Accession Number:

ADA279785

Title:

A Group Communication Approach for Mobile Computing Mobile Channel: An ISIS Tool for Mobile Services

Descriptive Note:

Corporate Author:

CORNELL UNIV ITHACA NY DEPT OF COMPUTER SCIENCE

Personal Author(s):

• Cho, Kenjiro
• Birman, Kenneth P.

Report Date:

1994-05-01

Pagination or Media Count:

18.0

Abstract:

This paper examines group communication as an infrastructure to support mobility of users, and presents a simple scheme to support user mobility by means of switching a control point between replicated servers. We describe the design and implementation of a set of tools, called Mobile Channel, for use with the ISIS system. Mobile Channel is based on a combination of the two replication schemes the primary-backup approach and the state machine approach. Mobile Channel implements a reliable one-to-many FIFO channel, in which a mobile client sees a single reliable server servers, acting as a state machine, see multicast messages from clients. Migrations of mobile clients are handled as an intentional primary switch, and hand-offs or server failures are completely masked to mobile clients. To achieve high performance, servers are replicated at a sliding-window level. Our scheme provides a simple abstraction of migration, eliminates complicated hand-off protocols, provides fault-tolerance and is implemented within the existing group communication mechanism.

Descriptors:

• *COMPUTER COMMUNICATIONS
• *MOBILE
• *FAULT TOLERANT COMPUTING
• *COMPUTER NETWORKS
• CONTROL
• TOOLS
• MACHINES
• FAULT TOLERANCE
• HAND HELD
• APPROACH
• SWITCHES
• CHANNELS
• SWITCHING
• MIGRATION
• WINDOWS
• FAILURE
• MOBILITY

Subject Categories:

• Computer Systems

Distribution Statement:

APPROVED FOR PUBLIC RELEASE