Service Function Chaining Sunil Kumar Sinha Internet-Draft Infinite Computing Solutions Intended status: Informational Amardeep Sinha Expires: December 9, 2018 Reliance Jio Infocomm Limited Yogesh Chandeshware Mavenir Devendra Kumar Singh Ericsson June 10, 2018 5G System Split Bearer in Dual Connectivity of WiFi draft-sfc-sinha-5g-bearer-dc-wifi-00 Abstract This document attempts the case for new work that needs to be developed for 5G users to improve faster download and upload of user's data in a scenario of dual-connectivity for non-3GPP access outlinig the poor wifi coverage issues. This document also outlines the faster user data mechanism accompanying non-3GPP access of 5G user device via split bearer in case of a poor coverage. 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 Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on December 9, 2018 Copyright Notice Copyright (c) 2018 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 (https://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. sinha Expires December 9, 2018 [Page 1] Internet-Draft 5G Split Bearer DC of WiFi June 2018 Table of Contents: 1. Introduction................................................2 2. Conventions and Terminology.................................2 3. User data flow for Dual Connectivity for non-3GPP Access and problem statement...........................................2 3.1 5G System Architecture..................................2 3.2 QoS.....................................................3 3.3 Dual Connectivity.......................................3 3.4 Problem Statement.......................................3 4. Proposal for Split Bearer in Dual-Connectivity of Non-3GPP access.............................................4 5. IANA Considerations.........................................5 6. Security Considerations.....................................5 7. Privacy Considerations .....................................5 8. Acknowledgements............................................5 9. References1.................................................5 9.1. Normative References...................................6 9.2. Informative References.................................6 Authors' Addresses.............................................7 1. Introduction 5G System has been evolved to serve user in more efficient way of meeting higher download and upload of user data, 5G Users accessing the network via wireline and wireless, in addition to Residential Gateway RG and IoT support.In 5G System, access and user experience are a challenging for poor radio coverage for both wi-fi and RAN. The proposal in this document address to the problem of non-3GPP access only when having poor coverage. 2. Conventions and 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 [1]. 3. User data flow for Dual Connectivity for non-3GPP Access and problem statement 3.1 5G System Architecture 5G System supporting UE access to the network function and services via non-3GPP is shown in Figure-1. An example of such access is like WLAN or Wi-Fi. The N3IWF interface connect UE with 5G core network via N2 and N3 interface. sinha Expires December 9, 2018 [Page 2] Internet-Draft 5G Split Bearer DC of WiFi June 2018 +-------------------------------+ | | | +------------------+ | | | |N8 |N15 | | | | +------+ | | +------+ N13 +-----+ | | NSSF |---+ | | | AUSF |-------| UDM | | +------+ | | | +------+ +-----+ | | | | | | | | | | | | | N22| | | |N12 |N10 +-----+ N5 +----+ | | | +---+ | | PCF |------| AF | | | | | | +-----+ +----+ | | | | | | +--------+ +-------+ +-----+ | UE---|AP|N3IWF|-----| AMF |------------| SMF |-------+ +--------+ N2 +-------+ N11 +-----+ N7 | | |N3 |N4 | | | +-----+ N6 +-------------+ +------------------------------| UPF |--------| Service N/W | +-----+ +-------------+ Figure 1 : Simplified 5G System Architecture for Wi-Fi access 3.2 QoS QFI is defined as QoS Flow ID is a identity to QoS flow in the 5G System. All data traffic within a PDU session are each labelled or identified by QFI, implies same QFI labelled data flow will receive same traffic forwarding treatment like scheduling, priority, etc. Data flow is via N3 (and N3 and N9) interface, being encapsulated end-to-end. This flow is controlled by SMF, who provides QoS profile during session establishment to R(AN) and provide the PDR to the UPF. Please Note that like 4G System, default QoS flow is applied to each PDU session and retain till lifetime span of connectivity. In case of non-3GPP access QFI is delivered to N3IWF entity (or NG-RAN) for every time User Plane of the PDU session is established, modified or activated. 3.3 Dual Connectivity Dual connectivity (DC) concept developed for 3GPP access, functionality support the network to make use of additional radio resource to achieve required throughput in downlink and uplink of user data. Same concept has been introduced in this document for non-3GPP access via Access-Point acting as master-AP and Secondary-AP. 3.4 Problem Statement sinha Expires December 9, 2018 [Page 3] Internet-Draft 5G Split Bearer DC of WiFi June 2018 Problem statement 1: 5G user accessing network over wifi connection often have non-coverage issue resulting in poor user experience Proposal made in this document to make user of wifi access nearest to user and delivering the user data without affecting user experience. 4. Proposal for Split Bearer in Dual-Connectivity in Non-3GPP access Referring to document [20160157293 A1], the solution proposed in this document to solve the degrade wifi radio resource connected to UE. N3IWF /WLC acting as a Wi-Fi aggregation point will deliver user-data via more than one AP (Access Point). As shown in figure 2 below,in case of wifi dual connectivity (DC), different from 3GPP standard, N3IWF have full control to on the deliver of user data by splitting it into multiple Access Points. 'Wifi Aggregation' functionality of WLC. 5G user being served by multiple Access Points and each of these Access Points has independent connectivity with N3IWF, which is different from DC functionality of 3GPP. Master-AP +-----+ | AP1 |-----+ +-----+ | | | |Y1 |Y2 +-----+ | | | | +-----+ N2 +-----+ N11 +-----+ UE |N3IWF|------| AMF |-------| SMF | | +-----+ +-----+ +-----+ | | | | +-----+ | | | | | | | |Y1 Y2| | | | | |N3 |N4 +-----+ | | | | AP2 |-----+ | | +-----+ | | Secondary-AP | | | +-----+ N6 +-------------+ +---------------------| UPF |------| Service N/W | +-----+ +-------------+ Figure 2: Bearer split in Dual-Connectivity in Non-3GPP access N3IWF have enhanced aggregation feature of governing single user data on multiple Access Points. That is N3IWF control user data delivery via two Access Points namely Master-AP and Secondary-AP. Based on Wi-Fi radio resource condition, N3IWF SHOULD take decision to split user data delivery via multiple Access-Points. sinha Expires December 9, 2018 [Page 4] Internet-Draft 5G Split Bearer DC of WiFi June 2018 N3IWF MUST also completely switch all the user data to Secondary-AP and releasing them from Master-AP. Thereafter Secondary-AP will be referred as Master-AP. 5. IANA Considerations None. 6. Security Considerations Security considerations related to the 5G Systems are discussed in [NGMN]. Due to the request for intrinsic realization of security such aspects have to be considered by design for architecture and protocols. Especially as a joint usage of resources and network functions by different separate logical network slices (e.g. in terms of virtual network functions) seems to be inevitable in the framework of 5G the need for strong security measures in such an environment is a major challenge. 7. Privacy Considerations Support of full privacy of the users (customers and tenants / end service providers) is a basic feature of the next generation trusted and reliable communications offering system. Such a high degree of ensured privacy shall be reflected in the proposed architecture and protocol solutions. Especially as Identifiers and mapping of locators to them are addressed some privacy concerns arise. Mobility solutions tend to expose unique identifiers. A solution inside the mobile network exposes these identifiers to the network operator, which is not a big deal since the network operator already has information about the device's location. In contrast, an IP level solution exposes both the identifiers and the locations at the IP layer. That means that web sites, for example, can now track the device's successive locations by watching the IP address. Solutions such as transporting the identifiers not as part of the IP header should be considered. 8. Acknowledgements This work has been partially performed in the framework of the cooperation Config. Contributions of the project partners are gratefully acknowledged. The project consortium is not liable for any use that may be made of any of the information contained therein. Comments, constructive critisms from Karthik Palaniswamy and Nagesh V. J. are respectfully acknowledged. 9. References sinha Expires December 9, 2018 [Page 5] Internet-Draft 5G Split Bearer DC of WiFi June 2018 9.1. Normative References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . 9.2. Informative References [TS23.501] "3GPP TS23.501, System Architecture for the 5G System (Release 15)", March 2018. [TS36.300] "3GPP TS36.300, Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description", March 2018. [20160157293 A1] "Method to Provide Dual Connectivity Using LTE Master eNodeB and Wi-Fi Based Secondary eNodeB", June,2016. [TS23.502] "3Procedures for the 5G System", March 2018. [TS23.228] "IP Multimedia Subsystem (IMS)", March 2018. [TR38.801] "Study on new radio access technology: Radio access architecture and interfaces", March 2017. [TR23.793] "Study on Access Traffic Steering, Switch and Splitting support in the 5G system architecture.", April 2018. [TR23.793] "Study on Access Traffic Steering, Switch and Splitting support in the 5G system architecture.", April 2018. [ETSI GR NGP 004] "Next Generation Protocol (NGP):Evolved Architecture for mobility using. Identity Oriented Networks.",January 2018 [ETSI GR NGP 001] "Next Generation Protocol (NGP); Scenario Definitions". ,May 2017 [NGMN] NGMN Alliance, "NGMN White Paper", February 2015. sinha Expires December 9, 2018 [Page 6] Internet-Draft 5G Split Bearer DC of WiFi June 2018 Authors' Addresses Sunil Kumar Sinha FF-01, Rainbow Residency, Green Glan layout, Bellandur, Bangalore Karnataka, India Email: sunilkumarsinha9@gmail.com Amardeep Sinha C-1003, Yashodeep Heights, Sec-29C, Airoli, Navi-Mumbai, Maharashtra, India Email: sinha.amardeep@gmail.com Yogesh Chandeshware Shasi Nivas, 1st Street , F main, Vijaya Vank Colony Extn, Banaswadi, Bangalore Karnataka, India Email: yogeshjc017@gmail.com Devendra Kumar Singh C-411, Dodabakundi , Outer Ring Road, Near Alpine Eco Apartment, Ferns City, Chinnapalya, Bengaluru, India Email: dev.singh.raj@gmail.com sinha Expires December 9, 2018 [Page 7]