KAMPALA UNIVERSITY SCHOOL OF COMPUTER SCI & IT COURSE WORK NAME : MIGADDE RICHARD REG NO : 16/KUS/BCSIT/485U COURSE : CSIT UNIT : MOBILE COMPUTING YEAR : THREE SEMESTER : TWO Dimensions of mobility: The set of properties that distinguishes the mobile computing system from stationary computing system. Dimensions of mobility are as follows: 1. Location Awareness. The definition of the mobile says the first dimension of mobile computing is the location. As the mobile devices donot work in a particular location, the location of the mobile devices may changes in every moment of time so the primary design issue is the location management in the development of mobile devices. 2. Network connectivity Quality of Service (QOS). The company focuses that our device is easily compatible for any type of network. The QOS is defined as “The collective effort of service performances, which determine the degree of satisfaction of a user of this service”. The services can have qualitative and quantitative. 3. Limited Device Capabilities (Particularly Storage and CPU). The important issue is the storage related issues. The company’s concern should be regarding the storage capacity of our device to improve the storage capacity of a mobile. 4. Limited Power Supply. The mobile devices are totally based on battery power, which provides less power supply 5. Platform proliferation. We need to design such type of device, which would support any platform and any network. Mobility characteristics Location changes Location management-cost to locate is added to communication Heterogeneity in services Bandwidth restrictions and variability Dynamic replication of data Data and services follow users Querying data-location-based responses Security and authentication System configuration is no longer static Mobility constraints CPU Power Variable Bandwidth Delay tolerance, but unreliable Physical size Constraints on peripherals and GUIs Frequent Location changes Security Heterogeneity Expensive Mobility of physical devices can be viewed at three different levels: Macro-mobility: This is mobility through a global network. While moving in such a network, it should be possible to communicate without breaking the existing access. Mobile IP, which is the protocol that takes care of macro-mobility. Micro-mobility: This is mobility of a device in one single administrative domain of the global network. For cellular networks, this is the lowest level of mobility. Cellular IP is the protocol designed to take care of micro-mobility. Adhoc-mobility: This is mobility with in a mobile adhoc network (MANET), caused by device mobility constantly changing the network topology.