Wireless_communications_on_the_topic_by_WC

wireless and communication

1. Wireless Communications (18EC71) Name USN Aditi 1DA20EC005 Anusha C R 1DA20EC015 Arun Kumar N 1DA20EC020 Bindushree M 1DA20EC025 Topic : Network Interface for CDMA System

2. Modern wireless cellular systems employ sophisticated network management systems to oversee the operation of an entire network. Most service providers have one or several network operations centers that serve as control points for nationwide cellular networks. AT&T has a NOC that oversees its entire U.S. wireless cellular network located in the Seattle, Washington, area. A typical network management system consists of several layers of management that deal with various levels of the network infrastructure. At the highest level is usually a network management system, then there is usually a subnetwork management system, and then at the lowest level a network element management system.

3. The highest level of network management gives an overarching view of the entire network including all of the subnetworks that it comprises. This computer-based system usually provides a platform that allows one to monitor the overall network. The system typically provides integrated graphical views of the complete network and modular software applications that may be used to support the operation and maintenance of the entire network, and it further provides the means by which operators are able to assess the quality of network service and to provide corrective action when network problems occur. There are basically five functions that a wireless network management system will perform Network surveillance or fault management Performance management Trouble management Configuration management Security management

4. Fault management is concerned with the detection, isolation, and repair of network problems to prevent network faults from causing unacceptable network degradation or downtime. Using the tools provided by the system, a human operator can attempt to repair the problem from the NOC. Performance management functions are concerned with monitoring and analyzing the performance in real time by evaluating factors like call quality,data throughput and overall efficiency Trouble management functions allow for the display and subsequent description of occurrences that have affected the network and also provide the operator with the ability to communicate this information to other persons involved the maintenance of the network. Configuration management functions are used to setup the administration and configuration of the network. These functions support the installation of new work elements as well as the interconnection of network nodes. Security management functions are implemented to protect the CDMA network from unauthorized access and potential threats. R e gualarly update security protocols and encryption mechanism.

5. Subnetwork Management and Element Management Subnetwork management involves overseeing and controlling specific portions of the CDMA network, often organized based on geographical or functional criteria. Subnetwork management in CDMA involves a range of tasks to optimize resource allocation, enhance network performance, and ensure a reliable and secure communication environment. The computer system used for this function provides an operator with access to one or more MSCs for the performance of the various functions listed earlier. The packet core network management system is concerned with the PCN node of the CDMA system. Besides the standard functions of fault and performance management, the PCN management platform can perform statistics administration, online documentation backup and restore functions, and maintain dynamic network topology maps and databases Elemental management in CDMA is crucial for maintaining the reliability, efficiency, and security of the network. It involves a combination of monitoring, configuration, and control activities to optimize the performance of individual network elements and contribute to the overall success of the CDMA network.

6. Recently, most wireless equipment vendors are offering integrated network solutions to service providers by providing microwave links capable of T1/E1/J1 transport or higher data rates for backhaul of aggregated nals to the PSTN. Several vendors offer high-capacity microwave radio systems that offer OC3/STM-1 ata rates with the ability to transport asynchronous transfer mode (ATM) traffic. As service providers rade their systems to offer 3G CDMA services with high-data-rate access, the C-RAN will need to be interconnected and serviced by data transport technologies that offer higher data rates than T-carrier trans- technology. At this point, it appears that ATM has been selected to be the data transport technology sound which the next generation of radio access networks for 3G CDMA systems will be designed.

7. System communication links refer to the pathways through which different components or systems exchange information. These links can include wired connections like Ethernet cables or wireless connections such as Wi-Fi and Bluetooth. Efficient communication links are crucial for the seamless operation of interconnected devices and systems. Today, equipment vendors are still using legacy channelized T1/E1/J1 copper pairs for connectivity from the MSC to the PSTN. Recently, however, CDMA equipment vendors have started to add fiber-optic interfaces to deliver SONET signals at data rates of 155.52 mbps Channelized TI/E1/J1 with control information is used over the A interface between the MSC and the BSC. Between the BSC and the RBSs unchannelized T1/E1/J1 is used. Between the MSC and the various network elements such as HLR, AC, and so on, signaling protocol over T1/E1/J1 timeslots. T1/E1/J1 is used to transport data between the nodes and the MSC. Data between the service nodes and the PDN is typically carried by Ethernet at 10/100 mbps.

8. Subscriber Devices Subscriber device (SD) is a generic term used to describe several types of wireless phones and data devices that perform CDMA encoding/ decoding and vocoding operations for the transmission of voice data in a wireless mobile environment. Each subscriber device has a band or set of radio bands over which it can operate and various modes of possible operation. Subscriber devices can be divided into two categories depending upon their applications. Portable devices can operate in the cellular, PCS or in both bands and can handle the transmission of voice, data, and other non voice applications. Typically these types of SDs are used by people for mobile voice connectivity first, with the other data capabilities being of secondary importance.

9. Wireless local loop (WLL) devices can handle the transmission of data over the CDMA system and typically are used with a laptop or personal digital assistant (PDA) type of device for high-speed Internet access. In the near future, the latter type of SD will probably be used to provide Voice over IP (VoIP) capabilities that will allow wireless video conferencing over either a laptop of tablet PC. In the coming years, the typical SD will include additional functionality for multimedia applications and the ability to use any additional frequency bands that might support CDMA services .

10. It is a standard developed by the  European Telecommunication Standards Institute(ETSI)  to describe protocols for 2G networks. It acted as a replacement for 1G cellular networks. GSM is basically an open, digital cellular radio network and operates in almost all the countries. It is not only used for voice calls but also for data computing and text messages . While CDMA(Code Division Multiple Access) doesn’t support calls and data computing at the same time. Characteristics GSM makes use of the narrowband Time Division Multiple Access (TDMA) technique for transmitting signals. GSM is a circuit-switching system that works by dividing each 200 kHz channel into eight 25 kHz time-slots. GSM operates on the mobile communication bands 900 MHz and 1800 MHz in most parts of the world.

11. GSM Services Telephone Services(Teleservices): It gives voice communication and additional communication between two end users Bearer Services or Data Services : Provides the ability to transmit the data between network interfaces Supplementary Services : Supplementary services include several forms of call forward caller identification, call waiting, multiparty conversations, charging information, and call barring of outgoing or incoming calls GSM is a digital cellular system designed to support a wide variety of services, depending on the user contract and the network and mobile equipment capabilities.

12. Phase 1 Phase 2

13. Gsm radio frequency carriers

14. As shown by Figure 5-2, the A, B, and C bands are each 15-MHz wide and the D, E, and F bands are each 5-MHz wide. There is also limited usage of other bands for GSM at 450 and 850  MHz. In figure 5-3 Each of these timeslots represents a physical channel. Therefore, each GSM TDMA frame represents eight physical channels. Furthermore, besides voice and data traffic there are a host of different system messages and other overhead information constantly being transmitted between the base transceiver station (BTS) and the MS

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