MaGMA: Supporting Groupware in

Wireless Networks

Idit Keidar

Technion EE

Joint work with N. Lavi and I. Cidon

Agenda

Motivation Solutions known to date Our proposed architecture Group management solutions Simulation and analysis Future work Conclusions

Current Application Trends

Groupware and collaborative applications are widely used. Chat, Instant-Messaging, VoIP, VCoIP, Net-meeting Exchange, Lotus notes, webex Multiplayer interactive games Push-to-talk (PTT)

Current Cellular Trends

Simple groupware such as Instant Messaging widely used

Major cellular providers (Orange, Verizon, Nextel) offer PTT services

The Yankee Group (Sep. 2003): In 2003, $84 million PTT revenue, 2.3 million

PTT subscribersBy 2008, $10.1 billion PTT revenue, 340 million

PTT subscribers

Future Cellular Trends

Richer groupware applicationsData+ voice+ video

Adopting TCP/IP infrastructure Session Initiation Protocol (SIP) signalingOMA, 3GPP, 3GPP2 standards

Wireless Networks Trends

Maturing standards (Wi-Fi, WiMAX) High availability of hot spots Supported in PDAs, Pocket PCs, laptops,

and cellular-phones Emerging standards and working groups:

IETF-MIP, Open Mobile Alliance, 4G

Mobile Networks Trend

Groupware popularity +

Wireless access

availability

B3G Convergence

Cellular going IP +

The Future Network IP based

Cellular Net.

The I nternet

AccessPoint

AccessPoint

Mobile User

Mobile User

Stationary User

Cell

The Challenges

Supporting groupware! W

here is the group’s home?

Supporting Mobility

! Where is the MN?

Supporting RT services!

Mobile Groupware Design Goals

Mapping group names to subscribers Mobility support Seamless handoff QoS support for RT applications Transport efficiency Transport reliability Roaming, AAA Scalable Support for incremental deployment

Solution Known to Date

Mobility solutions: MIP+route optimization, SIP mobility Not for groupware! Based on home per address The group needs a home too

Groupware solutions Not for mobility Mostly based on single server

Why?

HA 2

HA 1

GroupHome

Our Solution

Mobility SupportT

ran

spo

rt E

ffic

ien

cy

Mobility and Group Management Mobility and Group Management ArchitectureArchitecture

MaGMA’s Architecture

Servers: Mobile Group Managers (MGMs) as part of the infrastructure

Clients: Mobile Nodes (MNs), served by local MGMs

MN

MN

MN

MGM

MGM

MGM

new addres

s

Hello!

MaGMA’s Architecture (cont.)

MGM5

MGM4

MGM2 MGM3

MGM1

MN 2

MN 3

MN 1MN 4

MN 5

MN 6

Domain-4

Group Blue Group

Red

MaGMA’s Key Advantages

Distributed architecture No bottlenecks, no triangle routing, no SPoF

Eliminates the “home” concept, for both mobility and group support

Incorporates smooth handoff Supports RT groupware Various group management solutions optimized

for different settings e.g., subscription versus overlay model

Group Management Approach I

Subscription model Good for lightweight servers, small groups

MGM2MGM1

MN 3

MN 1

MN 2

joinleavemove

ret./subsc.view

Group-XMN1MN2MN3

Group-XMN1MN2MN3

forward local events

Group-XMN1MN2MN3

Group Management Approach II

Multicast overlay model Scalable in group size, good for low battery clients

MGM2MGM1

MN 3

MN 1

joinleavemove

join/leave/

handoff

MN 2

localViewMN1

groupViewMGM1groupView

MGM2localView

MN2MN3

data

Further Enhancements: MaGMA Overlay MGMs organized in overlay Multicast data forwarded over the overlay

MGM

MGM

Router

Router

MaGMA’s ImplementationSOHO

NetworksAccess

NetworksCore

Network

Controller

Controller

Router

DHCP

PSTN Switch

Root Router

MGM

Simulation & Analysis: Subscriber vs. Mcast Overlay Control Overhead Evaluation

Simulation: MaGMA vs. MIP Transport Delay

MGM1 functions as the HA

MN

MGM0

MGM2MGM1 MGM3

source

5Mb 20ms

Simulation: MaGMA vs. MIP Packet Loss During Movement

MGM3MGM2 MGM4source

MN

•Link BW: 5mbps

•Link delay: 40ms

•MGM1 functions as HA

•CBR, 20 bytes, 100pkts/sec

MGM1

MIP’s update delay: depends on distance from HA

MaGMA’s update delay: (1) depends on distance between MGMs

(2) When moving into active domain: wireless handoff time

Data Packet - Header Overhead

Unicast Multicast

UDP

IP

UDP

IP

UDP

IP

UDP

IP

IP

UDP

IP

group

UDP

IP

IP

IP

MaGMA Prototype

NIST-SIP

MaGMA Parser

Group App.

db

Microsoft-SIP

MaGMA Engine

Group App.

* Based on Microsoft RTC client

Future Work

Application services application server session migration floor-control

AAA MGM failures and dynamic changes Hybrid networks: ad-hoc and access point

Conclusions

Wireless networks (Wi-Fi, WiMAX) will merge with the Internet and cellular infrastructure

Users will demand support for groupware such as PTT

Current IP mobility solutions - inadequate for RT

Our solution provides comprehensive support for group management and RT applications

More Information…

N. Lavi, I. Cidon and I. Keidar: “Supporting Groupware in Mobile Networks”6th IFIP IEEE International Conference MWCN, Oct. 2004.

N. Lavi, I. Cidon and I. Keidar:“MaGMA: Mobility and Group Management Architecture for Real-Time Collaborative Applications in Converged Wireless Networks”To appear in WCMC Journal, Wiley.

http://comnet.technion.ac.il/magma