Long – term evolution or LTE is a standard for wireless technology based upon GSM/EDGE and UMTS/HSPA technologies. It offers increased network capacity and speed to mobile device users. It is an extension of the 3G technology for high-speed mobile communications. LTE-Advanced is an improvement over LTE that meets the criteria of 4G wireless communications as laid down by IMT-Advanced standards. It provides greater speeds and better quality of communications. Both LTE and LTE-A are used for mobile broadband communications and in VoIP. Features of LTE LTE was specified by The 3rd Generation Partnership Project (3GPP) release 8 was ... Read More

Fourth Generation (4G) mobile phones provides broadband cellular network services and is successor to 3G mobile networks. It provides an all IP based cellular communications. The capabilities provided adhere to IMT-Advanced specifications as laid down by International Telecommunication Union (ITU).FeaturesIt provides an all IP packet switched network for transmission of voice, data, signals and multimedia.It aims to provide high quality uninterrupted services to any location at any time.As laid down in IMT-Advanced specifications, 4G networks should have peak data rates of 100Mbps for highly mobile stations like train, car etc., and 1Gbps for low mobility stations like residence etc.It also ... Read More

CDMA2000 is a code division multiple access (CDMA) version of IMT-2000 specifications developed by International Telecommunication Union (ITU). It includes a group of standards for voice and data services − Voice − CDMA2000 1xRTT, 1X Advanced Data − CDMA2000 1xEV-DO (Evolution-Data Optimized) Features CDMA2000 is a family of technology for 3G mobile cellular communications for transmission of voice, data and signals. It supports mobile communications at speeds between 144Kbps and 2Mbps. It has packet core network (PCN) for high speed secured delivery of data packets. It applies multicarrier modulation techniques to 3G networks. This gives higher ... Read More

Enhanced Data-rates for GSM Evolution (EDGE) is an improved version of GSM providing higher data transmission rate than GSM, while being compatible with the older systems. Features It was standardized by 3GPP as a part of GSM family and was deployed in GSM networks in 2003. The other names for EDGE are Enhanced GPRS (EGPRS) and IMT-Single Carrier (IMT-SC). It is compatible with any packet – switched application. It is also backward – compatible, i.e. compatible with existing or older versions. It enables data to be sent over a GSM TDMA systems at speeds of 384Kbps. GSM uses the ... Read More

Third generation mobile phones, or “3G Internet” mobile phones, is a set of standards for wireless mobile communication systems, that promises to deliver quality multimedia services along with high quality voice transmission.Features3G systems comply with the International Mobile Telecommunications-2000 (IMT-2000)specifications by the International Telecommunication Union (ITU).The first 3G services were available in 1998.It provides high speed transmission having data transfer rate more than 0.2Mbps.Global roaming services are available for both voice and data.It offers advanced multimedia access like playing music, viewing videos, television services etc.It provides access to all advanced Internet services, for example surfing webpages with audio and video.It ... Read More

Definition In cellular communications, the handoff is the process of transferring an active call or data session from one cell in a cellular network or from one channel to another. In satellite communications, it is the process of transferring control from one earth station to another. Handoff is necessary for preventing loss of interruption of service to a caller or a data session user. Handoff is also called handover. Situations for triggering Handoff Handoffs are triggered in any of the following situations − If a subscriber who is in a call or a data session moves out of ... Read More

The dining philosophers problem states that there are 5 philosophers sharing a circular table and they eat and think alternatively. There is a bowl of rice for each of the philosophers and 5 chopsticks. A philosopher needs both their right and left chopstick to eat. A hungry philosopher may only eat if there are both chopsticks available.Otherwise a philosopher puts down their chopstick and begin thinking again.The dining philosopher is a classic synchronization problem as it demonstrates a large class of concurrency control problems.Solution of Dining Philosophers ProblemA solution of the Dining Philosophers Problem is to use a semaphore to ... Read More

The producer consumer problem is a synchronization problem. There is a fixed size buffer and the producer produces items and enters them into the buffer. The consumer removes the items from the buffer and consumes them.A producer should not produce items into the buffer when the consumer is consuming an item from the buffer and vice versa. So the buffer should only be accessed by the producer or consumer at a time.The producer consumer problem can be resolved using semaphores. The codes for the producer and consumer process are given as follows −Producer ProcessThe code that defines the producer process ... Read More

The readers-writers problem relates to an object such as a file that is shared between multiple processes. Some of these processes are readers i.e. they only want to read the data from the object and some of the processes are writers i.e. they want to write into the object.The readers-writers problem is used to manage synchronization so that there are no problems with the object data. For example - If two readers access the object at the same time there is no problem. However if two writers or a reader and writer access the object at the same time, there ... Read More

A remote procedure call is an interprocess communication technique that is used for client-server based applications. It is also known as a subroutine call or a function call.A client has a request message that the RPC translates and sends to the server. This request may be a procedure or a function call to a remote server. When the server receives the request, it sends the required response back to the client. The client is blocked while the server is processing the call and only resumed execution after the server is finished.The sequence of events in a remote procedure call are ... Read More