Wireless Networks - Essay Example

Name: Class: Unit: Introduction Antennas play a very important role in wireless communication systems. According to Yang (2003), antennas play an important role of converting electronic signals to electromagnetic waves in an efficiency manner. According to Jensen and Wallace (2004), antennas refer to devices that convert electromagnetic radiations/signals into electric currents in conductors. This depends on whether they used as transmitters or receivers. It’s composed of electrical circuits that provide interconnecting links between free space and receivers or between transmitters and free space. This essay will outline various antennas, their characteristics and later examine an organization in UAE. 1. Omni-directional antenna and its characteristics Omni-directional antennas are antennas that radiates or receive radio frequencies in all directionsand in one plane. While transmitting, their radiating power decreases with the elevation angle below or above the plane (Ding & Xiao, 2012). They are antennas that do not favor any given direction. They are characterized by several properties. First, Omni-directional antennas receive and propagate signals in all the directions. Hence, in all horizontal directional, Omni-directional antenna propagates radio frequency signal with equal power. Additionally, in the vertical plane, the antenna radiates uniformly across all horizontal angles. It is associated with beams both in the upper and lower lobes.Secondly, the signals are received equally (Carr, 1993). Thirdly,signals transmitted are of the same strength and are propagated in all directions. This is based on the fact that they are all directional(Ding & Xiao, 2012).Additionally, since they have a radiation cone of 360 degrees which works in all directions, they do not need to be pointed. Further, Omni-directional antennas are characterized by gain ratings (decibel isotropic, dBi) which are related to performance. Higher dBi ratings imply a larger horizontal plane of signal coverage thus losing the vertical reach (Ding & Xiao, 2012). On the other hand, lower dBi ratings imply a larger vertical plane coverage thus losing the horizontal reach. They are further characterized by their coverage pattern which is torus shaped. 2. Semi-directional antenna (Yagi) and its characteristics Semi-directional (Yagi) refers to antennas that propagate radio frequency in constricted fashion(Neelgar and Raju, 2011). Their mode of propagation is defined through a specific angle. Neelgar and Raju argued that semi-directional antennas are designed to provide specific and directed radio frequency signal coverage over a large area. It’s characterized by several properties. First, Yagi consists or two or more elements i.e. the driven elements which is the dipole and the parasitic element which include both directors and reflectors(Neelgar and Raju, 2011).They note thatYagi antenna has resonant elements which cause radio frequency signals to be directed in a given direction which gives the antenna gain in that specific direction.In this note, more elements in a Yagi imply a higher gain and a narrower bandwidth. The Yagi is further characterized by its means of propagation(Jensen and Wallace 2004). Jensen and Wallace argue that Yagi antenna propagate its electromagnetic field energy in the direction running from the driven element towards the directors. Additionally, Jensen and Wallace noted Yagi antennas to be most sensitive to incoming electromagnetic field signals in these similar directions.Semi-directional antennas (Yagi) are further characterized by gain they provide (Rattan et al., 2008). They noted that Yagi antenna gain is of importance since it enables the transmitted power to be directed in areas where it’s needed. Further, they argue that when Yagi is used for reception, the gain property enables maximum signal reception from the same area. Additionally, semi-directional antennas can be mounted to support either vertical or horizontal polarization. This property enables it to be used for point-to-point applications such as base stations and repeater station sites(Rattan et al., 2008). Moreover, Yagi are characterized by their wavelength whereby they have a center frequency of λ (λ is based on the length of dipole radiator). They are further characterized by the gain property which is proportional to the number of driver elements(Rattan et al., 2008). Rattan et al. further note beam pattern as another characteristic of Yagi antennas. Being a semi-directional antenna, it transmits its energy in main lobe but with fairly high side lobe levels. 3. Directional (full directional) antenna and its characteristic Directional antennas refer to antennas that transmit or receive signals strongly in one direction(Nipun2015). To transmit or receive signals from directional antennas, both transmitter and receiver have to be pointed towards each other. Example of directional antenna is the parabolic dish antenna. Directional antenna has the ability to focus their strengths in a particular direction(Nipun 2015). Directional antennas have several characteristics. First, while in vertical planes, directional antennas radiate uniformly across all azimuth angles(Nipun 2015). When in this plane, the antenna has a main beam with lower and upper lobes. Secondly,according to Nipu, directional antennas are categorized by the radiations which are directed towards specific angle instead of uniformly across all plane angles. Further, directional antennas are normally used to transmit electromagnetic signals to fixed receivers. For example spaceships signals to their control center and vice versa, satellite televisions in homes. Additionally, according to Nipun (2015),directional antennas focus their radio frequency energy in a given direction. Hence as their gain increases, their coverage distance increases. They are further categorized by the property of radio frequency energy which can be diverted in a given direction to increase the distance of coverage. 4. Case study of Etisalat in UAE Etisalat is a leading UAE telecommunication operator which servers 11.6 million residential customers(Etisalat.ae, 2016). Moreover, it serves over 300,000 small, medium and government customers within UAE. To remain at the leading edge, Etisalat must deploy many innovative technologies and services to its target market. It must ensure that its customers are effectively connected at all times. This call for Etisalat to invest in building networksthat are capable of driving success to its customers and one that keep them connected(Etisalat.ae, 2016). Currently, it has the widest 3g and 4G mobile technology in UAE. It achieves this through a well-connected network infrastructure. From the above diagram, point to multi-point (PtMP) connection was used. Point-to-multipoint refers to a system that allow users to be connected to a given electromagnetic radio frequency signal through a single transmitter(Zhuang& Ismail, 2012). It functions by transmitting data from one point to different points simultaneously. During communication, data is replicated to all but specific selected stations.It consists of a central base which supports other subscribed stations and a bridge where all data within the communication passes(Zhuang& Ismail, 2012). PtMP connection was chosen because it allows multiple stations/sites to communicate with each other.Moreover, it is easy to deploy. From the diagram, Omni-directional and directional antennas were chosen. There are several reasons for choosing Omni-directional antennas in receiving the signals. First, the antennas are cost effective (Choudhury et al., 2001). Omni-directional antenna is a gain antenna system thus having the capability of covering long distances. Secondly, this antenna requires less equipment to assemble. It requires less installation equipment thus providing ease during management and handling. Thirdly, since one can propagate around corners by using high gain antennas, Omni-directional antennas are reliable and cheap. Additionally, since they have a 360 degree horizontal coverage, they canreceive signals in any direction without troubles (Choudhury et al., 2001).Incase of signal failure, one just needs to switch the position of the antenna. Further, Omni-directional radiations within azimuthal, plane have the capability of covering large service area(Zhuang& Ismail, 2012).Zhuangand Ismail further noted that, since it propagates in all directions, Omni-directional antenna has a better Omni-directional radiation with a higher gain.Additionally, it was used because it provides high gain levels which lead to enhanced budget links. Improved budget links imply high data rates or increased range. This acts as means of suppressing cross-network interferences. The directional antenna was chosen for various reasons. First, it increases the distance that will be covered by a signal in one direction while reducing in the other directions(Zhuang& Ismail, 2012). Secondly, directional antenna acts as a means of decreasing interferences at the receiving end. This is based on the fact that there are few signals moving towards the receiver antenna as it’s only listening to signals that are pointing its direction. Thirdly, they it’s security sensitive. Directional antennas are used to prevent wormhole attacks (Choudhury et al., 2001). This is based on the fact that controlling the direction of the signal improves the signal security. Further, the reason for using directional antenna is to reduce the possibility of interferences. This is based on the fact that directional antennas propagate signals in a given direction. Additionally, directional antenna was used to enhance the reusability of the signal. They allow use of repeaters within the network. Conclusion Radio frequency antennas play a very important role in communication. When choosing the right antenna to use, there are considerations that one need to make. Security, interferences, cost, distance are some of the considerations to make. Additionally, increased technological advancements have seen major improvements in wireless communication. However, basic long range mode of communication will still hold their importance in communication. References Choudhury, R. R., Yang, X., Ramanathan, R., &Vaidya, N. H. (2002).Using directional antennas for medium access control in ad hoc networks.In Proceedings of the 8th annual international conference on Mobile computing and networking (pp. 59-70). Etisalat.ae,.(2016). Etisalat - Company Profile - Company Profile.Etisalat.ae. Retrieved 27 October 2016, from http://www.etisalat.ae/en/aboutus/etisalatcorporation/corporation/profile/company- profile.jsp Jensen, M. & Wallace, J. (2004).A Review of Antennas and Propagation for MIMO Wireless Communications.IEEE Transactions On Antennas And Propagation, 52(11), 2810-2824. http://dx.doi.org/10.1109/tap.2004.835272 Neelgar, B. &Raju, G. (2011).Impedance Characteristics of Log Periodic Antenna. International Journal Of Computer Applications, 21(1), 12-19 http://dx.doi.org/10.5120/2476-3331 Nipun,. (2015). Difference Between Omni and Directional Antenna. Pediaa.Com. Retrieved 27 October 2016, from http://pediaa.com/difference-between-omni-and-directional-antenna/ Poole, I. (2016). Yagi Antenna Tutorial | Yagi-Uda Aerial | Radio-Electronics.com.Radio- electronics.com. Retrieved 26 October 2016, from http://www.radio- electronics.com/info/antennas/yagi/yagi.php Rattan, M., Patterh, M., &Sohi, B. (2008). Optimization of the Yagi-Uda Antenna for Gain, Impedance, and Sidelobes Using Simulated Annealing. Electromagnetics, 28(4), 283- 295.http://dx.doi.org/10.1080/02726340802040120 Yang, H. (2003).Analysis of RF radiation interference on wireless communication systems. IEEE Antennas And Wireless Propagation Letters, 2(1), 126-129. http://dx.doi.org/10.1109/lawp.2003.816634 Zhuang, W. & Ismail, M. (2012).Cooperation in wireless communication networks.IEEE Wireless Communications, 19(2), 10-20. http://dx.doi.org/10.1109/mwc.2012.6189408 Read More