Chapter review with news article Essay Example | Topics and Well Written Essays - 750 words

Chapter review with news article - Essay Example approaches that are included a wide range of activities that are undertaken in the bid to obtain the best results from a group of people or employees of an organisation or firm. The system is a continuous concept that involves developing the employee’s goals as well as objectives, supervising the procedures concurrently with the goal that need to be achieved, analysing the outcomes and finally noting their performance. The whole of the process involves the technique of receiving and giving out feedback information. Performance management systems are usually carried so as to address various key issues; the first concept covered by performance management systems is the strategy. The strategy is important in the determination of the relationship between the various individual output in relation to the strategic objectives. Performance management systems are also responsible for the evaluation processes that are essential in the analysis of the objectives that have been obtained. Additionally, development is also a key factor that can be determined through performance management systems. Finally, diagnosis is also an aspect that can be evaluated through performance management system. Performance debates or discussion are the means by which the managers are able to come up with personalised work objectives together with their employees. This is the opportunity that the managers are able to talk about the measures that need to be undertaken in support of development of the work performance. On the contrary, the types of discussions that are held are always dependent on the various stages of the management cycle whilst the principles are always constant. It is preferable that there be at least one meeting session of discussing the performance schedule and at least two meetings for the discussion of the objectives that have been achieved. On the other hand, instances of informal meeting always create the opportunities to have discussions that are related to the

Design and Planning of 2G, 3G and Channel Modelling of 4G

Design and Planning of 2G, 3G and Channel Modelling of 4G Chapter 1 Fundamentals of Cellular Communication In this chapter, all the background knowledge which is required for this project has been discussed. 1.1 Cell The area covered by single BTS(base transceiver station) is known as cell. 1.1.1 Shape of cell The shape of cell depends upon the coverage of the base station. The actual coverage of the base station is called footprint and is found with the help of measurements from the field. We can make our calculations easier by using the shape of circle noting that there would not be spaces between them. As, the purpose is to provide coverage to each and every subscriber. But if there are spaces between the coverage areas then the person in that specific area will not be able to get any coverage. To cover the problem of interleaving spaces, the shapes that can be used theoretically are: Square Triangle Hexagon But in selection criteria one thing must be kept in mind that every person within a cell get same coverage specially the person at the edges of the cell. So hexagon is the shape among these three choices with largest coverage area. Its coverage area and shape is closest to the circle and it helps tessellate. Omnidirectional antenna is used in the center of it, and if we want to use sectored directional antenna then it must be used at any three corners of it. 1.1.2 Area of the Cell The area of a cell with radius R is shown in figure 1.1(a), is given by: 1.2 Frequency planning While developing the cellular system, it has limited capacity due to the given bandwidth. So, in order to solve this problem Cellular Systems have to depends on an intelligent and more use of channels through out the area. Every cellular base station is alloted a group of different radio channels to be used in a cell. Base station in the adjacent cells use completely different frequencies. For this purpose antennas are used such that their power may get limited within the cell. In this way the allocated frequencies maybe reused in different cells again. The process of allocating and selecting channel groups for all the base stations in a system is known as frequency reuse or frequency planning. We use two types of antennas: Omnidirectional antenna Sectored directional antenna Omnidirectional antennas are used in the cells which are centrally excited and sectored directional antennas are used in the edge excite cells. To understand the concept of frequency reuse, let us say that S are the total no. of duplex channels available for use, k number of channels given to each cell i.e. k S=kN (1.2) Where N is no. of cells which uses the complete set of available frequencies known as cluster frequency reuse factor (1.3) Each cell is in the cluster is assigned of the available channels. The radio frequency from 3Hz to 3000GHz are separated into 12 bands, as shown in the table. Frequency spectrum has different propagation characteristics. As far as concerned to the mobile communication, we only pay attention to the UHF spectrum. 1.2.1 Cluster size(N) If we use N large (a large cluster), the ratio of the cell radius and the distance between co-channel decreases, which causes weaker co-channel interference. But if N is smaller, by keeping the cell size same then we more clusters are needed to cover an area. Hence the capacity is increased. So if we use N larger then the quality of voice is good but the capacity is less and vice versa. 1.3 Interference Interference is one of the major factor in the capacity and performance of a cellular network. The interference is due to a call in the neighbouring cell, another base station operating in the same frequency. Interference causes crosstalk and noise. There are two types of interference. Adjacent channel interference Co-channel interference 1.3.1 Adjacent channel interference Adjacent channel interference results from the signals which are side by side in frequencies to the desires signal. Adjacent channel interference is caused by wrong filtering, like incomplete filtering of not wanted modulation in frequency modulation (FM) systems, not proper tuning, or poor control of frequency. It causes problem. Adjacent channel interference can be reduced by careful channel assignment, filtering and power control within a cell. 1.3.2 Co-channel interference Co-channel cells are the cell which use the same set of frequencies. For example, in the figure 1.2 all the letter ‘A are the co-channel cell because they use the same set of frequencies. Interference due to the co-channel cells is called co-channel interference. It can be reduced by using greater value of N(cluster size). If D is the distance between the co-channel cells and R is radius of the cell, then by using greater value of N the ratio between D to R is increased hence reducing co-channel interference. The relation can b written as: 1.4 Improving coverage and capacity The number of channels assigned to a cell became insufficiently as the demand of wireless system increases. To provide more channels per coverage, some techniques are introduced which improve the coverage and capacity. These techniques are: Cell splitting Sectoring Microcell zone concept 1.4.1 Cell Splitting Cell splitting is the process of dividing a cell into smaller cells. In this process we reduce the antenna height and power of the base station. Cell splitting increases the capacity by increasing frequency reuse factor. In cell splitting Channel assignment techniques remain the same. SIR remains the same Trunking inefficiency do not get suffer. Trunking efficiency is the measure of the number of users which can be offered a particular Grade of service with the specific configuration of the channels. The grade of service (GOS) is the measure of the ability to access a trunked system during the busy hours. The radius of the new cell is reduce to half. So power is also reduced. 1.4.2 Sectoring Sectoring uses directional antennas for controlling the interferences and frequency reuse of channels. The co-channel interference is reduced and thus increasing system performance by using directional antenna. A cell is normally divided into three 120 sectors or six 60 °sectors. When sectoring is used, the channels used in a particular cell are broken into sectored groups and are used only within a particular sector. The no. of channels get divided into sectored groups, so the trunking efficiency is reduced. In sectoring SIR is improved by reducing interference and trunking efficiency is reduced. Handoff increased in sectoring. The s/I improvement allows to decrease the cluster size N in order to improve the frequency reuse, and thus the system capacity. Further improvements in s/I is achieved by downtilting the sector antennas. 1.4.3 Microcell Zone Concept Microcell Zone concept distributes the coverage of a cell and extends the cell boundry to hard to reach places. It maintains the S/I and trunking efficiency, and increases the coverage and capacity of an area. 1.5 Radio wave propagation Radio waves propagate through different channels and by different ways to reach the MS(Mobile Station). It also depends upon the speed of the wave. The propagation of radio waves depends into two types: Large scale propagation Small scale propagation(Fading) 1.5.1 Large scale propagation The model predicts that the average signal strength for all transmitter-receiver (TR) distance on a scale known as large scale propogation model. 1.5.2 Small scale propagation The models that predicts the rapid fluctuation of the received signal strength over a short distance known as small scale propagation model or fading. 1.5.3 Free Space Propagation Model The free space propagation model is used when the transmitter and receiver have line of sight (LOS) between them to predict the received signal strength. Where Pr = received power. Pt = transmitted power, Gt and Gr = transmitter and receiver antenna gain, do= T-R separation, L = system loss factor ÃŽ » = wavelength. 1.6 Propagation Mechanisms The propagation mechanisms which effect propagation are: Reflection Scattering Diffraction Reach directly (in case of Line of Sight) If there is line of sight signal reach the Mobile station directly and signal power is very strong. 1.6.1 Reflection Reflection occurs when an electromagnetic wave falls upon an object which is large as compare to the wavelength of the wave. It occurs from buildings, walls, surface of earth etc. 1.6.2 Diffraction Diffraction happens when the path between the transmitters and receivers is disturbed by a surface with sharp edges. It source is any sharp edge object. Knife edge diffraction Model is used for diffraction. 1.6.3 Scattering Scattering occurs when an electromagnetic wave falls upon an object which has small dimension as compared to the wavelength of the wave. Scattering occurs due to small objects, rough surfaces or any irregularities. Objects such as lamp posts, trees scatter the radio waves. Radar Cross Section Model is used for sectoring. 1.7 Small Scale Fading Fading is the fluctuation in the received signal strength over very short distance. Fading is due to reception of different versions of same signals. Following are the factors which influence Small-Scale Fading are: Multipath propagation: Due to absence of LOS signal follows the multipath due to reflection, diffraction, scattering. Speed of the mobile: Fading also accurs due to the movement of the mobile as the signal strength changes. Speed of the surrounding objects: Fading also occurs due to the movement of mobile, if the speed of the surrounding object is much faster then the speed of the mobile then it also induces Doppler shift. The transmission BW (bandwidth) of the signal: The received signal is distorted if the transmitted signal bandwidth is greater than the bandwidth of the channel. 1.8 GSM The first GSM network was launched in 1991. The GSM network was structured hierarchically. It consists of one administrative region, which is assigned to MSC. Each administrative region is consists of at least one location area (LA). LA is also called the visited area. An LA consists of several cell groups. Each cell group is assigned to a base station controller (BSC). Cells of one BSC may belong to different LAs. GSM distinguishes explicitly between users and identifiers. The user identity associates with a MS by mans of personal chip cards, the subscriber identity module (SIM). The SIM is portable and transferable MSs. The mobile Roaming number is a temporary location-dependent ISDN number. It is assigned by a locally responsible Visited Location Number (VLR). The GSM network can defined into four major parts. Mobile station (MS). Base station Sub-system (BSS). Network and switching Sub-system (NSS). Operation and support Sub-system (OSS). 1.8.1 Mobile station A mobile station consists of two parts. Mobile equipment and terminal. Subscriber identity module (SIM). 1.8.2 THE Terminal There are different types of terminal distinguished principally by their power and application: The fixed terminals are installed in cars. The GSM portable terminals can be used in the vehicles. The hand held terminals have experienced a biggest success depending upon their weight and volume, which are decreasing continuously. These terminals can emit power of 2 w. The evolution of technologies decreases the maxpower to 0.8 watts. 1.8.3 SIM Sim is a smart card which identifies the terminal. Using the sim card in the mobile, the user can access all the services provided by the provider. Terminal does not operate without the sim,. Personal identification number(PIN) helps protect sim. 1.9 The Base Station Subsystem The BSS connects the MS to Network Switching Sub-system. It is incharge of transmission as well as reception. The BSS is further divided into two main parts. Base transceiver station (BTS) or base station. Base Station Controller(BSC). 1.9.1 The Base Transceiver Station The BTS deals with the transceivers and antennas which are used in each cell of a network. BTS is usually in the center of cell. Size of the cell is defined by its transmitting power. Each BTS has one to sixteen transceivers which depends upon the density of users. 1.10 The Base Station Controller The BSC controllers the group of BTS and manages radio resources. The BSC is incharge of handover, frequency hoping and exchange of radio frequency power level of BTSs. 1.11 The Network and Switching Subsystem It is to manage the communication between mobile and other users, such as ISDN users, telephony users. It store the information in data bases about the subscriber and manage their mobility. 1.12 The Mobile Services Switching Center (MSC) It is the central component of the NSS. Network Switching Functions are performed by the MSC. It provides connection to more other networks. Chapter 2 Planning One of the important phase of the project in which all the detail information is gathered about different areas and their population including city boundary, market analysis and roads are the key features in these details are city profiling. This phase is divided into different tasks. 2.1 Lahore City Map First is to get the detailed map of the Lahore city, which includes all the aspects related to the project. These are following:- Area division Dense area Sub-urban area open area Boundaries of City 2.2 Boundary Marking The project â€Å"Radio Frequency Planning † is basically the frequency planning of the city, not to its belongings areas. The exact boundary of the city is marked in order to concentrate on the marked area. 2.3 Population Population of the city plays an important role in the frequency planning. It helps a lot in the estimations and assumptions. The population of the city is around 10 million. 2.4 Estimations and Assumptions This part is mainly concerned with the frequency planning. When a new telecommunication company comes in the market, it estimates it users. This estimation is done with respect to the total population of the particular area. The estimations are done to estimate the users on urban, suburban and open areas. 2.5 Area Division The area division depends upon the percentage of population in an area and type of area as it is the important factor in the site as wall as frequency planning. The Lahore city is divided into three major areas. 2.5.1 Urban Area Urban area is an area which is surrounded by more density of humans and structures in comparison to the areas surrounding it 2.5.2 Sub-Urban Area Suburban area is districts located either inside a town or citys outer premises or just outside its limits. 2.5.3 Open Area Open area is partially settled places away from the large cities. Such areas are different from more intensively settled urban and suburban areas. There are less population as compared to urban and sub-urban areas. 2.6 Site Planning 2.6.1 Map of Lahore 2.6.2 Urban Area 2.6.3 Sub-Urban Area 2.6.4 Open Area HATA Model for Urban Area = Path loss in Urban Areas in decibel (dB) = Height of base station in meters (m) = Height of mobile station Antenna in meters (m) = Frequency of Transmission in megahertz (MHz). = Distance between the base station and mobile stations in kilometers To calculate radius of a site of Urban Area For Downlink =-75 dBm(this power covers both indoor and outdoor coverage range -70 to -90 dBm ) = 35 m(Average height of antenna in city is 30 to 200 m) = 1.5 m = 13 dBm = 46 dBm (Max Power transmitted by Base Station) = Cable loss = 2.01 dBm = 945 Mhz (Downlink frequency 935 to 960 MHz) = Combine Loss= 5.5 dBm Putting in HATA equation For Uplink = -102 dbm(Min Power received by Base Station) = 29.1 dBm (Max transmitted power mobile) = 900 MHz (890 to 915 MHz) Putting in HATA equation We will be using d=0.90 Km as it covers both Uplink and Downlink. For Sub-Urban Area For Downlink For downlink of Suburban parameters are same as for Urban. For Uplink Uplink parameters are also same as Urban Areas We will be using d=2.32 Km for Suburban Area. For Open Areas Downlink For downlink parameters are same as Urban Areas For Uplink We will be using d=8 for Open Areas. We will be using 65 degree directional Antennas. Angle between 2 consecutive lobes is 120 degree. r=Radius of lobes For Full Lobe For All 3 Lobes Area of site in Urban Area of site in Suburban Area of site in Fields(Open Area) Calculations for Number of BTS 2.7 Frequency Planning One of the breakthrough in solving the problem of congestion and user capacity is the cellular concept. Cellular radio systems rely on reuse of channels throughout a coverage region. A group of radio channels are allocated to each cellular base station to be used within a area known as cell. Different channels are assingned in the adjacent cells of the base station. The same group of channels can be used by limiting the coverage area, within the boundaries of a cell to cover different levels, within tolerable limits. Frequency planning is the design process of selecting, allocating or assinging channel group stations within a system. The theoretical calculations, and fixed size of a cell is assumed, that can differentiate no of channels in a cell and from that can differentiate cluster size and will differ, the capacity of the cellular system. There is a trade between the interference abd capacity in theoretical calculation as if we reduce the cluster size more cells are needed to cover the area and more capacity. But from another perceptive small cluster size causes the ratio between cell radius, and the distance between co-channels cells to increase, leading to stronger co-channels interference. In practical calculations, a fixed no of channels are allocated to a cell. One channel per lobe 3channels are allocated to a cell. The capacity can be increased by allocating 2 channels per lobe or 6 channels per cell. But after allocating channels once, they will remain fixed for the whole cellular system and frequency planning. Now as with the fixed no of channels as per cell, the capacity will remain constant of the system and we can achieve weaker co-channel interference, by having a small cluster size(N). A cluster size of 7 is selected in this project, which is also discussed. So in later practical world , there is not a trade-off between capacity and co-channel interference. 2.7.1 Calculations The city of Lahore is divided into 120 cells. We take 3 channels per cell that gives us 1 cell = 3 channels Reuse factor = 1/N = 1/7 Which means that frequency can be reused after a cluster of 7 cells. That gives us the total of 7 x 3 =21+ 2(guard cells)=23 channels We will be using 23 channels with a reuse factor of 1/7. 2.8 Implementation in GAIA Figure 2.1 is a snapshot of GAIA planning tool showing us the structure of an urban area. This figure illustrates the urban boundary which we calculate during city profiling. It also shows the antenna system used, in this case 3 sectors with 120 degree azimuth spacing is used. Antennas are installed on the rooftop of buildings or houses due to dense population and to provide a better coverage. Figure 2.2 shows us the planning of a Sub-Urban area with sites more distance apart as population is less, compared to urban. In Sub-Urban 3 sector cell is used which is similar to the ones used in Urban Figure 2.3 shows us the coverage planning of a network in an open area. Here the sites are further apart as open area has least population. 3 sector cell is used with the antennas installed above a steel structure for better coverage. Figure 2.4 shows the sector wise cell area of the sites in the urban area of the city in GAIA, which can be differentiated with the help of different color for each sector, also it shows the coverage area of every site. We have used grid approach in this planning, it is the most widely used and most effective technique used theoretically and practically. Figure 2.5 shows the cell boundary of sites in Sub-urban area of the city. Figure 2.6 shows the cell boundary in the open area of the city. Figure 2.7 illustrates the signal strength in the urban area of the city. Because of the dense population the signal power is strong throughout to ensure high quality calls to the subscribers with minimum interference and call drop. Figure 2.8 shows the 2G signal strength in the Sub-urban areas where population density is low and so the power required is less as compared to urban areas. Figure 2.9 shows the serving signal strength in open area. The signal is the weakest as there is the least number of people in open area. CHAPTER 3 FUNDAMENTALS OF 3G 3.1 INTRODUCTION The Universal Mobile Telephony System (UMTS) or 3G as it is known is the next big thing in the world of mobile telecommunications. It provides convergence between mobile telephony broadband access and Internet Protocol (IP) backbones. This introduces very variable data rates on the air interface, as well as the independence of the radio access infrastructure and the service platform. For users this makes available a wide spectrum of circuit-switched or packet data services through the newly developed high bit rate radio technology named Wideband Code Division Multiple Access (WCDMA). The variable bit rate and variety of traffic on the air interface have presented completely new possibilities for both operators and users, but also new challenges to network planning and optimization. The success of the technology lies in optimum utilization of resources by efficient planning of the network for maximum coverage, capacity and quality of service. This part of our project aims to detail method of UMTS Radio Network (UTRAN) Planning. The new technologies and services have brought vast changes within the network planning; the planning of a 3G network is now a complex balancing act between all the variables in order to achieve the optimal coverage, capacity and Quality of Service simultaneously. 3.2 WCDMA In UMTS access scheme is DS-CDMA (Direct Sequence CDMA) which involves that a code sequence is directly used to modulate the transmitted radio signal with information which is spreaded over approximately 5 MHz bandwidth and data rate up to 2 Mbps. Every user is assigned a separate code/s depending upon the transaction, thus separation is not based on frequency or time but on the basis of codes. The major advantage of using WCDMA is that there is no plan for frequency re-use. 3.3 NODE B Node B functions as a RBS (Radio Base Station) and provides radio coverage to a geographical area, by providing physical radio link between the UE (User Equipment) and the network. Node B also refer the codes that are important to identify channels in a WCDMA system. It contains the RF transceiver, combiner, network interface and system controller, timing card, channel card and backplane. The Main Functions of Node B are: Closed loop power control CDMA Physical Channel coding Modulation /Demodulation Micro Diversity Air interface Transmission /Reception Error handling Both FDD and TDD modes are supported by Single node B and it can be co-located with a GSM BTS to reduce implementation costs. The conversion of data from the Radio interface is the main task of Node B. It measures strength and quality of the connection. The Node B participates in power control and is also responsible for the FDD softer handover. On the basis of coverage, capacity and antenna arrangement Node B can be categorizes as Omni directional and Sectorial: OTSR (Omni Transmitter Sector Receiver) STSR (Sector Transmitter Sector Receiver) 3.3.1 OTSR (Omni Transmit Sector Receive) The OTSR configuration uses a single (PA) Power Amplifier, whose output is fed to a transmit splitter. The power of the RF signal is divided by three and fed to the duplexers of the three sectors, which are connected to sectorized antennas. 3.3.2 STSR (Sectorial Transmit Sector Receive) The STSR configuration uses three (PA) Power Amplifier, whose output is fed directly to the duplexers of the three sectors, which are connected to sectorized antennas. Node B serve the cells which depend on sectoring. 3.4 ACCESS MODES 3.4.1 FDD (Frequency Division Duplex) A duplex method whereby uplink and downlink transmissions use two separated radio frequencies. In the FDD, each downlink and uplink uses the different frequency band. 3.4.2 TDD (Time Division Duplex) It is a method in which same frequency is used for the transmission of downlink and uplink by using synchronized time intervals. Time slots are divided into transmission and reception part in the physical channel. 3.4.3 Frequency Bands 3.4 CELLULAR CONCEPT The UMTS network is third generation of cellular radio network which operate on the principle of dividing the coverage area into zones or cells (node B in this case), each of which has its own set of resources or transceivers (transmitters /receivers) to provide communication channels, which can be accessed by the users of the network. A cell is created by transmitting numerous number of low power transmitters. Cell size is determined by the different power levels according to the subscriber demand and density within a specific region. Cells can be added to accommodate growth. Communication in a cellular network is full duplex, which is attained by sending and receiving messages on two different frequencies. In order to increase the frequency reuse capability to promote spectrum efficiency of a system, it is desirable to reuse the same channel set in two cells which are close to each other as possible, however this increases the probability of co-channel interference . The performance of cellular mobile radio is affected by co channel interference. Co-channel interference, when not minimized, decreases the ratio of carrier to interference powers (C/I) at the periphery of cells, causing diminished system capacity, more frequent handoffs, and dropped calls. Usually cells are represented by a hexagonal cell structure, to demonstrate the concept, however, in practice the shape of cell is determined by the local topography. 3.4.1 Types of Cell The 3G network is divided on the basis of size of area covered. Micro cell the area of intermediate coverage, e.g., middle of a city. Pico cell the area of smallest coverage, e.g., a hot spot in airport or hotel. Macro cell the area of largest coverage, e.g., an complete city. 3.5 FADING Fading is another major constraint in wireless communication. All signals regardless of the medium used, lose strength this is known as attenuation/fading. There are three types of fading: Pathloss Shadowing Rayleigh Fading 3.5.1 Pathloss Pathloss occurs as the power of the signal steadily decreases over distance from the transmitter. 3.5.2 Shadowing Shadowing or Log normal Fading is causes by the presence of building, hills or even tree foilage. 3.5.3 Rayleigh Fading Rayleigh Fading or multipath fading is a sudden decrease in signal strength as a result of interference between direct and reflected signal reaching the mobile station. 3.6 HANDOVER IN CDMA The term handover or handoff refers to the process of transferring data session or an ongoing call from channel to channel connected to the core network to another. The handover is performed due to the mobility of a user that can be served in another cell more efficiently. Handover is necessary to support mobility of users. Handover are of following types (also known as handoff): Hard Handover Soft Handover Softer Handover 3.6.1Hard.Handover In Hard handover the old radio links in the UE are dispose of before the new radio links takes place. It can be either seamless or non-seamless. In seamless hard handover, the handover is not detected by the user. A handover that needs a change of the carrier frequency is a hard handover. 3.6.2Soft.Handover Soft handover takes place when cells on the same frequency are changed. Atleast one radio link is always kept to the UTRAN in the removal and addition of the radio links. It is opperated by means of macro diversity in which many radio links are active. 3.6.3Softer.handover It is one of the important case of soft handover which describe the removal and addition of the radio links which is being belonged by the same Node B. Macro diversity can be performed in the NODE B with maximum ratio combining in softer handover. There are inter-cell and intra-cell handover. Handover 3G 2G (e.g. handover to GSM) FDD inter-frequency hard handover TDD/FDD handover (change of cell) TDD/TDD handover FDD/TDD handover (chan Design and Planning of 2G, 3G and Channel Modelling of 4G Design and Planning of 2G, 3G and Channel Modelling of 4G Chapter 1 Fundamentals of Cellular Communication In this chapter, all the background knowledge which is required for this project has been discussed. 1.1 Cell The area covered by single BTS(base transceiver station) is known as cell. 1.1.1 Shape of cell The shape of cell depends upon the coverage of the base station. The actual coverage of the base station is called footprint and is found with the help of measurements from the field. We can make our calculations easier by using the shape of circle noting that there would not be spaces between them. As, the purpose is to provide coverage to each and every subscriber. But if there are spaces between the coverage areas then the person in that specific area will not be able to get any coverage. To cover the problem of interleaving spaces, the shapes that can be used theoretically are: Square Triangle Hexagon But in selection criteria one thing must be kept in mind that every person within a cell get same coverage specially the person at the edges of the cell. So hexagon is the shape among these three choices with largest coverage area. Its coverage area and shape is closest to the circle and it helps tessellate. Omnidirectional antenna is used in the center of it, and if we want to use sectored directional antenna then it must be used at any three corners of it. 1.1.2 Area of the Cell The area of a cell with radius R is shown in figure 1.1(a), is given by: 1.2 Frequency planning While developing the cellular system, it has limited capacity due to the given bandwidth. So, in order to solve this problem Cellular Systems have to depends on an intelligent and more use of channels through out the area. Every cellular base station is alloted a group of different radio channels to be used in a cell. Base station in the adjacent cells use completely different frequencies. For this purpose antennas are used such that their power may get limited within the cell. In this way the allocated frequencies maybe reused in different cells again. The process of allocating and selecting channel groups for all the base stations in a system is known as frequency reuse or frequency planning. We use two types of antennas: Omnidirectional antenna Sectored directional antenna Omnidirectional antennas are used in the cells which are centrally excited and sectored directional antennas are used in the edge excite cells. To understand the concept of frequency reuse, let us say that S are the total no. of duplex channels available for use, k number of channels given to each cell i.e. k S=kN (1.2) Where N is no. of cells which uses the complete set of available frequencies known as cluster frequency reuse factor (1.3) Each cell is in the cluster is assigned of the available channels. The radio frequency from 3Hz to 3000GHz are separated into 12 bands, as shown in the table. Frequency spectrum has different propagation characteristics. As far as concerned to the mobile communication, we only pay attention to the UHF spectrum. 1.2.1 Cluster size(N) If we use N large (a large cluster), the ratio of the cell radius and the distance between co-channel decreases, which causes weaker co-channel interference. But if N is smaller, by keeping the cell size same then we more clusters are needed to cover an area. Hence the capacity is increased. So if we use N larger then the quality of voice is good but the capacity is less and vice versa. 1.3 Interference Interference is one of the major factor in the capacity and performance of a cellular network. The interference is due to a call in the neighbouring cell, another base station operating in the same frequency. Interference causes crosstalk and noise. There are two types of interference. Adjacent channel interference Co-channel interference 1.3.1 Adjacent channel interference Adjacent channel interference results from the signals which are side by side in frequencies to the desires signal. Adjacent channel interference is caused by wrong filtering, like incomplete filtering of not wanted modulation in frequency modulation (FM) systems, not proper tuning, or poor control of frequency. It causes problem. Adjacent channel interference can be reduced by careful channel assignment, filtering and power control within a cell. 1.3.2 Co-channel interference Co-channel cells are the cell which use the same set of frequencies. For example, in the figure 1.2 all the letter ‘A are the co-channel cell because they use the same set of frequencies. Interference due to the co-channel cells is called co-channel interference. It can be reduced by using greater value of N(cluster size). If D is the distance between the co-channel cells and R is radius of the cell, then by using greater value of N the ratio between D to R is increased hence reducing co-channel interference. The relation can b written as: 1.4 Improving coverage and capacity The number of channels assigned to a cell became insufficiently as the demand of wireless system increases. To provide more channels per coverage, some techniques are introduced which improve the coverage and capacity. These techniques are: Cell splitting Sectoring Microcell zone concept 1.4.1 Cell Splitting Cell splitting is the process of dividing a cell into smaller cells. In this process we reduce the antenna height and power of the base station. Cell splitting increases the capacity by increasing frequency reuse factor. In cell splitting Channel assignment techniques remain the same. SIR remains the same Trunking inefficiency do not get suffer. Trunking efficiency is the measure of the number of users which can be offered a particular Grade of service with the specific configuration of the channels. The grade of service (GOS) is the measure of the ability to access a trunked system during the busy hours. The radius of the new cell is reduce to half. So power is also reduced. 1.4.2 Sectoring Sectoring uses directional antennas for controlling the interferences and frequency reuse of channels. The co-channel interference is reduced and thus increasing system performance by using directional antenna. A cell is normally divided into three 120 sectors or six 60 °sectors. When sectoring is used, the channels used in a particular cell are broken into sectored groups and are used only within a particular sector. The no. of channels get divided into sectored groups, so the trunking efficiency is reduced. In sectoring SIR is improved by reducing interference and trunking efficiency is reduced. Handoff increased in sectoring. The s/I improvement allows to decrease the cluster size N in order to improve the frequency reuse, and thus the system capacity. Further improvements in s/I is achieved by downtilting the sector antennas. 1.4.3 Microcell Zone Concept Microcell Zone concept distributes the coverage of a cell and extends the cell boundry to hard to reach places. It maintains the S/I and trunking efficiency, and increases the coverage and capacity of an area. 1.5 Radio wave propagation Radio waves propagate through different channels and by different ways to reach the MS(Mobile Station). It also depends upon the speed of the wave. The propagation of radio waves depends into two types: Large scale propagation Small scale propagation(Fading) 1.5.1 Large scale propagation The model predicts that the average signal strength for all transmitter-receiver (TR) distance on a scale known as large scale propogation model. 1.5.2 Small scale propagation The models that predicts the rapid fluctuation of the received signal strength over a short distance known as small scale propagation model or fading. 1.5.3 Free Space Propagation Model The free space propagation model is used when the transmitter and receiver have line of sight (LOS) between them to predict the received signal strength. Where Pr = received power. Pt = transmitted power, Gt and Gr = transmitter and receiver antenna gain, do= T-R separation, L = system loss factor ÃŽ » = wavelength. 1.6 Propagation Mechanisms The propagation mechanisms which effect propagation are: Reflection Scattering Diffraction Reach directly (in case of Line of Sight) If there is line of sight signal reach the Mobile station directly and signal power is very strong. 1.6.1 Reflection Reflection occurs when an electromagnetic wave falls upon an object which is large as compare to the wavelength of the wave. It occurs from buildings, walls, surface of earth etc. 1.6.2 Diffraction Diffraction happens when the path between the transmitters and receivers is disturbed by a surface with sharp edges. It source is any sharp edge object. Knife edge diffraction Model is used for diffraction. 1.6.3 Scattering Scattering occurs when an electromagnetic wave falls upon an object which has small dimension as compared to the wavelength of the wave. Scattering occurs due to small objects, rough surfaces or any irregularities. Objects such as lamp posts, trees scatter the radio waves. Radar Cross Section Model is used for sectoring. 1.7 Small Scale Fading Fading is the fluctuation in the received signal strength over very short distance. Fading is due to reception of different versions of same signals. Following are the factors which influence Small-Scale Fading are: Multipath propagation: Due to absence of LOS signal follows the multipath due to reflection, diffraction, scattering. Speed of the mobile: Fading also accurs due to the movement of the mobile as the signal strength changes. Speed of the surrounding objects: Fading also occurs due to the movement of mobile, if the speed of the surrounding object is much faster then the speed of the mobile then it also induces Doppler shift. The transmission BW (bandwidth) of the signal: The received signal is distorted if the transmitted signal bandwidth is greater than the bandwidth of the channel. 1.8 GSM The first GSM network was launched in 1991. The GSM network was structured hierarchically. It consists of one administrative region, which is assigned to MSC. Each administrative region is consists of at least one location area (LA). LA is also called the visited area. An LA consists of several cell groups. Each cell group is assigned to a base station controller (BSC). Cells of one BSC may belong to different LAs. GSM distinguishes explicitly between users and identifiers. The user identity associates with a MS by mans of personal chip cards, the subscriber identity module (SIM). The SIM is portable and transferable MSs. The mobile Roaming number is a temporary location-dependent ISDN number. It is assigned by a locally responsible Visited Location Number (VLR). The GSM network can defined into four major parts. Mobile station (MS). Base station Sub-system (BSS). Network and switching Sub-system (NSS). Operation and support Sub-system (OSS). 1.8.1 Mobile station A mobile station consists of two parts. Mobile equipment and terminal. Subscriber identity module (SIM). 1.8.2 THE Terminal There are different types of terminal distinguished principally by their power and application: The fixed terminals are installed in cars. The GSM portable terminals can be used in the vehicles. The hand held terminals have experienced a biggest success depending upon their weight and volume, which are decreasing continuously. These terminals can emit power of 2 w. The evolution of technologies decreases the maxpower to 0.8 watts. 1.8.3 SIM Sim is a smart card which identifies the terminal. Using the sim card in the mobile, the user can access all the services provided by the provider. Terminal does not operate without the sim,. Personal identification number(PIN) helps protect sim. 1.9 The Base Station Subsystem The BSS connects the MS to Network Switching Sub-system. It is incharge of transmission as well as reception. The BSS is further divided into two main parts. Base transceiver station (BTS) or base station. Base Station Controller(BSC). 1.9.1 The Base Transceiver Station The BTS deals with the transceivers and antennas which are used in each cell of a network. BTS is usually in the center of cell. Size of the cell is defined by its transmitting power. Each BTS has one to sixteen transceivers which depends upon the density of users. 1.10 The Base Station Controller The BSC controllers the group of BTS and manages radio resources. The BSC is incharge of handover, frequency hoping and exchange of radio frequency power level of BTSs. 1.11 The Network and Switching Subsystem It is to manage the communication between mobile and other users, such as ISDN users, telephony users. It store the information in data bases about the subscriber and manage their mobility. 1.12 The Mobile Services Switching Center (MSC) It is the central component of the NSS. Network Switching Functions are performed by the MSC. It provides connection to more other networks. Chapter 2 Planning One of the important phase of the project in which all the detail information is gathered about different areas and their population including city boundary, market analysis and roads are the key features in these details are city profiling. This phase is divided into different tasks. 2.1 Lahore City Map First is to get the detailed map of the Lahore city, which includes all the aspects related to the project. These are following:- Area division Dense area Sub-urban area open area Boundaries of City 2.2 Boundary Marking The project â€Å"Radio Frequency Planning † is basically the frequency planning of the city, not to its belongings areas. The exact boundary of the city is marked in order to concentrate on the marked area. 2.3 Population Population of the city plays an important role in the frequency planning. It helps a lot in the estimations and assumptions. The population of the city is around 10 million. 2.4 Estimations and Assumptions This part is mainly concerned with the frequency planning. When a new telecommunication company comes in the market, it estimates it users. This estimation is done with respect to the total population of the particular area. The estimations are done to estimate the users on urban, suburban and open areas. 2.5 Area Division The area division depends upon the percentage of population in an area and type of area as it is the important factor in the site as wall as frequency planning. The Lahore city is divided into three major areas. 2.5.1 Urban Area Urban area is an area which is surrounded by more density of humans and structures in comparison to the areas surrounding it 2.5.2 Sub-Urban Area Suburban area is districts located either inside a town or citys outer premises or just outside its limits. 2.5.3 Open Area Open area is partially settled places away from the large cities. Such areas are different from more intensively settled urban and suburban areas. There are less population as compared to urban and sub-urban areas. 2.6 Site Planning 2.6.1 Map of Lahore 2.6.2 Urban Area 2.6.3 Sub-Urban Area 2.6.4 Open Area HATA Model for Urban Area = Path loss in Urban Areas in decibel (dB) = Height of base station in meters (m) = Height of mobile station Antenna in meters (m) = Frequency of Transmission in megahertz (MHz). = Distance between the base station and mobile stations in kilometers To calculate radius of a site of Urban Area For Downlink =-75 dBm(this power covers both indoor and outdoor coverage range -70 to -90 dBm ) = 35 m(Average height of antenna in city is 30 to 200 m) = 1.5 m = 13 dBm = 46 dBm (Max Power transmitted by Base Station) = Cable loss = 2.01 dBm = 945 Mhz (Downlink frequency 935 to 960 MHz) = Combine Loss= 5.5 dBm Putting in HATA equation For Uplink = -102 dbm(Min Power received by Base Station) = 29.1 dBm (Max transmitted power mobile) = 900 MHz (890 to 915 MHz) Putting in HATA equation We will be using d=0.90 Km as it covers both Uplink and Downlink. For Sub-Urban Area For Downlink For downlink of Suburban parameters are same as for Urban. For Uplink Uplink parameters are also same as Urban Areas We will be using d=2.32 Km for Suburban Area. For Open Areas Downlink For downlink parameters are same as Urban Areas For Uplink We will be using d=8 for Open Areas. We will be using 65 degree directional Antennas. Angle between 2 consecutive lobes is 120 degree. r=Radius of lobes For Full Lobe For All 3 Lobes Area of site in Urban Area of site in Suburban Area of site in Fields(Open Area) Calculations for Number of BTS 2.7 Frequency Planning One of the breakthrough in solving the problem of congestion and user capacity is the cellular concept. Cellular radio systems rely on reuse of channels throughout a coverage region. A group of radio channels are allocated to each cellular base station to be used within a area known as cell. Different channels are assingned in the adjacent cells of the base station. The same group of channels can be used by limiting the coverage area, within the boundaries of a cell to cover different levels, within tolerable limits. Frequency planning is the design process of selecting, allocating or assinging channel group stations within a system. The theoretical calculations, and fixed size of a cell is assumed, that can differentiate no of channels in a cell and from that can differentiate cluster size and will differ, the capacity of the cellular system. There is a trade between the interference abd capacity in theoretical calculation as if we reduce the cluster size more cells are needed to cover the area and more capacity. But from another perceptive small cluster size causes the ratio between cell radius, and the distance between co-channels cells to increase, leading to stronger co-channels interference. In practical calculations, a fixed no of channels are allocated to a cell. One channel per lobe 3channels are allocated to a cell. The capacity can be increased by allocating 2 channels per lobe or 6 channels per cell. But after allocating channels once, they will remain fixed for the whole cellular system and frequency planning. Now as with the fixed no of channels as per cell, the capacity will remain constant of the system and we can achieve weaker co-channel interference, by having a small cluster size(N). A cluster size of 7 is selected in this project, which is also discussed. So in later practical world , there is not a trade-off between capacity and co-channel interference. 2.7.1 Calculations The city of Lahore is divided into 120 cells. We take 3 channels per cell that gives us 1 cell = 3 channels Reuse factor = 1/N = 1/7 Which means that frequency can be reused after a cluster of 7 cells. That gives us the total of 7 x 3 =21+ 2(guard cells)=23 channels We will be using 23 channels with a reuse factor of 1/7. 2.8 Implementation in GAIA Figure 2.1 is a snapshot of GAIA planning tool showing us the structure of an urban area. This figure illustrates the urban boundary which we calculate during city profiling. It also shows the antenna system used, in this case 3 sectors with 120 degree azimuth spacing is used. Antennas are installed on the rooftop of buildings or houses due to dense population and to provide a better coverage. Figure 2.2 shows us the planning of a Sub-Urban area with sites more distance apart as population is less, compared to urban. In Sub-Urban 3 sector cell is used which is similar to the ones used in Urban Figure 2.3 shows us the coverage planning of a network in an open area. Here the sites are further apart as open area has least population. 3 sector cell is used with the antennas installed above a steel structure for better coverage. Figure 2.4 shows the sector wise cell area of the sites in the urban area of the city in GAIA, which can be differentiated with the help of different color for each sector, also it shows the coverage area of every site. We have used grid approach in this planning, it is the most widely used and most effective technique used theoretically and practically. Figure 2.5 shows the cell boundary of sites in Sub-urban area of the city. Figure 2.6 shows the cell boundary in the open area of the city. Figure 2.7 illustrates the signal strength in the urban area of the city. Because of the dense population the signal power is strong throughout to ensure high quality calls to the subscribers with minimum interference and call drop. Figure 2.8 shows the 2G signal strength in the Sub-urban areas where population density is low and so the power required is less as compared to urban areas. Figure 2.9 shows the serving signal strength in open area. The signal is the weakest as there is the least number of people in open area. CHAPTER 3 FUNDAMENTALS OF 3G 3.1 INTRODUCTION The Universal Mobile Telephony System (UMTS) or 3G as it is known is the next big thing in the world of mobile telecommunications. It provides convergence between mobile telephony broadband access and Internet Protocol (IP) backbones. This introduces very variable data rates on the air interface, as well as the independence of the radio access infrastructure and the service platform. For users this makes available a wide spectrum of circuit-switched or packet data services through the newly developed high bit rate radio technology named Wideband Code Division Multiple Access (WCDMA). The variable bit rate and variety of traffic on the air interface have presented completely new possibilities for both operators and users, but also new challenges to network planning and optimization. The success of the technology lies in optimum utilization of resources by efficient planning of the network for maximum coverage, capacity and quality of service. This part of our project aims to detail method of UMTS Radio Network (UTRAN) Planning. The new technologies and services have brought vast changes within the network planning; the planning of a 3G network is now a complex balancing act between all the variables in order to achieve the optimal coverage, capacity and Quality of Service simultaneously. 3.2 WCDMA In UMTS access scheme is DS-CDMA (Direct Sequence CDMA) which involves that a code sequence is directly used to modulate the transmitted radio signal with information which is spreaded over approximately 5 MHz bandwidth and data rate up to 2 Mbps. Every user is assigned a separate code/s depending upon the transaction, thus separation is not based on frequency or time but on the basis of codes. The major advantage of using WCDMA is that there is no plan for frequency re-use. 3.3 NODE B Node B functions as a RBS (Radio Base Station) and provides radio coverage to a geographical area, by providing physical radio link between the UE (User Equipment) and the network. Node B also refer the codes that are important to identify channels in a WCDMA system. It contains the RF transceiver, combiner, network interface and system controller, timing card, channel card and backplane. The Main Functions of Node B are: Closed loop power control CDMA Physical Channel coding Modulation /Demodulation Micro Diversity Air interface Transmission /Reception Error handling Both FDD and TDD modes are supported by Single node B and it can be co-located with a GSM BTS to reduce implementation costs. The conversion of data from the Radio interface is the main task of Node B. It measures strength and quality of the connection. The Node B participates in power control and is also responsible for the FDD softer handover. On the basis of coverage, capacity and antenna arrangement Node B can be categorizes as Omni directional and Sectorial: OTSR (Omni Transmitter Sector Receiver) STSR (Sector Transmitter Sector Receiver) 3.3.1 OTSR (Omni Transmit Sector Receive) The OTSR configuration uses a single (PA) Power Amplifier, whose output is fed to a transmit splitter. The power of the RF signal is divided by three and fed to the duplexers of the three sectors, which are connected to sectorized antennas. 3.3.2 STSR (Sectorial Transmit Sector Receive) The STSR configuration uses three (PA) Power Amplifier, whose output is fed directly to the duplexers of the three sectors, which are connected to sectorized antennas. Node B serve the cells which depend on sectoring. 3.4 ACCESS MODES 3.4.1 FDD (Frequency Division Duplex) A duplex method whereby uplink and downlink transmissions use two separated radio frequencies. In the FDD, each downlink and uplink uses the different frequency band. 3.4.2 TDD (Time Division Duplex) It is a method in which same frequency is used for the transmission of downlink and uplink by using synchronized time intervals. Time slots are divided into transmission and reception part in the physical channel. 3.4.3 Frequency Bands 3.4 CELLULAR CONCEPT The UMTS network is third generation of cellular radio network which operate on the principle of dividing the coverage area into zones or cells (node B in this case), each of which has its own set of resources or transceivers (transmitters /receivers) to provide communication channels, which can be accessed by the users of the network. A cell is created by transmitting numerous number of low power transmitters. Cell size is determined by the different power levels according to the subscriber demand and density within a specific region. Cells can be added to accommodate growth. Communication in a cellular network is full duplex, which is attained by sending and receiving messages on two different frequencies. In order to increase the frequency reuse capability to promote spectrum efficiency of a system, it is desirable to reuse the same channel set in two cells which are close to each other as possible, however this increases the probability of co-channel interference . The performance of cellular mobile radio is affected by co channel interference. Co-channel interference, when not minimized, decreases the ratio of carrier to interference powers (C/I) at the periphery of cells, causing diminished system capacity, more frequent handoffs, and dropped calls. Usually cells are represented by a hexagonal cell structure, to demonstrate the concept, however, in practice the shape of cell is determined by the local topography. 3.4.1 Types of Cell The 3G network is divided on the basis of size of area covered. Micro cell the area of intermediate coverage, e.g., middle of a city. Pico cell the area of smallest coverage, e.g., a hot spot in airport or hotel. Macro cell the area of largest coverage, e.g., an complete city. 3.5 FADING Fading is another major constraint in wireless communication. All signals regardless of the medium used, lose strength this is known as attenuation/fading. There are three types of fading: Pathloss Shadowing Rayleigh Fading 3.5.1 Pathloss Pathloss occurs as the power of the signal steadily decreases over distance from the transmitter. 3.5.2 Shadowing Shadowing or Log normal Fading is causes by the presence of building, hills or even tree foilage. 3.5.3 Rayleigh Fading Rayleigh Fading or multipath fading is a sudden decrease in signal strength as a result of interference between direct and reflected signal reaching the mobile station. 3.6 HANDOVER IN CDMA The term handover or handoff refers to the process of transferring data session or an ongoing call from channel to channel connected to the core network to another. The handover is performed due to the mobility of a user that can be served in another cell more efficiently. Handover is necessary to support mobility of users. Handover are of following types (also known as handoff): Hard Handover Soft Handover Softer Handover 3.6.1Hard.Handover In Hard handover the old radio links in the UE are dispose of before the new radio links takes place. It can be either seamless or non-seamless. In seamless hard handover, the handover is not detected by the user. A handover that needs a change of the carrier frequency is a hard handover. 3.6.2Soft.Handover Soft handover takes place when cells on the same frequency are changed. Atleast one radio link is always kept to the UTRAN in the removal and addition of the radio links. It is opperated by means of macro diversity in which many radio links are active. 3.6.3Softer.handover It is one of the important case of soft handover which describe the removal and addition of the radio links which is being belonged by the same Node B. Macro diversity can be performed in the NODE B with maximum ratio combining in softer handover. There are inter-cell and intra-cell handover. Handover 3G 2G (e.g. handover to GSM) FDD inter-frequency hard handover TDD/FDD handover (change of cell) TDD/TDD handover FDD/TDD handover (chan

Do Large Lecture Halls Offer a Good Learning Environment? :: Teaching Education

Do Large Lecture Halls Offer a Good Learning Environment Higher education comes in many forms, from small private colleges with one professor for every seven students, to enormous universities which utilize teaching assistants for almost all offered classes. The question I have as a student at Purdue, a university with around 35,000 students, is are large lecture halls with more than two hundred students effective places for learning to occur? When there are that many pupils in a classroom, it is nearly impossible for an instructor to take attendance. What is the motivation to attend class? Further, are students able to understand material presented in a classroom when there are hundreds more people in the classroom rustling papers, dropping pens, and whispering sarcastic comments about the lecture? In order to answer some of the above questions, I decided to study one of my largest lecture classes, Psychology 120 under Bob Melara. Class is held in an enormous lecture hall, which seats over five hundred students. In order to learn the answers, I did research for several weeks. I handed out questionnaires to other students at Purdue and observed Melara’s class for about two weeks. In addition, I interviewed Saree Strom, a student in the honors section of Psychology 120. The class of Melara’s that I studied meets every Monday, Wednesday, and Friday between 4:30 and 5:20 PM. Class is held in the giant lecture hall on the first floor of the Lily Hall of Sciences on State Street. There are about five hundred students in this section, and the seats are set up like a stadium so that each row is higher than the one below it. In addition to the regular class, the honors students meet Wednesday from 5:30 to 6:20. As honors students, their responsibilities increase to planning and leading small groups for each of the four labs that all students are required to do during the semester. There are twenty honors students in this section. The students in psychology discovered on the first day of class that the professor was a little out of the ordinary. He walked into class and announced, â€Å"Hello, my name is Robert Melara, but I am not overly fond of that name. What you refer to me as when I am not around is unimportant, but please address me only as Bob.† His hair is sort of long and shaggy, and it appears as though he never combs it.

Negative Influence of Social Media Essay

Today, Mass Media is notoriously known to project a negative influence on teens and society. It manipulates several aspects of our lives including, but not limited to, the choices we make about our overall physical appearance, how we perceive beauty, healthy decisions we make regarding drug and alcohol use, engaging in premarital sex, and our peer and social interactions. We emulate what the media portrays as acceptable and desirable, though it goes against the norms and values put forth from society. As we mature, our goals and values seem to change as we break from the traditional values and connect with those portrayed as cool and current, through the media and pop culture. During adolescence, one often struggles with choosing between what is right from wrong and the media often accentuates the lives of celebrities. Young children are known to emulate their role models, unconscious of the consequences that may result in their actions. The media has been proven to be detrimental to the health and lifestyle of the youth. The media has a strong impact on the appearance satisfaction of today’s youth. Young women are constantly comparing their bodies to the ones seen advertised on television commercials. Around 10 million females and 1 million males in the United States are suffering from eating disorders such as anorexia, bulimia, etc. After seeing these beautiful and flawless models on billboards and advertisements, many women are disturbed with their personal body images. This is known to be a main contributor to eating disorders around the world. Thus, the media has the effect to change one’s mental set up. Beauty and Body Image in the Media† is an article that explains the negative affect the media has on young women and how they view themselves. Images of female bodies are seen in films, TV, magazines, ads, etc. These models are engraving the perfect body image into the minds’ of the youth. Women’s magazines are full of ads influencing women that if they lose weight they’ll have it all. Researchers have observed that these images of thin and airbrushed models are associated with depression, loss of self-esteem, and the development of harmful eating habits. It’s been suggested that almost half of all preadolescent girls are dissatisfied with their appearances and either diet or think about dieting. Further, 50 to 70 percent of average weight girls feel that they’re overweight and 90 percent of women are frustrated with their body images. These advertisements are not only advertising their products, but they’re also selling an entire way of life. The media promotes tan, fit, and outward physical perfection in men and women. It is not only middle-aged adults who seek cosmetic surgery to alter their appearance. Today, children also undergo cosmetic procedures. In fact, in 2005 it was reported that children under the age of 18 underwent approximately 333,000 cosmetic procedures. Some included liposuction, breast augmentation, otoplasties (ear pinnings), and rhinoplasties (nose jobs). Teenagers of both genders are trying to acquire a perfect figure rather than living a healthy lifestyle and appreciating themselves for who they truly are. The media also has a reputation for promoting unhealthy choices, such as unprotected premarital sex and drug and alcohol use. The media is sending the wrong message to young adults that taking part in these activities is okay. The article, â€Å"The Media’s Influence Undermines America’s Morals†, by Tim LaHaye contains numerous examples of how the media is detrimental to the future of the United States. AIM, Accuracy In Media, and PMRC, Parents Music Resource Center, are organizations that support government regulation of the media. They believe that the media is destroying our culture and altering our values. Moviemakers, producers, and journalists are provoking sexual immorality in our society by explicitly exposing and promoting sexual relationships. The media is even found glamorizing teen pregnancies in the MTV series, 16 and Pregnant and Teen Mom. LaHaye states that, â€Å"the media’s power is seen in its degrading influence not only on the nation’s morals, but on†¦ virtually every area of life. † Music also plays a huge role in influencing teens toward becoming sexually active and provocative. â€Å"Rock Music Has a Negative Effect on the Youth†, by Rob Lamp is another article which states that rock music is somewhat accountable for the increase in teenage pregnancies. A counselor for pregnant teenagers believes that young girls are emulating celebrities. They are buying their albums and dressing like them. Today, 30 percent of all women loose their virginity before age sixteen. Violence sexuality has also become popular in music videos and song lyrics. Rap lyrics are being criticized by child advocate groups such as the American Academy of Pediatrics, for imparting the wrong message to the youth about sex and drugs. Misogamy is a derogatory or hateful comment geared towards girls and women and a lot of rap artists tend to include misogamy in their lyrics. The  APA has determined that today’s youth actually spends more time listening to and reading to the lyrics via the Internet to their favorite music than they do watching television. This council urges parents to be vigilant when it comes to knowing what their children are listening to. Lamp also states â€Å"the kind of electronic music played at raves has been associated with the use of drugs and alcohol. † The Robert Wood Johnson foundation backed a report titled â€Å"Substance Abuse: The Nations Number One Health Problem†, which shows juveniles are starting to use drugs and alcohol between the ages of 12 and 13. In fact, by eighth grade 52 percent of adolescents have used alcohol and 20 percent have used marijuana. This figure jumps to 80 percent use of alcohol and 49 percent use of marijuana by the 12th grade. A research conducted in 1997 showed that in the 200 most popular movie rentals, alcohol appears almost 93 percent of the time and illicit drugs appeared roughly 25 percent of the time. Further, of the 1,000 most popular songs, 27 percent were shown to include alcohol or drug references. These numbers have surely risen since 1997. In addition to music videos and song lyrics promoting premarital sex and drug/alcohol use, this form of media is also seen promoting violent behavior among adolescent teens. Robert Lamp also believes that â€Å"heavy metal and rap have been associated with reckless behavior and below-average academic performance†¦ heavy metal and rock music have also been associated with an increasing risk of suicide, depression, delinquency risk behavior, smoking, and conduct problems† (Neale 1). In recent years, lyrics are becoming more vulgar and inappropriate. The violence heard in rock music instigates adolescents to commit violent crimes. In Northport NY, a seventeen-year-old boy was slaughtered; the names of Ozzy Osbourne and his former band members were spray painted at the crime scene, along with many satanic symbols. Doctor Guttman, a Professor of Psychiatry at Northwestern University states that, â€Å"Rock has so often been involved in these things (violence, teen suicide, etc. ) many of us in psychiatry have had to take it more seriously. † 45 percent of about 1,200 rock music videos supervised were viewed as explicitly violent. Video games and movies also play a prominent role in promoting violence among youth. The article â€Å"Most Teens Play Violent Video Games†, by Ben Berkowitz and published in the Washington Post, states that â€Å"70 percent of American teenage boys have played the violent, but popular â€Å"Grand Theft Auto† video game, and they are more likely to have been in a fight than those who have not played. † It is clear that the violence depicted through these games are mimicked by youth who have difficulty distinguishing between fantasy and what is appropriate and acceptable in a realistic environment. Tim LaHaye gives a real life example of how the media affects certain people. In San Diego, a High School honor student watched An ABC horror movie on the life of Lizzy Borden, an infamous axe murderer in the 1890’s. After viewing this film, he decided to murder his mother, father, and sister. These examples illustrate how juvenile violence is promoted through music, video games, and movies. We live in a society that depends greatly on the media to impart information, allow for communication, and provide entertainment on a regular basis throughout our daily lives. It is vital that we are attentive and vigilant in deciding what our youth should be allowed to view and listen to, as we know there is a direct connection between what one consumes and what one in turn values, how one behaves and how one interacts in society. Too much exposure to the negative aspects of the media can be detrimental to one’s mental, emotional and physical health. The media influences how we perceive beauty, the healthful decisions we make, and how we interact socially. The negative media is harmfully transforming our ethical values of life and our outlook on society.

Mussolini’s Relationship with Hitler

There were many similarities between Mussolini and Hitler even though the two exhibited some differences. Having risen to power earlier, in the 1920s, Mussolini was the senior between the two and had a great influence on Hitler. Hitler saw in him a teacher who helped him shape his policies. The two however had individual characteristics that made their lives quite different. As much as Hitler went to school and graduated as a fine art student, Mussolini was self – educated (Trifkovic 1993). The latter had a larger than life approach to life and he wanted to be perceived as a superman by the people. In this way he would fake pictures portraying him as a master of various skills including a pilot, wrestler etc. On the other hand Hitler had a less colorful view of life. He was more successful in battle; being able to win majority of the wars that he staged against his enemies. In this way Germany was able to conquer other nations. As much as his friend found it easy to conquer other nations due to his early war experience and the huge army back at home; Mussolini had a difficult time in winning battles. In most of the battles he had to depend on the assistance of the Germans in order to become victorious (Carpi 1994). The two leaders were nevertheless hungry for power and were inclined to totalitarian leadership. They both had been wounded in battle and had almost taken a similar avenue to power (Hayes 1995). There election promise to restore hope and help solve the unemployment problem earned them the support and sympathy from the majority voters. In some way they did not fail as both German and Italy significantly reduced the levels of unemployment in the initial years of their leadership (Cassels 1963). The two had a hot cold relationship. Despite the signing the Pact of Steel, which called for cooperation between the two countries in matters economical, militaristic and on foreign policy issues; still there are times when one of the countries would act without due consultation with the other. Ascension to Power There is great similarity in the manner that the two leaders campaigned for political leadership and got elected to the office. There countries by the time were facing unemployment problems, hopelessness and disillusionment. The citizens were therefore anticipating for someone who would literary save them from the situation. The coming of both Mussolini and Hitler was perceived as a great relieve to the economic situation of the time. There campaign which was fierce propaganda helped to catapult the two dictators into office. This propaganda continued to play a key role in the governments and administration of the day; the citizens were totally unaware of the true information that the government was acting upon. In times of war or when the government made important decisions that directly or indirectly affected the lives of the citizens; there were totally kept in the dark (Weber 1982). The two dictators all had a similar script to help them rule over the people (Flood 1989). They were at a point of establishing a new leadership whereby the individual was the one and only decision maker. This totalitarian government did not tolerate any form of opposition either from an individual or groups. It was therefore common for those who expressed ideas or views that were opposed to the leader to either face prosecution without trial or they were simply liquidated. The two leaders had an unquenchable thirst for power. This trait seemed to have cemented their relationship as they tended to see oneself in the character of the other. Hitler had been able to learn from Mussolini the way to govern a nation with the full authority centered on one individual. In mastering the way Mussolini carried out the affairs of the nation and particularly the conduct of the military; Hitler was eventually able to come up with his own style of leadership (Flood 1989). He was however very critical to avoid the mistakes that his friend had made. So in imitating his manner and way of leadership, he was also aware of the pitfalls that come with overindulgence more so exhibitionism. Foreign Policy It is because of the thirst for power and having the same style of leadership that the two dictators had to settle for an agreement such that they will support one another in case of war. This agreement otherwise referred to as the Pact of Steel was more in favor of Hitler’s Germany that is was for Italy (Corrado 1993). There was an unquenchable thirst for power on the part of Mussolini – for he had seen a powerful ally in Germany – that made him sign the deal. Later on it came to Italy’s realization that Germany was too aggressive in a bid to try and expand its influence thus fought a number of war expecting the cooperation of Italy. At least in two instances Italy declined to get involved in the wars despite the agreement. In both the 1939 and 1940 war, the former being the German’s invasion of Poland, there had been no cooperation between the countries. In the latter case the hesitation came since Mussolini had seen the possibility of Germany benefiting entirely from the invasion. The foreign policies of both Mussolini and Hitler were primarily addressing the expansion of their empire. The two would not squander any opportunity to try and spread there influence. For instance the involvement of Italy in the Spanish war was basically as a result of hunger for power by Mussolini. In this civil war that proved to be quite unpopular in Italy; was a way to get another member to the club of dictators. Already Hitler and Mussolini had perceived themselves as the most powerful nations in Europe. The two come up with an axis to which the other European countries revolved. According to Mussolini Italy would not miss the opportunity to spread its power and influence to other nations. In this stance Italy was backed by Germany and together they rallied their support for Franco. The two were in favor of another establishment of a Fascist dictatorship in Europe. In this war there combined force succeeded in having Franco joining the club of dictators. The effect of this war was a further alienation of Italy from the rest of Europe. It implied that the only option and way that was open to Italy was to augment its friendship with Germany. The Military The military might of Germany was not only one of the best but also the biggest. It was said to be five times more that the limit set by international standards. The significance of the great numbers of the officers was apparent. The nation went and fought many wars and was able to be successful in most of them. The military had been well equipped with sophisticated weapons and personnel that made it difficult to be defeated by any other nation. The two leaders were so much fascinated by the army such that even they themselves would always be seen in the army uniforms. In these military activities the leaders also were able to influence one another in one way or another. For instance the Nazi salute came from a direct imitation from the Mussolini army. Similarly there are a number of ideas that Mussolini borrowed from Hitler after he had visited his country and allowed to see the military. On seeing the military might of the Germans he made up his mind to maintain friendship with Hitler. Mussolini knew little about the military hence it was always divided and fragmented. There seemed to be no way to make the factions stick together and be loyal to their commander-in – chief. For a period of a decade or so Mussolini tried to consolidate and manage the military effectively. He could achieve but little success in this regard as his military exhibited weakness due to the internal divisions. This can be contrasted to his friend whose military was so compact and their loyalty was not compromised. The military was more of a cult than a professional body meant to safeguard the security of the nation. The German soldiers were simply dehumanized such that they were like automatons to follow orders that were given by their superiors. Together in Fascism Fascism seemed to have glued the two dictators together. They both found great relieve and prestige in holding absolute power. Fascism is regarded as unmasked capitalism since it has as its core value the idea of big business (Weber 1982). The two dictators were beneficiaries of the big business helping them ascend to leadership positions. It was therefore there prime role to ensure that the idea does not die with their coming into power. Fascism therefore continued to appeal to the emotions of the masses as it took on symbolism such as the hand salute, flags and creeds. Both Hitler and Mussolini exhibited these qualities and also the tendency towards racism, nationalism and sadism. Fascism detested so much the status quo and this has been the defining trait of both the dictators. Mussolini ensured that all political parties were dissolved. This gave him absolute power to rule over the state of Italy. He got to control each and everything in the country; the most powerful ministries were placed in his hands. These include defense, home and foreign affairs and corporations. Similarly he employed a lot of propaganda machinery such that the citizens are kept out of the picture. Everyone was made to believe that Fascism was the one and only system that could work in the 20th century (Griffin 2000). The other forms of government such as democracy and liberalism were to be shunned since they were outdated and could not be adopted. This manner of leadership was much akin to that of Adolph Hitler, just like his friend, he accomplished most of his goals through propaganda. A student of Mussolini, Hitler perfected the art of propaganda (Sternhell 1994). He was able to persuade the entire nation to support his goals and ideals in order to achieve a common purpose. Hitler had an entire ministry allotted to propaganda. Initially Mussolini held the policy of privatization of industries to the satisfaction of the financers. This was however a short term measure as the policy was reversed such that the government took on the control of the industries (Seldes 1935). As Mussolini struggled to ensure economic and financial independence of Italy – it was vital the country to have enough resources. This was not the case with Italy which struggled with limited resource allocation. To some extend Hitler had the resources to sustain his economy. He was able to solve the unemployment problem in the country and meet the demands of the huge army. Though the nation had been sidelined by other nations due to its aggressive behavior, still the economy did not flounder. This success story did not last for long as there were many obstacles on the way of achieving the goals that the leaders had set in mind. The Fascism ideology failed in its endeavor to bring some substantial changes in the human person and the society at large. First the two major personalities that stood for the idea actually met the most miserable of deaths. No one really wants to remember the actions of the two dictators. Similarly the goals of Fascism namely to come up with a society and human beings that are heroically moral were never to be realized. At first both Mussolini and Hitler were revered and admired by the citizen as they seem to have brought the changes that were badly needed by them and the society as a whole (Trifkovic 1993). This did not last long more so for Mussolini whom everyone soon realized his true character. The alienation of the two individuals by the civilized nations of Europe show how they were affected by their policies. However one cannot simply dismiss Mussolini as a failure who brought nothing but misery to his country. On the contrary Mussolini has been noted to have established the most stable government ever. It is as a result of his government that the nation of Italy can boast of a stable foundation. Similarly the good infrastructure of the country traces its roots back to the leadership of Mussolini. This is not to approve of his character or Fascism as a form of leadership. Any leader can take advantage of any form of leadership. In the case of Mussolini and Hitler the two used the power that had been bestowed on them to ensure that no one opposes their leadership. They systematically eliminated the individuals or groups that were not in favor of their policies. Common Tendencies Since Mussolini and Hitler were regarded as friends they were prone to show similarities in their actions. In some of their actions however the two lacked straight forwardness and tended to be some aspect of distrust. Germany and Italy both left the League of Nations, the former in 1933 while the latter – incensed by the imposition of sanctions by the league after invading Ethiopia – left in 1939. This shows how closely the two leaders influenced the behavior of one other. The attempt to try and occupy Albania by Mussolini had been noted as being synonymous with Hitler’s invasion and later occupation of Czechoslovakia and Austria. This attempt, unlike that of Hitler, did not bear any fruit as the Italian forces were defeated and forced to withdraw from Albania. The foreign policy of the two dictators were therefore similar to a greater extend but the political and military might of Germany was far much superior compared to that of Italy. It is for this reason that analysts were concerned that Mussolini was in fact simply a puppet of his comrade. The foreign policies of Mussolini and Hitler were meant for the achievement of power and status. There were both in favor of the expansion of their empires. To achieve this purpose the dictators employed force and diplomacy. For instance in 1935 take over of Ethiopia, Mussolini had to use force. Similarly Hitler had to threaten with the use of force in order to occupy Austria. In this way the two dictators exhibit the same manner of approach in an attempt to gain power. In brief the two fascist dictators were cut in the same cloth (Trifkovic 1993). There character though seemed to show some variation it was nonetheless the same. Everything that the two dictators did could be brought down to the thirst for power. This was mostly accomplished through wars. The Wars The civil war in Spain that lasted for three years saw the exhibition of new weapons and brought to the fore rivalries between the nations. The war simply showed who is who in the world. There were democracies on one hand comprising of countries such as Belgium, Britain, France and Holland. One the other hand there were the totalitarian regimes which included Russia, Italy and Germany. The might of these nations was to be exhibited in Spain during the civil war. Countries such as France and Britain however did not want to get involved in the crisis and therefore kept off the battlefield. This war was therefore fueled by external forces with little participation of internal forces. In participating in the war, Mussolini was acting against the will of a significant number of Italians. The war was not popular with the majority people since it was simply meant to quench the thirst for power of an individual. Mussolini wanted to have another dictator to join in Europe to join him and Hitler. In this endeavor together with Hitler they recorded huge success after General Franco won the war. Italy had been reluctant to join the First World War due to domestic policies that favored a liberal stance. By then Mussolini was allied to the socialist party thus held to the principles of the party. He later on changed his mind and joined Hitler’s faction on the battlefield. This angered the socialist party leadership thus resulting to his expulsion from the party. Similarly in the Second World War Mussolini was reluctant to join his friend as he was unsure on which side to fight. He was later to make up his mind after he had witnessed the progress in the war. Despite the fact that Hitler was more successful in war compared to Mussolini, the wars kept their relationship close and tight. The invasion of Italy to both Greek and Ethiopia – the former due to the supposed killing of her soldiers while the latter just a revenge mission on an occurrence that happened many years back – led the country to face sanctions from the League of Nations. This was very disagreeable to Mussolini thus making him withdraw from the league. He, just as his friend Hitler had come to the realization that the league could not stand on the way to acquisition of colonies. In order to understand the two leaders one has to place their actions in their respective context. It was the time when the nation’s exalted wars and there was much honor and prestige in conquering another nation. The philosophy of the time was mostly in the favor of the Germanys. This is notably Fred rich Nietzsche whom it is said to have influenced both Hitler and Mussolini with his idea of the superman. This idea was later to become the obsession of Mussolini. He wanted everyone to believe that he had extraordinary qualities. In his approach to many issues and problems that faced his country, Mussolini lacked a realistic approach. Betrayal In one way or another friendship between Mussolini and Hitler has not been smooth running. There have been ups and downs; sometimes they did cooperate while other times the two were totally on different paths. In most cases Mussolini was the victim of the betrayal as he was the lesser of the two in the relationship. In the Pact of Steel for instance the two were to stand by one another in case one declared war on another country. This was not to be as Italy was reluctant to join Germany in its attempt to invade Poland; an incidence that caused the Second World War (Trifkovic 1993). In failing to join his friend in war despite the deal that had been made earlier on, Mussolini was declaring his independence. There is also the possibility that the army was not prepared to fight at the time. The failure to abide by the Pact of Steel can also be as a result of the feeling that Hitler was opportunistic. His military was in fact more aggressive compared to that of Italy. This meant that Italy will serve as the puppet to be manipulated by Germany. Considering the character of both Mussolini and Hitler, none would be willing to accept such a demeaning position. Even with the apparent friendship between Mussolini and Hitler, the latter was said to have recommended Hitler for excommunication to the pope. This action, considering the closeness of the two, had two implications; one is that in essence it sounds factual and quite obvious. On the other hand it is shocking for the suggestion to come from ones friend. The two had cooperated in many things and continued to do so. In fact when everyone else seemed to turn his back against Mussolini, it is Hitler that came to his rescue. The incidence is therefore quite shocking as it is interesting. For no one really knew the true character of these individuals. Not even there closest friends. Nevertheless the two did cooperate in many spheres of life. If it were not for the support of the Germany military, then Mussolini will not have achieved some of the victories that were pegged to his name and regime (Cassels 1963). The most significant aspect of the relationship is the rescue that was carried out by the German soldiers. Mussolini having been arrested and imprisoned in the mountain top; it took the world by storm to see that the German soldiers were able to rescue him (Trifkovic 1993). This was a true display of friendship between Hitler and Mussolini. In fact after the rescue Mussolini was reported to have anticipated his friend’s assistance. Likewise Hitler could not afford to do nothing considering that the friend has been kept in prison. Conclusion It is apparent that for anyone to effectively discuss the actions of Mussolini he will not avoid to mention Hitler. The two cooperated in a number of ways and in carrying out the affairs that badly affected the world. Among the things that fascinated the two principles were war and the military. The obsession with both the military and war made them to always show up in the public in full military uniforms. Nothing however is more notable of the two than their thirst for power. It is primarily for the want of excessive power that the two Fascist dictators saw a similarity in one another bringing them closer together. Even though Mussolini had pioneered in totalitarian leadership, it is Hitler that perfected the practice. He learned from the failures of Mussolini thus able to avoid the pitfalls. In brief, the relationship between Mussolini and Hitler had been a friendly one till when death set them apart.