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 subscribers  By 2008, $10.1 billion PTT revenue, 340 million PTT subscribers

Future Cellular Trends Richer groupware applications  Data+ voice+ video Adopting TCP/IP infrastructure  Session Initiation Protocol (SIP) signaling  OMA, 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

The Challenges Supporting groupware! Where 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?

Our Solution Mobility Support Transport Efficiency Mobility and Group Management Architecture

Our Solution Mobility and Group Management Architecture

MaGMA’s Architecture Servers: Mobile Group Managers (MGMs) as part of the infrastructure Clients: Mobile Nodes (MNs), served by local MGMs new addres s Hello!

MaGMA’s Architecture (cont.) 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 join leave move ret./subsc. view Group-X MN1 MN2 MN3 Group-X MN1 MN2 MN3 forward local events Group-X MN1 MN2 MN3

Group Management Approach II Multicast overlay model  Scalable in group size, good for low battery clients join leave move join/leave/ handoff localView MN1 groupView MGM1 groupView MGM2 localView MN2 MN3 data

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

MGM Router MaGMA’s Implementation SOHO Networks Access Networks Core Network 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

Simulation: MaGMA vs. MIP Packet Loss During Movement Link BW: 5mbps Link delay: 40ms MGM1 functions as HA CBR, 20 bytes, 100pkts/sec  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 UnicastMulticast UDP IP UDP IP UDP IP UDP IP UDP IP group UDP 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” 6 th IFIP IEEE International Conference MWCN, Oct 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.