Asymmetric multiprocessor systems are a part of multiprocessor systems along with symmetric multiprocessor systems. Multiprocessor systems have multiple processors working in parallel that share the computer clock, memory, bus, peripheral devices etc.Features of Asymmetric MultiprocessingSome of the key points about asymmetric multiprocessing are explained with the help of the following diagram −Here are the points −All the processors are not treated equally in asymmetric multiprogramming. For example, a processor may handle only I/O related operations and another may handle only operating system code. This is in direct contrast to symmetric multiprocessing systems because there all processors are treated equally and ... Read More

Low earth orbit (LEO) satellites systems orbit below 2000 km from the earth’s surface, i.e. below the lower Van Allen belt. They move at very high speeds and may not have any fixed space with respect to the earth.The following diagram depicts LEO satellites in their orbits.Features of LEO SatellitesA network of LEO satellites are needed for global coverage as their orbits are not geostationary.These satellites are not as powerful as the MEO and GEO satellites.Due to their high speeds, satellites move in and out of the earth station’s range from time to time. So, data is handed off from ... Read More

Most computer systems are single processor systems but multiprocessor systems are increasing in importance nowadays. These systems have multiple processors working in parallel that share the computer clock, memory, bus, peripheral devices etc.There are mainly two types of multiprocessor systems. These are −Symmetric Multiprocessor SystemAsymmetric Multiprocessor SystemIn symmetric multiprocessing, multiple processors share a common memory and operating system. All of these processors work in tandem to execute processes. The operating system treats all the processors equally, and no processor is reserved for special purposes.Features of Symmetric Multiprocessing (SMP)Some of the key points about symmetric multiprocessing are explained with the help ... Read More

VSATs (Very Small Aperture Terminals) is a two way, lost cost, ground micro station for transmitting data to and from communication satellites. A VSAT has a dish antenna with diameters between 75 cm to 1 m, which is very small in comparison with 10 m diameter of a standard GEO antenna. It accesses satellites in geosynchronous orbits or geostationary orbits. Data rates in VSATs ranges from 4 Kbps to 16 Mbps.Configurations of VSATsStar Topology − This has a central uplink site which transmits data from and to each VSAT through the satellite.Mesh Topology − Each VSAT transmits data via the ... Read More

Geosynchronous Satellite and Geosynchronous Orbit (GSO)A geosynchronous satellite is a communication satellite that has an orbital period same as the period of rotation of the earth. Hence, it appears to be permanently in the same area of the sky at a particular time each day when viewed by an observer on the earth.The orbit in which a geosynchronous satellite is placed is called geosynchronous orbit (GSO). Its orbital period is the sidereal day, i.e. 23 hours 56 minutes 4 seconds and its orbital altitude is 35, 800 km.Geostationary Satellite and Geostationary Orbit (GEO)A circular geosynchronous satellite which is placed at ... Read More

Cache is a type of memory that is used to increase the speed of data access. Normally, the data required for any process resides in the main memory. However, it is transferred to the cache memory temporarily if it is used frequently enough.A diagram to better understand the data transfer in cache management is as follows −Cache PerformanceThe cache performance can be explained using the following steps −If a process needs some data, it first searches in the cache memory. If the data is available in the cache, this is termed as a cache hit and the data is accessed ... Read More

An operating system is a construct that allows the user application programs to interact with the system hardware. Operating system by itself does not provide any function but it provides an atmosphere in which different applications and programs can do useful work.The operating system can be observed from the point of view of the user or the system. This is known as the user view and the system view respectively. More details about these are given as follows −User ViewThe user view depends on the system interface that is used by the users. The different types of user view experiences ... Read More

A distributed system contains multiple nodes that are physically separate but linked together using the network. All the nodes in this system communicate with each other and handle processes in tandem. Each of these nodes contains a small part of the distributed operating system software.A diagram to better explain the distributed system is −Types of Distributed SystemsThe nodes in the distributed systems can be arranged in the form of client/server systems or peer to peer systems. Details about these are as follows −Client/Server SystemsIn client server systems, the client requests a resource and the server provides that resource. A server ... Read More

The peer to peer computing architecture contains nodes that are equal participants in data sharing. All the tasks are equally divided between all the nodes. The nodes interact with each other as required as share resources.A diagram to better understand peer to peer computing is as follows −Characteristics of Peer to Peer ComputingThe different characteristics of peer to peer networks are as follows −Peer to peer networks are usually formed by groups of a dozen or less computers. These computers all store their data using individual security but also share data with all the other nodes.The nodes in peer to ... Read More

In client server computing, the clients requests a resource and the server provides that resource. A server may serve multiple clients at the same time while a client is in contact with only one server.The different structures for two tier and three tier are given as follows −Two - Tier Client/Server StructureThe two tier architecture primarily has two parts, a client tier and a server tier.The client tier sends a request to the server tier and the server tier responds with the desired information.An example of a two tier client/server structure is a web server. It returns the required web ... Read More