Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
1 © Nokia 2018
WiFi Integration
in Evolution to 5G networks
Satish Kanugovi ([email protected])
WiFi Knowledge Summit, Bangalore
March 9, 2018
Outline
• Integrating WiFi Access into the 5G Core
• Multi-Access Edge Computing and WiFi Access
• Common Capacity Management Frameworks
- IETF - Multi Access Management Services (MAMS)
- 3GPP – Access Traffic Steering, Switching and Splitting (ATSSS)
Integrating WiFi Access into the 5G Core
• Non-3GPP access networks are connected to 5G core network via a Non-3GPP Inter-Working Function (N3IWF).
• The N3IWF interfaces to 5G core network control-plane functions and user-plane functions via N2 interface and N3 interface, respectively.
• Only Untrusted Non 3GPP Access is currently in scope, Trusted being discussed for R-16
Non-roaming architecture for 5G core network with non-3GPP accessSource: 3GPP TS 23.501
Untrusted Non-
3GPP AccessUE
N3IWF
3GPP
Access
Data Network
HPLMN
Non-3GPP
Networks
UPF
N3 N6
Y1
Y2
AMF SMF
N2
N2N4
N3
NWu
N11
N1
N1
5G Control Plane for WiFi Access
• UE gets an IP address via the non-3GPP access.
• UE initates IPsec Security Association (SA) with the selected N3IWF by initiating an IKE initial exchange
• UE initiates an IKE_AUTH exchange indicating the use of EAP (EAP-5G) signalling.
• The N3IWF responds with an IKE_AUTH response message which includes an EAP-Request/5G-Start packet and informs UE to encapsulated NAS messages within EAP-5G packets.
• Once the IPsec SA is established between the UE and N3IWF, "signalling IPsec SA“, all NAS messages between the UE and N3IWF are exchanged via this SA.
NAS
EAP-5G
IKEv2 IKEv2
NAS
N2
stack
N2
stackIP IP
Non-3GPP
IP
Non-3GPPLower
layers
Lower
layers
UEUntrusted non-3GPP
access networkN3IWF AMF
Nwu N2
RelayEAP-5G
NAS
IPsec IPsec
NAS
N2
stack
N2
stackIP IP
Non-3GPP
IP
Non-3GPPLower
layers
Lower
layers
UEUntrusted non-3GPP
access networkN3IWF AMF
Nwu N2
Relay
IKEv2 IKEv2
N2
stack
N2
stackIP IP
Non-3GPP
IP
Non-3GPPLower
layers
Lower
layers
UEUntrusted non-3GPP
access networkN3IWF AMF
Nwu N2
Control Plane before the signalling IPsec SA is established between UE and N3IWFSource: 3GPP TS 23.501
Control Plane after the signalling IPsec SA is established between UE and N3IWFSource: 3GPP TS 23.501
Control Plane for establishment of user-plane via N3IWFSource: 3GPP TS 23.501
5G User plane for WiFi Access
• Data, 5G PDUs, over the Non 3GPP access is sent inside the secure tunnel between UE and N3IWF
• UDP can be used as tunnelling protocol in IPsec for NAT traversal.
PDU Layer
GRE GRE
PDU
Layer
N3
stack
N9
stackIP IP
Non-3GPP
IP
Non-3GPPLower
layers
Lower
layers
UEUntrusted non-3GPP
access networkN3IWF
UPF(PDU
Session Anchor)
Nwu N3
Relay
N3
stack
N9
stack
Relay
N9UPF
IPsec IPsec
User Plane for Non 3GPP Access via N3IWFSource: Figure 8.3.2-1, 3GPP TS 23.501
Edge Computing –“Mobile” to “Multi Access”
• ETSI MEC is working on standards for enabling benefits of Edge Computing framework to applications
• In Phase 1, MEC (Mobile Edge Computing) focused on Edge Computing framework for Mobile (cellular) networks
• In Phase 2, Scope has evolved into a Multi Access Edge Computing Platform with support 3GPP and non-3GPP access technologies (WiFi and fixed) Overview of Multi Access Edge Computing [1]
Extending MEC to WiFi networks
• ETSI MEC Phase 1 has published Radio Network Information Service (RNIS) APIs for Applications take advantage of real time radio network information to improve service delivery
- http://www.etsi.org/deliver/etsi_gs/MEC/001_099/012/01.01.01_60/gs_MEC012v010101p.pdf
- MEC applies Analytics (e.g. Mashup) on information coming from multiple RATs and provide feedback (e.g. ETSI RNIS APIs) in a way suitable for use by applications
- Can be easily extended to support information exposure from additional RATs, like Wi-Fi, 5G, DSL, individually or in combination.
• ETSI MEC Phase 2 will extend the information exposure to other access technologies
• New Service to specify WiFi access information. Some examples of nature of information that could be exposed:
- BSS Load (station count, channel utilization, admission capacity)
- STA statistics (STA counters, BSS avg delay, etc)
- Estimated throughput UL/DL
- WAN metrics (DL speed/load, UL speed/load)
- STA RSSI
• Builds on existing and ongoing work from WFA e.g. Multi-AP Services, Data Elements and Hotspot 2.0.
WiFi + Cellular – Common Capacity Management
• Application QoE (quality of experience) varies with choice of access technology
• Performance depends on factors like radio conditions, user population, actual network
utilization
• Wi-Fi offers good capacity with small number of users which quickly degrades, low
throughputs and large unpredictable delays due to poor MAC efficiency.
• LTE offers predictable performance but capacity is limited by available licensed
spectrum
• Combining the best of WiFi and Cellular can deliver the best value from the network
IETF MAMS
• MAMS (Multi Access Management Services) is a framework for - Integrating different access network domains based on user plane (e.g. IP layer) interworking,
- with ability to select access and core network paths independently
- and user plane treatment based on traffic types
- that can dynamically adapt to changing network conditions
- based on negotiation between client and network
• The technical content is available as the following drafts*- Multi Access Management Services (MAMS) Framework – https://datatracker.ietf.org/doc/draft-kanugovi-
intarea-mams-framework/
- MAMS JSON definitions of Control Plane Messages: https://www.ietf.org/id/draft-agarwal-intarea-mams-protocol-json-00.txt
- MAMS User Plane Specification: https://tools.ietf.org/html/draft-zhu-intarea-mams-user-protocol-02
*Currently under review, Co-authors: Nokia, Intel, Broadcom, Huawei, AT&T, KT,
• MAMS functional elements
- Network Connection Manager (NCM)
• Intelligence in the network to configure network paths and user plane protocols based on client negotiation
• Gateway for common multi-network view, network policy input and Interface to Application Platforms
- Client Connection Manager (CCM)
• Negotiates client’s capabilities and needs with the NCM and configures network path usage
- NCM – CCM message exchange enables
• Dynamic selection of best network paths
• Flexible configuration of MADP protocols and parameters
• Overlay and Extensible messaging (e.g. JSON over WebSocket)
- Multiple Access Data Proxy (C/N-MADP)
• C-MADP handles user plane functions at the client and N-MADP at network.
• User plane distribution and aggregation across configured network paths.
• Supports any user plane protocols including existing IETF protocols like TCP, UDP, MPTCP, SCTP, QUIC, GRE, …
MAMS Architectural Framework
DSL/FIXED
ACCESS NODE
(ROUTER)
WI-FI ACCESS
NETWORK
(ACCESS
POINT)
ACCESS NETWORKS
DSL/FIXED
CORE
WLAN
CORELTE CORE
CORE NETWORKS
LTE ACCESS
NETWORK (ENB)
NETWORK
CONNECTI
ON
MANAGER
(NCM)
NETWORK
MULTI
ACCESS
DATA
PROXY
(N-MADP)
MAMS Enabled Network
APPLICATION
SERVER
CLIENT
CLIENT
CONNECTI
ON
MANAGER
(CCM)
CLIENT
MULTI
ACCESS
DATA
PROXY
(C-MADP)
5G
(GNB)
5G CORE
MEC
(Access Edge)
Core User Plane
Gateway
(multiple)
NCM and N-
MADP
instances
can be
hosted at
Access Edge
and/or Core
Gateways
MAMS
Control Plane
MAMS
User Plane
• Applications accessed via LTE core (cellular
service subscription and authentication) can
take advantage of Wi-Fi capacity in uplink
and downlink
• Flexibility in choosing Wi-Fi access even
when LTE core is used as IP anchor
• Support high bandwidth demanding video
downloads on LTE connections using Wi-Fi
DL
• Support LTE Core routed cloud video
content uploads using Wi-Fi UL
• MEC controls and monitors usage of Wi-Fi
access
MAMS at MEC integrating LTE and Wi-Fi networksUse case 1: Support high UL/DL BW applications with LTE [7]
WI-FI ACCESS
NETWORK
(ACCESS POINT)
ACCESS NETWORKS
WLAN
CORELTE CORE
CORE NETWORKS
LTE ACCESS
NETWORK (ENB)
(NCM) (N-MADP)
APPLICATION
SERVER
CLIENT
CLIENT
CONNECTION
MANAGER
(CCM)
CLIENT MULTI
ACCESS DATA
PROXY
(C-MADP)
MEC
• Enterprise improves its services by offloading
Uplink of Enterprise services to LTE uplink that
are then shunted across back to the enterprise
WLAN infrastructure
• All enterprise traffic stays local – avoids traversal
through operator core
• ‘Big’ gains in VoWiFi capacity
• Simple, scalable solution towards all-wireless
enterprise that leverages LTE
- Internet access possible through enterprise core
MAMS at MEC integrating LTE and Wi-Fi networksUse Case 2: Using LTE UL to improve QoE for ‘Wi-Fi’ Apps [7]
WI-FI ACCESS
NETWORK
(ACCESS POINT)
ACCESS NETWORKS
WLAN
CORELTE CORE
CORE NETWORKS
LTE ACCESS
NETWORK (ENB)
(NCM) (N-MADP)
APPLICATION
SERVER
CLIENT
CLIENT
CONNECTION
MANAGER
(CCM)
CLIENT MULTI
ACCESS DATA
PROXY
(C-MADP)
MEC
3GPP Access Traffic Steering, Switching and Splitting (ATSSS)
• 3GPP TR 23.793 has in its scope the study of architectural aspects and solutions for
extending the 5G System (5GS) to support Access Traffic Steering, Switching and
Splitting (ATSSS) between 3GPP and non-3GPP access networks.
• Initially, the study considers ATSSS solutions that enable traffic selection, switching and
splitting between NG-RAN and untrusted non-3GPP access networks.
• Subsequently, after the 5GS architecture is enhanced to support trusted non-3GPP
access networks.
Proposed Solutions in ATSSS TR 23.793 (0.2.0, work in progress)
Solution 1: Proposed architecture framework for ATSSS
UE Untrusted Non - 3GPP Access
3GPP Access
Data Network N3IWF
UPF
AMF SMF PCF AF
AUSF UDM
N2
N3
N3
N2 N14
N1 N15
N6
N4
N13
N12 N10 N8
N5 N7 N11
N9
Y1
Y2 N1 NWu
UE - AT3SF
UP - AT3SF
SM - AT3SF PC - AT3SF
UDR - AT3SF
N25
Virtual
Interface
NG-RAN
UPF-2
(optional)
UPF-1
(optional)
UPF-A
IP
5GWL
AN
Child PDU
session #1
UE
N6AMF
N2
N2
N3
N3
SMFN4N11
WLAN
AN
N3IWFChild PDU
session #2
Multi-Access
PDU session
Solution 2: Support of Multi-Access PDU Sessions
Traffic Distribution function
Traffic Recombination function
ATSSS Policy Enforcement function
Path performance measurement Path performance measurement
User plane
SMF
Link detection
Control plane
UE
Traffic Steering Switching & Splitting rules
PDU session data
ATSSS Traffic
Control function
PDU session data
UPF
ATSSS Traffic
Control function
Traffic Distribution function
Traffic Recombination
function
PCFATSSS Policy Control function
Traffic Steering Switching & Splitting policies
3GPP access
Non-3GPP access
N3
N3
N4
NCP
Encapsulation
NCP
Decapsulation
NCP
Decapsulation
NCP
Encapsulation
Solution 3: NCP based architecture framework for ATSSS
References
[1]MEC Introduction Slides, ETSI MEC
[2] MEC Deployments in 4G and Evolution Towards 5G, ETSI MEC Whitepaper
[3] 3GPP TS 23.501, System Architecture for the 5G System; Stage 2 (R15)
[4] 3GPP TS 23.502, Procedures for the 5G System; Stage 2 (R15)
[5] 3GPP TR 23.793, Study on Access Traffic Steering, Switching and
Splitting support in the 5G system architecture (R16)
[6] IETF MAMS Framework draft (under review) - http://www.ietf.org/id/draft-kanugovi-intarea-mams-framework-00.txt
[7] MAMS (Multi Access Management Services) framework for MEC, Broadband Forum Birds of a Feather Webinar - MEC Part 2, BBF2017.556