Nomadic Computing - An Opportunity
Leonard Kleinrock (UCLA), 1995
Summary. The author presents nomadicity as a new paradigm
in computer use and communications and laid down challenging problems
too numerous to list in this summary.
A key statement from the paper:
The ability to automatically adjust all aspects of the
user's computing, communication and storage functionality in
a transparent and integrated fashion is the essense of
a nomadic environment.
More Detail...
Protocols developed for nomadic computing must satisfy
these sytems requirements:
- Heterogeneous infrastructure (wireline/wireless)
- Ability to deal with unpredictability of
- user behavior
- network capability
- computing platform
- Graceful degradation
- Scale wrt:
- heterogeneity
- address space
- QoS
- bandwidth
- geographical dimensions
- number of users
- Integrated access to services
- Ad-hoc access to services
- Network-independent applications from user and developer
perspective
- Match data transmission rate to bw availability
- compression
- approximation
- partial information
- Cooperation among system elements such as
- sensors
- actuators
- devices
- network
- operating systems
- file system
- middleware
- application
The components to solve the above needs might include:
- An integrated software framework which presents a
common virtual network layer.
- Appropriate replicatin services at various levels.
- File synchronization
- File hoarding
- Consistency services
- Adaptive database mgt
- Location services to keep track of people and devices
- Resource discovery
- Profile discover (network profile?)
The author uses as an example environment the intelligent room
in which books answer user inquiries about book availability and
whereabouts.
The author lists challenges associated with wireless communications,
one of a plethora of nomadicity challenges. He decomposes the possible
wireless communication scenarios into the following and lists issues
arising in each scenario:
- Static topology with One-Hop Communication.
No motion among the system elements; all transmitters can
reach their destinatios with no relay.
- Static topology with Multi-Hop Communication..
Topology is still static, but transmitters may not be able to reach
their destination so multi-hop relay communications is
sometimes necessary.
- Dynamic topology with Multi-Hop.
Devices (users, radios) are allowed to move which causes
the network connectivity to change dynamically.