Mobile Computing Issues

Introduction
• There are several characteristics of wireless networks and mobile devices that give rise to issues that do not pose a problem in fixed, wired infrastructure.
– Adaptive behaviour p – Battery power
– Limitation on local resources
– Small display size
– Disparity in the availability of remote services
– Unpredictable variation in QoS.

Issues in Mobile Computing

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Adaptive Behaviour

Effective use of smart space space. Invisibility.
Localised scalability.
Masking uneven conditioning.

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• Other reasons for a mismatch:
– The availability of compute servers or data-staging server is location-dependent and affects techniques such as cyber foraging.
– In case of mobile code, low-level resources and interactive resources may vary widely between the source and destination systems. As time elapses, the resource level may change, for example, residual power on a laptop is depleted as battery drains.

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• Adaptive behaviour arises due to a significant mismatch between supply and demand for resources.
– Often in low level systems, e.g. bandwidth, memory.
• As a mobile user moves, services and resources may become available or disappear.
• Mismatch may occur even when the user is static static. • The system has to handle the variation in a way that minimises inconvenience to users and does not abruptly interfere with the task the user is trying to accomplish.

• Adaptability is critical to support pervasive computing. • Pervasive computing extends the problem domain:
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• The mismatch cannot be ignored as it will result in unsatisfactory user experience.
• Adaptation is important not only as users move resource-rich to resource-poor environment but also in the other direction.
– E a user should not b d i d of b tt quality
E.g.
h ld t be deprived f better lit video or speedier file transfer if more