  The authors welcome contributions
   and suggestions, including those related to further validations of
   the principles by implementing prototype and/or proof of concept in
   the lab and in the production environment.

9.  Acknowledgements

   We thank all contributors, reviewers, and the chairs for the valuable
   time in providing comments and feedback that helped improve this
   draft.  We specially want to mention the following members of the
   IRTF Information-Centric Networking Research Group (ICNRG), listed in
   alphabetical order: Thomas Jagodits, Luca Muscariello, David R.
   Oran, Akbar Rahman, Ravishankar Ravindran, Martin J.  Reed, and
   Thomas C.  Schmidt.

   The IRSG review was provided by Colin Perkins.

10.  References

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10.1.  Normative References

   [TS24.008]
              3GPP, "Mobile radio interface Layer 3 specification; Core
              network protocols; Stage 3", 3GPP TS 24.008 3.20.0,
              December 2005,
              <http://www.3gpp.org/ftp/Specs/html-info/24008.htm>.

   [TS25.323]
              3GPP, "Packet Data Convergence Protocol (PDCP)
              specification", 3GPP TS 25.323 3.10.0, September 2002,
              <http://www.3gpp.org/ftp/Specs/html-info/25323.htm>.

   [TS29.274]
              3GPP, "3GPP Evolved Packet System (EPS); Evolved General
              Packet Radio Service (GPRS) Tunneling Protocol for Control
              plane (GTPv2-C); Stage 3", 3GPP TS 29.274 10.11.0, June
              2013, <http://www.3gpp.org/ftp/Specs/html-info/29274.htm>.

   [TS29.281]
              3GPP, "General Packet Radio System (GPRS) Tunneling
              Protocol User Plane (GTPv1-U)", 3GPP TS 29.281 10.3.0,
              September 2011,
              <http://www.3gpp.org/ftp/Specs/html-info/29281.htm>.

   [TS36.323]
              3GPP, "Evolved Universal Terrestrial Radio Access
              (E-UTRA); Packet Data Convergence Protocol (PDCP)
              specification", 3GPP TS 36.323 10.2.0, January 2013,
              <http://www.3gpp.org/ftp/Specs/html-info/36323.htm>.

10.2.  Informative References

   [ALM]      Auge, J., Carofiglio, G., Grassi, G., Muscariello, L.,
              Pau, G., and X. Zeng, "Anchor-Less Producer Mobility in
              ICN", Proceedings of the 2Nd ACM Conference on
              Information-Centric Networking, ACM-ICN'15, ACM DL,
              pp.189-190, September 2013,
              <https://dl.acm.org/citation.cfm?id=2812601>.

   [BROWER]   Brower, E., Jeffress, L., Pezeshki, J., Jasani, R., and E.
              Ertekin, "Integrating Header Compression with IPsec",
              MILCOM 2006 - 2006 IEEE Military Communications
              conference IEEE Xplore DL, pp.1-6, October 2006,
              <https://ieeexplore.ieee.org/document/4086687>.

   [CCN]      "Content Centric Networking", <http://www.ccnx.org>.

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   [CHENG]    Liang, C., Yu, R., and X. Zhang, "Information-centric
              network function virtualization over 5g mobile wireless
              networks", IEEE Network Journal vol. 29, number 3, pp.
              68-74, June 2015,
              <https://ieeexplore.ieee.org/document/7113228>.

   [EMBMS]    Zahoor, K., Bilal, K., Erbad, A., and A. Mohamed,
              "Service-Less Video Multicast in 5G: Enablers and
              Challenges", IEEE Network vol. 34, no. 3, pp. 270-276, May
              2020, <https://ieeexplore.ieee.org/document/9105941>.

   [EPCCUPS]  Schmitt, P., Landais, B., and F. Yong Yang, "Control and
              User Plane Separation of EPC nodes (CUPS)", 3GPP The
              Mobile Broadband Standard, July 2017,
              <http://www.3gpp.org/news-events/3gpp-news/1882-cups>.

   [FOTIOU]   Fotiou, N. and G. Polyzos, "ICN privacy and name based
              security", ACM-ICN '14: Proceedings of the 1st ACM
              Conference on Information-Centric Networking ACM Digitial
              Library, pp. 5-6, September 2014,
              <https://dl.acm.org/doi/10.1145/2660129.2666711>.

   [GALIS]    Galis, A., Makhijani, K., Yu, D., and B. Liu, "Autonomic
              Slice Networking", draft-galis-anima-autonomic-slice-
              networking-05 (work in progress), September 2018.

   [GRAYSON]  Grayson, M., Shatzkamer, M., and S. Wainner, "Cisco Press
              book "IP Design for Mobile Networks"", Cisco
              Press Networking Technology series, June 2009,
              <http://www.ciscopress.com/store/
              ip-design-for-mobile-networks-9781587058264>.

   [HICN]     Muscariello, L., Carofiglio, G., Auge, J., and M.
              Papalini, "Hybrid Information-Centric Networking", draft-
              muscariello-intarea-hicn-04 (work in progress), May 2020.

   [I-D.anilj-icnrg-dnc-qos-icn]
              Jangam, A., suthar, P., and M. Stolic, "QoS Treatments in
              ICN using Disaggregated Name Components", draft-anilj-
              icnrg-dnc-qos-icn-02 (work in progress), March 2020.

   [I-D.oran-icnrg-qosarch]
              Oran, D., "Considerations in the development of a QoS
              Architecture for CCNx-like ICN protocols", draft-oran-
              icnrg-qosarch-05 (work in progress), August 2020.

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   [ICN5G]    Ravindran, R., suthar, P., Trossen, D., and G. White,
              "Enabling ICN in 3GPP's 5G NextGen Core Architecture",
              draft-ravi-icnrg-5gc-icn-03 (work in progress), July 2020.

   [ICNLOWPAN]
              Gundogan, C., Schmidt, T., Waehlisch, M., Scherb, C.,
              Marxer, C., and C. Tschudin, "ICN Adaptation to LowPAN
              Networks (ICN LoWPAN)", draft-irtf-icnrg-icnlowpan-08
              (work in progress), May 2020.

   [ICNQoS]   Al-Naday, M., Bontozoglou, A., Vassilakis, G., and M.
              Reed, "Quality of Service in an Information-Centric
              Network", 2014 IEEE Global Communications Conference IEEE
              Xplore DL, pp. 1861-1866, December 2014,
              <https://ieeexplore.ieee.org/document/7037079>.

   [IPoICN]   Trossen, D., Read, M., Riihijarvi, J., Georgiades, M.,
              Fotiou, N., and G. Xylomenos, "IP over ICN - The better
              IP?", 2015 European Conference on Networks and
              Communications (EuCNC) IEEE Xplore DL, pp. 413-417, June
              2015, <https://ieeexplore.ieee.org/document/7194109>.

   [MBICN]    Carofiglio, G., Gallo, M., Muscariello, L., and D. Perino,
              "Scalable mobile backhauling via information-centric
              networking", The 21st IEEE International Workshop on Local
              and Metropolitan Area Networks, Beijing, pp. 1-6, April
              2015, <https://ieeexplore.ieee.org/document/7114719>.

   [MECSPEC]  "Mobile Edge Computing (MEC); Framework and Reference
              Architecture", ETSI European Telecommunication Standards
              Institute (ETSI) MEC specification, March 2016,
              <https://www.etsi.org/deliver/etsi_gs/
              MEC/001_099/003/01.01.01_60/gs_MEC003v010101p.pdf>.

   [MPVCICN]  Jangam, A., Ravindran, R., Chakraborti, A., Wan, X., and
              G. Wang, "Realtime multi-party video conferencing service
              over information centric network", IEEE International
              Conference on Multimedia and Expo Workshops (ICMEW) Turin,
              Italy, pp. 1-6, June 2015,
              <https://ieeexplore.ieee.org/document/7169810>.

   [MUTHANA]  Muthana, A. and M. Saeed, "Analysis of User Identity
              Privacy in LTE and Proposed Solution", International
              Journal of Computer Network and Information
              Security(IJCNIS) MECS Press, pp. 54-63, January 2017,
              <http://www.mecs-press.org/ijcnis/ijcnis-v9-n1/
              v9n1-7.html>.

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   [NDNRTC]   Gusev, P., Wang, Z., Burke, J., Zhang, L., Yoneda, T.,
              Ohnishi, R., and E. Muramoto, "Real-time Streaming Data
              Delivery over Named Data Networking,", IEICE Transactions
              on Communications vol. E99.B, pp. 974-991, May 2016,
              <https://doi.org/10.1587/transcom.2015AMI0002>.

   [NGMN]     Robson, J., "Backhaul Provisioning for LTE-Advanced and
              Small Cells", Next Generation Mobile Networks, LTE-
              Advanced Transport Provisioning, V0.0.14, October 2015,
              <https://www.ngmn.org/wp-content/uploads/
              Publications/2015/150929_NGMN_P-
              SmallCells_Backhaul_for_LTE-Advanced_and_Small_Cells.pdf>.

   [NS3EPC]   Baldo, N., "The ns-3 EPC module",  NS3 EPC Model,
              <https://www.nsnam.org/docs/models/html/
              lte-design.html#epc-model>.

   [NS3LTE]   Baldo, N., "The ns-3 LTE module",  NS3 LTE Model,
              <https://www.nsnam.org/docs/models/html/
              lte-design.html#lte-model>.

   [OFFLOAD]  Rebecchi, F., Dias de Amorim, M., Conan, V., Passarella,
              A., Bruno, R., and M. Conti, "Data Offloading Techniques
              in Cellular Networks: A Survey", IEEE Communications
              Surveys and Tutorials, IEEE Xplore DL, vol:17, issue:2,
              pp.580-603, November 2014,
              <https://ieeexplore.ieee.org/document/6953022>.

   [OLTEANU]  Olteanu, A. and P. Xiao, "Fragmentation and AES Encryption
              Overhead in Very High-speed Wireless LANs", Proceedings of
              the 2009 IEEE International Conference on Communications
              ICC'09, ACM DL, pp.575-579, June 2009,
              <http://dl.acm.org/citation.cfm?id=1817271.1817379>.

   [Open5GCore]
              Open5GCore, M., "Open5GCore - Fundamental 4G Core Network
              Functionality",  Open5GCore, <https://www.open5gcore.org>.

   [RFC4594]  Babiarz, J., Chan, K., and F. Baker, "Configuration
              Guidelines for DiffServ Service Classes", RFC 4594,
              DOI 10.17487/RFC4594, August 2006,
              <https://www.rfc-editor.org/info/rfc4594>.

   [RFC6459]  Korhonen, J., Ed., Soininen, J., Patil, B., Savolainen,
              T., Bajko, G., and K. Iisakkila, "IPv6 in 3rd Generation
              Partnership Project (3GPP) Evolved Packet System (EPS)",
              RFC 6459, DOI 10.17487/RFC6459, January 2012,
              <https://www.rfc-editor.org/info/rfc6459>.

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   [RFC7476]  Pentikousis, K., Ed., Ohlman, B., Corujo, D., Boggia, G.,
              Tyson, G., Davies, E., Molinaro, A., and S. Eum,
              "Information-Centric Networking: Baseline Scenarios",
              RFC 7476, DOI 10.17487/RFC7476, March 2015,
              <https://www.rfc-editor.org/info/rfc7476>.

   [RFC7927]  Kutscher, D., Ed., Eum, S., Pentikousis, K., Psaras, I.,
              Corujo, D., Saucez, D., Schmidt, T., and M. Waehlisch,
              "Information-Centric Networking (ICN) Research
              Challenges", RFC 7927, DOI 10.17487/RFC7927, July 2016,
              <https://www.rfc-editor.org/info/rfc7927>.

   [RFC7945]  Pentikousis, K., Ed., Ohlman, B., Davies, E., Spirou, S.,
              and G. Boggia, "Information-Centric Networking: Evaluation
              and Security Considerations", RFC 7945,
              DOI 10.17487/RFC7945, September 2016,
              <https://www.rfc-editor.org/info/rfc7945>.

   [RFC8569]  Mosko, M., Solis, I., and C. Wood, "Content-Centric
              Networking (CCNx) Semantics", RFC 8569,
              DOI 10.17487/RFC8569, July 2019,
              <https://www.rfc-editor.org/info/rfc8569>.

   [RFC8609]  Mosko, M., Solis, I., and C. Wood, "Content-Centric
              Networking (CCNx) Messages in TLV Format", RFC 8609,
              DOI 10.17487/RFC8609, July 2019,
              <https://www.rfc-editor.org/info/rfc8609>.

   [SDN5G]    Page, J. and J. Dricot, "Software-defined networking for
              low-latency 5G core network", 2016 International
              Conference on Military Communications and Information
              Systems (ICMCIS) IEEE Xplore DL, pp. 1-7, May 2016,
              <https://ieeexplore.ieee.org/document/7496561>.

   [TLVCOMP]  Mosko, M., "Header Compression for TLV-based Packets",
              ICNRG Buenos Aires IETF 95, April 2016,
              <https://datatracker.ietf.org/meeting/interim-2016-icnrg-
              02/materials/slides-interim-2016-icnrg-2-7>.

   [TOURANI]  Tourani, R., Misra, S., Mick, T., and G. Panwar,
              "Security, Privacy, and Access Control in Information-
              Centric Networking: A Survey", IEEE Communications Surveys
              and Tutorials Volume 20, Issue 1, pp 566-600, September
              2017, <https://ieeexplore.ieee.org/document/8027034>.

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   [TS23.203]
              3GPP, "Policy and charging control architecture", 3GPP
              TS 23.203 10.9.0, September 2013,
              <http://www.3gpp.org/ftp/Specs/html-info/23203.htm>.

   [TS23.401]
              3GPP, "General Packet Radio Service (GPRS) enhancements
              for Evolved Universal Terrestrial Radio Access Network
              (E-UTRAN) access", 3GPP TS 23.401 10.10.0, March 2013,
              <http://www.3gpp.org/ftp/Specs/html-info/23401.htm>.

   [TS23.501]
              3GPP, "System Architecture for the 5G System", 3GPP
              TS 23.501 15.2.0, June 2018,
              <http://www.3gpp.org/ftp/Specs/html-info/23501.htm>.

   [TS23.714]
              3GPP, "Technical Specification Group Services and System
              Aspects: Study on control and user plane separation of EPC
              nodes", 3GPP TS 23.714 0.2.2, June 2016,
              <http://www.3gpp.org/ftp/Specs/html-info/23714.htm>.

   [TS29.060]
              3GPP, "General Packet Radio Service (GPRS); GPRS Tunneling
              Protocol (GTP) across the Gn and Gp interface", 3GPP
              TS 29.060 3.19.0, March 2004,
              <http://www.3gpp.org/ftp/Specs/html-info/29060.htm>.

   [TS33.310]
              3GPP, "Network Domain Security (NDS); Authentication
              Framework (AF)", 3GPP TS 33.310 10.7.0, December 2012,
              <http://www.3gpp.org/ftp/Specs/html-info/33310.htm>.

   [TS33.320]
              3GPP, "Security of Home Node B (HNB) / Home evolved Node B
              (HeNB)", 3GPP TS 33.320 10.5.0, June 2012,
              <http://www.3gpp.org/ftp/Specs/html-info/33320.htm>.

Authors' Addresses

   Prakash Suthar
   Google Inc.
   Mountain View, California  94043
   USA

   Email: psuthar@google.com

Prakash Suthar, et al.   Expires August 26, 2021               [Page 39]
Internet-Draft       draft-irtf-icnrg-icn-lte-4g-09        February 2021

   Milan Stolic
   Cisco Systems Inc.
   Naperville, Illinois  60540
   USA

   Email: mistolic@cisco.com

   Anil Jangam (editor)
   Cisco Systems Inc.
   San Jose, California  95134
   USA

   Email: anjangam@cisco.com

   Dirk Trossen
   Huawei Technologies
   Riesstrasse 25
   Munich  80992
   Germany

   Email: dirk.trossen@huawei.com

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