LT LTE/ E/EPC EPC Ar Archite itectur cture e fo for r On-De - PowerPoint PPT Presentation

New Control Pla Ne trol Plane e in in 3GPP 3GPP LT LTE/ E/EPC EPC Ar Archite itectur cture e fo for r On-De On Deman mand d Connec ectiv tivity ity Se Serv rvic ice Siwar BEN HADJ SAID¹, Malla la Reddy SA SAMA¹, Karine GUILLOUARD¹, Lucian SUCIU¹, Gwendal SIMON², Xavier LAGRANGE² and Jean Marie BONNIN² ¹Orange Labs, France ²Télécom Bretagne, France IEEE CloudNet’13 San Francisco, USA 11-13 Nov 2013 France Telecom - Orange confidential

Outline Introduction & Background I. OF-Based LTE/EPC Architecture II. I. Architecture Description II. Data Plane Establishment Procedure On-Demand Connectivity Service III. I. Resiliency II. Load Balancing Implementation Challenges IV. Conclusion & perspectives V. France Telecom - Orange confidential 2

Introduction  Mobile data traffic has been growing at an unprecedented rate over the last few years.  Huge data traffic increase and may cause signaling storms in the network. – Smartphones and tablets generate 40% of the data traffic and 99% of the signaling traffic. France Telecom - Orange confidential 3

LTE/EPC Architecture  The LTE/EPC has been designed to support only packet based services.  The EPC has a flat, all-IP architecture with separation of control plane and data plane. MME S6a (Diameter) HSS Control Plane User Plane S11 (GTP-C) S1 (S1-AP) eNB SGW-C PGW-C S5 (GTP-C) External Packet SGi SGW-D S5 (GTP-U) PGW-D S1(GTP-U) Data Networks UE eNB Evolved Packet Core (EPC) E-UTRAN France Telecom - Orange confidential 4

LTE/EPC Drawbacks  The initial attachments lead to a systematic establishment of the data plane, even when there is no data traffic to be sent.  The data plane establishment procedure is unaware of the session type.  The TEID values are locally allocated by each node  new TEID values should be exchanged for each node relocation. France Telecom - Orange confidential 5

LTE/EPC Drawbacks - 2  SGW could be a bottle neck for possible user traffic congestion.  Network equipment failure. PGW This PGW can be Home any where in all PDN over the world SGW PGW Semi-distributed PGW IMS GW (SGi) Internet This PGW could be allocated per (Ex. SIPTO above RAN) county or region. France Telecom - Orange confidential 6

OF-Based LTE/EPC Architecture  Separation of control and MME SGW-C data plane from SGW. API S5 (GTP-C) OpenFlow Controller  Replacing S1-MME and S11 OpenFlow interfaces with OF. protocol  SGW-D represents an PGW-C SGW-D advanced OF switch that is eNB PGW-D able to en/decapsulate GTP S5 (GTP-U) packets. UE SGW-D ) U - P T G ( 1  Unique TEID values per S session. SGW-D eNB  eNB keeps the same radio functions. France Telecom - Orange confidential 7

On-Demand Connectivity Service - Resiliency - Load Balancing France Telecom - Orange confidential 8

Resiliency – 3GPP LTE/EPC case  The 3GPP restoration procedure related to the SGW failure is not transparent as it cuts off active sessions.  Session re-establishment of impacted users may generate significant amount of signaling. France Telecom - Orange confidential 9

Resiliency – OF-Based LTE/EPC case  Easily manage the active sessions during any SGW-D failures.  Less packet loss.  Centralized the TEID allocation function. France Telecom - Orange confidential 10

Load Balancing – 3GPP LTE/EPC case  SGW and PGW selection is performed by the MME.  Offline weight factors in DNS server.  Proactive load balancing.  SGW could be a bottle neck for possible user traffic congestion. France Telecom - Orange confidential 11

Load Balancing – OF-Based LTE/EPC case  Real time load statistics.  Free the overloaded SGW by moving some sessions seamlessly to another SGW in the same domain. France Telecom - Orange confidential 12

Implementation Challenges  SGW control and data plane separation.  Building mobile network based OF controller.  The OF protocol should be extended to transport the UE-MME exchanges transparently, e.g. – Authentication messages – Mobility messages  Shifting all control plane entities into cloud platform. France Telecom - Orange confidential 13

Conclusion & Perspectives  Proposal osal: OpenFlow-based control plane for LTE/EPC architecture – The SGW control plane is separated from the data forwarding plane – The SGW control plane is centralized and uses the OpenFlow protocol to remotely manage the SGW data forwarding plane  The proposed architecture ensures the on-demand connectivity service even in critic situation such as network equipment failure and overload situations  Perspect spectives: ives: – Realize a testbed to validate the resiliency and load balancing aspects in our proposal – Try to make standardize the OF-based LTE/EPC in ONF working groups. France Telecom - Orange confidential 14

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