DISTRIBUTED/DYNAMIC MOBILITY MANAGEMENT(DMM) PROBLEM STATEMENT

Dapeng Liu (China Mobile)Hidetoshi Yokota (KDDI)Charles E. Perkins (Tellabs)Melia Telemaco (Alcatel-Lucent)Pierrick Seite (France Telecom)H. Anthony Chan (Huawei)Wassim Haddad (Ericsson)Hui Deng (China Mobile)Elena Demaria (Telecom Italia)Carlos Bernardos (UC3M)Jun Song (ZTE)

Nov. 2010

Outline

• Introduction of Distributed and Dynamic Mobility Management

• Problem Statement of Dynamic Anchor

• Problems with Centralized Mobility Anchor

• Summary

Introduction of Distributed and Dynamic Mobility Management- Background and Current Status

IETF#78Bar Bof

• China Mobile/KDDI/France Telecom/Telecom Italia• Alcatel-Lucent/Ericsson/Tellabs/Huawei/ZTE/UC3M/NSN• Finished PS/Scenario drafts

• More discussion in IETF• MEXT DMM session in IETF#79

• IETF#78 Barbof• Around 30 attendees• 5 presentations

Interestgroup Next

Assumptions and Methodology of DMM

Introduction of Distributed and Dynamic Mobility Management- Assumptions and Methodology

• Based on current mobility architecture• No New Mobility Architecture

• Progressive Approach• Deployment considerations -> protocol extensions

• Dynamic Anchoring -> Distributed Anchoring

• Flat Data Plane• Offload traffic to the nearest

GW

• Centralized Control Plane

• Centralized control and management

DMM Introduction --- Network Evolution TrendMobile Network is Evolving Towards Flat Architecture

Flat NetworkArchitecture

Wi-Fi

User Plane: Flat

Account User DataPolicyManagement

Control Plane: Centralized

BSC

BTS

SGSN

GGSN

2G

RNC

NB

SGSN

GGSN

3G

eNB

SGW

PGW

LTE/SAELTEDriving Force of Network

Architecture Evolution

3GPP is Specifying LIPA(Local IP Access) andSIPTO (Selected IP Traffic Offload) Architecture

• Traffic Offloading• Traffic is increasing very fast in

the era of Mobile Internet

• Operator needs to lower the operation cost

• Content is Distributed to Network Edge

• CND/Cache

Backhaul

Residential / Enterprise network

H(e)NBH(e)NB-

GW

Mobile Operator Core Network

MN

LIPA L-GW

DMM Introduction --- Network Evolution Trend

Local IP Access （ LIPA ） Scenario

• All the Traffic Needs to go through an Centralized Anchoring Point • Content servers and cache servers are getting deployed at the edge of the

network (, which is good for fixed network providers and users)• Centralized mobility anchor in the mobile core is not very suitable for accessing

the localized content server scenario

L-GW

L-GW L-GW

Local Content

Internet

P-GW

L-GW

S-GW

L-GWL-GW

Centralized Mobility Anchor

• Anchoring at the local gateway (L-GW) is beneficial for both operators (efficient resource usage) and end users (lower latency)

• It becomes more efficient if the L-GW allows the mobile to choose a seamless connection or a shortest-path connection (valid only at the current location)

Mobility Anchor Needs to be Distributed along with the Local Gateways

DMM Introduction - Motivation

Outline

• Introduction of Distributed and Dynamic Mobility Management

• Problem Statement of Dynamic Anchor

• Problems with Centralized Mobility Anchor

• Summary

Problem Statement of Dynamic Anchor• Infrequent Mobility for Mobile Internet Users

• Mobile devices remain attached to the same point of attachment

• Application may Not Require Mobility• Example ： YouTube/hulu/Web

• However, current mobility support has been designed to be always on

• Maintain the context for each mobile subscriber as long as they are connected to the network.

• This can result in a waste of resources and ever-increasing costs for the service provider.

Infrequent mobility and intelligence of many applications suggest that mobility can be provided dynamically, thus simplifying the context maintained in the different nodes of the mobile network.

Mobility Anchor Need to be Dynamically Assigned

Problem Statement of Dynamic Anchor

MA1 MA MA MA2MA

CN

MN MN

• It should be enough to provide handover capability only when it is really needed.

• If the mobile host is nomadic meaning once attached, rarely moved, or is idle in most of time

• If the mobile node moves away from MA1, while maintaining communications, two mobility anchors will come into play.

• MA1 for the traffic initiated via MA1,MA2 for traffic initiated via MA2

Dynamic Anchor Example

MA: Mobility Agent

Outline

• Introduction of Distributed and Dynamic Mobility Management

• Problem Statement of Dynamic Anchor

• Problems with Centralized Mobility Anchor

• Summary

Problem Statement of Centralized Mobility Anchor

Distributed Mobility Management Concept

MA: mobility Agent

Home network withCentralized Mobility

AnchorVisited network

MN CN

MA MA MA MA

MN CN

Problems with Centralized Mobility Anchor-(1) Routing

• Routing via a centralized anchor is often longer, so that those mobility protocol deployments that lack optimization extensions results in non-optimal routes, affecting performance

• Routing optimization may be an integral part of a distributed design.

MA MA MA MA

MN CN

• As mobile network becomes more flattened, centralized mobility management can become more non-optimal, especially as the content servers in a content delivery network (CDN) are moving closer to the access network

• In contrast, distributed mobility management can support both hierarchical network and more flattened network.

SGW SGW SGW

MN

P-GW

CDN/Cacheserver

CDN/Cacheserver

CDN/Cacheserver

Problems with Centralized Mobility Anchor-(2) Non-Optimal for Flat Architecture

• Centralized route maintenance and context maintenance for a large number of mobile hosts is more difficult to scale.

• Distributed Mobility Agent maintain less context

MA Mobility domain

MN2

MN5

MN8

MN0

MN12 MN14

Problems with Centralized Mobility Anchor-(3) Scalability

• Excessive signaling overhead should be avoided when end nodes are able to communicate end-to-end

• Capability to selectively turn off signaling that are not needed by the end hosts will reduce the handover delay

Home networkwith MA Visited network

MN CN

Problems with Centralized Mobility Anchor-(4) Signaling Overhead

• Scalability may worsen when lacking mechanism to distinguish whether there are real need for mobility support

• Dynamic mobility management, i.e., to selectively provide mobility support, is needed and may be better implemented with distributed mobility management.

MN2

MN3

MN1

MN4

MN5

MN7

MN8

MN6

MN9

MN0

MN12

MN13

MN11

MN14

MN15

Problems with Centralized Mobility Anchor-(5) Dynamic Mobility

• Deployment is complicated with numerous variants and extensions of mobile IP

• These variants and extensions may be better integrated in a distributed and dynamic design which can selectively adapt to the needs.

L-GW

L-GW L-GW

Local Content

Internet

P-GW

L-GW

S-GW

L-GWL-GW

Problems with Centralized Mobility Anchor-(6) Integration Different Mobile IP

• Centralized approach is generally more vulnerable to a single point of failure and attack

• Requiring duplication and backups, • Distributed approach intrinsically mitigates the problem to a local

network so that the needed protection can be simpler.

MA MA MA MA

MN CN

Problems with Centralized Mobility Anchor-(7) Single Point of Failure

Outline

• Introduction of Distributed and Dynamic Mobility Management

• Problem Statement of Dynamic Anchor

• Problems with Centralized Mobility Anchor

• Summary

Summary - Motivation of New Mobility Management

Mobility Management Need Optimization

Traffic/Mobility Model Changed

Operator Need to Simplify Network and Reduce Cost

Network Architecture is Evolving

• Traffic offloading is leading to evolve the network architecture towards flat architecture

• Current Mobility management is not optimized for flat architecture

• “Always-on Mobility Support” causes waste of network recourse

• Mobile Internet traffic grows very fast, mobile operator’s network faces challenges• All traffic going to mobile core network model will increase the cost• Cache/CDN is leading distribution of

content to network edge• Mobility model is changed:: low mobility/smart applications

• Centralized anchor will lead to no-optimal route and too much tunnels in flat architecture • Large amount of mobility context management leads to high cost of network element• To support telecom level high availability, centralized anchor have to be designed complex

Why new mobilitymanagement?

• Mobility anchor also need to be distributed to network edge to support traffic offloading

• Dynamic Mobility can reduce the complexity and reduce cost

Summary – What We Have Now

• Problem statement for distributed and dynamic mobility management• http://tools.ietf.org/html/draft-chan-distributed-mobility-ps-00

• Use case scenarios for Distributed Mobility Management• http://tools.ietf.org/html/draft-yokota-dmm-scenario-00

• Other drafts

• http://tools.ietf.org/html/draft-liu-distributed-mobility• http://tools.ietf.org/html/draft-seite-netext-dma• http://tools.ietf.org/html/draft-chan-netext-distributed-lma-03• http://tools.ietf.org/html/draft-haddad-mext-mobisoc-00

• P. Bertin, S. Bonjour, and J-M Bonnin, “Distributed or Centralized Mobility?” Proceedings of Global Communications Conference (GlobeCom 2009).

• M. Fisher, F.U. Anderson, A. Kopsel, G. Schafer, and M. Schlager, “A Distributed IP Mobility Approach for 3G SAE,” 19th International Symposium on Personal, Indoor and Mobile Radio Communications, (PIMRC 2008).

• L. Zhang, R. Wakikawa, and Z. Zhu, “Support Mobility in the Global Internet,” Proceedings of ACM Workshop on MICNET, MobiCom 2009, Beijing, China, 21 September 2009.

• P. Bertin, S. Bonjour, and J-M Bonnin, “A Distributed Dynamic Mobility Management Scheme Designed for Flat IP Architectures,” Proceedings of 3rd International Conference on New Technologies, Mobility and Security, (NTMS 2008).

• H. Anthony Chan, “Proxy Mobile IP with Distributed Mobility Anchors,” GLOBECOM 2010 Workshop on Seamless Wireless Mobility, Miami, USA, 6-10 December 2010.

• H. Anthony Chan, “Integrating PMIP into LISP Network,” draft-chan-lisp-pmip-00.txt, October 2010.

Other references

Thanks ！Q&A