Location Independence

Location Independence

INTRODUCTION

VISION
STATEMENT

THE PLATFORM
IS THE WEB

LOCATION
INDEPENDENCE

BANDWIDTH
TOLERANCE

EASY DATA
RETRIEVAL

YOU CAN TRUST
IT

IT JUST WORKS

Increasingly, users are mobile. For example, today I could start composing an email message on the Alpha in my office, then decide to go for a coffee break at a local cyber-cafe and make a few more edits using one of their rental PC's, then go home and finish the composition on my home Macintosh. Next morning when I arrive in my office, the correctly updated draft would be sitting in the composition window on my Alpha, ready for me so send. Equally, I should be able to start creating a presentation for a customer while in my office, then fly to Tokyo and finish it from the PC kindly provided in my hotel room.

If you ask me what computer I use, it's the closest one. If you ask me where my data is stored, its in the web.

Put more concretely, the system should never lock a user's state into a computer that he might not later be able to access. If the user moves, that shouldn't remove him from his data (and in general he can't take all his data with him).

From the point of view of the user, this is an extension of the notion that the platform is the web. If that's true, then accessing the web must be sufficient to access his data.

From the point of view of the system manager, less computers are essential for maintaining the users data. The manager is much less worried, for example, about backing up the local disks of office PC's, because none of the user's important data resides there.

From the point of view of system design, there are several implications. Foremost, the memory and file system resources of the end-user's workstation (Alpha, PC, Mac or NC) are convenient temporary resting places for data, but everything must move in a timely manner back to its true home somewhere in the web. At its best, this should be done completely transparently to the user, by background tasks that ensure the web-based storage receives an up-to-date copy of the data before the user has had time to move to a new computer. Note that this is a much weaker requirement than fully synchronized data replication.