Mobile Network Architecture & Protocols WINLAB IAB Meeting October 29-30, 2001

Transcription

1 Mobile Network Architecture & Protocols WINLAB IAB Meeting October 29-30, 2001 I. Seskar, D. Raychaudhuri

2 MobNets: Introduction This project aims to explore the fundamentals of nextgeneration mobile network architectures and protocols, looking beyond the issues addressed by today s mobile IP, WLAN and 3G solutions. Problem: Standardization process is to long for today's fast paced technological innovations Solution needs ability to evolve the protocol to meet future needs while minimizing standards complexity Need for customization

3 MobNets: Multimode Networks Cellular/2.5G,3G,4G,? Bluetooth<-> 3G IWF Bluetooth UWB,? net link Unified Mgmt Layer Bluetooth<->WLAN IWF PHY IWF1 IWF2 BT WLAN 3G Protocol stacks WLAN<->3G IWF WLAN, HyperLAN, UWB,? Emerging Multimode Networks Multiple devices with multitude of interfaces Techniques for seamless service: - Authentication, global roaming - Security issues - Dynamic handoff - End-to-end QoS control - Network management - Service level agreements (SLA)

4 MobNets: Protocol Design Scenarios 1. Compatible upgrades to WLAN protocols for service features such as flow QoS and multicasting; 2. Interworking of multiple radio link technologies such as Bluetooth, , GPRS and 3G/WCDMA; 3. Data caching in the network in context of mobile Infostations type services; 4. Content delivery techniques for mobile users, including those based on variations of IP multicast and new semantic routing techniques. [This project involves collaboration with Semandex Networks, a NJ-based startup that has developed an XML content router product.]

5 MobNets: Dynamic Protocol Upgrades Already exists in application layer protocols and middleware components as pluggable modules (WEB browser plug-ins, VoIP applications etc.) and is slowly moving into lower layers. What is needed is a framework that provides a uniform set of APIs and methods used to select, download, configure, and monitor each protocol layer. In addition, successful solution has to: be applicable to endpoint devices as well as routers. provide security and fault-recovery deal with legacy devices be flexible

6 MobNets: Dynamic Protocol Upgrades (cont) Upgradeable layer part TRA NET LLC MAC PHY Upgrade controller Assumptions: Well defined interfaces at every layer Exposed data structures and parameters supporting methods and algorithms Modular approach IP as a base for control connectivity Controller that ensures transfer, module correctness and integration into the stack Exposing parameters to higher layers

7 MobNets: Interworking Peer-level collaboration of network entities supporting global roaming, handoff, etc Bluetooth vcard/vcal WAE vcard/vcal WAE WAP FTP HTTP OBEX WAP AT Comm. TCS BIN SDP UDP/TCP IP LLC MAC DSSS FHSS INFRARED UDP/TCP IP PPP RFCOMM HC Interface L2CAP LMP Baseband Bluetooth Radio AUDIO = Context transfer

8 MobNets: Infostation Caching Opportunistic caching in Infostation environment: content caches in the Infostatons increased multicasting of popular content Server Intranet/Internet Locally relevant + user-specific data Router Infostation cache Infostation 1 Infostation cache Infostation M Movement of users

9 MobNets: Content Routing Emerging content-routing techniques will facilitate real-time, location-aware information delivery in a scalable way (collaboration with Semandex Networks )... Interest profile User XML Descriptor Content Provider SX Semantic Router A SX Semantic Router B Source: Dan Reininger, Semandex Networks

10 MobNets: Approach Open architecture network in mobile context tasks: Identify radio and mobility related parameters Design open APIs Develop dynamic downloading of service module software for all network levels (assumption is that the system is TCP/IP based) Address legacy support issues Develop support for incremental service deployment Develop service description concept Develop conflict resolution mechanisms

11 MobNets: Experimental Testbed Network nodes with Open API (Router/Server/Controler) WINLAB Network Off-the-shelf Access Point To other nodes Control links Internet To other nodes Integrated Control links Off-the-shelf Bluetooth Access Point WINLAB Network Purpose: Evaluate different approaches in terms of protocol functionality Evaluate software performance Enable rapid prototyping Implement open architecture network on a generic hardware platform Provide support for legacy device integration

12 MobNets: Testbed node Each node has 3 general purpose PCs: 1U form factor Single or dual CPU configuration with up to 1 GB of memory Quad 100 Mb/s Ethernet Single/Dual CPU Display Controller Bus Controllers Memory Controller Peripherals (USB, etc.) IDE Controller Dual Ethernet PCI bus Dual Ethernet PC Card (PCMCIA) control links DDR Memory up to 1 GB HD Card Bluetooth Card P C Node can be used as: Router P C P C Server/Cache Access point Or combination of the three to other nodes

13 MobNets: Software platform Main SW features: Open Linux OS By using packet filters minimizes driver development Multiple independent developers each with separate protocol stack Uses existing TCP/IP stack for control only Custom protocol stack Packet filter Applications LL Open API Kernel protocol stack Driver Ext Driver Ext Driver Ext Java based Bluetooth Ethernet

14 MobNets: Software platform (cont) Benefits of using Java: Code portability Huge existing code base Existing security/authentication model Support for pluggable entities Support for important concepts (runtime loading, concurrency, CORBA, RMI etc.) Support for XML based protocols Drawbacks: Performance hit Re-implementation of TCP/IP

15 MobNets: Status The project is in its initial phase with the following sub-projects currently underway: Architectural design and network testbed establishment. Generic API for b and Bluetooth access points development /Bluetooth interworking development User space TCP/IP protocol development