ICN Research Group Prakash Suthar Internet-Draft Milan Stolic Intended status: Informational Anil Jangam Cisco Systems Inc. Expires: September 29, 2017 March 28 2017 Native Deployment of ICN in 3G, LTE, 4G Mobile Networks draft-suthar-icnrg-icn-lte-4g-00 Abstract Mobile networks using LTE, 4G are complex. Managing mobility and content delivery using IP is complex and not optimized. IP unicast routing from server to clients is used for delivery of multimedia content to User Equipment (UE), where each user gets separate stream. From bandwidth and routing perspective this approach is inefficient. Multicast and broadcast technologies have emerged recently for mobile networks, but their deployments are very limited or at an experimental stage due to complex architecture and radio spectrum issues. ICN is a rapidly evolving technology for efficient multimedia content delivery, however majority of the work is focused either on fixed networks or unlicensed WiFi-based wireless networks. The main focus of this draft is on native deployment of ICN in cellular mobile networks by embedding into 3GPP protocol stack at IP level or replacing IP for non-IP datagrams. ICN has an inherent capability for anchorless mobility, security and it is optimized for content delivery using local caching at the edge. We believe that native or dual stack (with IP) deployment will bring all inherent benefits of ICN and help in optimizing mobile networks. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress". Prakash, et.al. Expires September 29, 2017 [Page 1] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright and License Notice Copyright (c) 2017 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 Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 2. LTE, 4G Mobile Network . . . . . . . . . . . . . . . . . . . . 3 2.1 Typical Network Overview . . . . . . . . . . . . . . . . . 3 2.2 Virtualizing Mobile Networks . . . . . . . . . . . . . . . 5 3. Content Delivery using IP Transport . . . . . . . . . . . . . 5 4. Content Delivery using ICN Protocol . . . . . . . . . . . . . 6 5. ICN Deployment in LTE Mobile Networks . . . . . . . . . . . . 7 5.1 ICN Deployments for Mobility Management . . . . . . . . . . 8 5.2 Deploying ICN Protocol in Mobile Devices . . . . . . . . . 10 5.2.1 Dual stack or triple stack (IPv4, IPv6, IPv4v6, ICN) . 10 5.2.1 Native ICN deployment in UE . . . . . . . . . . . . . . 11 5.3 ICN Deployment in Base Station (BS) . . . . . . . . . . . . 12 5.3.1 ICN Deployment in SGW/PGW . . . . . . . . . . . . . . . 14 6. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 7 References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 7.1 Normative References . . . . . . . . . . . . . . . . . . . 17 7.2 Informative References . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18 Prakash, et.al. Expires September 29, 2017 [Page 2] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 1 Introduction Currently LTE, 4G and future 5G mobile networks use IP as payload for content delivery, and standardized routing protocols such as OSPF, ISIS, BGP etc. for transport. With LTE/4G technology mobile network is all IP network. When UE is powered up, it establishes a radio link with closest base station (BS). After radio link establishment, UE performs attach procedures (as documented in 3GPP TS23.401) which include authentication, authorization, mobility management and session establishment with mobile core. For one successful attach procedure, mobile gateway (PGW) creates one session per UE and assigns IP address(es) based on how many services are created [TS23.401]. One of the biggest challenges with IP routing is that it is not optimized for content delivery even though it is the efficient routing protocol. ICN offers an opportunity to re-architect mobile networks by leveraging inherent capabilities of seamless anchorless mobility, authentication and optimized signaling. 1.1 Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC2119]. 2. LTE, 4G Mobile Network 2.1 Typical Network Overview With the introduction of LTE/4G systems transport and signaling for mobile networks are migrated to all-IP, covering all elements as outlined in Figure-1. "IP Design for Mobile Networks"[GRAYSON] provides detailed 3GPP interface design and call flows. For each UE attached to the Base station (BS) and with successful authentication with mobile core, there is a separate dedicated overlay GTP (GPRS Tunneling Protocol) between BS and Serving Gateway (SGW), Packet Data Network Gateway (PGW). For high level understanding we can consider this architecture as hub (PGW) and spoke (UE) because for each attached UE there is GTP tunnel between BS to SGW/PGW. Prakash, et.al. Expires September 29, 2017 [Page 3] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 +-------+ Diameter +-------+ | HSS |------------| SPR | +-------+ +-------+ | | +------+ +------+ S4 | +-------+ |2G/3G |---| SGSN |----------------|------+ +------| PCRF | ^ | BS | | |---------+ +---+ | | +-------+ +-+ | +------+ +------+ S3 | | S6a | |Gxc | | | | +-------+ | | |Gx +-+ | +------------------| MME |------+ | | | UE v | S1MME +-------+ S11 | | | | +----+-+ +-------+ +-------+ |4G/LTE|------------------------------| SGW |-----| PGW | | BS | 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 | +-----+ +---------+ +---------+ | | +-+ +-+ | | | | +-+ +-+ UE UE Figure-1: LTE, 4G Mobile Network Overview It is also important to understand the GTP tunnel overhead because this has impact on bandwidth available for actual user traffic. For average packet size of ~500 bytes GTP overhead is ~15%. Additionally, if IPSec is used for security (which is often required if the Service provider is using a 3rd party backhaul network), then it will add ~15-23% overhead based upon transport/tunneling model, and encryption and authentication header algorithms used [IPSEC]. The content delivered to mobile devices is unicast inside GTP tunnel. If the impact of GTP, IPSec and unicast traffic is combined, the content delivery is not efficient. For radio protocols we can use different header compression mechanisms to reduce the overhead impact, but gain is not significant. For example, by using some of the header compression mechanisms like robust header compression (ROHC) and enhanced compression of the real-time transport protocol (ECRTP), impact of overhead created by GTP, IPsec etc. is reduced to some extent [BROWER]. For commercial mobile networks 3GPP has adopted Prakash, et.al. Expires September 29, 2017 [Page 4] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 different header compression mechanism to achieve efficiency in content delivery [TS23.323] which can also be used in ICN to further improve efficiencies. 2.2 Virtualizing Mobile Networks Typical mobile networks are built to support millions of subscribers, however virtualization with network slicing provides a mechanism where network can be segmented and personalized to provide specific set of services for enterprise applications, Mobile Virtual Network Operators (MVNO), public safety virtual networks etc. Virtual packet cores are opening way for many innovative use cases applicable to enterprise markets, however most of these use cases are for smaller throughput but complex policy and specialized services. Although virtualization is growing, the call flow is still the same, therefore issues related to ICN are the same for traditional and virtual mobile networks. There is also work underway to separate control and user plane so that the network can scale better. Virtualized mobile networks and network slicing with control and user plane separation provide mechanism to evolve GTP-based architecture to open-flow SDN-based signaling. Protocol evolution to open-flow is still under study and research at 3GPP. 3. Content Delivery using IP Transport As mentioned earlier, content delivery in today's mobile networks is mostly unicast as described in 3GPP specification [TS23.401]. While the technology exists to address the issue of possible multicast delivery, there are many difficulties related to the implementation in the core and radio access network (RAN). As shown in Figure-1, user plane traffic is encapsulated inside GTP tunnel for UE attached using 3GPP interface, and GRE tunnel for UE attached using non-3GPP trusted and un-trusted interfaces. Tunneled traffic from UE gets de- capsulated at PGW and forwarded as native IP datagram on SGi interface towards Content Data Network (CDN). Many Service Provides use CDN caching in their networks to optimize content delivery, however caching servers are located in SGi network which is at centralized location in the Service Provider's Data Center. Distribution of caching servers at the edge is limited due to deployment challenges and issues related to GTP tunnel termination at PGW. This is a very inefficient concept because traffic has to traverse the entire backhaul path for the content to be delivered to the end-user. The issue of inefficient traffic path to deliver the content has to be addressed from a different perspective, by Prakash, et.al. Expires September 29, 2017 [Page 5] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 considering caching at edge and 4. Content Delivery using ICN Protocol Content delivery using ICN is different compared to the IP-based systems because it uses two simple types of messages, namely Interest and Data packet. Communication in ICN takes place between UE (Consumer/publisher) and content provider (publisher), where intermediate nodes facilitate delivery of content from the closest edge location if it has been cached. Details of the message are given in Figure-2 [ICN] +------------------------------------+ Interest | +------+ +------+ +------+ | +-----+ +-+ ---->| CS |---->| PIT |---->| FIB |--------->| CDN | | | | +------+ +------+ +------+ | +-----+ +-+ | | Add | Drop | | Forward UE <--------+ Intf v Nack v | Data | | +------------------------------------+ +------------------------------------+ +-+ | Forward +------+ | +-----+ | | <-------------------------------------| PIT |<---------| CDN | +-+ | | Cache +--+---+ | Data +-----+ UE | +--v---+ | | | | CS | v | | +------+ Discard | +------------------------------------+ Figure-2: ICN Protocol Architecture Every node in a physical path between a client and a content provider is called ICN forwarder or router, and it has the ability to route the request intelligently and also cache the content so that it can be delivered locally for subsequent request from any client. For mobile network, transport between a client and a content provider consists of several hops e.g. RAN, BS, Mobile Backhaul (MBH), IP core (CORE), Mobile Gateways (SGW/PGW) and CDN. Each of these elements are further connected using routing and switching. In order to perform mobile edge computing [MECSPEC] at base station, the MEC function is introduced. MEC has the capability of processing client requests and segregating control and user traffic at the BS rather than sending all requests to the mobile gateways. MEC transforms radio into an intelligent service edge that is capable of delivering highly Prakash, et.al. Expires September 29, 2017 [Page 6] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 personalized services from the edge of the network, while providing the best possible performance to the UE. MEC can be an ideal candidate for ICN forwarder in addition to its usual function. MEC can be physical or virtual network function (VNF), and can be co- hosted or integrated with either BS, cell site router or cloud RAN (C-RAN) function. In addition to MEC other transport elements, such as routers, can work as ICN forwarders as well. ICN uses two types of packets called "interest packet" and "data packet". Protocol architecture is defined but evolving based on active research and adding more capabilities. There are two variations of ICN implementations referred to as Content Centric Networking [CCN] and Named Data Networking [NDN]. The implementation difference between CCN and NDN is mainly related to the forwarding strategy, name resolution and underlying security architecture. Interest packet contains information such as Name of content, selectors filter which contains information about the order in which content is required, details of content provider or publisher(s) such as exclude/include filters etc. Nonce field is used to sign the packet where signature is put by a client. Guider field contains information such as lifetime and scope for packet. First ICN router will receive Interest packet and perform lookup if request for such content has come earlier from any other client. If yes it is served from the local cache, otherwise request is forwarded to the next-hop ICN router. Each ICN router maintains three data structures, namely Pending Interest Table (PIT), Forwarding Information Base (FIB), and Content Store (CS). The Interest packet travels hop-by-hop towards content provider. Once the Interest reaches the content provider it will return a Data packet containing information such as content name, signature, signed key and data itself. Data packet travels in reverse direction following the same path taken by the interest packet so routing symmetry is maintained. Details about algorithms used in PIT, FIB, CS and security trust models are described in different documents [CCN],[NDN] 5. ICN Deployment in LTE Mobile Networks LTE Mobile Network is quite complex with many different elements/functions, so it is important to analyze many different options to gradually deploy ICN without impacting performance and subscriber experience. Figure-3 provides high-level protocol level description of different elements such as UE, BS, Serving Gateway (SGW) and PDN Gateway (PGW). LTE mobile networks contain control plane (to handle signaling for mobility managements) and user plane (for delivery of contents). We analyzed different options for deploying ICN without Prakash, et.al. Expires September 29, 2017 [Page 7] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 degrading/impacting performance. +---------+ +---------+ | App | | CDN | +---------+ +---------+ | ICN | | ICN | |Forwarder|..|.................|................|..|Forwarder| +---------+ | | | +---------+ |ICN | IP |..|.................|................|..|ICN | IP | | | | | | | | | | +---------+ | +-----------+ | +----------+ | +---------+ | | | | Relay | | | Relay | | | | | PDCP | | |-----------| | |----------| | | PDCP | | |..|..| | |..|..| | |..|..| | | | | |PDCP|GTP-U | | |PDCP|GTP-U| | | | +---------+ | +-----------+ | +----------+ | +---------+ | RLC |..|..|RLC |UDP/IP|..|..|UDP | UDP |..|..| RLC | +---------+ | +-----------+ | +----------+ | +---------+ | MAC |..|..| MAC | L2 |..|..| L2 | L2 |..|..| MAC | +---------+ | +-----------+ | +----------+ | +---------+ | L1 |..|..| L1 | L1 |..|..| L1 | L1 |..|..| L1 | +---------+ | +-----------+ | +----------+ | +---------+ UE | BS(enodeB) | SGW | PGW LTE-uu S1-U S5/S8 Figure-3: ICN Deployment in LTE Mobile Networks 5.1 ICN Deployments for Mobility Management Mobility management includes signaling messages associated with Non- Acess Stratum (NAS). In this section we analyzed different mobility management messages and if there is any benefit to replace IP-based protocols for NAS signaling in the current architecture. It is important to understand a concept of point of attachment (POA) because it provides session management from the initial attachment to detachment (power off, handover, roaming to other network etc.). Also it is important to understand UE identity mechanism because it is used during the entire session management. Mobile devices have identities parameters such as IMSI, MSISDN, IMEI, IP Address and subscriber profiles. It is important to understand each parameter and its impact on mobility and session management. When UE connects to a network it has at least three points of attachment: (1) Base Station (BS) managing location or physical POA, (2) Authentication and Authorization (MME/SGSN, HSS/HLR, AAA etc.) managing identity or authentication POA and (3) Mobile Gateways Prakash, et.al. Expires September 29, 2017 [Page 8] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 (SGW, PGW, GGSN, PDSN/HA) managing logical or session management POA. Although most of ICN research documents state that it supports seamless mobility for any device or that mobility is built into ICN protocols, it might complicate cellular mobile networks [TS23.401]. We need to analyze impact of POA on mobility management because we want to maintain uninterrupted content delivery when mobile device changes physical locations or uses different access mechanism. For mobile devices location and physical identity split is a fundamental requirement at network layer (IP) to handle mobility. Unique and stable identifiers of network hosts and information objects enable uninterrupted content delivery irrespective of mobile device's location. If the device is attached to one gateway then we can use IP address, but research has shown that IP addressing does not satisfy this property because for multiple PDN connections device is assigned many IP addresses, and it is up to the application to choose which PDN is used to fetch the content. In order to understand the impact to the identity of authentication POA, let us review mobility management (MM) messages and complexities involved. When a UE is powered on it performs attach procedure by initiating NAS, other MM messages. On an average there are 40+ messages exchanged between UE and different elements such as Mobility Management Entity (MME), Home Subscriber System (HSS), PGW and Policy Control Rule Function (PCRF). IP is embedded very deeply into these messages as layer-3 transport and TLV carrying additional attributes. +---------------------------+-------+-------+-------+-------+------+ | NAS Signaling Type | 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 | 1 | | 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 | 0 | 0 | 0 | 0 | | Total | 34 | 2 | 14 | 6 | 3 | +---------------------------+-------+-------+-------+-------+------+ Figure-4: Typical Mobility Management Messages After analyzing message structure for the above messages and complexities, their inter-dependencies, the conclusion was that it is not beneficial to deploy ICN for control plane and mobility management functions. It is important to note that even though we do not implement ICN in control plane, we still need capabilities in MME, HSS and PCRF to understand ICN functions. Prakash, et.al. Expires September 29, 2017 [Page 9] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 When UE initiates attach request using the identity as ICN, MME must be able to parse that message and create a session. MME forwards UE authentication to HSS so HSS must be capable of authenticating ICN- capable UE and authorizing create session [TS23.401]. 5.2 Deploying ICN Protocol in Mobile Devices UE protocol stack is quite complex because it has to support multiple access radio connectivity to the BS(s), authentication POA and logical/session management POA to mobile gateways such as SGW/PGW. High level protocol stack is given in Figure-6 below, however more details are given in 3GPP specifications [TS23.323]. 3GPP Rel.13 onward specifications provides options for IP and non-IP PDN types. We will leverage "Non-IP" PDN deploy ICN protocol stack in a mobile device. 5.2.1 Dual stack or triple stack (IPv4, IPv6, IPv4v6, ICN) Figure-5 provides high level protocol stack changes and new functions in UE +-----------------------------------+ | Applications/Contents (existing) | +-----------------+-----------------+ | +-----------------+-----------------+ | Forwarding Function (new) | +------+---------------------+------+ | | +------+------+ +------+------+ |ICN function +-------+ IP function | | (New) | | (Existing) | +------+------+ +---+---------+ | (native) | (overlay) +------+------------------+---------+ | PDCP (updated to support ICN) | +-----------------+-----------------+ | +-----------------+-----------------+ | RLC (Existing) | +-----------------+-----------------+ | +-----------------+-----------------+ | MAC Layer (Existing) | +-----------------+-----------------+ | +-----------------+-----------------+ Prakash, et.al. Expires September 29, 2017 [Page 10] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 | Physical L1 (Existing) | +-----------------------------------+ Figure-5: Dual stack ICN Deployment in UE The following new functions are added to support dual stack ICN deployments - Insert "Forwarding Function" between Applications/Contents (existing) and network layer (IP function). Forwarding function contains decisions algorithms to route the request from Applications/Contents, based on criteria such as application preference (ICN vs IP transport), content locations, content types, publishers details, cost, network congestions, QoS and any other customizable parameters. Network function can also provide input for Forwarding Function for decision algorithms. - Insert "ICN Function" by modifying existing PDCP and IP Function. If "Forwarding Function" sends content request using ICN message such as "Interest" then ICN function will be used to process. If UE doesn't support ICN then it will be overlaid on top of IP. - Modification in existing PDCP to support ICN in addition to IP. There is no impact on lower layers except for ICN name size. If ICN name is bigger then it will have impact on radio physical layer resource blocks. 5.2.1 Native ICN deployment in UE Figure-6 provides high level protocol stack changes and new functions in UE The following new functions are added to support dual stack ICN deployments - Insert "Forwarding Function" between Applications/Contents (existing) and network layer (IP function). Forwarding function contains decisions algorithms to route the request from Applications/Contents, based on criteria such as application preference (ICN vs IP transport), content locations, content types, publishers details, cost, network congestions, QoS and any other customizable parameters. Network function can also provide input for Forwarding Function for decision algorithms. - Insert "ICN Function" by modifying existing PDCP and replacing IP Function. In this scenario UE will have native support for ICN Prakash, et.al. Expires September 29, 2017 [Page 11] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 - Modification in existing PDCP layer. Currently PDCP is configured for IP transport and it uses header compression mechanism for IP. When ICN is used, it will require changes in PDCP layer. Currently PDCP uses Robust header compression (RoHC) Compression on air interface. With ICN we will use the same RoHC (RFC3095) header compression technique but update algorithms for ICN. +-----------------------------------+ | Applications/Contents (existing) | +-----------------+-----------------+ | +-----------------+-----------------+ | Forwarding Function (new) | +-----------------+-----------------+ | +-----------------------------------+ | ICN function | | (New) | +------+----------------------------+ | (native) +------+------------------+---------+ | PDCP (updated to support ICN) | +-----------------+-----------------+ | +-----------------+-----------------+ | RLC (Existing) | +-----------------+-----------------+ | +-----------------+-----------------+ | MAC Layer (Existing) | +-----------------+-----------------+ | +-----------------+-----------------+ | Physical L1 (Existing) | +-----------------------------------+ Figure-6: Dual stack ICN Deployment in UE 5.3 ICN Deployment in Base Station (BS) In order to deploy ICN in radio Base Station (a.k.a. as eNodeB) for LTE/4G network in user plane (Figure-7:ICN Deployment in Base station for User Plane), we need to modify existing Layer-3 (IP layer). At layer-3 we need to incorporate ICN function in addition to the existing IP function. The main goal of introduction of the ICN function is to enable delivery of content using either ICN or IP or both based on the preference of mobile device (UE). Description of the required changes is as follows: Prakash, et.al. Expires September 29, 2017 [Page 12] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 +-------+ | +-------+ | +-------+ |GTP-U |..|..|GTP-U |..|..|GTP-U | +-------+ | +-------+ | +-------+ +-----+ | +-----+ +-------+ | +-------+ | +-------+ |PDCP |.....|PDCP | | UDP |..|..| UDP |..|..| UDP | +-----+ | +-----+ +-------+ | +-------+ | +-------+ +-----+ | +-----+ +-------+ | +-------+ | +-------+ | RLC |.....| RLC | |ICN|IP |..|..|ICN|IP |..|..|ICN|IP | +-----+ | +-----+ +-------+ | +-------+ | +-------+ +-----+ | +-----+ +-------+ | +-------+ | +-------+ | MAC |.....| MAC | | MAC |..|..| MAC |..|..| MAC | +-----+ | +-----+ +-------+ | +-------+ | +-------+ +-----+ | +-----+ +-------+ | +-------+ | +-------+ | PHY |.....| PHY | | ETH |..|..| ETH |..|..| ETH | +-----+ | +-----+ +-------+ | +-------+ | +-------+ Uu S1U S5/S8 UE Base Station SGW PGW Figure-7: ICN Deployment in Base station for User Plane When a UE is powered up it will perform attach procedures, and on successful attachment UE can have either ICN or IP or both ICN + IP identity. When user initiates any application on UE, it sends a content request to BS, the request is forwarded by to SGW/PGW using the following order as per Figure-8: User Plane traffic forwarded by Base station on S1U. - UE sends ICN request, then BS can forward this request using ICN transport (if transport exists) or ICN as overlay on IP (if transport is IP) - UE sends IP request, then BS forwards the request using IP natively (if transport is IP). Transport is built either as dual stack (IP +ICN) or native IP. More details about algorithms used in BS are given in next section. - UE sends ICN or IP request, then such request is received with additional qualifiers such as weight, priority, cost etc. and BS will use algorithms and built in logic to interpret priority to forward request using either ICN or IP (If transport is IP). Transport is built either as dual stack (IP +ICN) or native IP. Prakash, et.al. Expires September 29, 2017 [Page 13] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 Base Station (eNodeB) +---------------+ | UE request | ICN +---------+ +--->| content using |-- transport --> | | | |ICN protocol | | | | +---------------+ | | | | | | +---------------+ | | +-+ | | UE request | IP |To mobile| | | +------>| content using |-- transport --> | GW | +-+ | | IP protocol | |(SGW/PGW)| UE | +---------------+ | | | | | | +---------------+ | | | | UE request | Dual stack | | +--->| content using |-- IP+ICN --> | | |IP/ICN protocol| transport +---------+ +---------------+ S1U Figure-8: User Plane traffic forwarded by Base station on S1U 5.3.1 ICN Deployment in SGW/PGW Mobile gateways a.k.a. Evolved Packet Core (EPC), which include SGW, PGW, GGSN (For 3G) are hosting session management functions for UE from initial attach to disconnection. When UE is powered on, it performs NAS signaling and after successful authentication with HSS, it attaches with PGW as per detailed 3GPP messages [TS23.401]. Details of changes required for deploying ICN are described in Figure-9: Modified UE attach procedures for ICN Deployment. 1. Attach:- When UE sends attach request to BS, it contains parameters called Protocol Configuration Option Information Element Information Elements (PCO-IE) containing UE capabilities [TS23.401]. We can use PCO IE TLV to carry ICN related capabilities from UE 2. Attach:- BS forwards attach request to MME, with PCO-IE TLV containing UE capabilities. MME performs authentication and on successful authentication authorization with HSS and communicates to UE using 5. Authentication/security 12.Create Session:- MME forwards Create Session request (CSR) to SGW with PCO-IE capabilities. 13. Create Session request:- SGW forwards Create Session request Prakash, et.al. Expires September 29, 2017 [Page 14] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 (CSR) to PGW with PCO-IE capabilities. 14. IP-CAN Session:- PGW performs session creation function including policy download from PCRF and quota from quota management server. On successful attachment, PGW sends back response to SGW (15. CSR Response) 18. UE Attach:- UE gets successful attachment to PGW with ICN identity. Now it can send/receive content using ICN protocols. +--+ +--+ +---+ +---+ +---+ +----+ +---+ |UE| |BS| |MME| |SGW| |PGW| |PCRF| |HSS| +-++ +-++ +-+-+ +-+-+ +-+-+ +--+-+ +-+-+ | | | | | | | |1.Attach| | | | | | |------->| | | | | | | |2.Attach| | | | | | |------->| | | | | +----------------------------------------------------------+ | | | | | | | | | +----------------------------------------------------------+ | 5. Authentication/security | | | +---------------------------------------------------->| | | | | | | | +----------------------------------------------------------+ | | | | | | | | | +----------------------------------------------------------+ | | |12.Create | | | | | | session+ | | | | | |------->| | | | | | | |13.Create | | | | | | session| | | | | | +------->| | | | | | | |14.IP+CAN | | | | | | session| | | | | | +------->| | | | | |15.Res | | | | | |16.Res |<-------| | | | | |<-------| | | | | |17.Attach | | | | | | accept | | | | | | |<-------| | | | | |18.UE | | | | | | |attached| | | | | | |<-------| | | | | | | | | | | | | Figure-9: Modified UE attach procedures for ICN Deployment Prakash, et.al. Expires September 29, 2017 [Page 15] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 6. Summary We have discussed complexities of LTE network and key dependencies for deploying ICN in control and user plane. Different deployment options described cover different aspects such as interoperability and multi-technology which is a reality for any mobile provider. The ICN deployment options described in Section 3 are based on limited simulation, however the concept works. We can definitely deploy ICN for content delivery in user plane either as an overlay, dual stack or natively (by integrating ICN with CDN, BS, SGW, PGW and routers etc.) however actual deployment scenarios will be specific to a mobile network. As per Cisco Visual Networking Index [VNXIDX] by year 2020, over 80% of mobile traffic will be video and if this can be delivered using ICN from locally cached at BS/MEC, it will be a significant benefit. In order to deploy ICN in LTE mobile gateways, further research is necessary to add capabilities such as modification of PCO-IE field to carry ICN-specific parameters and this has to be standardized by 3GPP by updating TS23.401 attach procedures. Further research is also required for understanding the ICN capability to support deep packet inspection, lawful intercept, billing and mediation because in current architecture all these functionalities are closely associated with IP. In addition, 5G architecture and possible use of ICN provides new capabilities such as network slicing and separation of control and forwarding plane, allowing eNodeB/MEC to function as forwarding plane [CHENG]. Recent research for delivering real-time video content using ICN also proved to be efficient [NDNRTC]. The key aspect for ICN is its seamless integration in LTE and 5G networks with tangible benefits so that we can optimize content delivery using simple and scalable architecture. Prakash, et.al. Expires September 29, 2017 [Page 16] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 7 References 7.1 Normative References [GRAYSON] Grayson M, Shatzkamer K, Wainner S.; Cisco Press book "IP Design for Mobile Networks" by. page 108-112. [IPSEC] Cisco IPSec overhead calculator tool . [BROWER] Brower, E.; Jeffress, L.; Pezeshki, J.; Jasani, R.; Ertekin, E. "Integrating Header Compression with IPsec", Military Communications Conference, 2006. MILCOM 2006. IEEE, On page(s): 1 - 6. [TS23.323] 3GPP TS25.323 Rel. 13 Packet Data Convergence Protocol (PDCP) specification, 11 Dec 2015. [TS23.203] 3GPP TS23.203 v13.7.0 (2016-03) Rel. 13, Policy and charging control and QoS architecture, 15 March 2016 [TS23.401] 3GPP TS23.401 v13.7.0 (2016-03) Rel. 13, E-UTRAN Access procedures architecture, 12 November 2015. 7.2 Informative References [MECSPEC] European Telecommunication Standards Institute (ETSI) MEC specification ETSI-GS-MEC-IEG-001 V1.1.1 (2015-11). [ICN] draft-wissingh-icnrg-terminology-01 [NDNPUB] Named Data Networking . [CCN] Content Centric Networking . [NDN] Lixia Z., Lan W. et al. SIGCOMM Named Data Networking, . [CARLOS] Carlos A., Torsten B. Vasilios S., Information-Centric Networking in Mobile and Opportunistic Network, Springer International Publishing Switzerland, LNCS 8611, pp 14-30, 2014. Prakash, et.al. Expires September 29, 2017 [Page 17] Internet-Draft Deploying ICN in 5G/LTE Mobile Networks March 28 2017 [RAVI] Ravishankar R., Samantha L., Wang G. Supporting seamless mobility in named data networking IEEE ICC 10-15 June 2012, pages 5854-5869. [VNIIDX] Cisco Visual Networking Index (VNI) dated 16 Feb 2016, . [CHENG] Chengchao L., F. Richard Yu, Information-centric network fucntion virtualization over 5G mobile wireless networks, IEEE network (Volume:29, Issue:3), page 68-74, 01 June 2015. [NDNRTC] Peter Gusev,Zhehao Wang, Jeff Burke, Lixia Zhang et. All, IEICE Trans Communication, RealtimeStreaming Data Delivery over Named Data Networking, Vol E99-B, No.5 May 2016. Authors' Addresses Prakash Suthar 9501 Technology Blvd. Rosemont, Illinois 50618 EMail: psuthar@cisco.com Milan Stolic 9501 Technology Blvd. Rosemont, Illinois 50618 EMail: mistolic@cisco.com Anil Jangam 3625 Cisco Way San Jose, CA 95134 USA Email: anjangam@cisco.com Prakash, et.al. Expires September 29, 2017 [Page 18]