Internet DRAFT - draft-sfc-sinha-5g-bearer-filter-dual-access
draft-sfc-sinha-5g-bearer-filter-dual-access
Service Function Chaining Sunil Kumar Sinha
Internet-Draft Infinite Computing Solutions
Intended status: Informational Amardeep Sinha
Expires: December 18, 2018 Reliance Jio Infocomm Limited
Harsh Vardhan Singh Chauhan
Nokia
Manish Srivastava
Commscope Networks
June 19, 2018
5G-Core System Split Bearer's FILTER for Dual Access
draft-sfc-sinha-5g-bearer-filter-dual-access-00
Abstract
This document attempts the case for new work that need to be
developed for 5G user to improve faster download and upload of user's
data via FILTER mechanism to be implemented at UPF user plane data
for dual-access outlining the poor radio coverage issue. FILTER
template governs the user data split at UPF with maintaining agreed
PCC rules to achieve required throughput.
Status of This Memo
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This Internet-Draft will expire on December 18, 2018.
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Table of Contents:
1. Introduction...................................................2
2. Conventions and Terminology....................................2
3. User data flow for Dual Access and problem statement...........2
3.1 5G System architecture.....................................2
3.2 QoS........................................................3
3.3 Dual Connectivity..........................................4
3.4 Problem Statement..........................................4
4. 5G-Core System split bearer's FILTER for dual Access...........4
5. Security Considerations........................................6
6. IANA Considerations............................................6
7. Privacy Considerations ........................................6
8. Acknowledgements...............................................7
9. References.....................................................7
9.1. Normative References......................................7
9.2. Informative References....................................7
Authors' Addresses................................................7
1. Introduction
5G system have been evolved to server user in more efficient way of
meeting higher download and upload of user data, whereas 5G Users
accessing the network via wireline and wireless, in addition to this
Residential Gateway RG and IoT support is also defined. Access and
user experience is a challenging for poor radio coverage (for both
wi-fi and RAN). Hence re-engineering proposal has made in this
document of 5G-Core entity UPF which is connected to Data Network
handling user plane.
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 [RFC2119].
3. User data flow for Dual Access and problem statement
3.1 5G System architecture
A simplified architectural diagram of 5G-system catering to both
access type 3GPP and Wi-Fi being supported by UE is shown in Figure 1
below.
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+--------------------------------------------------------+
| +----------------------------+ |
| | +------------------+ | |
| | | | | |
| | | |N8 |N15 |
| | | | | |
| +------+ | | +------+ N13 +---+ | |
| | NSSF |--+ | | | AUSF |-------|UDM| | |
| +------+ | | | +------+ +---+ | |
| | | | | | | |
| | | | | | | |
N3| N22| | | |N12 N10| +---+ N5 +--+ |
| | | | +---+ | |PCF|------|AF| |
| | | | | | +---+ +--+ |
| | | | | | | |
+-----+ +---------+ +-----+ | |
| RAN |------| AMF |-----------| SMF |----+ |
+-----+ N2 +---------+ N11 +-----+ N7 |
| | | |
+--+ Uu | | | |
| |-----+ |N2 |N4 |
|UE| | | |
| |-----+ | | |
+--+ Y1 | +----------+ +---------+ |
| | | |
| | | |
+--------+ N3 +-----+ N6 +-------------+ |
|AP+N3IWF|---------------| UPF |------| Service N/W | |
+--------+ +-----+ +-------------+ |
| |
+-------------------------------+
Figure 1 : Simplified 5G System Architecture for Multi access
For the clarity in the current document proposal, multiple node/
function like UDSF, NRF, and interfaces N9, N14 are not shown.
5G-system supporting UE access to the network function and services
via non-3GPP like WLAN or Wi-Fi. The N3IWF interface connect UE with
5G-core network via N2 and N3 interface.
3.2 QoS
QFI is defined as QoS Flow ID is an 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 receives
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.
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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) functionality support the network to make use
of additional radio resource to achieve required throughput in
downlink and uplink of user data. This was introduced in 4G system
support 5G data speed by addition of dual connectivity of UE with
eNBs, master eNB and secondary eNB and /or eNodeB in congestion with
gNB. This is achieved by addition of secondary eNodeB to the Master
eNodeB. MeNB has full control to add, delete and HO(handover) of
eNodeBs as and when needed.
3.4 Problem Statement
Problem statement: In spite, in a Dual connectivity of 5G system,
Master-gNB may have degrade radio condition and neither another
Master-gNB nor secondary gNB available to support user data traffic
and Secondary-gNB is available with sufficient radio resource.
4. 5G-Core System split bearer's FILTER for dual Access
4G system was designed such that it provides one default bearer for
each APN type (service type). That is UE after attach procedure with
access network, PGW create default data bearer of QCI=9 for data
service. Again, if UE has voice capability, then it triggers new PDN
connect request for APN=ims for voice & Video services, for which
P-GW creates QCI=5 bearer as a default bearer.
5G system is designed to support dual access mechanism such that
both 3GPP and non-3GPP access at same time. In this case P-GW needed
to maintain two default bearers for each APN instead of one, as
explained below.
Please note: How an APN with same name to maintain two defaults
bearers or APN name to be modified for each access type is out of
scope of this document. However, details of setup procedure and call
flow mechanism is beyond the scope of this draft,
draft-sinha-5g-split-bearer-dual-access-00 can be referred.
As shown in figure 2, for APN=data
- PGW will create a default bearer QCI=9 for Wi-Fi access
- PGW will create another default bearer QCI=9 for RAN access
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UPF
+---------------------------+
| |
| Default bearer QCI=9 | Access=Wifi
+-----+ N3 | |<==================>| | APN=data
|N3IWF|------------| |----------+
+-----+ | |<==================>| | |
| | Dedicated bearer || | |
Y1| | || | |
| | || | +--------+
UE -----+ | FILTER | |Data N/W|
| | || | +--------+
Uu| | || | |
| | Dedicated bearer || | |
+-----+ N3 | |<==================>| | |
| RAN |------------| |----------+
+-----+ | |<==================>| | Access=RAN
| Default bearer QCI=9 | APN=data
| |
+---------------------------+
Figure 2: 5G user for Data Service with default-bearer for each
access-type
and as shown in figure 3, for APN=ims
- PGW will create a default bearer QCI=5 for Wi-Fi access
- PGW will create another default bearer QCI=5 for RAN access
UPF
+---------------------------+
| |
| Default bearer QCI=5 | Access=Wi-Fi
+-----+ N3 | |<==================>| | APN=ims
|N3IWF|------------| |----------+
+-----+ | |<==================>| | |
| | Dedicated bearer || | |
Y1| | || | |
| | || | +--------+
UE -----+ | FILTER | | IMS N/W|
| | || | +--------+
Uu| | || | |
| | Dedicated bearer || | |
+-----+ N3 | |<==================>| | |
| RAN |------------| |----------+
+-----+ | |<==================>| | Access=RAN
| Default bearer QCI=5 | APN=ims
| |
+---------------------------+
Figure 3: 5G user for IMS Service with default-bearer for each
access-type
Take for example IMS registration via SIP protocol, UE will send sip
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registration for RAN on QCI=5 and for Wi-Fi on separate QCI=5
Taking an example of voice call, one voice call established over RAN
with QCI=1 and another voice call can be established in parallel over
Wi-Fi over separate QCI=1. This dedicated bearer MUST be implemented
with FILTER mechanism for data sharing.
In case of poor radio coverage of RAN, for example, split bearer
between RAN and Wi-Fi using this FILTER such that some part of audio
packets are delivered to user via RAN and some via Wi-Fi, thus
enhancing the user experience.
SMF will be splitting the downlink packet in SPLIT mode via FILTER
mechanism while maintaining PCC rule in tagged.
Traffic FILTER mechanism is needed to be implemented between each
QCI type for same APN, for only for DEDICATED bearer, not default
bearer. This Filter mechanism will control traffic packet
segmentation to be delivered on each of QCI.
5. Security Considerations
Security considerations related to the 5G systems are discussed in
[NGMN]. Due to the request for intrinsic realization of security
such aspects must 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.
6. IANA Considerations
None.
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
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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 criticisms from Karthik Palaniswamy and
Nagesh V. J. are respectfully acknowledged.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
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.
[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.
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[ETSI GR NGP 004]
"Next Generation Protocol (NGP): Evolved Architecture for
mobility using. Identity Oriented Networks.",January2018.
[ETSI GR NGP 001]
"Next Generation Protocol (NGP); Scenario Definitions".
,May 2017
[NGMN]
NGMN Alliance, "NGMN White Paper", February 2015.
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, Maharastra
India
Email: sinha.amardeep@gmail.com
Harsh Vardhan Singh Chauhan
Gwalior, MP
Email: chauhan.harsh_vardhan@nokia.com
Manish Srivastava
Gr Sagarnivas,
Central Jail Road,
Bangalore, Karnataka,
India
Email: manishshree92@gmail.com
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